AU2006204655B2

AU2006204655B2 - An extract of Dioscorea sp. and the medical uses thereof

Info

Publication number: AU2006204655B2
Application number: AU2006204655A
Authority: AU
Inventors: Rong-Tsun Wu
Original assignee: National Yang Ming University NYMU
Current assignee: National Yang Ming Chiao Tung University NYCU
Priority date: 2004-06-30
Filing date: 2006-09-01
Publication date: 2011-02-10
Anticipated expiration: 2024-06-30
Also published as: AU2004202986B2; AU2006204655B9; AU2004202986A1; AU2006204655A1

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant: NATIONAL YANG-MING UNIVERSITY Invention Title: AN EXTRACT OF DIOSCOREA SP. AND THE MEDICAL USES THEREOF The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 TITLE OF THE INVENTION AN EXTRACT OF DIOSCOREA SP. AND THE MEDICAL USES THEREOF CROSS-REFERENCE TO RELATED APPLICATIONS The entire disclosure in the complete specification of our Australian Patent 5 Application No. 2004202986 is by this cross-reference incorporated into the present specification. The present invention relates to an oral composition comprising an active extract of Dioscorea sp., in particular to an oral composition capable of enhancing the proliferation and differentiation of cells, and of alleviating the side effects induced by chemotherapy. 10 The present invention provides a method for treatment of osteoporosis and a method for alleviation of side effects caused by chemotherapy. BACKGROUND OF THE INVENTION Dioscorea, also known as "wild yam," is a member of the monocotyledonous family Dioscoreaceae, which is distributed in the tropical and subtropical regions. There are 15 about 650 species in the world, of which 93 species and 9 varieties are found in China, and 14 species and 5 varieties are found in Taiwan. Dioscorea is one of the very important pharmaceutical plants used in traditional Chinese medicine, and the medicinal effects thereof have been studied for years. In 1936, Tsukamoto et al isolated diosgenin, a steroid saponin of Dioscorea, from Dioscoreacea 20 family of plants and then use it as raw material for rapid synthesis of medicinal steroids. In a study by Aradhana, Rao Ar, Kale RK. (Indian Journal of Experimental Biology 30:367 370, 1992), it was indicated that diosgenin promotes the growth of epithelial cells of rat mammary glands. In Biochemical & Biophysical Research Communications 207(1):398 404, Feb/1 995, J.L. Beneytout et al. reported that diosgenin induces morphological and 25 biochemical changes in characteristic of megakaryocyte cells when diosgenin is added to human erythroleukemia (HEL) cell cultures and, thus, diosgenin can be used as a megakaryotic differentiation inducer of HEL cells. In Life Sciences 59(11):147-157, 1996, a steroid extract of Dioscorea was indicated to possess significant activities as an anti oxidant to modify serum lipid levels. 30 Dehydroepiandrosterone (DHEA) has a similar chemical structure to diosgenin, and is known to have anti-cancer, anti-oxidation, and anti-diabetic effects, as well as an effect on the regulation of bone mass. The serum levels of DHEA gradually decrease as 25271281 (GHMatters) 3 age increases, and are related to aging. It was speculated from various studies that the diosgenin extract of Dioscorea might be converted into DHEA in the human body and thus supplements the DHEA which decreases with aging. However, these studies were only conducted on old people taking diosgenin present in the Dioscorea to investigate if 5 diosgenin could reduce the over-oxidation of serum lipids, lower the triglycerides in blood serum and increase high density level (HDL) of cholesterol while decreasing the over oxidation damage of low density level (LDL) of cholesterol. Concerning the effect of DHEA on regulation of bone mass, in Life Science 62(1):59-68, 1998, Ben A.A. Scheven et al reported that DHEA and its sulfate derivative 10 (DHEA-S) failed on their own to exert direct, independent, significant effects on the growth and differentiation of human osteoblastic cells, but treating the cells in conjunction with a bone cell modulating agent, 1,25(OH) 2

D

3 , resulted in enhancement of specific alkaline phosphatase (ALP) activity, which is the specific maker of maturing osteoblastic cells. This study shows that the effects of DHEA and DHEA-S on osteoblastic cell growth and 15 differentiation are likely to be mediated via an effect on 1,25(OH) 2

D

3 -induced change in bone cells. In accordance with the present invention, it was found that the extract of a particular Dioscorea species (sp.) and the further extracted fractions possess biological activity on cell regeneration. Specifically, it was found that the extract of the Dioscorea sp. 20 and the further extracted fractions per se, without the presence of any bone cell modulating agent, can stimulate the proliferation and differentiation of the osteoprogenitor cells so as to supplement the osteoprogenitor cells in the bone and promote maturity of osteoblastic cells and mineralization of osteoblastic cells, thereby achieving bone repair, restoration and reproduction and in turn preventing and treating osteoporosis. Moreover, 25 the extract of the Dioscorea sp. not only stimulates the proliferation and differentiation of hematopoietic stem cells in bone marrow in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF), but also facilitates recovery of patients suffering from the deficiency of leukocytes and erythrocytes caused by anti-cancer drug treatment, and thus, can be used in combination with an anti-cancer drug as a chemotherapeutic 30 adjuvant. 25271281 (GHMatters) 4 BRIEF SUMMARY OF THE INVENTION The present invention provides a method for treating osteoporosis in a subject in need of such treatment, comprising administering orally to the subject an effective amount of an extract product of Dioscorea alata L. cv, Phyto capable of promoting proliferation and 5 differentiation of bone marrow cells in the subject, wherein the Dioscorea alata L. cv, Phyto is characterized by a RAPD fingerprint comprising at least 14 DNA bands ranging from 428bp, 452bp, 537bp, 602bp, 723bp, 817bp, 934bp, 1140bp, 1242bp, 1478bp, 1641bp, 1904bp, 2151bp and 2918bp, respectively, when genomic DNA of the Dioscorea alata L. cv, Phyto is amplified with a primer of SEQ ID NO: 9, and wherein the extract is 10 prepared by a process comprising: (a) extracting a tuber of Dioscorea alata L. cv, Phyto using an alcohol-based solvent in the presence of acetic acid to obtain an alcoholic product; (b) separating the alcoholic product obtained in step (a) to obtain a soluble fraction; and (c) removing the alcohol-based solvent from the soluble fraction obtained in step (b) to obtain the extract product. 15 The present invention also provides an extract product of Dioscorea alata L. cv, Phyto, wherein the Dioscorea alata L. cv, Phyto is characterized by a RAPD fingerprint comprising at least 14 DNA bands ranging from 428bp, 452bp, 537bp, 602bp, 723bp, 817bp, 934bp, 1140bp, 1242bp, 1478bp, 1641 bp, 1904bp, 2151bp and 2918bp, respectively, when genomic DNA of Dioscorea alata L. cv, Phyto is amplified with a primer 20 of SEQ ID NO: 9, and wherein the extract product is prepared by a process comprising: (a) extracting a tuber of Dioscorea alata L. cv, Phyto using an alcohol-based solvent in the presence of acetic acid to obtain an alcoholic product; (b) separating the alcoholic product obtained in step (a) to obtain a soluble fraction; and (c) removing the alcohol-based solvent from the soluble fraction obtained in step (b) to obtain the extract product. 25 BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not 30 limited to the precise arrangements and instrumentalities shown. In the drawings: 25271281 (GHMatters) 5 Fig. 1 show bar graphs identified as Figs. 1A and 1B. Fig 1A illustrates the effects of the extract of Dioscorea alata L. cv, Phyto (DioMs) and DHEA and Fig. 1 B illustrates the effects of each further extracted portion (DioMPw, DioMPb and DioMPe) on the proliferation of osteoprogenitor cells of C3H mice; 5 Fig. 2 includes bar graphs identified as Figs. 2A and 2B. Fig. 2A shows the effects of the extract of Dioscorea alata L. cv, Phyto and Fig. 2B illustrates the effects of each further extracted fraction on the differentiation of osteoprogenitor cells into matured osteoblastic cells of mice in vitro determined by alkaline phosphatase (ALP) activity; Fig. 3 is a bar graph showing the in vitro effects of the extract of Dioscorea alata L. 10 cv, Phyto on alkaline phosphatase (ALP) activity of the bone marrow cells derived from a patient suffering from glucocorticoid-induced osteoporosis; Fig. 4 includes bar graphs identified as Figs. 4A and 4B. Fig. 4A shows the in vivo effects of the extract of Dioscorea alata L. cv, Phyto on the differentiation of osteoprogenitor cells into matured osteoblastic cells of mice determined by alkaline 15 phosphatase (ALP) activity, Fig. 4B shows the effects of the extract on the mineralization of the bone mass in the bone marrow cells of the healthy mice determined by the nodule formation; Fig. 5 includes bar graphs identified as Figs. 5A and 5B. Fig. 5A shows the in vivo effects of the extract of Dioscorea alata L. cv, Phyto on alkaline phosphatase (ALP) 20 activity, and Fig. 5B shows the effects of the extract on the mineralization of the bone mass in the bone marrow cells of ovariectomized mice; Fig. 6 shows the RT-PCR result of cytokines in bone marrow cells isolated from mice which are orally administered the extract of Dioscorea alata L. cv, Phyto according to the present invention; 25 Fig. 7 consists of Figs. 7A-7E, which are phase contrast micrograph images showing the effect of the extract of Dioscorea alata L. cv, Phyto on morphological changes of the primary cultured mouse bone marrow cells in the presence of epithelial growth factor (EGF); Fig. 8 is a graph that shows the in vivo effect of the extract of Dioscorea alata L. 30 cv, Phyto on the leukocyte count in the peripheral blood of leucopenia mice induced by cyclophophamide (CY); 25271281 (GHMatters) 6 Fig. 9 is a bar graph showing the in vivo effect of the extract of Dioscorea alata L. cv, Phyto on red blood cell (RBC) count in the peripheral blood of cyclophosphamide (CP) induced leukopenic mice suffering from severe anemia; Fig. 10 is a bar graph showing the in vivo effect of the extract of Dioscorea alata L. 5 cv, Phyto on hemoglobin content in the peripheral blood of cyclophosphamide (CP) induced leukopenic mice suffering from severe anemia; Fig. 11 is a composite photographic image showing electrophoretic marker profiles of amplification products for a test panel of 14 Dioscorea species amplified with a single randomly amplified polymorphic DNA (RAPD) primer of SEQ ID NO: 9; and 10 Fig. 12 is a dendrogram illustrating a phylogenetic tree of 14 Dioscorea species based on their genetic similarity determined by RAPD analysis. DETAILED DESCRIPTION OF THE INVENTION As used herein the following terms may be used for better interpretation of claims and specification. 15 The term "primer" refers to a nucleic acid fragment or sequence that is complementary to at least one section along a strand of the sample nucleic acid, wherein the purpose of the primer is to sponsor and direct nucleic acid replication of a portion of the sample nucleic acid along that string. In RAPD amplification, single arbitrary primers are used to amplify non-targeted segments of nucleic acid which are located between the 20 primer sequence sites in opposing DNA strands. A "test panel" is herein defined as a particular group of organisms of individuals selected on the basis of their genetic similarity to each other, or their genetic dissimilarity to another group (i.e., another genus, species, subspecies). The term "RAPD" refers to "random amplified polymorphic DNA". "RAPD 25 amplification" refers to a method of single primer directed amplification of nucleic acids using short primers of arbitrary sequence to amplified non-targeted, random segments of nucleic acid as disclosed in U.S. Pat. No. 5,126,239, the disclosure of which is hereby incorporated by reference. "RAPD method" or "RAPD analysis" refers to a method for the detection of genetic polymorphisms involving the non-targeted amplification of nucleic 30 acids using short primers of arbitrary sequence, whereby the profile or fingerprint of "RAPD" amplification products is compared between samples to detect polymorphisms. 25271281 (GHMatters) 7 "RAPD primers" refers to primers of about 8 bp to about 13 bp, of arbitrary sequence, useful in the RAPD amplification or RAPD analysis according to the instant method. According to the present invention, Dioscorea alata L. cv, Phyto from which the extract product is made is characterized by a randomly amplified polymorphic DNA 5 (RAPD) fingerprint with a random primer (primer OPA-1 8) having an oligonucleotide sequence of AGGTGACCGT (SEQ ID NO: 9). The RAPD fingerprint is generated by a RAPD analysis, which involves amplifying genomic DNA of a plurality of Dioscorea species in the test panel with the OPA-1 8 primer. As the genomic DNA is amplified by polymerase chain reaction (PCR), a set of discontinuous DNA fragments are obtained for 10 each Dioscorea species and expressed as DNA bands of different molecular sizes on an electrophoretic gel. As explained in Example 10 below, and as shown in Fig. 11, there are 14 DNA bands ranging from 428bp, 452bp, 537bp, 602bp, 723bp, 817bp, 934bp, 1140bp, 1242bp, 1478bp, 1641bp, 1904bp, 2151bp and 2918bp, respectively, when genomic DNA from Dioscorea alata L. cv, Phyto is amplified with the OPA-18 primer of SEQ ID NO: 9. 15 Next, a similarity index, that is defined as a ratio of total RAPD bands shared between two species in a cluster analysis, is determined. The similarity index is determined based on the following equation: F = 2nxy/n. + ny wherein ny is the number of common DNA bands in Dioscorea species x and y, and nx 20 and ny are the total DNA bands in Dioscorea species x and y respectively. Based on the RAPD fingerprint results and a comparison with other known species of Dioscorea (see Fig. 12), it is believed that the Dioscorea alata L. cv, Phyto used in the invention is different from the known species of Dioscorea, and thus is new. The present invention is based on the discovery of the biological activities of the 25 extract of Dioscorea alata L. cv, Phyto as characterized in the invention, in particular the activity on cell regeneration. It was confirmed by the experiments that the extract and the further extracted fractions of Dioscorea alata L. cv, Phyto prepared in accordance with the method of this invention include active substances that enhance the proliferation and differentiation of mouse bone marrow progenitor cells. Specifically, the extract and the 30 further extracted fractions of Dioscorea alata L. cv, Phyto enhance cell proliferation of functional osteoprogenitor cells and even extensively induce the differentiation of osteoprogenitor cells into osteoblastic cells and enhance the mineralization of osteoblastic cells. Moreover, the extract of Dioscorea alata L. cv, Phyto can alleviate the side-effects 25271281 (GHMatters) 8 caused by an anti-cancer drug. Specifically, the extract restores the leukocytes and erythrocytes present in the peripheral blood of the mice treated with cyclophosphamide (CY). Therefore, the extract of Dioscorea alata L. cv, Phyto would be useful in the prevention and treatment of osteoporosis, a common disease in the aging process, and 5 may be used in combination with an anti-cancer drug as a chemotherapeutic adjuvant. Stem cells are cells capable of self-renewal and differentiation. Stem cells are present at the maximal level during the embryonic period, and gradually decrease in number with aging. Thus, it was speculated that there is an important correlation or association between stem cells and aging. The stem cells in adults can generate a 10 specific response toward a specific message transmitted through a microenvironment change generating new stem cells or differentiating into specific cells. When the stem cells receive a differentiation message, the stem cells rapidly reproduce in large amounts, and then finally proceed to differentiation. These stem cells are used for maintaining the balance of cells in adults, and replenish the number of cells that die due to natural causes 15 or injuries. The stem cells in bone marrow are divided into two types, the hematopoietic stem cells, which produce two more specialized types of stem cells, lymphoid progenitor cells (which give rise to T and B lymphocytes) and myeloid progenitor cells (which give rise to leukocytes, erythrocytes, and megakaryocytes), and stromal cells, which are the source of 20 the cells making up the supporting structure in the bone marrow. The stromal cells have the characteristic of adhering to the bottom of plastic culture plates during culturing, and can differentiate into osteoblasts, chondrocytes, adipocytes, and even myoblasts. Stromal cells are required for the growth and differentiation of hematopoietic stem cells. The production and number of stem cells will be greatly reduced as aging occurs, 25 leading to various problems of aging, in which osteoporosis is the most common. The causes of osteoporosis include the loss of balance between bone formation and resorption. The osteoblastic cells derived from the osteoprogenitor cells are responsible for bone formation consisted of the formation of the bone matrix and skeletal mineralization. Osteoprogenitor cells come from the stromal cells in the bone marrow. 30 Dexamethasone and ascorbic acid can promote the proliferation growth of osteoprogenitor cells, and enable the cells to differentiate into matured osteoblasts. During the differentiating process, different markers of osteoblasts are expressed: There is the deposition of collagenous matrix first, and after 10 to 14 days, alkaline phosphatase (ALP) 25271281 (GHMatters) 9 is expressed. Alkaline phosphatase is widely used as a biochemical marker for identification of osteoblast activity, but its actual function is yet unknown, though currently it is believed that it participates in the skeletal mineralization process. After continuous culture to 21 days, the cells will secrete osteocalcein, and finally mineralize to form bone 5 nodules. It was unexpectedly found in this invention that the extract of Dioscorea alata L. cv, Phyto or the further extracted fractions can be used to enhance the proliferation and differentiation of osteoprogenitor cells in the absence of any bone cell modulating agent, and thus, a composition comprising the active extract can be used in the treatment of the 10 osteoporosis. In the present invention, the extract is prepared from the root tuber part of Dioscorea alata L. cv, Phyto and may be obtained using methanol as the extracting solution. The preparation process involves (a) extracting a tuber of the Dioscorea alata L. cv, Phyto using an alcohol-based solvent in the presence of acetic acid to obtain an 15 alcoholic product; (b) separating the alcoholic product obtained in step (a) to obtain a soluble fraction; and (c) removing the alcohol-based solvent from the soluble fraction obtained in step (b) to obtain the extract product. The alcohol-based solvent may be a methanol-based solvent, an ethanol-based solvent, or mixtures thereof. In addition, the obtained extract may be further extracted on the basis of polarity, 20 so as to obtain the pharmacologically active fractions. The extract may be further subjected to partition chromatography comprising the steps of: (b) mixing a solvent mixture of ethyl acetate and water with the extract obtained from step (a) so as to separate an ethyl acetate from a water extract existing in the water phase; (c) adding n-butanol solvent into the water phase to perform further extraction so as to separate a butanol 25 extract from the remainder of water extract remaining in the water phase; and (d) adding 75% alcohol solvent into the water phase obtained from step (c) to extract and further remove polysaccharide so as to obtain a purified water extract. To confirm the biological activity of the components of Dioscorea alata L. cv, Phyto, an analysis on the biological activity of the extract of Dioscorea alata L. cv, Phyto 30 tuber and the further extracted fractions were conducted on cells obtained from normal mice and a human patient suffering from glucocorticoid-induced osteoporosis. From the experimental results shown in Fig. 1, it was unexpectedly found that the extract of Dioscorea alata L. cv, Phyto and the further extracted fractions enhance the 2527128_1 (GHMatters) 10 proliferation of the osteoprogenitor cells without the aid of any bone cell modulating agent. Under the same concentrations, DHEA exhibits no effect of enhancing the proliferation of osteoprogenitor cells. In Fig. 2, the results showed that the extracts of Dioscorea alata L. cv, Phyto significantly increase the amount of the expressed alkaline phosphatase in 5 normal cells, that is, the extracts prepared according to the present invention can stimulate the differentiation of osteoprogenitor cells into mature osteoblastic cells. The inventor further confirmed the effect on abnormal bone marrow cells derived from a human patient suffering from glucocorticoid-induced osteoporosis. Glucocorticoids are essential therapies for a variety of inflammatory and autoimmune diseases. However, 10 prolonged glucocorticoid use is one of the most common iatrogenic causes of osteoporosis. Glucocorticoids may increase bone loss through a variety of effects on osteobalsts, i.e., inhibition of the replication of the osteoblastic lineage, reduction of the genesis of new osteoblastic cells. From the results shown in Fig. 3, the inventor found that the active extract of the present invention increases the amount of the expressed 15 alkaline phosphatase in such cells, and thus, the function of osteoblastic cells may be recovered by treating a patient suffering from glucocorticoid-induced osteoporosis with the active extract. Moreover, in order to further confirm the effectiveness of the extract of Dioscorea alata L. cv, Phyto in treating osteoporosis in vivo, the inventor conducted experiments on 20 normal mice and the mice that are ovariectomized to induce osteoporosis, which are orally administered with the extract of the present invention. In Figs. 4-5, the results demonstrate that the extract of Dioscorea alata L. cv, Phyto, in vivo, increases the amount of the expressed alkaline phosphatase and the mineralization of the osteoblastic cells derived from normal mice and ovariectomized mice. 25 Therefore, the extract of Dioscorea alata L. cv, Phyto not only regulates the proliferation and differentiation of osteoprogenitor cells but also controls bone formation and remodeling, and thus, the active extract can prevent and treat osteoporosis. It was known that the proliferation and differentiation of bone marrow cells would be governed by certain factors, such as bone morphogenetic protein-2 (BMP-2), 30 transforming growth factor- J8 (TGF-8), interlukin-4 (IL-4), epidermal growth factor (EGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), etc. When the factor in the culture environment is changed, the stem cells differentiate into different cells in accordance with the specificity of such factors. For example, BMP-2, TGF-fi, IL-4, and 2527128_1 (GHMatters) 11 EGF are positively relevant to the proliferation and differentiation of the bone marrow stromal cells toward osteoblast lineage. In this study, the inventor conducted experiments to confirm the effects of the extract of Dioscorea alata L. cv, Phyto on gene expression of BMP-2, TGF- fl, and IL-4, and the effects of the extract and the further extracted fractions 5 of Dioscorea alata L. cv, Phyto on the proliferation and differentiation of bone marrow stem cells in the presence of EGF and GM-CSF. In Fig. 6, the data demonstrated that the extract of Dioscorea alata L. cv, Phyto increases the gene expression of BMP-2, TGF-fi, and IL-4, especially that of BMP-2 and TGF-fi. Moreover, from the experimental results shown in Fig. 7 and Table 2, the inventor 10 found that the extract of Dioscorea alata L. cv, Phyto stimulates the differentiation of the mouse bone marrow cells in the presence of EGF. The further extracted fraction of the extract, DioMPw, enhances the proliferation of mouse bone marrow cells. As to GM-CSF, GM-CSF can act on a specific receptor complex present on hematopoietic progenitor cells to stimulate myelopoiesis, and thus, can promote the 15 proliferation and differentiation of the hematopoietic progenitor cells in the bone marrow into monocytes, neutrophils, macrophages, etc.. Therefore, it is believed that GM-CSF has potential in therapy for restoring macrophages of a patient treated with chemotherapy. In this study, the inventor found that, in the presence of GM-CSF, the proliferation of the bone marrow cells was enhanced under the stimulation of the extract and the further 20 extracted fractions of Dioscorea alata L. cv, Phyto (see Table 3). In addition, the results show that the differentiation of the stem cells was enhanced by the further extracted fractions of Dioscorea alata L. cv, Phyto. Under the same conditions, DHEA exhibits the effect of enhancing cell differentiation, but cannot enhance cell proliferation. Therefore, this study suggests that the extract and the further extracted fractions of Dioscorea alata 25 L. cv, Phyto prepared according to the present invention may assist GM-CSF in restoring the number of macrophages reduced by chemotherapy through the proliferation and differentiation of the bone marrow cells, and may be used as a chemotherapeutic adjuvant. The inventor further confirmed the application of the extract of Dioscorea alata L. 30 cv, Phyto on chemotherapy as a chemotherapeutic adjuvant in vivo. Cyclophosphamide (CY) is a drug used to treat a number of cancers; however, it destroys the bone marrow function, decreases the blood cells such as leukocytes, macrophages, and erythrocyte, and causes many other adverse side effects. In the present invention, cyclophosphamide 25271281 (GHMatters) 12 is employed to cause leucopenia in mice to develop an animal model used to determine the function of the active extract of the present invention as a chemotherapeutic adjuvant. The obtained results showed that the active extract of the present invention prevented a decrease of leukocyte count and maintained the red blood cell count and hemoglobin 5 content at normal level, and thus, accelerated recovery from leucopenia in CY-treated mice. Therefore, the active extract of the present invention can be used as a chemotherapeutic adjuvant to alleviate adverse side effects induced by an anti-cancer drug. The experiments performed in accordance with the present invention clearly 10 demonstrate that the extract of Dioscorea alata L. cv, Phyto and the further extracted fractions thereof enhance the proliferation and differentiation of the osteoprogenitor cells in the absence of any bone cell modulation agent, and thus, the present invention provides an application of Dioscorea alata L. cv, Phyto in the treatment of osteoporosis. Moreover, the extracts prepared according to the present invention increase and restore the number 15 of the macrophages, leukocytes and erythrocytes which have been reduced by chemotherapy, and can thus be used as a chemotherapeutic adjuvant. The following examples are provided to illustrate the present invention. The examples are not intended to limit the scope of the present invention and they should be so interpreted. 20 EXAMPLES OF THE INVENTION Preparatory Step 1 Preparation of a Methanol Extract of Dioscorea alata L. cv, Phyto 25 Four (4) kg peeled tubers of Dioscorea alata L. cv, Phyto were immersed in 1% (v/v) acetic acid solution overnight. The solid portion obtained was then frozen at -70 0 C and lyophilized. The lyophilized portion was immersed in methanol in the presence of 1 % acetic acid. After stirring and adjusting the concentration of methanol to 40% by volume, the mixture solution was allowed to stand overnight, and then separated by centrifugation. 30 The obtained soluble fraction was lyophilized and is referred to as DioMs. DioMs was further subjected to partition chromatography, comprising the steps of: using a solvent mixture of ethyl acetate and water (1:1) to extract DioMs so as to separate an ethyl acetate extract (referred as DioMPe) from a water extract existing in the water 25271281 (GHMatters) 13 phase; adding n-butanol solvent into the water phase to perform further extraction so as to separate an butanol extract (referred as DioMPb) from the water extract remaining in the water phase; and adding 75% (v/v) alcohol solvent into the water phase to extract and further remove polysaccharide so as to obtain a purified water extract (referred as 5 DioMPw). Preparatory Step 2 Preparation of a Feed for Mice Containing a Methanol Extract of Dioscorea alata L. cv, Phyto 10 Purina Chow 5001, a commercially available mouse feed, was ground into powder. The lyophilized methanol extract of Dioscorea alata L. cv, Phyto was added in the ground feed in an amount to replace the same amount from the ground feed, to form a feed mixture. The feed mixture was uniformly mixed with distilled water, re-shaped by 15 extrusion molding, baked for 2 min. in a microwave oven at proper power, and refrigerated at -70*C after cooling to room temperature. After lyophilization, the feed mixture was formed into pellets very similar to the properties of the Purina Chow feed. The formed pellets are stored in -20*C refrigerator. The pellets were warmed to room temperature on the day of feeding, and were sterilized by UV lamp irradiation on a sterile work table. 20 Feed mixtures having different concentrations of methanol extract were prepared. Preparatory Step 3 Isolation and Culture of Bone Marrow Cells 25 Under sterile conditions, SPF grade C3H/HeN mice were sacrificed and their femoral bones were injected with a liquid culture of DMEM/F12 to flush out the bone marrow cells. The cells were filtered through sterile No. 53 nylon mesh. The single cell suspension so obtained was mixed with DMEM/F12 culture medium containing N2 to adjust to the proper concentration. 30 25271281 (GHMatters) 14 Preparatory Step 4 Preparation of Osteoprogenitor Cells from Mice Under sterile conditions, femoral bones of the SPF grade of C3H/HeN mouse were 5 obtained and injected with DMEM/F12. The bone marrow cells were flushed out and filtered through No. 53 sterile nylon mesh. The single cell suspension obtained was mixed with DMEM/F12 culture medium containing 15% FCS to adjust the concentration of the cells. The cells were cultured in DMEM/F12 medium containing 15% FCS, 50 pg/ml 10 ascorbic acid, 10mM sodium f glycerophosphate and 10 nM dexamethasone in a T-flask for 6 days. The culture medium was renewed every 3 days. The cell concentration was 106 cells/cm 2 . On the 6th day, the suspended cells and culture medium were drawn out. The adhering cell layer was washed with 1xPBS that had been warmed to room temperature, and then treated with 0.01% EDTA at 37 0 C for 5 to 10 minutes. The EDTA 15 was removed and the reaction was stopped in a culture medium containing FCS. The cells were all collected and centrifuged for 5 minutes at 1000 rpm. Example 1 The Proliferative Response of Osteoprogenitor Cells 20 of Mice Treated with the Methanol Extract and the Further Extracted Fractions of Dioscorea alata L. cv, Phyto The cells obtained in preparatory step 4 were dispersed using a 22G gauge needle and suspended in DMEM/F12 medium containing 15% FCS, 50 pg/ml ascorbic acid, 25 10mM sodium /-glycerophosphate and 10 nM dexamethazone to form a concentration of 4.5x1 04 cells/mI. 225 p1 cell suspension was added into each well of a 96-well microplate. After 3 hours, to the cell suspension in each well was added 25 pl methanol extract, each of the further extracted fractions and DHEA and incubated for 72 hours. Then, 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed. 1 30 mg/ml MTT solution was added in each well and reacted for 4 hours. MTT lysis buffer (20% SDS-50% DMF) was added in each well in the amount of 150 p1/well and reacted for 16 hours, and the absorbance was measured at O.D. 570 nm for the resultant cell suspension in each well. 25271281 (GHMatters) 15 As shown in Fig. 1, under the stimulation of the methanol extract of Dioscorea alata L. cv, Phyto, the proliferation of the osteoprogenitor cells was enhanced, in which the 0.01 and 0.1 pg/ml concentrations manifest significant enhancing effect. Under the same concentrations, DHEA exhibits no effect of enhancing the proliferation of osteoprogenitor 5 cells. The extracted fractions, DioMPe and DioMPb, enhance cell proliferation at 10-400 pg/ml, wherein DioMPe exhibits an excellent effect. Example 2 10 The Effect of the Methanol Extract and Different Extracted Fractions of Dioscorea alata L. cv, Phyto on the Differentiation of Matured Osteoblastic Cells of Mice Determined by Alkaline Phosphatase Activity (ALP) In Vitro 15 Osteoprogenitor cells collected in preparatory step 4 were incubated in a T-flask for 6 days. The cells were dispersed with 22G gauge needle, and the cell concentration was adjusted to 5x10 3 cell/cm 2 . The cells were then incubated in 6-well plates, in which 4.5 ml of cell culture medium was added in each well, and 0.5 ml methanol extract and each of the extracted fractions were added the next day. After incubation for 14 days, alkaline 20 phosphatase activity assay was conducted thereon, as described below. Drawing out the culture medium, the cell layer was washed several times with PBS. 0.5% Triton X-100 in PBS was added into each well. The resultant suspension was subjected to a freezing and thawing process at a temperature of 70*C and 37*C, respectively. The treatment was done twice so as to obtain a test sample. 50 pl of the 25 test sample was transferred from each well to an ELISA plate. 50 pl AMP-substrate buffer (2-amino-2-methyl-1-propanol (AMP, 0.5M) in distilled water, pH 10; 2mM magnesium chloride and 9mM p-nitrophenyl phosphate) was then added inot the ELISA plate so as to be reacted with the test sample at room temperature for 10-20 min. Immediately after the absorbance was measured at 410 nm wavelength using ELISA reader, the protein 30 concentration of each well was measured quantitatively. The measure alkaline phosphatase activity is expressed in unit/pg. As shown in Fig. 2, after 14 days of incubation of the bone marrow precursor cells, expression of alkaline phosphatase, which is the expressed marker specific to a matured 2527128.1 (GHMatters) 16 osteoblast, was noted. The methanol extract of Dioscorea alata L. cv, Phyto and each of further extracted fractions of the methanol extract significantly increase the amount of the expressed alkaline phosphatase, in which the methanol extract at 0.1 pg/ml, DioMPb at 0.1 pg/ml, DioMPe at 0.01-0.1 pg /ml, and DioMPw at 0.1 pg/ml showed the strongest 5 enhancement effect. Example 3 The effects of the Methanol Extract Dioscorea alata L. cv, Phyto on Alkaline Phosphatase (ALP) Activity of Bone 10 Marrow Cells Derived from a Patient Suffering from Glucocorticoid-induced Osteoporosis The patient's bone marrow cells obtained from the Taipei Veterans General Hospital were cultured in DMEM/F12 medium containing 15% FCS, 50 pg/ml ascorbic 15 acid, 10 mM sodium fl-glycerophosphate and 10 nM dexamethasone for 7 days. Alkaline phosphatase activity assay was conducted thereon. As shown in Fig. 3, expression of alkaline phosphatase was noted. Compared with the control group and positive group (1 nM estrogen, which is the known treatment for osteoporosis), the methanol extract of Dioscorea alata L. cv, Phyto increased the amount 20 of the expressed alkaline phosphatase, in which the methanol extract at 10 pg/ml showed the strongest enhancement effect. Example 4 The Effects of Methanol Extract of Dioscorea alata L. cv, Phyto 25 on Alkaline Phosphatase (ALP) Activity and on Mineralization of Bone Marrow Cells In Vivo Different dosages (0, 40, 200, and 1000 mg/kg) of methanol extract were prepared for oral administration. After oral administration of different dosages of the methanol 30 extract for 5 days, mice were sacrificed to obtain marrow cells thereof. (1) Alkaline Phosphatase Activity Assay The bone marrow cells of mice obtained were cultured in 96-well microplates at 2x105 cells/well, in which 250 pl of a-MEM medium containing 15% FCS, 50 pg/ml 2527128_1 (GHMatters) 17 ascorbic acid, 10 mM sodium fl-glycerophosphate and 10 nM dexamethasone was added, and incubated in a 5% CO 2 incubator at 370C for 2 days. 125 pl/well of culture medium was drawn out and replaced by 125 pl/well of fresh medium containing 15% FCS, 50 pg/ml ascorbic acid, 10 mM sodium fl-glycerophosphate, and 10 nM dexamethasone. 5 After 4 days incubation, an alkaline phosphatase activity assay was conducted thereon. As shown in Fig. 4A, expression of alkaline phosphatase was noted. In Fig. 4A, the methanol extract of Dioscorea alata L. cv, Phyto increases the amount of the expressed alkaline phosphatase, in which the methanol extract at 1000 mg/kg reaches up to 3 times enhancement as compared with the control group. 10 (2) Nodule Formation Assay This assay is used to analyze the mineralization of the bone mass. The bone marrow cells obtained from the mice orally administered different dosages (0, 40, 200, and 1000 mg/kg) of methanol extract were seeded in 24-well plates at lx106 cells/well, cultured in a-MEM medium containing 15% FCS, 50 pg/mI ascorbic acid, 10 mM sodium 15 8-glycerophosphate and 10 nM dexamethasone, and incubated in a 5% C02 incubator at 370C for 24 hrs. 500 pl/well of culture medium was drawn out and replaced by 500 pl/well of fresh medium containing 15% FCS, 50 pg/ml ascorbic acid, 10 mM sodium fl glycerophosphate and 10 nM dexamethasone. The cells were further incubated for 15 days to analyze the mineralization of the bone mass, and the culture medium renewed 20 every 4 days. Nodule formation assay was conducted thereon, as described below. Drawing out the culture medium, the cells were fixed by reacting them with 500 pl/well formalin for 30 minutes in a 5% C02 incubator at 370C. After removing formalin and rinsing the cells with sterilized water three times, 200 pl/well of 2% Alizarine Red S solution, which reacts with calcium, was added into the wells and the cells were further 25 incubated in a 5% C02 incubator at 370C for 10 minutes. Then, the Alizarine solution was removed and the cells were rinsed three times with absolute alcohol. The mineralized area of the bone mass was measured by Meta Image. As shown in Fig. 4B, compared with the control group, the methanol extract of Dioscorea sp. promotes mineralization of the bone mass, in which the methanol extract at 30 1000 mg/kg dosage showed the strongest enhancement effect of up to 3.5 times. 25271281 (GHMatters) 18 Example 5 The Effect of the Methanol Extract of Dioscorea alata L. cv, Phyto on Alkaline Phosphatase (ALP) Activity and on Mineralization of Bone Marrow Cells in 5 Ovariectomized Mice Model Under sterile conditions, a group of SPF grade C57BL/6j mice were subjected to a surgical operation to remove their ovaries so as to induce the occurrence of osteoporosis and another group was merely operated on without removal of the ovary for use as a 10 control group (referred to as pseudo operated mice). Different dosages (0, 40, 200, and 1000 mg/kg) of methanol extract were prepared for oral administration. After being orally administered with different dosages of the methanol extract for 42 days, the mice were sacrificed to obtain bone marrow cells thereof. 15 (1) Alkaline Phosphate Activity Assay The bone marrow cells obtained from the mice orally administered with different dosages (0, 40, 200, and 1000 mg/kg) of methanol extract and the pseudo operated mice were cultured in 96-well microplate at 2x105 cells/well, in which 250 pl of ct-MEM medium containing 15% FCS, 50 pg/mI ascorbic acid, 10 mM sodium 8-glycerophosphate and 10 20 nM dexamethasone was added, and incubated in a 5 % CO 2 incubator at 37 0 C for 2 days. 125 pl/well of fresh medium containing 15% FCS, 50 pg/ml ascorbic acid, 10 mM sodium fi-glycerophosphate and 10 nM dexamethasone was added. After 4 days incubation, an alkaline phosphatase activity assay was conducted thereon. As shown in Fig. 5A, expression of alkaline phosphatase was noted. In Fig. 5A, 25 the methanol extract of Dioscorea alata L. cv, Phyto is shown to increase the amount of the expressed alkaline phosphatase, in which the methanol extract at 1000 mg/kg showed the strongest enhancement effect. (2) Nodule Formation Assay The bone marrow cells obtained from the mice orally administered with different 30 dosages (0, 40, 200, and 1000 mg/kg) of methanol extract were seeded in 24-well plates at 1x106 cells/well, cultured in a-MEM medium containing 15% FCS, 50 pg/ml ascorbic acid, 10 mM sodium fi-glycerophosphate and 10 nM dexamethasone, and incubated in a 25271281 (GHMatters) 19 5% C02 incubator at 37*C for 24 hrs. 500 pl/well of culture medium was drawn out and replaced by 500 pl/well of fresh medium containing 15% FCS, 50 pg/ml ascorbic acid, 10 mM sodium fl-glycerophosphate and 10 nM dexamethasone. The cells were further incubated for 15 days to analyze the mineralization of the bone mass, and the culture 5 medium renewed every 4 days. A nodule formation assay was conducted thereon. As shown in Fig. 5B, compared with the control group, the methanol extract of Dioscorea sp. promotes mineralization of the bone mass, in which the methanol extract at 1000 mg/kg showed the strongest enhancement effect. 10 Example 6 The Effect of the Methanol Extract Dioscorea alata L. cv, Phyto on Gene expression of Cytokines in the Bone Marrow Cells Total RNA was extracted from the bone marrow cells obtained from Example 4 15 using an Ultraspec T M RNA isolation kit (Biotex laboratories Inc, U.S.A.). 5 pg total RNA and 2.5 pg oligo dT were heated at 700C for 10 minutes, cooled to room temperature for 10 minutes, then added with 4 p 10 mM dNTP, 0.5 pl rRNasin, 1 pl (10 units) AMV (Avian Myeloblastosis virus) reverse transciptase and the buffer thereof, and the final reaction volume was 26.5 pl. The cDNA was obtained by reacting the previous reaction solution at 20 420C for 60 minutes and then at 900C for 5 minutes. 2.5 pl resultant cDNA was added with 0.5 pi 10 mM dNTP, 0.5 pl polymerase (2 units) and the buffer thereof, 1 pl of 10 pM targeted primers, and the final volume of the reaction mixture was 25 pl. PCR was performed for proper cycles, each cycle consisting of 45 seconds of denaturation at 940C, 45 seconds of annealing at proper annealing temperature and 1 min of extension at 720C. 25 The reaction products were visualized by electrophoresis in 2% agarose gel. Sequences of the PCR primers are shown in Table 1. The experimental results are shown in Fig. 6. As shown in Fig. 6, the gene expression of BMP-2, TGF-/?, and IL-4 increased, especially BMP-2 and TGF-,6. Table 1 30 Sequences of the Primers used in RT-PCR Cytokine Sequence (5' to 3') a Size (bp) I L-4 sense ATG GGT CTC AAC CCC CAG CTA GT (SEQ ID NO:1) 25271281 (GHMatters) 20 antisense GCT CTT TAG GCT TTC CAG GAA GTC (SEQ ID NO:2) 399 TGF-3 sense TGG ACC GCA ACA ACG CCA TCT ATG CCA TCT ATG AGA AAA CC (SEQ ID NO:3) antisense TGG AGC TGA AGC AAT AGT TGG TAT CCA GGG CT (SEQ 525 ID NO:4) BMP-2 Sense CAT CCA GCC GAC CCT TG (SEQ ID NO:5) antisense CTC TCC CAC TGA CTT GTG (SEQ ID NO:6) 505 fl-actin Sense GAC TAC CTC ATG AAG ATC CT (SEQ ID NO:7) antisense CA CAT CTG CTG GAA GGT GG (SEQ ID NO:8) 510 aThe size of cytokine marker was determined by polymerase chain reaction (PCR) using the primers with reference to a 100bp DNA ladder. Example 7 5 Effects of Methanol Extract of Dioscorea alata L. cv, Phyto on Morphological Changes of Bone Marrow Cells of C3H Mice in the Presence of Epithelial Growth Factor (EGF) 1x10 4 cells/well bone marrow cells of mice obtained in preparatory step 3 were 10 seeded in a 96-well microplate containing DMEM/F12 culture medium with N2 and 10 ng/ml EGF and incubated in a 5% C02 incubator at 370 C for 24 hrs. The extract and DHEA were added into different wells respectively. Wells containing pure culture medium into which no methanol extract and DHEA were added, and which were subjected to the same incubation procedure, were used as positive control. In addition, for use as positive 15 control, the same procedure as that for control was repeated except that 50 ng/ml EGF was used. The proliferation responses were measured by a MTT assay. In accordance with the MTT assay, each of the wells was added with 1mg/ml MTT solution and, after 4 hours of reaction, MTT lysis buffer (20% SDS-50% DMF) was added thereinto in an amount of 150 pl/well. The resultant mixture was allowed to be reacted for 16 hours. The 20 absorbance was measured at O.D. 570 nm. As shown in Fig. 7, in the event that the progenitor cells in bone marrow induced with EGF proliferate, the methanol extract of Dioscorea alata L. cv, Phyto was found to further stimulate the bone marrow progenitor cells to differentiate significantly. It can be noted that a more desirable optimum result was obtained when the concentration of the 25 methanol extract used was at 10 pg/ml. It is further shown in Table 2 that when 10 pg/ml 25271281 (GHMatters) 21 of DioMPw was used as stimulation, the cells exhibited significantly enhanced proliferative effect. Where that 100 pg/ml of DioMPw were used, the proliferation rate of the cell might reach up to 1.9 times that of the control as manifested in Table 2. 5 Table 2 Group Concentration Proliferation Morphologic Index a Change b Control 1.00 + DHEA 0.0001 pg/ml 0.99 + 0.001 pg/ml 0.64 + 0.01 pg/mI 0.65 + 0.1 pg/ml 0.67 ++ 1 pg/mI 0.70 ++ DioMPw 10 ng/ml 1.09 100 ng/ml 1.13 1 pg/ml 1.17 10 pg/ml 1.34* 100 pg/ml 1.90* aData was analyzed by Student's t-test, and "*" means P<0.05 bMorphologic change was observed by microscope. Example 8 10 The Proliferation Response of Bone Marrow Cells of Mice Treated with Methanol Extract and the Further Extracted Fractions of Dioscorea alata L. cv, Phyto in the Presence of GM-CSF 15 1x104 cells/well bone marrow cells of mice obtained in preparatory step 3 were seeded in each well of the 96-well microplate, cultured in DMEM/F12 culture medium containing N2, and 4 ng/ml mGM-CSF. Methanol extracts of Dioscorea alata L. cv, Phyto with different concentrations were respectively added into the resultant cultured cells in the different wells. The resultant methanol extract containing cultured cells in different wells 25271281 (GHMatters) 22 were then incubated in a 5% CO 2 incubator at 37 0 C for 14 days. The cells cultured in DMEM/F12 medium containing N2 and 20 ng/ml mGM-CSF is used as positive control. A MTT assay was performed. In this respect, 1 mg/mI MTT solution was added in each well so as to react with the cultured cells therein for 4 hours. MTT lysis buffer (20% SDS-50% 5 DMF) was added in a n amount of 150 pl/well. The resultant mixture was allowed to react for 16 hours. The absorbance was measured at O.D. 570 nm. As shown in Table 3, under the stimulation of the methanol extract of Dioscorea alata L. cv, Phyto in concentrations ranging from 0.001 pg/mI to 1000 pg/ml, the fractions resulting from further extraction of the methanol extract are all found to have the ability to 10 enhance cell proliferation. Among them, DioMPb and DioMPe were particularly found to have excellent effect on the enhancement of proliferation. In addition, the 20-week adult mouse bone marrow cells were found to be able to differentiate upon stimulation by the methanol extract of Dioscorea alata L. cv, Phyto at concentrations of 1 pg/ml - 10 pg/ml. Among the extracted fractions of the methanol extract, which were extracted by a solvent 15 mixture of water and ethyl acetate extracted fraction and the 75% alcohol extracted fraction resulting from further extracting the water extract with the 75% alcohol, are found to accelerate the differentiation of 20-week old adult mouse bone marrow cells. Under the same conditions, however, DHEA, in contrast, exhibits only the effect of enhancing cell proliferation. Therefore, the extracts of Dioscorea alata L. cv, Phyto which exhibit 20 excellent effect on both the regeneration and differentiation of stem cells may assist GM CSF in restoring the number of macrophages reduced by chemotherapy, and may be used as a chemotherapeutic adjuvant. Table 3 Group Concentration Proliferation Morphologic Index a Change b Control 1.00 + DioMs 0.0001 pg/ml 1.08 + 0.001 pg/mI 1.19* + 0.01 pg/ml 1.68* + 0.1 pg/ml 1.95* + 1.0 pg/ml 1.78* ++ 25271281 (GHMatters) 23 10 pg/ml 1.82* +++ 100 pg/ml 1.49* + 1000 pg/ml 1.39* + DioMPe 0.01 pg/ml 0.98 + 0.1 pg/ml 1.11 ++ 1 pg/ml 1.35* ++ 10 pg/ml 2.64* +++ 100 pg/ml 0.83 300 pg/ml 0.97 DioMPb 0.01 pg/ml 1.07 + 0.1 pg/ml 1.23 + 1 pg/ml 1.34 + 10 pg/ml 1.41 + 100 pg/mt 1.90* + 300 pg/ml 2.02* + DioMPw 0.0001 pg/ml 1.06 + 0.001 pg/ml 1.08 + 0.01 pg/ml 1.12 ++ 0.1 pg/ml 1.18 ++ 1.0 pg/ml 1.31* +++ 10 pg/mI 1.56* + DHEA 0.0001 pg/ml 0.99 + 0.001 pg/mI 1.15 + 0.01 pg/ml 1.04 + 0.1 pg/ml 1.13 + 1 pg/mI 1.11 +++ 10 pg/ml 1.19* + aData was analyzed by Student's t-test, and means P<0.05 bMorphologic change was observed by microscope. cBone marrow cells were found dead under high concentration of DioMPe. 25271281 (GHMatters) 24 Example 9 The Effect of the Methanol Extract on the Number of Leukocyte and Red Blood Cells and 5 Hemoglobin Content in Peripheral Blood of Leukopenia Mice Induced by Cyclophosphamide Different dosages (0, 20, 100, and 500 mg/kg) of methanol extract were prepared for oral administration. The mice were intraperitoneally injected with 200 and 100 mg/kg 10 of cyclcophosphamide (CY) on day 0 and day 5 to cause leucopenia, and blood was drawn periodically to cause an anemia condition. The mice were orally administered different dosages of the methanol extract on day 1 until the mice were sacrificed. The peripheral blood collected from the retro-orbital sinus was sampled on days 0, 4, 8, and 12. 15 The blood (0.1 ml) obtained on days 0, 4, 8, and 12 was added with 25 pl EDTA solution (72 mg/ml) to prevent blood coagulation, and diluted 10x or 20x with Turk's solution (2% acetic acid with 0.01% crystal violet). The number of leukocytes were counted by microscope. To the blood (0.1 ml) obtained on day 8 was added 2 5 pl EDTA solution (72 mg/ml) 20 to prevent blood coagulation, and diluted 2000x with saline. The number of erythrocytes was counted. Hemoglobin (Hbg) content was determined as described by Worthington R E et al., Experimental Hematology, 15:85-92, 1987. From the results shown in Figs. 8-10, it is noted that the active extract of the present invention mitigates reduction of leukocyte number in peripheral blood and 25 accelerates recovery of leukocytes, and maintains the red blood cells and Hbg content at normal levels. 25271281 (GHMatters) 25 Example 10 Characterization of Dioscorea Species in a Randomly Amplified Polymorphic DNA (RAPD) analysis 5 DNA extraction The Dioscorea species from which the extracts were produced and administered as described above was harvested from the Yang-Ming Mountain in Taiwan. The unknown Dioscorea species (shown in duplicate as Sample No. 100 or 102) was characterized along with a test panel of 13 known Dioscorea species, including Dioscorea 10 alata L. cv. (cultivated variety) Tainung No. 1 (Sample No. 1), Dioscorea esculenta (Sample No. 3), Dioscorea bulbifera (Sample No. 4), Dioscorea alata L. cv. 8702 (Sample No. 5), Dioscorea alata L. cv. Sanzhi A (Sample No. 6), Dioscorea alata L. cv. Sanzhi B (Sample No. 7), Dioscorea a/ata L. cv. Dayeshoufeng (Sample No. 9), Dioscorea alata L. cv. Tainung No. 2 (Sample No. 10), Dioscorea alata L. cv. Jifa (Sample No. 67), Dioscorea 15 alata L. cv. Zhanger No. 2 (Sample No. 64), Dioscorea alata L. cv. Dashan No. 3 (Sample No. 13), Dioscorea alata L. cv. Dashan No. 2 (Sample No. 12) and Dioscorea alata L. cv. Taidong (Sample No. 11), all of which were grown in Taiwan. 0.2 g of fresh leaf of each Dioscorea sample was collected and ground in a mortar mixed with liquid nitrogen. The ground tissue was mixed with 900 pl of 2% CTAB 20 extraction buffer (containing 1.4 M NaCl, 100 mM Tris-HCI at pH 8.0, 20 mM EDTA and 0.2% fi-mecaptoethanol) in a 1.5 ml centrifuge tube, followed by incubating in a 650C water bath for 30 minutes. The sample was then centrifuged, and the supernatant was transferred to a clean tube added with 600 pl of chloroform/isoamylalcohol (24:1) and vortexed until the sample was in an emulsified state. The sample was further centrifuged, 25 and the supernatant was transferred to a clean tube and mixed with 40 p of 10% CTAB (containing 0.7M NaCl) and 400 pl of chloroform/isoamyl alcohol (24:1). The sample was centrifuged again, and the supernatant (400 pl) was transferred in a clean tube and mixed with 400 pl of CTAB precipitation buffer and left on ice for about 15-20 minutes to precipitate DNA. The DNA sample was rinsed with 400 pl of high-salt TE (10 mM Tris 30 HCl, pH 8.0; 1 mM EDTA; and 1 M NaCl) and 800 pl of 95% alcohol. The DNA sample was centrifuged, and the pellet was further rinsed with 400 pl of 75% alcohol before re suspending the DNA pellet in distilled and deionized (dd)H 2 0 and stored at -20*C. 25271281 (GHMatters) 26 RAPD reaction A random RAPD primer of SEQ ID NO: 9, in this case OPA-18 (AGGTGACCGT) (Operon Technologies, USA) was used to amplify genomic DNA of the Dioscorea species 5 in the RAPD analysis. Polymerase Chain Reaction (PCR) was carried out in a 25 pl volume containing 10x buffer, 2.5 mM of each dNTP (dATP, dCTP, dGTP, and dTTP), 2.0 pM of primer (Operon), 5 units of Taq DNA polymerase (TaKaRa Biomedicals), and 5 ng template DNA. Samples were subjected to 41 cycles consisting of denaturation for 1 min at 94 0 C, annealing for 1 min at 36 0 C, extension for 2 min at 72 0 C, and one final extension 10 cycle at 720C for 10 minutes. After completion of the PCR, 1OpL of reaction mixture was loaded into a 2% agarose gel, containing 0.5 pg/mL ethidium bromide for electrophoresis. Data Analysis In the gel electrophoresis, both first lane (on the far left) and last lane (on the far 15 right) of the gel were loaded with DNA molecular weight marker (M), such as CpX1 74 DNA/Haelll marker (Promega Co., USA) to provide reference bands of different sizes, such as 500bp, 1000bp, 1500bp, 2000bp, 2500bp, 3000bp, 3500bp and 4000bp, followed by loading the PCR sample of each Dioscorea species in each lane. The profile of amplified DNA products from each sample was visualized by fluorescent developer and 20 photographic images were captured using an image acquiring software, Alphalmager 1220. Since each Dioscorea species from the test panel produced its own DNA bands in the RAPD fingerprint, the RAPD fingerprint of the Dioscorea species of the invention was determined to distinguish from other Dioscorea species. As shown in Fig. 11, there are 14 DNA bands ranging from 428bp, 452bp, 537bp, 602bp, 723bp, 817bp, 934bp, 1140bp, 25 1242bp, 1478bp, 1641bp, 1904bp, 2151bp and 2918bp for characterizing the unknown Dioscorea species (shown in duplicate as samples No. 100 or 102) when genomic DNA of the Dioscorea species is amplified with the OPA-18 primer of SEQ ID NO: 9. A cluster analysis or pair analysis was also carried out using Gel-Compar software to calculate a similarity index between two Dioscorea species. Parameters subjected to 30 the analysis were from RAPD fingerprints. Next, with the unweighted pair-grouping mean arithmetical analysis (UPGMA), the similarity index (F) was calculated in a cluster analysis with the following equation: 25271281 (GHMatters) 27 F = 2n.y/n. + ny wherein ny is the number of common DNA bands in Dioscorea species x and y, and n, and ny are the total DNA bands in Dioscorea species x and y respectively (Nei, M. and W. H. Li. 1979, Mathematical Model for studying genetic variation in terms of restriction 5 endonucleases, Proc. Nati. Acad. Soc. U.S.A. 76: 5269-5273). Referring to Fig. 12, a phylogenetic tree was constructed based on the similarity index between 14 Dioscorea species in the test panel. As illustrated in Fig. 12, the unknown Dioscorea species has a similarity index of about 88.9% with Dioscorea alata L. cv. Sanzhi A or Dioscorea alata L. cv. Zhanger No. 2. Furthermore, the Dioscorea species 10 has a similarity index of about 37.5% with Dioscorea bulbifera or Dioscorea esculenta. Moreover, the unknown Dioscorea species has a similarity index of more than 75.5% with Dioscorea Dioscorea alata L. cv. Tainung No. 1, Dioscorea alata L. cv. 8702, Dioscorea alata L. cv. Sanzhi B, Dioscorea alata L. cv. Dayeshoufeng, Dioscorea alata L. cv. Tainung No. 2, Dioscorea alata L. cv. Dashan No. 3 or Dioscorea alata L. cv. Dashan No. 15 2. Based on the cluster analysis or pair analysis results, it was understood that the unknown Dioscorea species is different from known species, but more similar to Dioscorea alata sub-species. Therefore, the unknown Dioscorea species was named as Dioscorea alata L. cv. Phyto. 20 All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art 25 publications are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art, in Australia or in any other country. In the claims of this application and in the description of the invention, except where the context requires otherwise due to express language or necessary implication, 30 the words "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 25271281 (GHMatters) 28 It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the 5 present invention as defined by the appended claims. 25271281 (GHMatters) 29 Dioscorea alata sub-species. Therefore, the unknown Dioscorea species was named as Dioscorea alata L. cv. Phyto. All references, including any patents or patent applications, cited in this specification are hereby incorporated by reference. No admission is made that any 5 reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art, in Australia or 10 in any other country. In the claims of this application and in the description of the invention, except where the context requires otherwise due to express language or necessary implication, the words "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the 15 presence or addition of further features in various embodiments of the invention. It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present 20 invention as defined by the appended claims. H:\iochb\Keep\P62046 doc 0I/9/06

Claims

1. A method for treating osteoporosis in a subject in need of such treatment, comprising administering orally to the subject an effective amount of an extract product of 5 Dioscorea alata L. cv, Phyto capable of promoting proliferation and differentiation of bone marrow cells in the subject, wherein the Dioscorea alata L. cv, Phyto is characterized by a randomly amplified polymorphic DNA (RAPD) fingerprint comprising 14 DNA bands ranging from 428bp, 452bp, 537bp, 602bp, 723bp, 817bp, 934bp, 1140bp, 1242bp, 1478bp, 1641bp, 1904bp, 2151bp and 2918bp, respectively, when genomic DNA of the 10 Dioscorea alata L. cv, Phytois amplified with a primer of SEQ ID NO: 9, and the extract product is prepared by a process comprising: (a) extracting a tuber of the Dioscorea alata L. cv, Phyto using an alcohol-based solvent in the presence of acetic acid to obtain an alcoholic product; (b) separating the alcoholic product obtained in step (a) to obtain a soluble fraction; 15 and (c) removing the alcohol-based solvent from the soluble fraction obtained in step (b) to obtain the extract product.

2. The method of claim 1, wherein the alcohol-based solvent used in step (a) of the preparation process is a methanol-based solvent, an ethanol-based solvent, or a 20 mixture thereof.

3. The method of claim 1, wherein step (a) of the preparation process is conducted in the presence of 1% acetic acid.

4. The method of claim 1, wherein in step (a) of the preparation process, a 40% methanol solution in the presence of 1% acetic acid is used to extract the tuber of the 25 Dioscorea alata L. cv, Phyto.

5. The method of claim 1, wherein prior to step (a) of the preparation process, the tuber of Dioscorea alata L. cv, Phyto is subjected to a preliminary treatment including the steps of: 25271281 (GHMatters) 30 (a) immersing the tuber of the Dioscorea alata L. cv, Phyto in a 1% acetic acid solution to obtain an acetic acid-treated tuber; (b) freezing the acetic acid-treated tuber to obtain a frozen tuber of Dioscorea alata L. cv, Phyto; and 5 (c) lyophilizing the frozen tuber of Dioscorea alata L. cv, Phyto.

6. The method of claim 1, wherein in step (b) of the preparation process, the alcoholic product obtained in step (a) is separated by centrifugation.

7. An extract product of Dioscorea alata L. cv, Phyto, wherein the Dioscorea alata L. cv, Phyto is characterized by a RAPD fingerprint comprising 14 DNA bands 10 ranging from 428bp, 452bp, 537bp, 602bp, 723bp, 817bp, 934bp, 1140bp, 1242bp, 1478bp, 1641 bp, 1904bp, 2151 bp and 2918bp, respectively, when genomic DNA of Dioscorea alata L. cv, Phyto is amplified with a primer of SEQ ID NO: 9, and the extract product is prepared by a process comprising the steps of: (a) extracting a tuber of Dioscorea alata L. cv, Phyto using an alcohol-based 15 solvent in the presence of acetic acid to obtain an alcoholic product; (b) separating the alcoholic product obtained in step (a) to obtain a soluble fraction; and (c) removing the alcohol-based solvent from the soluble fraction obtained in step (b) to obtain the extract product. 20

8. The extract product of claim 7, wherein the alcohol-based solvent used in step (a) of the preparation process is a methanol-based solvent, an ethanol-based solvent, or a mixture thereof.

9. The extract product of claim 7, wherein step (a) of the preparation process is conducted in the presence of 1% acetic acid. 25

10. The extract product of claim 7, wherein in step (a) of the preparation process, a 40% methanol solution in the presence of 1% acetic acid is used to extract the tuber of Dioscorea alata L. cv, Phyto. 25271281 (GHMatters) 31

11. The extract product of claim 7, wherein prior to step (a) of the preparation process, the tuber of Dioscorea alata L. cv, Phyto is subjected to a preliminary treatment including the steps of: (a) immersing the tuber of Dioscorea alata L. cv, Phyto in a 1% acetic acid solution 5 to obtain an acetic acid-treated tuber; (b) freezing the acetic acid-treated tuber to obtain a frozen tuber of Dioscorea alata L. cv, Phyto; and (c) lyophilizing the frozen tuber of Dioscorea alata L. cv, Phyto.

12. The extract product of claim 7, wherein the alcohol product obtained in step 10 (a) is separated by centrifugation.

13. Use of an extract product of claim 7 in the manufacture of a medicament for treating osteoporosis by oral administration.

14. The method of claim 1, extract product of claim 7 or use of claim 13, substantially as hereinbefore described with reference to the examples, and or figures. 25271281 (GHMatlers)