KR102317222B1 - Composition for preventing, improving or treating colorectal cancer comprising Sageretia thea extract - Google Patents

Abstract

The present invention can provide a composition for preventing, ameliorating or treating colon cancer comprising an extract of the serrata asiatica as an active ingredient, and plant-derived anticancer effective for the prevention, improvement or treatment of colorectal cancer while having low side effects compared to general chemical anticancer agents compositions can be provided.

Description

Composition for preventing, improving or treating colorectal cancer comprising Sageretia thea extract

The present invention relates to an anti-cancer composition comprising an extract of the serrata asiatica, and more particularly, to a composition for preventing or treating colon cancer comprising the extract of the serrata asiatica.

Globally, cancer is considered one of the major health problems. Among cancers, colorectal cancer is the fourth most common malignancy in the world and the third leading cause of cancer death.

Although many anticancer drugs have been clinically developed for the treatment of colorectal cancer, many side effects occur with long-term use. For example, it has been reported that fluorouracil causes neutropenia, stomatitis and diarrhea, irinotecan causes bone marrow suppression, nausea and alopecia, and oxaliplatin causes paresthesia and renal dysfunction. Therefore, medicinal plant resources are being used as complementary and alternative therapies for cancer and have been considered a promising source for the development of anticancer drugs. In fact, clinically used anticancer drugs such as taxol, vinblastine, vincristine, irinotecan, and camptothecin have been developed using plant-derived products.

In cell cycle progression, cyclin D1 complexed with CDK4 and CDK6 induces phosphorylation of retinoblastoma proteins, thus promoting cell cycle progression. In addition, cyclin D1 is involved in the transcriptional activation of genes that induce cell growth, genetic instability, invasion and metastasis. Cyclin D1 is known to regulate apoptosis in addition to cell cycle regulatory functions, and inhibition of cyclin D1 expression induces apoptosis of various cancer cells. On the other hand, upregulation of cyclin D1 inhibits apoptosis in human choriocarcinoma cells. Cyclin D1 overexpression was observed in 63.6% of colorectal cancer, and cyclin D1 is known to be involved in the growth and differentiation of colorectal cancer. Therefore, cyclin D1 is a hallmark of colorectal cancer and has been considered as a potential target for colorectal cancer treatment. Recently, HO-1 has been proposed as a potential molecular anticancer drug target. HO-1, also known as heat shock protein 32, catalyzed the breakdown of heme into bilirubin, iron ions and carbon monoxide. HO-1 activation inhibits hydrogen peroxide and UV-induced oxidative cell damage, inflammatory mediator generation, and hyperglycemia induction. However, HO-1 has been reported to play a multifaceted role in cancer development. HO-1 increases the growth of several cancer cells, such as pancreatic cancer, melanoma, and rhabdomyosarcoma. In the opposite effect of HO-1, overexpression of HO-1 exhibits antiproliferative activity in breast cancer, prostate cancer and colorectal cancer cells. HO-1 also inhibits cell migration and growth of xenograft tumors in hepatocellular carcinoma.

Sageretia thea (S. thea), one of the Rhamnaceae family, is a traditional herbal medicine used in Korea and China to treat hepatitis and fever. In pharmacological studies, it has been reported that the fruits of the serrata have antioxidant, anti-diabetic and anti-melanin-producing activities. It has been reported that the leaves of the serrata asiatica inhibit the oxidation of low-density lipoproteins through antioxidant activity and HIV type 1 protease, but studies on the anticancer activity of the serrata have not been actively conducted.

On the other hand, in the prior art, Patent Publication No. 10-1743200 (a composition for skin whitening containing a fraction of the saponica fruit extract as an active ingredient), and Patent Publication No. 10-1716489 (a cosmetic composition containing an extract of the sorrel tree) are disclosed in the prior art. As it relates to a cosmetic composition containing an extract of serrata asiatica, there is no disclosure of anticancer effect, and there is no disclosure of anticancer effect, and there is no disclosure of anticancer effect, and there is no disclosure of the anticancer effect, and there is no disclosure of the anticancer effect. ) relates to a breast cancer composition, so it is not disclosed at all about the effect of preventing or improving colorectal cancer. Therefore, the inventors of the present invention tried to develop a composition for the prevention, improvement or treatment of colorectal cancer containing the extract of the serrata asiatica.

Registered Patent Publication No. 10-1743200 Registered Patent Publication No. 10-1716489 Registered Patent Publication No. 10-1831981

In order to solve the above problems, the present invention is to provide a composition for the prevention, improvement or treatment of colorectal cancer comprising an extract of the sorrel tree as an active ingredient.

In order to achieve the above object, the present invention provides a composition for preventing, improving or treating colorectal cancer, comprising an extract of the sorrel tree as an active ingredient.

The extract of the serrata asiatica includes extracts extracted from the fruits, leaves, branches, and the like of the serrata asiatica. In the present invention, the extract of the homogenous tree may include, but is not limited to, leaf or branch extracts of the homogenous tree preferably.

The extract may use a polar solvent or a non-polar solvent. The polar solvent may include water, a lower alcohol having 1 to 4 carbon atoms, acetone, dimethyl-formamide (DMFO), and dimethyl sulfoxide (DMSO). Acetone, acetonitrile, ethyl acetate, methyl acetate, fluoroalkane, pentane, hexane, 2,2,4-trimethylpentane, decane, cyclohexane, cyclopentane, diisobutylene, 1-pentene, 1 as a non-polar solvent -Chlorobutane, 1-chloropentane, o-xylene, diisopropyl ether, 2-chloropropane, toluene, 1-chloropropane, chlorobenzene, benzene, diethyl ether, diethyl sulfide, chloroform, dichloromethane, 1 ,2-dichloroethane, aniline, diethylamine, ether, carbon tetrachloride and THF.

The solvent in the present invention may be preferably water or alcohol, and the alcohol may be 60 to 90% (v/v).

The present invention may be used for the prevention, improvement or treatment of anticancer, preferably for the prevention, improvement or treatment of colorectal cancer.

When the composition of the present invention is prepared as a pharmaceutical composition, the pharmaceutical composition of the present invention includes a pharmaceutically acceptable carrier. Pharmaceutically acceptable carriers included in the pharmaceutical composition of the present invention are commonly used in formulation, and include lactose, dextrose, sucrose, sorbitol, mannitol, starch, acacia gum, calcium phosphate, alginate, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, methyl cellulose, methylhydroxybenzoate, propylhydroxybenzoate, talc, magnesium stearate and mineral oil, and the like. it's not going to be The pharmaceutical composition of the present invention may further include a lubricant, a wetting agent, a sweetening agent, a flavoring agent, an emulsifying agent, a suspending agent, a preservative, and the like, in addition to the above components.

The pharmaceutical composition of the present invention may be administered orally or parenterally, and is preferably applied by oral administration.

A suitable dosage of the pharmaceutical composition of the present invention is variously prescribed depending on factors such as formulation method, administration method, age, weight, sex, pathological condition, food, administration time, administration route, excretion rate and reaction sensitivity of the patient. can be

The pharmaceutical composition of the present invention is prepared in unit dosage form by formulating using a pharmaceutically acceptable carrier and/or excipient according to a method that can be easily carried out by a person of ordinary skill in the art to which the present invention pertains. or may be prepared by incorporation into a multi-dose container.

In this case, the formulation may be in the form of a solution, suspension, syrup, or emulsion in oil or aqueous medium, or may be in the form of an extract, powder, powder, granule, tablet or capsule, and may additionally include a dispersant or stabilizer.

The present invention is a composition for preventing, improving or treating colorectal cancer comprising an extract of the serrata asiatica, and it is possible to provide a composition for preventing, improving or treating plant-derived colorectal cancer with excellent anticancer effect while having lower side effects than general chemical anticancer agents. .

1 shows the effect of STL and STB on cell viability, protein levels of Cleaved PARP and cyclin D1 (A and B).
2 shows the results of induction of cyclin D1 degradation by STL and STB through Thr286 phosphorylation of cyclin D1.
3 shows that Cyclin D1 degradation by STL and STB is independent of ERK1/2 and p38.
Figure 4 shows that cyclin D1 degradation by STL and STB is GSK3β-dependent.
5 shows that HO-1 expression is increased by STL and STB.
6 shows that HO-1 expression by STL and STB occurs through Nrf2 activation, which is dependent on ROS-mediated p38 activation.
7 shows a series of procedures for reducing STL and STB-induced cell viability in colorectal cancer cells.

Hereinafter, the present invention will be described in detail by way of Examples and Experimental Examples.

However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the content of the present invention is not limited to the following Examples and Experimental Examples.

<Example>

Sangdong tree (certificate number: Jeong 201804 (ANH)) was provided by the Forest Medicinal Resources Research Institute of the National Academy of Forest Sciences in Yeongju. After immersing 20 g of the branches or leaves of the homogenous tree in 500 ml of 70% ethanol, the mixture was extracted by stirring at room temperature for 3 days. The ethanol soluble fraction was then filtered, concentrated to a volume of 100 ml using a vacuum evaporator and freeze-dried. Ethanol extracts extracted from the branches (STB) or leaves (STL) of the serrata were stored at -80 °C until use.

<Experimental example>

In order to confirm the preventive, ameliorating or therapeutic effect of the Sangdong tree extract of the present invention for colorectal cancer, the experiment was carried out in the following manner.

1. Experimental Materials and Methods

1-1. chemical reagent

LiCl (GSK3β inhibitor), MG132 (proteasome inhibitor), PD98059 (ERK1/2 inhibitor), SB230580 (p38 inhibitor), leptomycin B (LMB, nuclear release inhibitor), zinc protoporphyrin IX (ZnPP, HO-1 inhibitor) ), 3-(4,5-dimethylthizaol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), 5-Fluorouracil (5-FU) and oxaliplatin were obtained from Sigma Aldrich (St. Louis, MO, USA). Purchased. Antibodies against cyclin D1, phospho-cyclin D1 (Thr286), HA-tag, p-GSK3β, total-GSK3β, p-p38, total-p38, HO-1, Nrf2, cleaved PARP, TBP and β-actin It was purchased from Cell Signaling (Bervely, MA, USA).

1-2. cell culture

SW480 cells, one of the human colorectal cancer cell lines, have been widely used to investigate the efficacy of drugs in cancer prevention and treatment. Therefore, SW480 cells were used to investigate the anticancer activity of STB or STL. SW480 cells obtained from Korea Cell Line Bank were treated with 10% fetal bovine serum (FBS), 100 U/ml penicillin and DMEM/F-12 (Lonza, Walkersville, MD, USA at a concentration of 100 μg/ml). ) Streptomycin was incubated at 37° C. under an atmosphere of 5% CO _{2 .} STB or STL was dissolved in DMSO. DMSO as a solvent was used in the range of 0.1% (v/v) or less.

1-3. Check cell viability

An MTT assay was performed to assess cell viability. SW480 cells (3×10 ⁴ cells/well) were cultured in 96-well plates for 24 hours and then treated with STB or STL for 24 hours. After STB or STL treatment, 50 μl of MTT solution (1 mg/ml) was added to the cells and reacted for 2 hours. After 2 hours, the medium was removed and 100 μl of DMSO was added to the cells to obtain crystals. Absorbance was measured at 570 nm using a UV/Visible spectrophotometer (Human Cop., Xma-3000PC, Seoul, Korea).

1-4. cell cycle analysis

SW480 cells (5×10 ⁵ cells/well) were cultured in 6-well plates for 24 hours. STB or STL was treated with cultured SW480 cells for 24 hours. The cell cycle was analyzed with the EZCellTM Cell Cycle Analysis Kit (BioVision, Milpitas, CA, USA) using Flow Cytometry (FACSCalibur, USA).

1-5. Separation of cell nuclei

STL or STB were treated to SW480 cells (2×10 ⁶ cells/well) cultured in 6-well plates. To extract nuclear proteins, cells were washed three times with cold 1X PBS, and nuclear proteins were prepared using a nuclear extract kit (Active Motif, Carlsbad, CA, USA).

1-6. SDS-PAGE and Western blot

For protein extraction from SW480 cells, cells were washed three times with cold 1X PBS, and RIPA buffer (Boston Bio Products, Ashland, MA, USA) containing protease and phosphatase inhibitors (Sigma-Aldrich), 4 It was left at ℃ for 30 minutes. After 30 min, the cells were centrifuged at 15,000 x rpm at 4°C for 10 min, and the supernatant was taken for protein determination. Protein content was analyzed by BCA protein assay (Pierce, Rockford, IL, USA).

Equal amounts of protein were separated by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred to a PVDF membrane (Bio-Rad Laboratories, Inc., Hercules, CA, USA). The membrane was blocked in 5% nonfat milk in Tris buffered saline containing 0.05% Tween 20 (TBS-T) for 1 h at room temperature. Each primary antibody was treated with a PVDF membrane at 4° C. for 16 hours using 5% nonfat milk in TBS-T. After washing with TBS-T, the PVDV membrane was incubated with the secondary antibody at room temperature for 1 hour. did.

After washing with TBS-T, the protein bands were luminescent with ECL Western blotting substrate (Amersham Biosciences, Piscataway, NJ, USA) and using a LI-COR C-DiGit Blot Scanner (Li-COR Biosciences, Lincoln, NE, USA). visualized. The density of protein bands was calculated by UN-SCAN-IT gel version 5.1 (Silk Scientific Inc. Orem, UT, USA).

1-7. Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)

After each treatment, the cells were washed 3 times with cold 1X PBS to isolate total RNA from SW480 cells, and then total RNA was collected with RNeasy Mini Kit (Qiagen, Valencia, CA, USA). Total RNA was measured with an ultraviolet spectrophotometer (GeneQuant 1300, GE Healthcare Life Sciences, Marlborough, MA, USA).

cDNA was synthesized from 1 μg of total RNA using the Verso cDNA kit (Thermo Scientific, Pittsburgh, PA, USA). To amplify cDNA, PCR was performed using a PCR Master Mix Kit (Promega, Madison, WI, USA). The primer sequences of Cyclin D1 and GAPDH are shown in Table 1, and the density of the mRNA band was calculated by UN-SCAN-IT gel version 5.1 (Silk Scientific Inc., Orem, UT, USA).

gene primer SEQ ID NO: Cyclin D1 forward 5'-AACTACCTGGACCGCTTCCT-3' One reverse 5'-CCACTTGAGCTTGTCACCA-3' 2 GAPDH forward 5'-ACCCAGAAGACTGTGGATGG-3' 3 reverse 5'-TTCTAGACGGCAGGTCAGGT-3' 4

1-8. Transient transfection of expression vectors

HA-tagged wild-type Cyclin D1 (WT-Cyclin D1) or HA-tagged T286A Cyclin D1 (T286A-Cyclin D1) constructs were purchased from Addgene (Cambridge, MA, USA).

WT- or T286A-Cyclin D1 was transfected into SW480 cells for 48 h using PolyJet DNA transfection reagent (SignaGen Laboratories, Ijamsville, MD, USA).

1-9. statistical analysis

All data are expressed as mean ± SD (standard deviation) and statistical analysis was performed by one-way ANOVA RHK Dunnett test. *P <0.05 difference was considered statistically significant.

2. Experimental results

2-1. Effect of reducing cell viability and cyclin D1 levels in SW480 cells

To compare the inhibitory effects of STB and STL on cell viability, STB or STL was treated with SW480 cells for 24 hours, followed by MTT analysis. As a result, in STL and STB, the viability of SW480 cells was 20.1% and 24.3% at 25 μg/ml, 53.6%, 72.2% at 50 μg/ml, and 77.0% and 82.0% at 100 μg/ml (FIG. 1A), STL and The IC ₅₀ of STB was 48.51 ± 1.26 μg/ml and 31.93 ± 2.32 μg/ml, respectively. In addition, as a result of comparing the effects of STB or STL on the survival rate of SW480 cells, an anticancer drug used for colorectal cancer treatment, 5-FU and oxaliplatin, the inhibitory effects of 5-FU, oxaliplatin, STB or STL at 50 μg/ml were respectively 11.4%, 35.6%, 63.6% or 43.2% ( FIG. 1B ).

To investigate whether STL and STB affect apoptosis in SW480 cells, the effects of STL and STB on Cleaved PARP were evaluated. Treatment of STL and STB increased cleavage of PARP in SW480 cells (Fig. 1C). Cyclin D1 not only induces hyperproliferation of cancer cells, regulates apoptosis, but also increases cyclin D1 protein, which is observed in human colorectal cancer. Therefore, the effect of STL and STB on cyclin D1 was investigated.

STL and STB reduced cyclin D1 protein levels to 50 μg/ml but not cyclin D1 mRNA levels (Figure 1D). The cell cycle distribution of SW480 cells treated with STL and STB was analyzed by flow cytometry to determine whether the reduction of cyclin D1 protein level by STL and STB affects cell cycle arrest. In the assay results (Figure 1E), STL and STB induced the accumulation of the G0/G1 phase in a dose-dependent manner.

2-2. STB and STL induce phosphorylation of cyclin D1 threonine-286, leading to cyclin D1 proteasomal degradation.

We observed that STL and STB reduced cyclin D1 protein levels but not mRNA levels. This indicates that STL and STB can reduce cyclin D1 protein stability. To evaluate whether STL and STB induce cyclin D1 protein stability, cells were treated with STL or STB in the absence or presence of MG132 (proteasome inhibitor).

As a result, reduced cyclin D1 protein by STL and STB was observed in SW480 cells without MG132. However, pretreatment with MG132 reduced the reduction of cyclin D1 protein by STL and STB (Fig. 2A), indicating that STL and STB can induce cyclin D1 degradation.

Since cyclin D1 threonine-286 (Thr286) phosphorylation is known to contribute to cyclin D1 degradation, the effects of STL and STB on cyclin D1 Thr286 phosphorylation were investigated. Thr286 phosphorylation of cyclin D1 by STL and STB was observed to occur earlier than the decrease in cyclin D1 protein level by STL and STB (Fig. 2B).

To confirm that cyclin D1 degradation by STL or STB was due to Thr286 phosphorylation of cyclin D1, SW480 cells transduced with WT-cyclin D1 or T286A-cyclin D1 were treated with STB or STL.

HA-cyclin D1 was attenuated by STB or STL in cells transfected with WT-cyclin D1, and transfection with T286A-cyclin D1 blocked the reduction of HA-cyclin D1 by STB or STL (Fig. 2C). It was confirmed that Thr286 phosphorylation of Cyclin D1 could contribute to cyclin D1 degradation by STB or STL.

2-3. cyclin D1 proteasome degradation by STB and STL is dependent on GSK3β-induced Thr286 phosphorylation of cyclin D1.

Thr286 phosphorylation-dependent cyclin D1 degradation is known to be regulated by kinases such as extracellular signal-regulated kinase 1/2 (ERK1/2; extracellular signal-regulated kinase 1/2), p38, and glycogen synthase kinase 3 beta (GSK3β). Accordingly, STB or STL were treated with SW480 cells in the absence or presence of PD98059 (ERK1/2 inhibitor), SB203580 (p38 inhibitor) or LiCl (GSK3β inhibitor).

Reduction of cyclin D1 protein by STB and STL was observed in SW480 cells in the absence or presence of PD98059 or SB203580 (Figures 3A and 3B), suggesting that cyclin D1 degradation by STB and STL could be independent of ERK1/2 or p38. indicates that there is However, it was observed that pretreatment with LiCl inhibited the reduction of cyclin D1 protein by STB and STL (Fig. 4A). In addition, LiCl inhibited Thr286 STB and STL-mediated phosphorylation of cyclin D1 (Fig. 4B).

These data suggest that cyclin D1 degradation by STB and STL may be dependent on GSK3β-dependent Thr286 phosphorylation of cyclin D1. To investigate whether STB and STL activate GSK3β, phosphorylation of GSK3β as an active form by STB or STL was detected. STB and STL increased the phosphorylation of GSK3β ( FIG. 4C ).

GSK3β-dependent Thr286 phosphorylation of cyclin D1 induces redistribution of cyclin D1 from the cytoplasm to the nucleus, which is known to be involved in the degradation of cyclin D1. Therefore, we studied that the redistribution of cyclin D1 from the cytoplasm to the nucleus from the nucleus to the nucleus affects the cyclin D1 degradation mediated by STB and STL. LMB inhibited cyclin D1 degradation by STB and STL, compared with treatment of STB and STL in the absence of LMB (Fig. 4D), indicating that STB and STL inhibit GSK3β-dependent Thr286 phosphorylation of cyclin D1 and subsequently from the cytoplasm to the nucleus. This indicates that cyclin D1 degradation can be induced through cyclin D1 redistribution of

2-4. STB or STL confirms HO-1 expression upregulation

Heme oxygenase-1 (HO-1) exhibits antitumor activity in prostate and colorectal cancer. Since HO-1 activation reduces the survival rate of human colon cancer cells, it was evaluated whether STB and STL affect HO-1 expression in SW480 cells.

5A , STL and STB at 25 μg/ml slightly increased HO-1 expression, but HO-1 expression increased dramatically at STL and STB at 50 μg/ml, and a significant increase in HO-1 expression was observed to occur 24 h after STL and STB treatment (Fig. 5B).

To determine whether HO-1 expression by STB and STL contributes to cell death, SW480 cells were treated with STB or STL in the absence or presence of ZnPP (HO-1 inhibitor). As a result, cleaved PARP was increased by treatment with STB and STL in the absence of ZnPP, but the presence of ZnPP inhibited cleaved PARP by STB and STL (Fig. 5C). These results indicate that HO-1 may contribute to apoptosis by STB and STL.

2-5. ROS-induced p38 activation-dependent Nrf2 activation confirms the effect of increasing HO-1 expression by STB and STL

Under reactive oxygen species (ROS) mediated p38 activation, the nuclear factor erythrocyte 2-associated factor-2 (Nrf2) translocates to the nucleus where it binds to the antioxidant response element (ARE) in the HO-1 promoter region and HO- 1 Contributing to expression, we first evaluated whether STB and STL induce nuclear accumulation of Nrf2 in SW480 cells. As shown in Fig. 6A, nuclear levels of Nrf2 were increased by treatment with STB and STL (Fig. 6A). Therefore, we tested whether p38 and ROS affect the nuclear accumulation of Nrf2 induced by STB and STL in SW480 cells.

p38 inhibition by SB203580 blocked the nuclear accumulation of Nrf2 induced by ST-B and ST-L, leading to decreased HO-1 expression (Fig. 6B). In addition, blocking Nrf2 nuclear accumulation and HO-1 expression mediated by STB and STL was also observed in SW480 cells treated with NAC as a ROS scavenger (Fig. 6B).

As p38 activation is known downstream of ROS, we investigated whether ROS affects p38 activation by STB and STL. As shown in Figure 6C, STB and STL induced p38 phosphorylation in the absence of NAC, whereas NAC treatment attenuated p38 phosphorylation by STB and STL. These data indicate that STB and STL can induce apoptosis through Nrf2-dependent HO-1 expression through ROS-induced p38 activation.

In the above experiment, STL and STB increased HO-1 expression by inducing cyclin D1 degradation through GSK3β-dependent phosphorylation of cyclin D1 threonine-286 and activating Nrf2 through ROS-dependent p38 activation, and decreased the viability of SW480 cells ( 7) was confirmed.

These results suggest that STL and STB have a high potential for developing anticancer drugs for colorectal cancer.

<110> National Institute of Forest Science <120> Composition for preventing, improving or treating colorectal cancer comprising Sageretia thea extract <130> 19-11271 <160> 4 <170> KoPatentIn 3.0 <210> 1 <211> 20 <212> DNA <213> Artificial Sequence <220> <223> Forward primer for Cyclin D1 <400> 1 aactacctgg accgcttcct 20 <210> 2 <211> 20 <212> DNA <213> Artificial Sequence <220> <223> Reverse primer for Cyclin D1 <400> 2 ccacttgagc ttgttcacca 20 <210> 3 <211> 20 <212> DNA <213> Artificial Sequence <220> <223> Forward primer for GAPDH <400> 3 acccagaaga ctgtggatgg 20 <210> 4 <211> 20 <212> DNA <213> Artificial Sequence <220> <223> Reverse primer for GAPDH <400> 4 ttctagacgg caggtcaggt 20

Claims (3)

In the composition for the prevention, improvement or treatment of colorectal cancer comprising the extract of the sorrel tree as an active ingredient,
The extract is a composition for preventing, improving or treating colorectal cancer, characterized in that the extract is extracted with ethanol 70% (v/v). delete [Claim 2] The composition for preventing, improving or treating colon cancer according to claim 1, wherein the extract of the serrata asiatica is extracted from the leaves or branches of the rhododendron tree.

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