WO2003039538A1

WO2003039538A1 - Composition containing a flavonoid glycone and method for using same as anti-proliferative

Info

Publication number: WO2003039538A1
Application number: PCT/AU2002/001511
Authority: WO
Inventors: The Hung Huynh; Toan Thang Phan
Original assignee: Biotech Research Ventures Pte Ltd; Hughes, Edward, John, Langford
Priority date: 2001-11-07
Filing date: 2002-11-06
Publication date: 2003-05-15
Also published as: AUPR870501A0

Abstract

The present invention relates generally to the use of a flavonoid glycone alone or in combination with a therapeutically effective amount of another agent such as an anti-keloid agent to inhibit, prevent or otherwise suppress keloid fibroblast proliferation and/or collagen synthesis. The subject invention further contemplates a method of ameliorating the effects of keloids such as keloid-mediated heavy or excessive scarring by the systemic or topical application of a flavonoid glycone alone or in combination with another agent such as an anti-keloid agent. The present invention is particularly directed to the use of quercetin as well as derivatives and homolog thereof. The present invention further provides medicaments comprising a flavonoid glycone such as quercetin and one or more other anti-keloid agents and/or agents which inhibit one or more components in the insulin-like growth factor (IGF) signalling cascade. Such medicaments may be in the form of a single composition or a multi-part pharmaceutical pack where the active ingredients are admixed prior to administration.

Description

COMPOSITION CONTAINING A FLAVONOID GLYCONE AND METHOD FOR USING SAME AS ANTI-PROLIFERATIVE

FIELD OF THE INVENTION

The present invention relates generally to the use of a flavonoid glycone alone or in combination with a therapeutically effective amount of another agent such as an anti- keloid agent to inhibit, prevent or otherwise suppress keloid fibroblast proliferation and/or collagen synthesis. The subject invention further contemplates a method of ameliorating the effects of keloids such as keloid-mediated heavy or excessive scarring by the systemic or topical application of a flavonoid glycone alone or in combination with another agent such as an anti-keloid agent. The present invention is particularly directed to the use of quercetin as well as derivatives and homolog thereof. The present invention further provides medicaments comprising a flavonoid glycone such as quercetin and one or more other anti-keloid agents and/or agents which inhibit one or more components in the insulinlike growth factor (IGF) signalling cascade. Such medicaments may be in the form of a single composition or a multi-part pharmaceutical pack where the active ingredients are admixed prior to administration.

BACKGROUND OF THE INVENTION

Bibliographic details of references provided in the subject specification are listed at the end of the specification.

Reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any fonn of suggestion that this prior art forms part of the common general knowledge in any country.

Keloids are aesthetically disfiguring, fibro-proliferative scars that represent a pathological response to cutaneous injury. Their clinical features and characteristics differentiate them from hypertrophic scarring. Keloids are characterized by abnormal proliferation of fibroblasts, especially in the active growing phase (Yeh et al, Am. J. Physiol 273: E734- E742, 1997; Ladin et al, Wound Repair Regen. 6: 28-37, 1998; Santen et al, Endo. Rev. 11 221-265, 1990; Saed et al, Arch. Dermatol 134: 963-967, 1998). Keloid fibroblasts overproduce collagen as much as twenty times more than normal skin fibroblasts (Cohen et al, Keloids and Hypertropic Scars. In:. J. G. McCarthy (ed.), Plastic Surgery, pp. 132-1 Al, Saunders, USA, 1990; Ladin et al, Wound Repair and Regeneration 3: 6-14, 1995).

Existing medical and surgical strategies to prevent or to treat scars have been largely empirical and anecdotal based on the "best practices" of experienced clinicians. This relative lack of understanding about keloids is reflected in the multiple therapies currently available for its treatment, which usually result in high recurrence rates. The most common mode of treatment for keloids is intralesional injection of corticosteroids which is often not very effective (Tuan and Nichter, Mol. Med. Today 4: 19-24, 1998). Thus, there is an urgent need for novel treatment strategies of keloids.

Flavonoid glycones are commonly found in the diet. The most abundant are quercetin, rutin and robinin (Kahnau, World Rev. Nutr. Diet. 24: 117-191, 1976; Anton, Flavonoids and Traditional Medicine, New York: Alan R. Liss, Inc., 1988). The richest sources of quercetin are found in onion, apples and red wine (Hertog et al, Nutr. Cancer 20: 21-29, 1993). Quercetin is also identified as an active ingredient of medicinal plants such as Ginkgo biloba, Chromolaena odorata and Cudrania cochinchinesis (Anton, 1988, supra). Human consumption is estimated to be approximately 4 to 68 mg per day (Kuhnau, 1976, supra). Quercetin has a wide range of biological activity including inhibition of the Na^K^ATPase (Suolinna et al, J. Natl Cancer Inst. 53: 1515-1519, 1974), protein kinase C (Hofmann et al, Int. J. Cancer 42: 382-388, 1988), tyrosine kinase (Srivastava, Biochem. Biophys. Res. Commun. 131: 1-5, 1985), HIN reverse transcriptase (Ono et al, Eur. J. Biochem. 190: 469- 476, 1990), and pp60^sr0 kinase. Furthermore, quercetin is the first tyrosine kinase inhibitor to be described (Glossmann et al, Naunyn Schmiedebergs Arch. Pharmacol. 317: 100-102, 1981). It is a potent inhibitor of enzymes involved in the proliferation of signaling pathways including phosphatidyl-3 kinase (Matter et al, Biochem. Biophys. Res. Commun. 186: 624- 631, 1992) and l-ρhosphtidylinosotol-4 kinase (Yeh et al, Life Sci. 57: 1285-1291, 1995). It also has antiviral, anti-inflammatory and anti-microbial properties. It causes the cell cycle arrest of human leukemic T cells, human breast (Scambia et al, Br. J. Cancer (52:942-946, 1990), ovarian (Scambia et al, 1990, supra) and gastric cancer Yoshida et al, Cancer Res. 52: 6676-6681, 1992) cells. Quercetin also induces apoptosis through a pathway involving heat shock proteins (Wei et al, Cancer Res. 54: 4952-4957, 1994). Quercetin can down- regulate mutant p53 gene (Avila et al, Cancer Res. 54: 2424-2428, 1994).

hi work leading up to the present invention, the inventors sought to determine what effect, if any, quercetin had on keloid-derived fibroblast proliferation. The inventors surprisingly discovered that quercetin could inhibit keloid fibroblast proliferation and insulin-like growth factor (IGF) signalling pathways. Since the IGF system plays an important role in fibroblast proliferation and collagen production, it is proposed, in accordance with the present invention, that quercetin and other flavonoid glycones are useful as inhibitors of keloid formation and collagen synthesis and, hence, are useful in the manufacture of medicaments for the treatment of keloids including keloid-mediated heavy or excessive scarring.

SUMMARY OF THE INVENTION

Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or integer or group of elements or integers but not the exclusion of any other element or integer or group of elements or integers.

Keloids are characterized by abnormal proliferation of fibroblasts and overproduction of collagen. The inventors assessed the effects of quercetin on proliferation and the operation of the IGF system in keloid-derived fibroblasts. In accordance with the present invention, the inventors determined that quercetin significantly inhibits keloid fibroblast proliferation in a dose-dependent manner. Preferred dosages range from approximately 5 μg/ml to approximately 100 μg/ml. Levels of IGF-TR β subunits, PI-3 kinase p85, c-Raf, phospho Raf-1, phospho MAP kinase, phospho Elk-1 and phospho Akt-1 are also significantly reduced when keloid fibroblast cells are exposed to quercetin. IGF-1 is a mitogenic factor for fibroblasts and a stimulatory factor for collagen synthesis. Consequently, it is proposed that quercetin and its derivatives and homologs and other flavonoid glycones are useful for preventing, suppressing or otherwise inhibiting keloid fibroblast proliferation and collagen synthesis and are useful in the treatment of keloids and keloid-mediated heavy or excessive scarring.

The present invention provides, therefore, methods of treatment and medicaments for use in the treatment of keloids and keloid-mediated heavy or excessive scarring.

Accordingly, one aspect of the present invention contemplates a method for inhibiting, preventing or otherwise suppressing keloid fibroblast proliferation and/or collagen synthesis in a subject, said method comprising administering to said subject an effective amount of a flavonoid glycone or a derivative or homolog thereof.

Another aspect of the present invention provides a method for inhibiting, preventing or otherwise suppressing keloid fibroblast proliferation and/or collagen synthesis in a subject, said method comprising administering to said subject an effective amount of a flavonoid glycone or a derivative or homolog thereof, said flavonoid glycone or derivative or homolog having the structure of Formula (I):-

wherein:

X is selected from sulfur, oxygen, nitrogen and CRιR₂; and

Rl 10 is as defined below or is optionally a mono-, di- or tri-saccharide having the structures in Formulae (II), (III) and (IN), respectively:-

wherein:-

R¹ to R³⁹ are independently selected from hydrogen, F, Cl, Br, I, CΝ, ΝO₂, CF₃, CORi, CO₂Rι, ORi, SR_j, NRιR₂, N(=O)₂, NRιOR₂, ONRιR₂, SOR_u SO₂Rι, SO₃Rι, SONRϊR,, SO₂NR₁R₂, SO₃NR,R₂, P(Rι)₃, P(=0)(Rι)₃, Si(Rι)₃, B(Rι)₂, (C=X)Rι or X(C=X)Rι where X is as defined above;

R¹ to R³⁹ (and Ri and R₂) are each independently selected from hydrogen, Cι-C₂o alkyl (branched and/or straight chained), Cι-C₂o arylalkyl, C₃-C₈ cycloalkyl, C₆-Cι aryl, Cχ-Cu heteroaryl,

heterocycle, C₂-C₁o alkenyl (branched and/or straight chained aryl and heteroaryl can be attached), C₂-C₁o alkynyl (branched and/or straight chained aryl and heteroaryl can be attached), Ci-Cio heteroarylalkyl, -Cio alkoxyalkyl, Ci-Cio haloalkyl, dihaloalkyl, trihaloalkyl, haloalkoxy, Ci-Cio [CN, ORi, SR_b NRιR₂, N(=O)₂, NRιOR₂, ONR₁R2, SORi, SO₂Rι, SO₃R₁, SONRιR₂, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃, Si(Rι)₃, B(R ₂]alkyl; Aryl is C₆-Cι₄ with any mode of substitution containing F, Cl, Br, I, NO₂, CF₃, CN, CORi, CO₂R_b OR_ls SR_b NR₁R2, N(=O)₂, NRιOR₂, ONRιR₂, SOR_l5 SO₂R₁, SO₃R_l5 SONR,R₂, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃, Si(R₁)₃, B(R₁)₂]alkyl;

or a pharmaceutically acceptable salt or ester thereof.

A further aspect of the present invention contemplates a method for inhibiting, preventing or otherwise suppressing keloid fibroblast proliferation and/or collagen synthesis in a subject, said method comprising administering to said subject an effective amount of a quercetin or a derivative or homolog thereof.

Yet another aspect of the present invention provides for the use of quercetin or a derivative or homolog thereof in the manufacture of a medicament for the inhibition, prevention or suppression of keloid fibroblast proliferation and/or collagen synthesis.

Still another aspect of the present invention contemplates a method for modulating a physiological process mediated by the IGF signalling pathway, said method comprising administering to a subject an amount of a flavonoid glycone as herein defined effective to inhibit said IGF signalling pathway. Even still another aspect of the present invention provides a composition comprising a flavonoid glycone as herein defined or a salt or ester thereof or a derivative or homolog thereof and one or more pharmaceutically acceptable carriers and/or diluents and/or dispersants.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a graphical representation of the effects of quercetin on keloid fibroblast proliferation. Keloid fibroblasts were grown in serum-free medium (SFM) and in medium with 10% v/v fetal-calf serum as controls. Cells were also grown in media with doses of quercetin at 10 μg, 25 μg and 50 μg. Cell proliferation for controls and cells grown in different doses of quercetin was determined by the MTT assay at 24 hours (A), 72 hours (B) and 120 hours (C). Quercetin significantly inhibited keloid fibroblast proliferation.

Figure 2 is a photographic and graphical representation showing the effects of quercetin on IGF-IR, IRS-1 and phospho c-Raf (Ser259) levels. Keloid fibroblasts were incubated with medium containing 10% v/v fetal-calf serum in the presence or absence of indicated concentrations of quercetin for 48 hours. Blots were incubated with (A) α-tubulin (0.5 μg/ml), (B) anti-IGF-IRβ (1 μg/ml), (C) anti-IRS-1 (1 μg/ml), (D) anti-c-Raf (1 μg/ml) and (E) anti-phospho c-Raf (Ser259) (1 μg/ml) antibodies. Densitometric scanning of the IGF- IR, c-Raf, phospho c-Raf and IRS-1 is shown in (F). Quercetin significantly decreased IGF-IR, IRS-1, c-Raf and phospho c-Raf levels.

Figure 3 is a photographic and graphical representation showing the effects of quercetin on MAPK, phospho p44/42 MAP kinase (Thr202/Tyr204) and phospho Elk-1 (Ser383) levels. Keloid fibroblasts were incubated with medium containing 10% v/v fetal-calf serum in the presence or absence of indicated concentrations of quercetin for 48 hours. Blots were incubated with (A) α-tubulin (0.5 μg/ml), (B) anti-phospho p44/42 MAP kinase (Thr202/Tyr204) (1 μg/ml), (C) anti-MAPK (1 μg/ml) and (D) phospho Elk-1 (Ser383) (1 μg/ml) antibodies. Densitometric scanning of phospho MAKP and phospho Ekl-1 is shown in (E). Quercetin significantly decreased phospho MAPK and phospho Elk-1 levels.

Figure 4 is a photographic and graphical representation showing the effects of quercetin on PI-3 kinase p85 and phospho Akt (Ser473) levels. Keloid fibroblasts were incubated with medium containing 10%₀ v/v fetal-calf serum in the presence or absence of indicated concentrations of quercetin for 48 hours. Blots were incubated with (A) α-tubulin (0.5 μg/ml), (B) anti-PI-3 kinase p85 (1 μg/ml) and (C) anti-phospho Akt (Ser473) (1 μg/ml) antibodies. Densitometric scanning of PI-3 kinase p85 and phospho Akt is shown in (D). Quercetin significantly decreased phospho PI-3 kinase p85 and phospho Akt levels.

Figure 5 is a graphical representation showing the effects of IGF-I and IGF-IR antibodies on keloid fibroblast proliferation. Keloid fibroblasts were treated with serum free DMEM or serum free DMEM containing 1 μg/ml anti-human IGF-I or 1 μg/ml anti-human IGF-IR for 5 days. Keloid fibroblast proliferation was significantly decreased in the presence of anti-IGF-I and anti-IGF-IR antibodies.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention contemplates the use of a flavonoid glycone in the manufacture of a medicament to inhibit, prevent or otherwise suppress keloid fibroblast proliferation and/or collagen synthesis or to modulate any physiological process mediated by the IGF signalling cascade. The flavonoid glycone may be used alone or in combination with another agent, such as but not limited to, an anti-keloid agent. Examples of anti-keloid agents include other flavonoid glycones or agents which inhibit components of the IGF signalling cascade such as antibodies directed to, for example, IGF-1 or IGF-R. The medicament of the present invention is useful inter alia for treating or ameliorating the effects of keloids and keloid-mediated heavy or excessive scarring.

A "subject" includes a human, primate, livestock animal (e.g. sheep, cow, pig, horse, donkey, goat), laboratory test animal (e.g. mouse, rat, guinea pig, rabbit), companion animal (e.g. dog, cat) ora captive wild animal. Most preferably, the subject is a human or test animal.

By "administering" is meant the topical or systemic application of the flavonoid glycone. Topical administration is the preferred method of application.

Reference to a "flavonoid glycone" includes all derivatives and homologs thereof, whether or not the derivative or homolog is still strictly a flavonoid glycone. A flavonoid glycone is a multi-ring structure with generally either no saccharide side chain or a mono-, di- or tri- saccharide side chain. A derivative may occur in the core ring structure or in the saccharide side chain. Preferred derivatives are in the core ring structure. According to another embodiment, there is provided a method for inhibiting, preventing or otherwise suppressing keloid fibroblast proliferation and/or collagen synthesis in a subject, said method comprising administering to said subject an effective amount of a flavonoid glycone or a derivative or homolog thereof, said flavonoid glycone or derivative or homolog having the structure of Formula (I):-

wherein:

X is selected from sulfur, oxygen, nitrogen and CRιR₂; and

Rl is as defined below or is optionally a mono-, di- or tri-saccharide having the structures in Formulae (II), (III) and (IN), respectively:-

wherein: -

R¹ to R³⁹ are independently selected from hydrogen, F, Cl, Br, I, CN, NO₂, CF₃, CORi, CO₂Rι, ORi, SRi, NR₁R₂, N(=O)₂, NRιOR₂, ONRιR₂, SORj, SO₂R_l5 SO₃Rι, SONR1R2, SO₂NR!R₂, SO₃NRιR₂, P(Rι)₃, P(=0)(Rι)₃, Si(Rι)₃, B(Rι)₂, (C=X)Rι or X(C=X)Rι where X is as defined above;

R¹ to R³⁹ (and Ri and R₂) are each independently selected from hydrogen, C₁-C₂₀ alkyl (branched and/or straight chained), C₁-C2₀ arylalkyl, C₃-C₈ cycloalkyl, C₆-Cι₄ aryl, Cι-C₁₄ heteroaryl, Cι-Cι heterocycle, C₂-Cιo alkenyl (branched and/or straight chained aryl and heteroaryl can be attached), C₂-Cιo alkynyl (branched and/or straight chained aryl and heteroaryl can be attached), C1-C10 heteroarylalkyl, C₁-C₁₀ alkoxyalkyl, C₁-C₁₀ haloalkyl, dihaloalkyl, trihaloalkyl, haloalkoxy, C₁-C₁₀ [CN, OR_b SRi, NR1R₂, N(=O)₂, NR₁OR2, ONR₁R2, SORi, SO₂R SO₃R_b SONR1R2, SO₂NRιR₂, SO₃NRιR₂, P(Rι)3, P(=0)(Rι)₃, Si(Rι)₃, B(R₁)₂]alkyl; Aryl is C₆-Cι₄ with any mode of substitution containing F, Cl, Br, I, NO₂, CF₃, CN, CORi, CO₂R,, OR_u SR_b NRιR₂, N(=O)₂, NRιOR₂, ONRιR₂, SORi, SO₂R_u SO₃Rι, SONRιR₂, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃, Si(Ri)₃, B(R ₂]alkyl;

or a pharmaceutically acceptable salt or ester thereof.

A heteroaryl is an oxazolyl, thiazaoyl, thienyl, furyl, 1-isobenzofuranyL 3H-ρyrrolyl, 2H- pyrrolyl, N-pyrrolyl, imidazolyl, pyrazolyl, isothiazolyl, isooxazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyradazinyl, indolizinyl, isoindolyl, indoyl, indolyl, purinyl, phthalazinyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,2,3-oxadiazoyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,3,4-oxadiazolyl, 1,2,3,4-oxatriazolyl, 1,2,3,5-oxatriazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, azepinyl, oxepinyl, thiepinyl, benzofuranyl, isobenzofuranyl, thionaphthenyl, isothionaphthenyl, indoleninyl, 2-isobenzazolyl, 1,5-pyrindinyl, pyrano[3,4-b]pyrrolyl, isoindazolyl, indoxazinyl, benzoxazolyl, anthranilyl, quinolinyl, isoquinolinyl, cinnolinyl, quinazolinyl, naphthyridinyl, pyrido[3,4-b]pyridinyl, pyrido[3,2- bjpyridinyl, pyrido[4,3-b]pyridinyl, other variations not mentioned are included. Heterocyclic systems include partially and fully saturated heteroaryl derivatives. Heterocyclic systems maybe attached to another moiety via any number of carbon atoms or heteroatoms of the radical and are both saturated and unsaturated. R¹ connected to R², R² connected to R³, R³ connected to R⁴, R⁵ connected to R⁶, R⁶ connected to R⁷, R⁷ connected to R⁸, R⁸ connected to R⁹ and R⁹ connected to R¹⁰ is a selection of Cι-C₈ disubstituted (fused) saturated or unsaturated carbo- and heterocyclic rings further substituted by R_ls (C=X)Rι and X(C=X)Rι.

R¹ to R¹⁰ are each independently selected from Formula (I) or from Formulae (II) to (IV) where R¹¹ to R³⁹ and X are defined above.

R i l¹l¹ to R .1"3 to

R , 1^l5^D to R , 1¹6⁰, R τ, 17 to R 1^l8^δ, - Rr, 1^ι9^y to R ,2^z0^υ, R -r>2^Z1¹ to R ,22, τ R»23 to

R τ»25^o to R ,2^M6, R²⁷ to R²⁸, R²⁹ to R³⁰, R³¹ to R³², R³³ to R³⁴, R³⁵ to R³⁶ and R³⁷ to R³⁸ are X where X is as defined above, nitrogen and NRχR .

Most preferably, the flavonoid glycone is quercetin having the structure of Formula (V):-

The present invention contemplates derivatives and homologs of quercetin wherein the substituent groups are selected from those contemplated for Formula (I) above. A derivative or homolog may or may not be classified as a flavonoid glycone or quercetin. A homolog includes an analog. Derivatives of homologs may be naturally occurring or maybe synthetically generated.

The present invention extends to any flavonoid glycone effective in inhibiting, preventing or otherwise suppressing keloid fibroblast proliferation and/or collagen synthesis. An example of another flavonoid glycone is rutin, having the structure of Formula (VI):-

As indicated above, reference hereinafter to "quercetin" includes reference to its derivatives or homologs as well as other functionally related flavonoid glycones. Quercetin may be used alone or in combination with another anti-keloid agent. Examples of other anti-keloid agents include other flavonoid glycones and antibodies to one or more components in the IGF signalling cascade.

Accordingly, another aspect of the present invention contemplates a method for inhibiting, preventing or otherwise suppressing keloid fibroblast proliferation and/or collagen synthesis in a subject, said method comprising administering to said subject an effective amount of a quercetin or a derivative or homolog thereof.

Another aspect of the present invention provides for the use of quercetin or a derivative or homolog thereof in the manufacture of a medicament for the inhibition, prevention or suppression of keloid fibroblast proliferation and/or collagen synthesis. As indicated above, "administration" includes both topical and systemic applications including intra-lesional administration. Preferably, the flavonoid glycone is topically applied.

The quercetin may be used alone or in combination with one or more other agents such as anti-keloid agents. A "medicament" includes a pharmaceutical composition including liquid, gaseous, vapor or solid forms thereof. A medicament may also be provided with instructions for use. The medicament may also be in the form of a multi-part pharmaceutical pack where the individual components or groups of components are maintained separately but are admixed together prior to use. For example, the medicament comprises a multi-part pharmaceutical pack comprising:

a first compartment adapted to contain a flavonoid glycone capable of inhibiting, preventing or suppressing keloid fibroblast proliferation and/or collagen synthesis;

a second compartment adapted to contain a second flavonoid glycone or other agent capable of inhibiting, preventing or suppressing keloid fibroblast proliferation and/or collagen synthesis; and

optionally a third compartment adapted to contain one or more pharmaceutically acceptable carriers and/or diluents and/or dispersants;

said pharmaceutical pack having means to admix the components of the separate compartments together prior to use.

Without intending to limit the present invention to any one theory or mode of action, it is proposed that flavonoid glycones and in particular quercetin and its derivatives and homologs inliibit the IGF signalling pathway and in particular IGF-1 receptor (IGF-IR). It is proposed that by inhibiting the IGF signalling pathway, cellular proliferation is inhibited, prevented or otherwise suppressed.

Accordingly, another aspect of the present invention contemplates a method for modulating a physiological process mediated by the IGF signalling pathway, said method comprising administering to a subject an amount of a flavonoid glycone as herein defined effective to inhibit said IGF signalling pathway.

Preferably, the flavonoid glycone is quercetin or its derivatives or homologs.

The term "effective amount" or reference to an amount "effective" includes an amount of a flavonoid glycone such as quercetin which is administered for at time and under conditions sufficient to ameliorate the effects of keloid fibroblast proliferation and/or collagen synthesis and/or which inhibits the IGF signalling cascade.

The present invention further provides a composition comprising a flavonoid glycone as herein defined or a salt or ester thereof or a derivative or homolog thereof and one or more pharmaceutically acceptable carriers and/or diluents and/or dispersants.

Preferably, the flavonoid glycone is quercetin.

The flavonoid glycone may be present alone or in combination with other agents such as anti-keloid agents.

The composition may also be considered a pharmaceutical composition or a medicament.

Pharmaceutical forms of the composition contemplated herein include forms suitable for topical application or systemic administration. The compositions must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier can be a solvent or dilution medium comprising, for example, water, ethanol, polyol (for example, glycerol, propylene glycol and liquid polyethylene glycol, and the like), suitable mixtures thereof and vegetable oils or may be a dispersant. The proper fluidity can be maintained, for example, by the use of surfactants. The preventions of the action of microorganisms can be brought about by various anti-bacterial and anti-fungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thirmerosal and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminium monostearate and gelatin.

Sterile injectable solutions are prepared by incorporating the active compounds in the required amount in the appropriate solvent with the active ingredient and optionally other active ingredients as required, followed by filtered sterilization or other appropriate means of sterilization, h the case of sterile powders for the preparation of sterile injectable solutions, suitable methods of preparation include vacuum drying and the freeze-drying technique which yield a powder of active ingredient plus any additionally desired ingredient. The use of cream or gel-based compositions is particularly preferred.

When the flavonoid glycones are suitably protected, they may even be orally administered, for example, with an inert diluent or with an assimilable edible carrier, or it may be enclosed in hard or soft shell gelatin capsule, or it may be compressed into tablets. For oral therapeutic administration, the active ingredient may be incorporated with excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers and the like. Such compositions and preparations should contain at least 1% by weight of active compound. The percentage of the compositions and preparations may, of course, be varied and may conveniently be between about 5 to about 80% of the weight of the unit.

The amount of flavonoid glycone in such therapeutically useful compositions is such that a suitable dosage will be obtained. Preferred compositions or preparations according to the present invention are prepared so that a dosage unit form contains between about 1 μg and 1 mg of active compound per ml. Alternative dosage amounts include from about 5 μg to about 500 mg and from about 10 μg to about 100 mg or from about 10 μg to about 50 μg per ml. These dosages may be per individual or per kg body weight or per area of scarring or skin tissue. Administration may be per hour, day, week, month or year.

The tablets, troches, pills, capsules, creams and the like may also contain the components as listed hereafter. A binder such as gum, acacia, corn starch or gelatin; excipients such as dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid and the like; a lubricant such as magnesium stearate; and a sweetening agent such as sucrose, lactose or saccharin may be added or a flavouring agent such as peppermint, oil of wintergreen or cherry flavouring. When the dosage unit form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier. Various other materials may be present as coatings or to otherwise modify the physical form of the dosage unit. For instance, tablets, pills or capsules may be coated with shellac, sugar or both. A syrup or elixir may contain the active compound, sucrose as a sweetening agent, methyl and propylparabens as preservatives, a dye and flavouring such as cherry or orange flavour. Of course, any material used in preparing any dosage unit form should be pharmaceutically pure and substantially non-toxic in the amounts employed. In addition, the active compound(s) may be incorporated into sustained-release preparations and formulations.

Pharmaceutically acceptable carriers and/or diluents and/or dispersants include any and all solvents, dispersion media, coatings, anti-bacterial and anti-fungal agents, isotonic and absorption delaying agents and the like. The use of such media and agents for pharmaceutical active substances is well known in the art and except insofar as any conventional media or agent is incompatible with the active ingredient, their use in the therapeutic compositions is contemplated. Supplementary active ingredients can also be incorporated into the compositions.

Administration of the flavonoid glycone or agent, in the form of a pharmaceutical composition including a medicament, may be performed by any convenient means. Topical application to an affected area or intra-lesional administration is particularly preferred. The flavnoid glycone or agent may be administered by other means such as by the oral, intravenous (where water soluble), intranasal, intraperitoneal, intramuscular, subcutaneous, intradermal or suppository routes or implanting (e.g. using slow release molecules). With particular reference to use of flavonoid glycone or agent, these peptides may be administered in the form of pharmaceutically acceptable non-toxic salts, such as acid addition salts or metal complexes, e.g. with zinc, iron or the like (which are considered as salts for purposes of this application). Illustrative of such acid addition salts are hydrochlori.de, hydrobromide, sulphate, phosphate, maleate, acetate, citrate, benzoate, succinate, malate, ascorbate, tartrate and the like.

The most preferred amounts of quercetin are in the range from about 5 to about 100 μg/ml or more preferably from about 10 to about 50 μg/ml or even more preferably from about 10 to about 25 μg/ml.

Other agents such as other flavonoid glycones or antibodies to, for example, components of the IGF cascade pathway may be incorporated into the composition.

The flavonoid glycone such as quercetin or a medicament comprising same is particularly useful for the treatment of keloids or keloid-mediated scarring. The scarring is heavy or excessing scarring.

Accordingly, another aspect of the present invention provides a method for treating keloids or keloid-mediated scarring or to otherwise ameliorate the effects of keloid fibroblast proliferation or collagen synthesis in a subject, said method comprising administering to said subject an effective amount of a flavonoid glycone as defined herein for a time and under conditions sufficient to inliibit, prevent or otherwise suppress keloid fibroblast proliferation and/or collagen synthesis and/or the IGF signalling.

hi a related embodiment, the present invention further provides for the use of a flavonoid glycone as defined herein in the manufacture of a medicament for the treatment of keloids, keloid-mediated scarring and/or the amelioration of the effects of keloid fibroblast proliferation or collagen synthesis.

Preferably, the flavonoid glycone is quercetin or a derivative or homolog thereof.

Although the present invention is particularly directed to the amelioration of the effects of scarring such as for cosmetic purposes, the present invention further extends to the use of a flavonoid glycone such as quercetin to prevent or reduce scarring of internal organs or epithelial surfaces or surfaces comprising fibroblasts. This may be important, for example, to reduce scarring on heart tissue following heart surgery or the introduction of a stent to a vessel in the heart or following organ transplantation.

The present invention is further described by the following non-limiting Examples.

EXAMPLE 1

Media and chemicals

Dulbecco's modified Eagle's medium (DMEM), fetal calf serum (FCS), Hank's balanced salt solution (HBSS), streptomycin, penicillin, gentamycin and fungizone were from Gibco. Quercetin, MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide], sodium dodecyl sulfate (SDS), and N,N~dimethyformamide (DMF), phosphate buffered saline without calcium and magnesium (PBS), were purchased from Sigma Chemical Co (USA).

EXAMPLE 2

Fibroblast culture from earlobe keloids

Patients in the selected group were Chinese and had received no previous treatment for the keloids before surgical excision. Prior to keloid excision, a full history was taken and examination performed, complete with color slide photodocumentation and informed consent.

Dermis from the keloids was minced and incubated in a solution of collagenase type-I (0.5 mg/ml) and trypsin (0.2 mg/ml) at 37°C for 6 hours. Cells were pelleted and grown in tissue culture flasks. Fibroblast cell lines were maintained and stored at -150°C until use. Fibroblasts were randomly selected from a bank of 19 fibroblast cell lines (patient age ranges from 14-21 years). Only cells from the second passage were used for the experiments.

EXAMPLE 3 MTT [3 -(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide] assay for cell proliferation and viability

The MTT assay is used to quantify cell proliferation following treatment of cells with indicated doses of quercetin. Keloid-derived fibroblasts were seeded at a density of 2 x 10 cells per well in 96-well plates (Iwaki Glass Co) in Dulbecco's Modified Eagle's Medium containing 10%> v/v fetal bovine serum (DMEM/10% v/v FCS) for 24 hours following another 48 hour in serum-free DMEM. To investigate the effects of quercetin on fibroblast prohferation, cells were washed with phosphate buffer saline (PBS) and the different concentrations of quercetin in DMEM/10% v/v FCS were added simultaneously to cells. Control cells were grown in DMEM/10% v/v FCS without addition of quercetin. One group of fibroblasts cultured in serum-free DMEM was considered as base line for cell growth. At the different time points, cells were subjected to MTT assay. Briefly, 20 μl of MMT solution (5 mg/ml in PBS) was added to each well of 96-well plates and then incubated for 2 hours at 37°C. The medium was then removed, and blue formazan was eluted from cells by Hansen's method using 20% w/v sodium dodecyl sulfate (SDS) in a solution of N, N- dimethyformamide (DMF)/water (1:1 v/v) at pH 4.3. The plates were shaken on an orbital shaker to solubilize the crystals of formazan. The eluted samples were measured directly in the plate reader at 570 nm (Microplate Manager (registered trademark) 4.0 Bio-Rad Laboratories).

EXAMPLE 4

IGF-I and IGF-IR antibody treatment

Keloid fibroblasts were grown as described above. To investigate the effects of IGF-I and IGF-IR antibodies on keloid fibroblast cell proliferation, keloid fibroblasts were treated either with 1 μg/ml anti-human IGF-I or 1 μg/ml anti-human IGF-IR (R&D Systems) for 5 days. Cell proliferation was detennined using MTT assay as described above.

EXAMPLE 5 Western Blotting

To determine the changes in the expression of IGF-IR, IRS-1, c-Raf, PI-3 kinase p85, phospho c-Raf (Ser259), phospho Akt (Ser473), phospho ρ44/42 MAP kinase (Thr202/Tyr204) and phospho Elk-1 (Ser383), cells were seeded at a density of 5 x 10⁴ cells per 100 mm dish and treated with various doses of quercetin as described for cell proliferation assay. At the end of treatment, cells were lysed in lysis buffer (1 mM CaCl₂, 1 mM MgCl₂, 1% NP-40, 1 μg/ml leupeptin, 1 μg/ml aprotinin, 1 μM PMSF, and 100 μM NaV0₄). Proteins were subjected to Western blot analysis as described (Huynh et al, Cancer Res. 55: 2225-2231, 1995). Blots were incubated with indicated antibody and horseradish peroxidase-co jugated donkey anti-mouse or anti-rabbit secondary antibody (1:7500). Blots were visualized with a chemiluminescent detection system as described by the manufacturer (ECL, Amersham). Rabbit anti-c-Raf (Ser259), mouse anti-α tubulin, anti-phospho Elk-1 (Ser383) and rabbit anti-IGF-IRβ antibodies were purchased from Santa Cruz Biotechnology. Mouse anti-phospho specific MAPK (Thr202/Tyr204), phospho c-Raf (Ser259), phospho Akt (Ser473) antibody were from New England BioLabs, Beverly, MA.

EXAMPLE 6

Statistical analysis

All experiments were performed in quadruplicate, with the results reflecting the mean and standard deviation of the quadruplicate of each group. The results of MTT are reported as a mean ± ISD. Differences were considered significant at p<0.05. Data were analyzed by oneway analysis of variance (ANOVA) and post-hoc analyses after ANOVA employed the Scheffe's test.

EXAMPLE 7 Effect of quercetin on proliferation of keloid fibroblasts

The inventors determined the effect of quercetin on proliferation of keloid fibroblasts in vitro. Figure 1 shows the results of an experiment where keloid fibroblasts were exposed to either serum free medium, medium containing 10% v/v fetal bovine serum (growth medium) or growth medium containing various doses of quercetin for five days. There were no significant changes in cell proliferation across all the treatments as determined by MTT assay at day 1. Significantly increased in growth was observed on day 3 (Figure IB) and day 5 (Figure 1C) when keloid fibroblasts were grown in growth medium compared to serum free medium. Serum-induced keloid fibroblast prohferation was totally abolished at the dose of 10 μg/ml quercetin. Growth of keloid fibroblast in growth medium was reduced at higher doses of quercetin and was lower than that observed when keloid fibroblast was grown in serum free medium.

EXAMPLE 8 Effect of quercetin on IGF-1

Since activated IGF-IR initiates the IGF-I signaling cascade, the effects of quercetin on IGF- IR, IRS-1, c-Raf and phospho Raf levels in keloid fibroblasts were determined. Treatment of keloid fibroblast cells with quercetin resulted in a significant reduction in IGF-IR levels compared to keloid fibroblast grown in 10%> v/v FCS (Figure 2B) (p<0.01). Densitometric scanning showed that IGF-IR level in quercetin-treated keloid fibroblast cells was approximately 50%> of that seen in controls. Approximately 60%, 80%> and 56% reduction in IRS-1, c-Raf-1 and phospho c-Raf levels by 10 μg/ml quercetin (Figure 2E-2F). Although concentrations of quercetin up to 50 μg/ml did not further decrease in c-Raf expression, the basal phosphorylation of c-Raf-1 was completely abolished at this concentration (Figure 2E). Subsequent blotting of the blots with anti-α tubulin antibody showed relatively equal amounts of total protein loaded per lane (Figure 2A).

EXAMPLE 9 Effect of quercetin on PI-3 kinase, p85, MAPK and phospho MAPK

Since MAPK and PI-3 kinase are downstream of Raf and important for the effect of IGFs on the cellular proliferation, the inventors investigated the basal levels of PI-3 kinase p85, MAPK and phospho MAPK as well as the phosphorylation status of their downstream targets such as Akt and Elk-1, respectively. Treatment of keloid fibroblast cells with quercetin resulted in a dose-dependent decrease in levels of PI-3 kinase p85 and phospho Akt (Figure 3). While MAPK level was not affected by quercetin treatment, the phosphophorylation level of MAPK and its target Elk-1 were significantly reduced (pO.Ol) (Figure 4). The results indicate that quercetin is very potent to reduce the levels of several key proteins in the IGF signaling pathways. EXAMPLE 10

Effect of antibodies on IGF-1

To determine the role of the IGF-I autocrine loop in keloid fibroblast proliferation, keloid fibroblast cells were treated with anti-IGF-I or IGF-IR for 5 days. Figure 5 shows an approximate 37.5% and 37% reduction in proliferation by 1 μg/ml IGF-I and IGF-IR antibodies, respectively (pO.Ol). These results suggest that the prohferation of keloid fibroblast cells in vivo and in vitro may be a consequence of autocrine stimulation mediated by IGF-I expression.

EXAMPLE 11

Testing derivatives of quercetin

A series of derivatives of quercetin are generated synthetically and then tested as described above for quercetin. Examples of derivatives capable of generation include a range of substitutions as follows:-

Each derivative contains one of the substitutions listed above. Similar derivatives are made using two or more of the substitutions listed above.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.

BIBLIOGRAPHY

Anton, R. Flavonoids and Traditional Medicine.New York: Alan R. Liss, Inc., 1988.

Avila, M. A., Velasco, J. A., Cansado, J., and Notario, V. Quercetin mediates the down- regulation of mutant p53 in the human breast cancer cell line MDA-MB468. Cancer Res. 54: 2424-2428, 1994.

Cohen, I. K. and Peacock, E. E. Keloids and Hypertrophic Scars. In J. G. McCarthy (ed.), Plastic Surgery, pp. 732-747. Saunders, USA, 1990.

Glossmann, H., Presek, P., and Eigenbrodt, E. Quercetin inhibits tyrosine phosphorylation by the cyclic nucleotide- independent, transforming protein kinase, pp60src. Naunyn Schmiedebergs Arch. Pharmacol. 317: 100-102, 1981.

Hertog, M. G., Holhnan, P. C, Katan, M. B., and Kromhout, D. Intake of potentially anticarcinogenic flavonoids and their determinants in adults in The Netherlands. Nutr. Cancer 20: 21-29, 1993.

Hofmann, J., Doppler, W., Jakob, A., Maly, K, Posch, L., Uberall, F., and Grunicke, H. H. Enhancement of the antiproliferative effect of cis- diamminedichloroplatinum(JJ) and nitrogen mustard by inhibitors of protein kinase C. Int. J. Cancer 42: 382-388, 1988.

Huynh, H., Larsson, C, Narod, S., and Pollak, M. Tumour suppressor activity of the gene encoding mammary-derived growth inhibitor. Cancer Res. 55: 2225-2231, 1995.

Kuhnau, J. The flavonoids. A class of semi-essential food components: their role in human nutrition. World Rev. Nutr. Diet. 24: 117-191, 1976.

Ladin, D. A, Garner, W. L., and Smith, D. S. Jr. Excessive scarring as a consequence of healing. Wound repair and Regeneration 3: 6-14. 1995. Ladin, D. A., Hou, Z., Patel, D., McPhail, M., Olson, J. C, Saed, G. M., and Fivenson, D. P. p53 and apoptosis alterations in keloids and keloid fibroblasts. Wound Repair Regen. 6: 28-37, 1998.

Matter, W. F., Brown, R. F., and Vlahos, C. J. The inhibition of phosphatidylinositol 3- kinase by quercetin and analogs. Biochem. Biophys. Res. Commun. 186: 624-631, 1992.

Ono, K., Nakane, H., Fukushima, M., Chermann, J. C, and Barre-Sinoussi, F. Differential inhibitory effects of various flavonoids on the activities of reverse transcriptase and cellular DNA and RNA polymerases. Eωr. J. Biochem. 190: 469-476, 1990.

Saed, G. M., Ladin, D., Olson, J., Han, X., Hou, Z., and Fivenson, D. Analysis of p53 gene mutations in keloids using polymerase chain reaction-based single-strand conformational polymorphism and DNA sequencing. Arch. Dermatol.134: 963-967, 1998.

Santen, R. J., Manni, A., Harvey, H., and Redmond, C. Endocrine treatment of breast cancer in women. Endo. Rev. 11: 221-265, 1990.

Scambia, G., Ranelletti, F. O., Panici, P. B., Piantelli, M., Bonanno, G., De Vincenzo, R., Ferrandina, G., Rumi, C, Larocca, L. M., and Mancuso, S. Inhibitory effect of quercetin on OVCA 433 cells and presence of type II oestrogen binding sites in primary ovarian tumours and cultured cells. Br. J. Cancer 62: 942-946, 1990.

Srivastava, A. K. Inhibition of phosphorylase kinase, and tyrosine protein kinase activities by quercetin. Biochem. Biophys. Res. Commun. 131: 1-5, 1985.

Suolinna, E. M., Lang, D. R., and Racker, E. Quercetin, an artificial regulator of the high aerobic glycolysis of tumor cells. J. Natl Cancer Inst. 53: 1515-1519, 1974. Tuan, T. L. and Nichter, L. S. The molecular basis of keloid and hypertrophic scar formation. Mol. Med. Today 4: 19-24, 1998.

Wei, Y. Q., Zhao, X., Kariya, Y., Fukata, H., Teshigawara, K., and Uchida, A. Induction of apoptosis by quercetin: involvement of heat shock protein. Cancer Res. 54: 4952-4957, 1994.

Yeh, J. K., Chen, M. M., and Aloia, J. F. Effects of estrogen and growth hormone on skeleton in the ovariectomized rat with hypophysectomy. Am. J. Physiol 273: E734-E742, 1997.

Yeh, Y. A., Herenyiova, M., and Weber, G. Quercetin: synergistic action with carboxyamidotriazole in human breast carcinoma cells. Life Sci. 57: 1285-1292, 1995.

Yoshida, M., Yamamoto, M., and Nikaido, T. Quercetin arrests human leukemic T-cells in late Gl phase of the cell cycle. Cancer Res. 52: 6676-6681, 1992.

Claims

1. A method for inhibiting, preventing or otherwise suppressing keloid fibroblast proliferation and/or collagen synthesis in a subject, said method comprising administering to said subject an effective amount of a flavonoid glycone or a derivative or homolog thereof.

2. A method according to Claim 1 wherein the flavonoid glycone comprises the structure set forth in the structure of Formula (I):-

wherein:

X is selected from sulfur, oxygen, nitrogen and CRιR₂; and

Rl¹⁰ is as defined below or is optionally a mono-, di- or tri-saccharide having the structures in Formulae (II), (III) and (IV), respectively: -

wherein:

R¹ to R³⁹ are independently selected from hydrogen, F, Cl, Br, I, CN, NO₂, CF₃, CORi, CO₂Rι, ORi, SR_h NRιR₂, N(=0)₂, NR1OR2, ONRιR₂, SORi, SO₂Rι, SO3R1, SONR1R2, S0₂NRιR₂, SO₃NRιR_2; P(Rι)₃, P(=O)(Rι)₃, Si(Rι)₃, B(Rι)₂, (C=X)Rι or X(C=X)Rι where X is as defined above;

R¹ to R³⁹ (and Ri and R₂) are each independently selected from hydrogen, Ci- C₂₀ alkyl (branched and/or straight chained), C₁-C₂₀ arylalkyl, C₃-C₈ cycloalkyl, C₆-Cι₄ aryl, C₁-C₁₄ heteroaryl, Cι-Cι₄ heterocycle, C₂-C₁₀ alkenyl (branched and/or straight chained aryl and heteroaryl can be attached), C₂-C₁₀ alkynyl (branched and/or straight chained aryl and heteroaryl can be attached), C₁-C₁₀ heteroarylalkyl, C1-C1₀ alkoxyalkyl, C₁-C₁₀ haloalkyl, dihaloalkyl, trihaloalkyl, haloalkoxy, Cι-C₁₀ [CN, ORi, SR_b NR1R2, N(=0)₂, NRιOR₂, ONRιR₂, SORi, SO₂Rι, SO₃R_l5 SONR1R2, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃, Si(Rι)₃, B(Rι)₂]alkyl; Aryl is C₆-Cι₄ with any mode of substitution containing F, Cl, Br, I, NO₂, CF₃, CN, COR,_., CO₂Rι, ORi, SRi, NR1R2, N(=O)₂, NR1OR2, ONRιR₂, SORi, SO₂Rι, SO₃Rι, SONRιR₂, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃, SiCR a. BCR zJal yl;

or a pharmaceutically acceptable salt or ester thereof.

3. A method according to Claim 1 or 2 wherein the flavonoid glycone is quercetin or a derivative or homolog thereof.

4. A method according to Claim 3 wherein the effective amount of quercetin is from about 10 μg/ml to about 50 μg/ml.

5. A method for inhibiting, preventing or suppressing keloid fibroblast proliferation and collagen synthesis by administering an effective amount of a flavonoid glycone in combination with a therapeutically effective amount of another anti-keloid agent.

6. A method according to Claim 5 wherein the flavonoid glycone comprises the structure set forth in Formula (I):-

wherein:

X is selected from sulfur, oxygen, nitrogen and CRtR₂; and

Rl¹⁰ is as defined below or is optionally a mono-, di- or tri-saccharide having the structures in Formulae (II), (III) and (IV), respectively:-

wherein:-

R¹ to R³⁹ are independently selected from hydrogen, F, Cl, Br, I, CN, NO₂, CF₃, CORi, CO2R1, ORi, SRi, NRιR₂, N(=O)₂₎ NRιOR₂, ONR1R2, SORi, SO₂Rι, SO3R1, SONR1R2, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=0)(Rι)₃, Si(Rι)₃, B(Rι)₂, (C=X)Rι or X(C=X)Rι where X is as defined above;

R¹ to R³⁹ (and Ri and R₂) are each independently selected from hydrogen, C_\- C₂o alkyl (branched and/or straight chained), C₁-C₂₀ arylalkyl, C₃-C₈ cycloalkyl, C₆-Cι₄ aryl, C₁-C1₄ heteroaryl, C1-C₁₄ heterocycle, C₂-C₁₀ alkenyl (branched and/or straight chained aryl and heteroaryl can be attached), C₂-C₁₀ alkynyl (branched and/or straight chained aryl and heteroaryl can be attached), C₁-C1₀ heteroarylalkyl, C₁-C₁₀ alkoxyalkyl, C₁-C₁₀ haloalkyl, dihaloalkyl, trihaloalkyl, haloalkoxy, C1-C10 [CN, OR_b SRi, NRιR₂, N(=0)₂, NRιOR₂, ONR1R2, SORi, SO₂Rι, SO₃R_l5 SONR1R2, SO₂NRιR₂, SO₃NR!R₂, P(Rι)₃, P(=0)(Rι)₃, Si(Rι)₃, B(Rι)₂]alkyl; Aryl is C₆-Cι₄ with any mode of substitution containing F, Cl, Br, I, NO₂, CF₃, CN, CORi, CO2R1, ORi, SRi, NRιR₂, N(=O)₂, NR1OR2, ONRιR₂, SORi, S0₂Rι, SO3R1, SONR1R2, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=0)(Rι)₃, Si(Rι)₃, B(Rι)₂]alkyl;

or a pharmaceutically acceptable salt or ester thereof.

7. A method according to Claim 5 or 6 wherein the flavonoid glycone is quercetin.

8. A method according to Claim 7 wherein the effective amount of quercetin is from about 10 μg/ml to about 50 μg/ml.

9. A method according to Claim 5 or 6 or 7 wherein the other anti-keloid agent is a flavonoid glycone.

10. A method according to Claim 5 or 6 or 7 wherein the anti-keloid agent is an antibody to a component of the IGF cascade pathway.

11. A method according to Claim 10 wherein the antibody is directed to IGF or IGF-IR.

12. A pharmaceutical composition for inhibiting, preventing or suppressing keloid fibroblast proliferation and collagen synthesis, comprising a flavonoid glycone and a pharmaceutically acceptable carrier and/or diluent and/or dispersant.

13. A composition according to Claim 12 wherein the flavonoid glycone comprises the structure of Formula (I):-

wherein:

X is selected from sulfur, oxygen, nitrogen and CRιR₂; and

Rl 10 is as defined below or is optionally a mono-, di- or tri-saccharide having the structures in Formulae (II), (III) and (IV), respectively: -

wherein:-

R¹ to R³⁹ are independently selected from hydrogen, F, Cl, Br, I, CN, NO₂, CF₃, CORi, CO2R1, ORi, SRi, NRιR₂, N(-O)₂, NR1OR2, ONRιR₂, SORi, SO₂Rι, SO₃Rι, SONR1R2, SO2NR1R2, SO₃NR_!R₂, P(Rι)₃, P(=O)(Rι)₃, Si(R,)₃, B(Rι)₂, (C=X)Rι or X(C=X)Rι where X is as defined above;

1 ^0

R to R (and Ri and R₂) are each independently selected from hydrogen, Q- C₂₀ alkyl (branched and/or straight chained), C1-C20 arylalkyl, C₃-C₈ cycloalkyl, C₆-Ci4 aryl, C1-C14 heteroaryl, C₁-C₁₄ heterocycle, C₂-Cιo alkenyl (branched and/or straight chained aryl and heteroaryl can be attached), C₂-C₁₀ alkynyl (branched and/or straight chained aryl and heteroaryl can be attached), C1-C10 heteroarylalkyl, C₁-C₁₀ alkoxyalkyl, C₁-C₁₀ haloalkyl, dihaloalkyl, trihaloalkyl, haloalkoxy, C1-C₁₀ [CN, ORi, SRi, NR1R2, N(=O)2, NRιOR₂, ONR₁R2, SORi, SO₂Rι, SO₃Rι, SONRιR₂, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃, Si(Rι)₃, B(Rι)₂]alkyl; Aryl is C₆-Cι₄ with any mode of substitution containing F, Cl, Br, I, NO₂, CF₃, CN, CORi, CO₂Rι, ORi, SRi, NRιR₂, N(=O)₂, NRιOR₂, ONR1R₂, SORi, SO₂Rι, SO₃Rι, SONR₁R2, SO2NR1R2, SO₃NR_!R₂, P(Rι)₃, P(=0)(Rι)_3>

Si(Rι)₃, B(Rι)₂]alkyl;

or a pharmaceutically acceptable salt or ester thereof.

14. A composition according to Claim 12 or 13 wherein the flavonoid glycone is quercetin.

15. A composition according to Claim 14 wherein quercetin is present in an amount from about 10 μg/ml to about 50 μg/ml.

16. A pharmaceutical composition for inhibiting, preventing or suppressing keloid fibroblast proliferation and collagen synthesis, comprising an effective amount of a flavonoid glycone in combination with a therapeutically effective amount of another anti- keloid agent in the presence of a pharmaceutically acceptable carrier and/or diluent and/or dispersant.

17. A composition according to Claim 16 wherein the flavonoid glycone comprises the structure of Formula (I):-

wherein:

X is selected from sulfur, oxygen, nitrogen and CRιR₂; and Rl is as defined below or is optionally a mono-, di- or tri-saccharide having the structures in Formulae (II), (III) and (TV), respectively :-

wherein:-

R to R are independently selected from hydrogen, F, Cl, Br, I, CN, NO₂, CF₃, CORi, CO₂Rι, ORi, SRi, NR!R₂, N(-O)₂, NR₁OR2, ONRιR₂, SORi, SO₂Rι, SO₃Rι, SONR!R₂, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃, Si(Rι)₃, B(Rι)₂, (C=X)Rι or X(C=X)Rι where X is as defined above;

R¹ to R³⁹ (and Ri and R₂) are each independently selected from hydrogen, Ci- C₂o alkyl (branched and/or straight chained), Cι-C₂o arylalkyl, C₃-C₈ cycloalkyl, C₆-Cι₄ aryl, Cι-Cι₄ heteroaryl, Cι-Cι₄ heterocycle, C₂-Cιn alkenyl (branched and/or straight chained aryl and heteroaryl can be attached), C -C₁o alkynyl (branched and/or straight chained aryl and heteroaryl can be attached), C₁-C₁₀ heteroarylalkyl, C₁-C₁₀ alkoxyalkyl, C1-C10 haloalkyl, dihaloalkyl, trihaloalkyl, haloalkoxy, Cι-C₁₀ [CN, ORi, SRi, NRιR₂, N(=O)₂, NR1OR2, ONR₁R₂, SORi, SO₂Rι, SO₃R SONR1R2, S0₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃, Si(Rι)₃, B(Rι)₂]alkyl; Aryl is C₆-Cι₄ with any mode of substitution containing F, Cl, Br, I, NO₂, CF₃, CN, CORi, CO₂Rι, ORi, SRi, NRιR₂, N(=O)₂, NR1OR2, ONRιR₂, SORi, SO₂Rι, SO₃Rι, SONR₁R₂, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(R!)₃, Si(Rι)₃, B(Rι)₂]al yl;

or a pharmaceutically acceptable salt or ester thereof.

18. A composition as claimed in Claim 16 or 17 wherein the flavonoid glycone is quercetin.

19. A method according to Claim 16 wherein the other anti-keloid agent is a flavonoid glycone.

20. A method according to Claim 16 wherein the anti-keloid agent is an antibody to a component of the IGF cascade pathway.

21. A method according to Claim 20 wherein the antibody is directed to IGF or IGF-IR.

22. A method for inhibiting, preventing or otherwise suppressing keloid fibroblast proliferation and/or collagen synthesis in a subject, said method comprising administering to said subject an effective amount of a flavonoid glycone or a derivative or homolog thereof, said flavonoid glycone or derivative or homolog having the structure of Formula (I):-

wherein:

X is selected from sulfur, oxygen, nitrogen and CRiR₂; and

Rl 10 is as defined below or is optionally a mono-, di- or tri-saccharide having the structures in Formulae (II), (III) and (IV), respectively:-

wherein:-

R to R are independently selected from hydrogen, F, Cl, Br, I, CN, NO₂, CF₃, CORi, CO₂Rι, ORi, SRi, NRιR₂, N(=O)₂, NR1OR2, ONRιR₂, SORi, SO₂Rι, SO₃Rι, SONR1R2, SO₂NRιR₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃, Si(Rι)₃, B(R ₂, (C=X)Rι or X(C— X)Rι where X is as defined above;

R¹ to R³⁹ (and Ri and R ) are each independently selected from hydrogen, Ci- C₂₀ alkyl (branched and/or straight chained), C₁-C₂₀ arylalkyl, C₃-C₈ cycloalkyl, C₆-Cι₄ aryl, Cι-Cι₄ heteroaryl, C1-C₁₄ heterocycle, C₂-C₁₀ alkenyl (branched and/or straight chained aryl and heteroaryl can be attached), C₂- 0 alkynyl (branched and/or straight chained aryl and heteroaryl can be attached), C₁-C₁₀ heteroarylalkyl, -Cio alkoxyalkyl, C₁-C₁₀ haloalkyl, dihaloalkyl, trihaloalkyl, haloalkoxy, C1-C10 [CN, OR_b SRi, NR1R2, N(=O)₂, NR₁OR₂, ONR1R2, SORi, SO2R1, SO₃Rι, SONR1R2, SO₂NRιR₂, SO₃NRιR₂, P(Ri)₃,

Si(Rι)₃, B(Rι)₂]alkyl; Aryl is C₆-Cι₄ with any mode of substitution containing F, Cl, Br, I, NO₂, CF₃, CN, CORi, CO₂Rι, ORi, SRi, NRιR₂, N(=O)₂, NRιOR₂, ONRιR₂, SORi, SO2R1, S0₃Rι, SONR1R2, SO₂NR,R₂, SO₃NRιR₂, P(Rι)₃, P(=O)(Rι)₃,

Si(Rι)₃, B(Rι)₂]alkyl;

or a pharmaceutically acceptable salt or ester thereof.

23. A method for inhibiting, preventing or otherwise suppressing keloid fibroblast proliferation and/or collagen synthesis in a subject, said method comprising administering to said subject an effective amount of a quercetin or a derivative or homolog thereof.

24. Use of quercetin or a derivative or homolog thereof in the manufacture of a medicament for the inhibition, prevention or suppression of keloid fibroblast proliferation and/or collagen synthesis.

25. A method for modulating a physiological process mediated by the IGF signalling pathway, said method comprising administering to a subject an amount of a flavonoid glycone as herein defined effective to inhibit said IGF signalling pathway.

26. A composition comprising a flavonoid glycone as herein defined or a salt or ester thereof or a derivative or homolog thereof and one or more pharmaceutically acceptable carriers and/or diluents and/or dispersants.