Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
2001-06-29
2003-02-25
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C424S070100, C424S061000
Reexamination Certificate
active
06524599
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention is related to compositions comprising the extract of the milk-thistle plant (
Silybum marianum
), soybean protein, and alpha tocopherol, either singly or in combination, for application to skin, hair and nails.
BACKGROUND OF THE INVENTION
The skin is the largest organ of the human body, which primarily functions to protect the body's internal organs from the outside environment. The outside environment that the skin must endure may consist of large fluctuations in both temperature and humidity. Further, the skin may be exposed to radiation from the sun or other sources. Additionally, the skin is routinely exposed to wind, dust, dirt and other harsh chemicals. Finally, the skin must survive the daily rituals that may include washing, shaving, and/or the application of cosmetics.
These environmental factors contribute to the aging of the skin. In particular, these environmental factors have been known to cause aging lines, wrinkles, skin dryness characterized by the loss of the skin's natural oils and moisture, skin fading, age spots, and the loss of skin elasticity.
As humans age, the skin becomes dry, loses its elasticity, and begins to wrinkle. These are the primary visible effects of chronological aging. Following menopause, it has been shown that skin thickness decreases and collagen levels in the skin diminish, which may further contribute to these negative age-related changes in the skin. Scientific studies strongly suggest that these changes may be attributed to menopausal and/or age-related hormonal fluctuations. More specifically, research suggests that estrogen deficiency may primarily be responsible.
Estrogen works by interacting with estrogen receptors in the body and signaling genes in cells to be switched on or off. Flipping these switches can cause the body to generate new cells or to produce special substances. Following menopause, the production of estrogen in the female body is markedly reduced. Although the exact mechanisms are unknown, this reduction in estrogen is believed to contribute to decreases in skin thickness, dryness, and loss of elasticity. Estrogen receptors have been detected in the skin. It has been shown that systemic and topical estrogen improve skin thickness, increase collagen levels, and minimize wrinkling and dryness.
Although estrogen is important, researchers also believe that decreased estrogen levels are only part of the aging equation; free radical attacks caused by exposure of the skin to environmental elements like sunlight, smoke, and pollution also contributes to premature aging of the skin. Antioxidants can help counter these effects by neutralizing free radicals, and estrogens are strong antioxidants with even stronger activity than vitamin E and vitamin C.
The extract of the milk thistle plant,
Silybum marianum,
which belongs to the aster family (Asteraceae or Compositae), comprises silymarin as the active constituent. Silymarin consists of a mixture of three bioflavinoids (flavonolignans), silybin, silydianin, and silychristine, found in the fruit, seeds, and leaves of the milk thistle plant. Silybin is the main component of silymarin, amounting to 60-70% by weight, and is thought to have the most biological activity. Standardized commercially available extracts of milk thistle, used in the preparation of the compositions of the present invention, typically contain 70-80% by weight of silymarin. These commercial preparations are variously referred to herein as milk thistle extract, lady's thistle extract, or silybum extract.
Historically, milk thistle extract has been used to treat disorders of the spleen, liver and gall bladder. Silymarin has been shown to have utility in many liver disorders including hepatitis, alcoholic liver disease, and hepatitis. It has also been shown to be useful for the treatment of toxin-induced liver toxicity including poisoning from death cap mushroom (
Amanita phalloides
). The mechanism of action for the beneficial effects of silymarin in liver disease is unknown, although antioxidant activity is a leading theory. In the animal model of cirrhosis produced by bile duct obliteration, silymarin has an antifibrotic effect. Oral doses of 1000 mg can be administered daily to humans without toxicity, and in animals, there is no known lethal dose.
Mechanistic studies have shown silymarin to be a very strong antioxidant compound capable of scavenging both free radicals and reactive oxygen species (ROS), thus increasing the antioxidant potential of cells by ameliorating the deleterious effects of free radical reactions. Furthermore, since an increase in ornithine decarboxylase (ODC) activity in epidermis is a prerequisite for skin tumor promotion, it has been shown that silymarin possesses strong inhibitory effects against the induction of epidermal ODC and messenger RNA expression in mouse models, caused by 12-O-tetradecanoylphorbol-13-acetate (TPA). In addition, silymarin has been shown to afford substantial protection against photocarcinogenesis in a mouse model. This effect of silymarin is due to the inhibition of several different events associated with UVB-induced tumor initiations and tumor promotion, by virtue of its strong anti-oxidant activity.
Soybean protein comprises soy isoflavones, which are phytoestrogens i.e., substances that mimic the activity of estrogen. The estrogenic effect of phytoestrogens is considerably weaker than estrogens, but is appreciable, and both oral and topical application of phytoestrogens have been shown to have many beneficial effects for the skin. In addition to estrogenic activity, soy isoflavones have antioxidant properties, and like other antioxidants, help to prevent free-radical damage to DNA. Phytoestrogens have also been effective for preventing skin cancer in mice, both orally and topically.
Three key isoflavones found in soy are genistein, diadzein and glycitein. Genistein is found most abundantly in soy, and there is a strong body of research supporting the benefits that genistein provides the skin. Genistein is a strong antioxidant, and may be effective in preventing cancer. Although its exact anti-cancer mechanism is unknown, genistein has been proven to protect against sunburn in humans, and to block the formation of reactive oxygen species. This makes soy isoflavones an ideal alternative to estrogen therapies, and perfect for use on maturing skin. A commercially available source for soy isoflavones used in the preparation of the compositions of the present invention, is a mixture comprising soy bean protein, water and butylene glycol. The percentage of genistein and diadzein present in the soy isoflavones used in the compositions of the present invention is between 0.01 to 0.03% by weight and 0.07 to 0.15% by weight respectively.
Vitamin E (tocopherol) is a generic term for compounds that have a 6-chromanol ring, an isoprenoid side chain, and the biologic activity of &agr;-tocopherol. The vitamin E group contains &agr;-, &bgr;-, &ggr;-, and &dgr;-tocopherols, which vary in the extent to which the chromanol ring is methylated. D-&agr;-tocopherol is the only naturally occurring stereoisomer and the most potent in biologic assays. Vitamin E is a great source of vitamin for many different reasons including heart protection, cancer prevention, and immunity booster. Vitamin E is the body's most important lipid-soluble antioxidant, especially in cell membranes and lipoproteins. As an antioxidant, it protects other fat-soluble vitamins from oxidative damage. It is necessary for tissue repair; it is a natural anticoagulant; and promotes wound healing. The terms vitamin E and alpha tocopherol as used herein are intended to be synonymous with one another, and refer to D-&agr;-tocopherol.
Green tea extract has been shown to have powerful anticarcinogenic properties, and has been shown to inhibit cancers in test tube and animal studies. Green tea extract contains polyphenols (also known as catechins) which are natural antioxidants. Catechins scavenge peroxyl radicals in a liposomal and i
Howard S.
Jenkens & Gilchrist, P. C.
Skinceuticals, Inc.
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