Chapter 32 Future Cosmeceuticals of Dermatologic Importance
ANTIOXIDANTS
Our skin is continuously exposed to oxidative stress leading to accelerated aging by damaging DNA, lipids, and proteins. Various endogenous antioxidant systems are designed to protect us from these oxidative stresses. Oxidative stress results from many sources including genetics, environmental factors, and ultraviolet (UV) radiation. The action mechanism of antioxidants in induction is such that they prevent free radicals from forming chain reactions that have the capability of damaging cells during oxidation of other molecules. Antioxidants are comprised of various molecules such as alpha lipoic acid (ALA), coenzyme Q-10, polyphenols, idebenone, kinetin, and vitamins A, B, C, and E. Antioxidants are widely used as treatments in many human diseases and have now become a vital source in cosmeceuticals because of their strong photoprotective effects, thereby resulting in reduction of erythema, sunburn cell formation, DNA changes, and carcinogenesis Fig. 32.1.
GENISTEIN
Although numerous in vitro studies have shown its potential in anticancer properties, evidence is lacking on its effect on skin carcinogenesis, but there is scientific support for its potential. Genistein has been found to have chemopreventive and strong anticancer activities. It has been shown to inhibit the activity of tyrosine protein kinase (TPK), topoisomerase II (Topo II), and ribosomal S6 kinase (RS6K) in cell culture. It has also been shown to inhibit growth of the ras oncogene and decrease PD6F-induced c-fos and c-jun expression in fibroblasts. Experiments were conducted to prove that genistein substantially blocks subacute and chronic UVB- and PUVA-induced cutaneous damage (Box 32.1; Figs 32.2 and 32.3).
Box 32.1 Clinical effects of genistein