Cosmetic Regulation of Sebaceous Gland Activity

Abstract

There is over one hundred thousands of sebaceous glands in humans. They are uneven distributed all over the skin. Sebaceous glands belongs to holocrine type glands. Their activity is regulated by both internal and external factors and active substances. To the endogenous factors belongs hormones mostly androgens and progestagens. Estrogens play the minor role inhibiting the sebum secretion. Other hormones like propiomelanocortin and somatotropin have some activity but are not very important for the sebaceous glands secretion. The development of those glands is strongly determined on the presence of several cytokines like IL-1, TGF-β, EGF and IGF-1. Also the PPAR (α,β and γ) receptors are engaged in the sebum composition and releasing control. Among the exogenous substances on the top of list are retinoids, particularly 13-cis retinoic acid which inhibits the activity and size of sebaceous glands even by 90%. Of importance are also compounds inhibiting 5-α-reductase like organic acids zinc salts, zinc oxide, azelaic acid and vitamins of the B group the proven activity have pyridoxal phosphate (vitamin B6). Indirect action provide also some skin microrganisms producing many substances which stimulate sebaceous gland and antioxidants inhibiting sebum trasformations.