Potential reversal of chronological and photo-aging of the skin by topical application of natural substances

Abstract

Aging changes in the skin, in which degenerative changes exceed regenerative changes, are characterized by thinning and wrinkling of the epidermis together with the appearance of lines, creases, crevices and furrows, especially accentuated in lines of facial expression. These changes are brought about both by chronological (genetically determined) and photo (solar radiation-determined) factors. The reason for the readily apparent surface morphological alterations is found in changes in the underlying dermis characterized by the loss of fascicular and soluble collagen and elastin fibres, with lessened support of epidermal layers, and lessened circulatory perfusion. Many so-called ‘antiaging’; actions of topically-applied materials are nothing more than transient hydrational/moisturizing effects, which, while lessening the prominence of undesirable surface defects and blemishes, do nothing to change the dermal losses. True ‘antiaging’ actions would require evidence for the return toward normal of the regenerative/degenerative balance exemplified by increased collagen and elastin synthesis. Evidence is accruing that four groups of topically applied substances, namely, (a) nonsaponifiable fractions of avocado and soybean oils, (b) vitamin A derivatives, (c) alpha-hydroxy acids (AHAs), and (d) extracts of Aloe vera, possess activities which reverse the degenerative skin changes seen with aging by stimulating the synthesis of collagen and elastin fibres, thereby restoring toward normal the regenerative/degenerative equilibrium.