One of the most widely embraced cosmeceutical agents is vitamin E, namely a-tocopherol (aT) and its esters. Although vitamin E oil has traditionally been used to help heal cuts and scars, few people realise that the majority of topical vitamin E preparations on the market contain the biologically inactive form, aT acetate (esterified vitamin E). Attachment of the acetate component to the 'hot spot' of vitamin E confers greater stability. However, esterified aT preparations are severely confined where pro-oxidants proliferate. Even if an esterified aT preparation is applied, it is questionable as to the rate and extent of release (de-esterification) of the vitamin.
Recent research from Germany, presented at the 2001 European Society for Dermatological Research (ESDR) meetings in Stockholm has shown that vitamin E concentrations in both the epidermis and upper dermis and lower dermis and parts of subcutis decline with age in human skin. The challenge has been to develop a dermal form of vitamin E that is stable and capable of delivering the payload continuously. French researchers have developed a delta-tocopherol (given its superior antioxidant activity invitro) that is connected to a carbohydrate molecule, displaying superior antioxidant activity in skin models and verified delivery of the 'liberated' tocopherol. Because this form is more stable in both the presence of heat and light it may evolve into the next generation of active tocopherols for cosmeceutical applications.
Soy Increases Hair Growth
Other data presented at the ESDR meetings include exploration of the 'other side' of soy isoflavones. French researchers compared the effects of a soyextract vs. genistein and daidzein (isoflavones devoid of their carbohydrate conjugates) and daidzin and puerarin (carbohydrate conjugated isoflavones; puerarin is present in abundance within kudzu [Pueraria lobata]) on different hormone elements and isolated human hair follicles. 'Activation' of the gene coding for an enzyme implicated in androgenetic hair loss (5alpha-reductase; the target of the drug finasteride, for androgenetic alopecia) was inhibited by both genistein and puerarin. Genetic activation of an enzyme involved in the conversion of testosterone into estrogens (aromatase) was increased by genistein and, to a lesser extent, daidzein. The soy extract stimulated one of the estrogen receptors (b receptor) greater than genistein and daidzein, although the latter two were stimulatory themselves. Receptors for testosterone-like molecules (androgens) were decreased by genistein, and half as much by daidzein. But what does all this molecular hormone 'geek speak' mean? The researchers found a 30 per cent increase in hair growth with the soy extract. Woven together, these data suggest that an isoflavone mixture, perhaps ideally from soy (but yet to be confirmed) could arrest hair loss in conditions where androgens are playing an operative role. Obviously this concept needs to proved in a hair-losing human, with many hair follicles.
The much-maligned avocado was the focus of other new research from France. This fatty fruit, when forced to dry under certain conditions, produces a long and novel chemical called Avocadofuran (Af). Skin cells exposed to Af released greater amounts of a cell-to-cell communicator chemical (cytokine) called TGFbeta-1 (Transforming Growth Factor Beta-1). This increased release was attended by increased collagen secretion by the skin cells. They also showed human skin 'incubated' with Af to display increased cholesterol and ceramide synthesis without altering the total lipid content of the skin (unlike that seen with lactic acid). The humble avocado may yield a new class of cosmeceutical bioactives with applications for anti-aging and hydration.
Anthony L. Almada, BSc, MSc
Founder, President and Chief Scientific Officer
IMAGINutrition®, Inc. and MetaResponse Sciences®
30131 Town Center Drive, Suite 211
Laguna Niguel, CA 92677