Phytosphingosine for Skin Differentiation and Other Topics: Literature Findings

By: Charles Fox, Independent Consultant

Posted: December 1, 2009, from the December 2009 issue of Cosmetics & Toiletries.

This month’s survey of recent patent and research literature describes money-making ideas for personal care product development, including silicone resin waxes to modify texture and rheology, imidazoline for hair conditioning, gallnut and Eclipta prostrata to minimize hair dye damage, renewable propanediol, and an in vitro measurement for SPF, among others.

Skin and Skin Care
Phytosphingosine for keratinocyte differentiation: Schiemann et al. published on polar emollients in cosmetic formulations to enhance the penetration and biological effects of phytosphingosine on skin.¹ Recent cosmetic and dermatological work has focused on actives to support the biological functions of the skin, such as protecting against physical and chemical stress, UV irradiation and microbes.

As is well-known, keratinocytes represent key elements of the skin barrier since they form the outermost, water-impermeable layers of skin. To reduce the amount of water that evaporates from skin, keratinocytes undergo a unique differentiation process from the stratum basale to the stratum corneum (SC). The SC is then formed from end-differentiated keratinocytes called corneocytes.

The other main constituents of the water-impermeable barrier are barrier lipids such as ceramides, cholesterol and free fatty acids. Ceramides are formed by keratinocytes by amidation of sphingoid bases such as phytosphingosine with fatty acids. Furthermore, phytosphingosine is a natural antimicrobial compound that is involved in several cellular processes including cell differentiation and anti-inflammation.

The present study aimed to evaluate the effects of phytosphingosine as an active ingredient in cosmetic formulations to determine whether the type of formula influences its biological activity. Cultured keratinocytes were incubated with phytosphingosine and gene expression profiling was performed using DNA micro arrays, which revealed that phytosphingosine significantly promoted cell differentiation.