The team comprised of colleagues from the San Gallicano Dermatological Institute and Department of Clinical Dermatology in Rome, working with Procter & Gamble’s London Innovation Centre, who funded the project, to investigate the effects of the GSS complex on skin ageing.
They found that a twice daily topical application of a cosmetic formulation containing a GSS Complex can, from as early as 4 weeks onwards, provide improvement in several biophysical parameters of photoaged female facial skin, leading to an improvement in skin barrier function, skin topography, biomechanical properties and corresponding clinical appearance.
From this, they say that the GSS complex shows promise, therefore, as a cosmetic technology to help prevent and treat aged and photoaged facial skin.
Silk-derived sericin has been used in medical and cosmetic applications due to a wide variety of reported efficacy, including anti-oxidant, anti-bacterial, anti-microbial, anti-wrinkle, wound healing, UVR-resistant and moisture-absorbing/moisture-desorbing properties.
GSS is produced from irodori silk cocoons, known for their distinctive gold colour and use in fine silk garments in Japan, and is obtained using a novel extraction method that allows the extraction of GSS without hydrolysis of the flavonoids that provide its colour.
In the study, GSS was combined at 2.0% (w/v) with niacinamide and an olive oil extract (Signaline manufactured by Ashland) (0.1% w/v) to form a complex of cosmetic actives with a predicted complementary broad range of effect on ageing facial skin, based on P&G in vitro studies.
A range of non-invasive bioengineering methods were then deployed in an 8-week randomised, double-blinded, vehicle-controlled, split-face study among 40 female subjects aged 40–70.
Endpoints that weremeasured included expert grades of skin condition, stratum corneum (SC) hydration, SC barrier function, elasticity and surface topography.
The study, published in the International Journal of Cosmetic Science, showed that GSS complex produced significant single-variable (P < 0.05) improvements in SC hydration, barrier function, elasticity and surface topography compared with the Vehicle control.