In vivo skin antioxidant effect of a new combination based on a specific Vitis vinifera shoot extract and a biotechnological extract.

BACKGROUND AND OBJECTIVES

Ultraviolet (UV) light produces reactive oxygen species (ROS) in skin, which accelerate aging by damaging DNA, proteins, lipids, and other cellular constituents. The aims of this study were to 1) evaluate the antioxidant properties of a Vitis vinifera shoot extract on cultured normal human keratinocytes, 2) compare the in vivo antioxidant of this extract in combination with a biotechnological extract (Ronacare Hydroine), and 3) evaluate the efficacy on photoaging skin of a serum based on a combination (Vitis vinifera shoot extract in hydroglycolic solution, or Sarmentine, and Ronacare Hydroine) after a 4-week application, and to quantify the additional improvement given by applying a cream with the serum.

METHODS/STUDY DESIGN: An in vitro study was conducted to evaluate the antioxidant properties of Vitis vinifera shoot extract added to cultured normal human keratinocytes. A fluorescent probe was used to quantify cytoplasmic endogenous species formed in response to oxidative stress induced by H2O2. The antioxidant activity of Vitis vinifera shoot extract was compared to that of a solvent control and 2 positive controls, vitamin E and vitamin C. In the first in vivo study, 2 test products were included in a comparative, randomized, single-blind trial in which 27 subjects acted as their own (untreated) controls. Products were applied 4 times to randomized areas of the inner surface of the forearm for one day. The following day, treated and untreated (control) areas of stratum corneum were sampled for fluorimetric analysis. A decrease in fluorescence compared with untreated control reflected a decrease in the level of ROS, in which case the product had a scavenging effect. The 2 products contained a combination of Sarmentine and Ronacare Hydroine, whose antioxidant properties were under investigation. Other products were known antioxidants. In the second in vivo study, 60 female subjects applied either serum or serum plus cream twice daily for 28 days for clinical evaluation. Overall improvement was rated on a quartile scale (0%-25%, 26%-50%, 51%-75%, 76%-100%) and changes in firmness, radiant glow, evenness, smoothness, wrinkles, fine lines, hydration, texture, and softness were rated on a negative to positive scale (-5=worse to +5=greatly improved).

RESULTS AND CONCLUSIONS

Vitis vinifera shoot extract appears to have significantly stronger in vitro antioxidant capacity than vitamin C or vitamin E. In the same vehicle (placebo emulsion), ascorbic acid (0.5%), Sarmentine (1%), and the Sarmentine (1%) plus Ronacare Hydroine (1%) combination had a significant in vivo antioxidant effect versus a nontreated area. The combination Sarmentine (1%) plus Ronacare Hydroine (1%) showed a higher efficacy than Sarmentine alone. The dermatologic evaluation showed that a 4-week twice-daily application of a serum containing the combination improved the main clinical signs of photoaged skin. The addition of the cream with the serum appears to enhance the serum-induced improvement of most of the skin characteristics.