Skin-whitening effects of Mediterranean herbal extracts by in vitro and in vivo models.

Several plant extracts are able to protect skin against ultraviolet-light-induced damage and hyperpigmentation in a safe way. The anti-melanogenic effect of herbal extracts seems to be related to their antioxidant activity and their polyphenolic content. In this study, the skin-whitening effect of some Mediterranean species, already known for their strong antioxidant and radical scavenger activity, has been evaluated by in vitro and in vivo models. The results obtained showed that herbal extracts possessed an inhibitory effect on tyrosinase enzyme. Each extract showed a similar inhibiting activity even though it was less intensive than kojic acid and hydroquinone. Otherwise, a significant higher activity than kojic acid and hydroquinone was observed when the herbal extracts were combined. Furthermore, the anti-melanogenic activity and an evaluation of skin tolerance were affected by in vivo methods.