Origanum essential oils reduce the level of melanin in B16-F1 melanocytes
Résumé
BACKGROUND: Hyperpigmentation disorders are considered signs of skin aging and are esthetically unpleasant. Most active ingredients fighting against hyperpigmentation disorders are mostly targeting the tyrosinase activity.
OBJECTIVE: In this article, we seek to study the effect of two Origanum essential oils (EO) on the melanogenic activity of MEL B16-F1 murine melanocytes. We also explore the effect of their main component, carvacrol, and propose a model for its anti-melanogenic activity.
METHOD: MEL B16-F1 melanocytes were exposed to different concentrations of essential oils and of carvacrol. Inhibition of tyrosinase production and reduction of melanin production were determined by spectrophotometric measurements.
RESULTS: Essential oils of Origanum syriacum and Origanum ehrenbergii showed a significant reduction in the melanin production by 14% and 17% respectively at 40µg mL-1. However, they did not show a significant effect on the intracellular tyrosinase production. Same effect was found with Carvacrol that showed a reduction in the melanin production by around 30% at 45 µg mL-1.
CONCLUSION: Our results are in favor for an anti-melanogenic activity of the studied EO. We propose a mechanism for the inhibition of the tyrosinase activity that is based on the binding of carvacrol to tyrosinase that catalyzes its oxidation, preventing thus the oxidation of tyrosine and causing a deregulation in the melanogenesis pathway. This mechanism of competitive inhibition could be similar to the mechanism of action of hydroquinone.