Screening of mahoran plants for cosmetic applications.

This study’s main aim is to identify plant species showing anti-oxidant, anti-inflammatory and skin whitening properties. A selection of 89 samples from previous infield studies on the traditional uses of plants in Mayotte were analyzed. The anti-oxidant activity was assessed using the α, α-diphenyl-β-picrylhydrazyl (DPPH) method developed by Blois [1]. The anti-inflammatory activity and the skin whitening activity were both assessed through the study of inhibition kinetics from specific enzymes: respectively, lipoxygenase (EC 1.13.11.12) due to its important role in the leukotriene pathway and tyrosinase (EC. 1.14.18.1) as it takes part in the melanogenesis pathway. The IC 50 value for each sample and for each activity was obtained using UV/Vis spectrophotometric technics. These IC 50 were then compared with the ones obtained from known molecules found in the literature: namely, (±)-6-Hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (IC50 = 4,388 µM) for the anti-oxidant activity, nordihydroguaiaretic acid (IC50 = 3,5µM) for the anti-inflammatory activity and kojic acid (IC50 = 722 µM) for the anti-tyrosinase activity. The most effective anti-oxidant activity was observed in fresh leaves from Acalypha wilkesiana Müll.Arg. (IC50 = 0,381 g/L) and Leea guineensis G. Don. (IC50 = 0,225 g/L) as well as in dried roots from Litchi chinensis Sonn. (IC50 = 0,346 g/L). All results are expressed in grams of fresh matter. According to the preliminary tests for the-anti-inflammatory and skin whitening activities, the crude extracts from Kalanchoe pinnata Lam. Pers., Litchi chinensis Sonn., Zingiber zerumbet (L.) Sm., Leea guineensis G. Don. and Paullinia pinnata L. are likely to show promising activities.