Effect of a Garcinia gardneriana (Planchon and Triana) Zappi hydroalcoholic extract on melanogenesis in B16F10 melanoma cells

Ethnopharmacology relevance: Garcinia gardneriana (Planchon and Triana) Zappi (Clusiaceae) is popularly called "bacopari" in southern Brazil. The leaves of this plant are traditionally used to treat skin disorders. Aim of study: This study evaluated the effects of a hydroalcoholic extract of Garcinia gardneriana leaves (HEGG) on B16F10 murine melanoma cells in order to search for new depigmenting agents. Materials and methods: The effects of HEGG were assessed in melanin content assays in B16F10 melanoma cells compared with the reference drug kojic acid (500 mM). Melanin content was measured after spontaneous melanogenesis, UVB-induced melanogenesis and melanogenesis induced by alpha-MSH. At the same time, cell viability-assays were conducted. Intracellular and mushroom tyrosinase activity assays were employed to evaluate the effect of HEGG on tyrosinase activity. Results: HEGG decreased the level of melanin under all three experimental conditions of melanin content evaluation without reducing cell viability. In intracellular tyrosinase assays, the enzyme's activity was reduced about 19% with extract concentrations ranging 0.1-10 mu g/mL. In the mushroom tyrosinase activity assay a maximal inhibition of 35% (1000 mu g/mL) was observed. Conclusion: These results suggest that HEGG inhibition relates to its tyrosinase activity. Therefore, the hydroalcoholic extract of Garcinia gardneriana shows great potential for use as a depigmenting agent in hyperpigmentation disorders. (C) 2013 Elsevier Ireland Ltd. All rights reserved.