Antioxidant activities and melanogenesis inhibitory effects of terminalia chebula in B16/F10 melanoma cells

To examine the potential of Terminalia chebula as a whitening agent, we measured antioxidant activity using DPPH· , ABTS·+ assays and ferric-reducing antioxidant power (FRAP) assays, and depigmenting activity using B16F10 melanoma cells. The intracellular reactive oxygen species (ROS) level was monitored by H2DCFDA fluorescence labeling, and melanin contents in B16F10 melanoma cells by 960 J/m2 dose of UVA-induced oxidative stress. The radical-scavenging activities of T. chebula extract (TCE) were measured in terms of EC50 values using DPPH·, ABTS·+ assays and FRAP value were 280.0 μg/mL, 42.2 μg/mL and 113.1 μmol FeSO₄ 7H ₂O/g, respectively. We found that ROS and melanin concentrations were reduced by TCE treatments of 25 μg/mL under UVA-induced oxidative stress. Tyrosinase activity and melanin contents in a-melanocyte stimulating hormone (MSH)-induced melanoma cells both decreased dose-dependently in the treatment groups. TCE similarly reduced melanogenesis in B16F10 melanoma cells stimulated by a-MSH as compared to arbutin as a positive control. T. chebula may prove to be a useful therapeutic agent for hyperpigmentation and an effective component in skin whitening andor lightening cosmetics.