Abstract

The current study was attempted to investigate the effect of melanogenesis and the mechanism behind both hypo and hyperpigmentation by oxidized and non-oxidized Piper betle extracts and on B16F1 melanoma cells. Supplementation with oxidized or non-oxidized Piper betle extracts did not show any significant cytotoxicity (90 % intact cells) in B16F1 melanoma cells. However, the activity of tyrosinase and the levels of lipid peroxidation product (thiobarbituric acid reactive substances), and melanin secretion was significantly decreased with improved antioxidant status after 48 h of incubation with increasing dose (25/35/50 µg/ml) of non-oxidized Piper betle extract in B16F1 melanoma cells. However, slightly decreased antioxidant status with increased melanin content was observed at 72 h (Piper betle extract). The above results indicated that as the duration increased the effect of non-oxidized Piper betle extract on melanin synthesis started to decline. In addition, when oxidized Piper betle extract (35/50 µg/ml) was incubated with B16F1 cells hyperpigmentation was noted within 48 h by enhancing the levels of thiobarbituric acid reactive substances (35 %) and melanin secretion as well as tyrosinase activity (max at 72 h) with lowered tyrosinase inhibitory activity. Taking together that oxidized Piper betle extract might be the reason for the hyperpigmentation and might contribute to various dermal disorders and thus non-oxidized Piper betle extract to be recommended for treating various dermal disorders.