Synergistic effect of Camellia sinensis and Withania somnifera on hydrogen peroxide-induced oxidative stress: an in vitro study

Abstract

Camellia sinensis (CS) and Withania somnifera (WS) are well-known to have antioxidant and anti-ageing effects. However, information on their synergistic antioxidant effect is still not known. In this study, we have compared the % cell viability of oxidative stress induced 3T3-L1 cell lines after treatment with CS, WS alone and in combination. The methanolic extracts of CS and WS were prepared by three cycles of maceration with 24 h duration each. The effect of CS and WS alone and in combination was determined under three different conditions viz. pre-treatment, co-treatment and post-treatment at 24hrs, 48hrs and 72hrs with the help of MTT assay. CS+WS were found to show synergistic effect under pre-treatment conditions with % cell viability of 95.39 ± 0.7% at an optimum concentration of WS+CS (4.87μg/ml+15.22μg/ml) after 72 hrs. The combination index was found to be less than 1 at 24 hrs (0.278), 48 hrs (0.172) and 72 hrs (0.126) for combination of CS+WS indicating a synergistic effect of plant combination.