In vitro antioxidant and antiproliferative activity of microwave-extracted green tea and black tea (Camellia sinensis): a comparative study

The present study compared the antioxidant and antiproliferative activities of green and black tea samples extracted by microwave heating. The antioxidant potential was analyzed at different concentrations of 20, 50, 70 and 100 μg/ml through 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, reducing power, lipid peroxidation and oxidative damage to DNA. The standards α-tocopherol (TO), rhutin (RH) and butylated hydroxyl toluene (BHT) were used for comparison. Green tea extract was found to have a higher total phenolic and flavonoid content (659 and 1680 mg GAE/ml of extract, respectively) than black tea extract (596 and 1586 mg GAE/ml of extract, respectively). All the antioxidant assays revealed that the antioxidant potential of green tea extract was better than that of black tea extract but lower than that of the standards. Green tea extracts (86.05%) also showed a higher antiproliferative effect than black tea extracts (59.34%). It was concluded that green tea exhibited better antioxidant and antiproliferative potential than black tea.