Antioxidant Activity of Theaflavin and Thearubigin Separated from Korean Microbially Fermented Tea

Abstract

Theaflavins (TF) and thearubigins (TR) were separated from Korean microbially fermented tea leaves. Contents of TF (74.4 μM/g) and TR (37.2%) were higher than reported for black tea fermented by oxidase. Antioxidant activities of TF, TR and EGCG were analyzed and protective effects of COS?7 cells against copper and cadmiuminduced toxicity were investigated. TF and TR exhibited good inhibition rates of about 85～90% for antioxidant and scavenging activities of free radicals and protected COS?7 cells against apoptosis or damage caused by stress, such as cadmium and copper-oxidative injury, free radicals etc. These results indicate that TF, TR and EGCG have antioxidant and scavenging activities against free radicals and protect COS?7 cells from Cu, Cd induced injury.