Hypocholesterolaemic and antioxidant effects of kombucha tea in high-cholesterol fed mice

BACKGROUND: Traditional kombucha tea (TKT) is produced by mixed tea fungus. We previously proposed Gluconacetobacter sp. A4 as the key functional strain in kombucha culture, because it had strong ability to produce D-saccharic acid-1,4-lactone (DSL, a crucial functional component in KT). This study investigated the hypocholesterolaemic and antioxidant activities of TKT and modified KT (MKT, tea broth fermented by single Gluconacetobacter sp. A4). RESULTS: In vitro, TKT and MKT, but not DSL equally increased the radical scavenging effects and inhibited low density lipoprotein (LDL) oxidation. In vivo, the total cholesterol and LDL-cholesterol (LDL-C) lowering effects were not different between MKT and TKT. Compared with TKT, MKT showed a significantly elevated effect on the increase of antioxidantive enzymes activities (total antioxidant capacity and superoxide dismutase) and the decrease of malondialdehyde. Meanwhile DSL demonstrated an enhanced activity in lipid profile and antioxidant activities. CONCLUSION: KT had the hypocholesterolaemic and antioxiclant effects. These effects were largely attributed to DSL. MKT was similar to or even more powerful than TKT in antioxiclant and hypocholesterolaemic effects. Thus, Gluconacetobactersp, A4 was further established as the main functional microorganism in kombucha culture. Moreover, KT may be useful in treating obesity. (c) 2008 Society of Chemical Industry