In vitro antioxidant, anti-mutagenic, anti-cancer and anti-angiogenic effects of Chinese Bowl tea

The in vitro bioactivities of Chinese Bowl tea for its antioxidant, anti-mutagenic, anti-cancer and anti-angiogenic effects were investigated. The tea extract showed high antioxidant activity both in the DPPH and hydroxyl radical scavenging activities. At concentrations of 1.25 and 2.5 mg/plate, the tea extract exhibited an anti-mutagenicity induced by MNNG (N-methyl-N′-nitro-N-nitrosoguanidine) against the Salmonella typhimurium TA100 strain. High concentration (200 μg/mL) of the tea extract significantly induced apoptosis in human tongue carcinoma TCA8113 cells by upregulating Bax, caspase-3, and caspase-9, and downregulating Bcl-2. The expression of genes associated with inflammation, e.g., NF-κB, iNOS, and COX-2, was significantly downregulated by the tea extract, demonstrating its anti-inflammatory properties. In addition, the tea showed strong anti-angiogenic effect at high concentrations. Moreover, LC-MS/MS analysis showed that gallic acid, beta-resorcylic acid, quercetin and kaempferol and their derivatives may contribute to the above mentioned effects. Especially beta-resorcylic acid showed strong anticancer effect in vitro. Beta-resorcylic acid was tested by MTT and RT-PCR assays. 100 μg/mL beta-resorcylic acid showed the effect as 200 μg/mL Bowl tea did, which indicated that it is an important compound in Bowl tea.