Beneficial effects of different tea flowers against human breast cancer MCF-7 cells

Tea is a popular beverage with health benefits. The enriched tea polyphenols including catechins have been reported to perform anti-cancer, anti-oxidant, anti-inflammatory and anti-bacterial activity. In this study, we compared the levels of catechins and caffeine in tea flowers from six different species of Camellia japonica, Camellia tenuifolia, Camellia oleifera, 2 savoury Camellias and Camellia sinensis. C. sinensis detected a variety of catechins, while only (+)-catechin and (−)-epicatechin can be detected by the isocratic HPLC system in other tea flowers. The total catechin content was also lower in these tea flowers. In addition, the water extract of tea flowers was used to test the biological functions including anti-proliferative and apoptotic effects in human breast cancer MCF-7 cells. The water extract of C. sinensis remained most active among six different species using both MTT assays and the cleavage analysis of apoptosis-related molecules, PARP and Bid. The major bioactivity of C. sinensis comes from (−)-epigallocatechin-3-gallate and (−)-epigallocatechin, not detected in other five species. Interestingly, we found that C. tenuifolia still had potent bioactivity. It is likely that bioactive molecules other than catechins exist in C. tenuifolia.