Discovery of Se-containing flavone in Se-enriched green tea and the potential application value in the immune regulation

Selenium (Se)-enriched green tea has been recognized as a possible source of supplemental Se, while the structural and physiological activities of Se-containing flavone are still unclear. In this study, a Se-containing flavone was isolated from Se-enriched green tea by high-speed counter-current chromatography (HSCCC) and characterized through UHPLC-Q-Orbitrap, FT-IR and NMR. Results proved that HSeO3- can be combined with the alcohol hydroxyl of 2-phenylchromone in flavone and the content of Se-containing flavone in tea was 15690.4 μg L-1. Additionally, Se-containing flavone can effectively inhibit the production of nitric oxide (NO), and downregulate expression of TNF-α and IL-6. Compared with regular flavone extracted from green tea (43.24 pg mL-1), release of IL-10 was higher in Se-containing flavone group (53.37 pg mL-1), indicating that Se-containing flavone played an important role in the process of severe inflammatory injury. The results indicated that Se-containing flavone was an attractive natural ingredient for developing novel functional foods.