Catapult steam explosion significantly increases cellular antioxidant and anti-proliferative activities of Adinandra nitida leaves

摘要

Leaves of Adinandra nitida, traditionally brewed as a health tea beverage in China, were treated with instant catapult steam explosion (ICSE) under various steam pressures (0.5-3.0 MPa) and residence times (30-120 s). The effects of ICSE on the flavonoids of the leaves and their cellular antioxidant and anti-proliferative activities and cytotoxicity against HepG2 cells were investigated. HPLC analysis showed that the treatment caused decreases and eventual disappearance of camellianin A and B with consequent formation of apigenin, which was attributed to discrepancy in the thermal stability of these flavonoids. The conversion of camellianin A and B to apigenin resulted in significant increases in the cellular antioxidant and anti-proliferative activities of Adinandra nitida leaves, with the EC50 values reduced by 53.7 and 68.1%, respectively. The study shows that ICSE could be an efficient, economical and environment-friendly method for modifying the polyphenolic composition and improve the bioactivities of Adinandra nitida leaves. (C) 2016 Published by Elsevier Ltd.