Oolong tea prevents cardiomyocyte loss against hypoxia by attenuating p‐JNK mediated hypertrophy and enhancing P‐IGF1R, p‐akt, and p‐Bad^ser136 activity and by fortifying NRF2 antioxidation system

Abstract

Abstract Tea, the most widely consumed natural beverage has been associated with reduced mortality risk from cardiovascular disease. Oolong tea is a partially fermented tea containing high levels of catechins, their degree of oxidation varies between 20%‐80% causing differences in their active metabolites. In this study we examined the effect of oolong tea extract (OTE) obtained by oxidation at low‐temperature for short‐time against hypoxic injury and found that oolong tea provides cyto‐protective effects by suppressing the JNK mediated hypertrophic effects and by enhancing the innate antioxidant mechanisms in neonatal cardiomyocytes and in H9c2 cells. OTE effectively attenuates 24 h hypoxia‐triggered cardiomyocyte loss by suppressing caspase‐3‐cleavage and apoptosis in a dose‐dependent manner. OTE also enhances the IGFIR/p‐Akt associated survival‐mechanism involving the elevation of p‐Bad ser136 in a dose‐dependent manner to aid cellular adaptations against hypoxic challenge. The results show the effects and mechanism of Oolong tea to provide cardio‐protective benefits during hypoxic conditions.