Specific blockage of caspase-1 activation by purple bamboo-salt prevents apoptosis of auditory cell line, HEI-OC1.

Cisplatin is a highly effective chemotherapeutic agent but with significant ototoxic side effects. Apoptosis is an important mechanism of cochlear hair cell loss following exposure to an ototoxic level of cisplatin. The present study investigated the effects of purple bamboo-salt (BS) on cisplatin-induced apoptosis. We demonstrated that apoptosis induced by cisplatin was inhibited by treatment with BS in a dose-dependent manner. Activation of caspase-3, caspase-8, and caspase-9 was observed within cisplatin-treated HEI-OC1 cells. BS inhibited activation of caspase-3, caspase-8, and caspase-9. BS also inhibited release of cytochrome c and translocation of apoptosis-inducing factor. BS inhibited cisplatin-induced reactive oxygen species production. Lastly, BS suppressed cisplatin-induced caspase-1 activation. In conclusion, these findings show that BS blockage of a critical step in apoptosis may be a useful strategy to prevent harmful side effects of cisplatin ototoxicity in patients undergoing chemotherapy.