Protective effect of a Chrysanthemum indicum containing formulation in cadmium-induced ototoxicity.

Chungshinchongyitang (CSCYT) is an herbal drug formula containing Chrysanthemum indicum and 13 other herbs used for treating auditory diseases. Irreversible hearing loss is a characteristic effect of a number of heavy metals. Cadmium (Cd(2+)) is an environmental contaminant that causes a variety of adverse effects. In the present study, we investigate the protective effects of CSCYT against Cd(2+) induced ototoxicity in vitro and ex vivo. The findings of this study show that CSCYT prevents the destruction of hair cell arrays induced by Cd(2+) in the rat organ of Corti primary explants. CSCYT inhibited cell death, release of cytochrome c and generation of reactive oxygen species induced by Cd(2+) in HEI-OC1 auditory cell line. In addition, we also demonstrated that CSCYT exerted its effect by modulating of apoptosis via the caspase-3 activation and extracellular signal-regulated kinase activation. These results are expected to improve the understanding of the pharmacological mechanism of CSCYT and aid in the development of potential therapeutic strategies against ototoxicity.