Allicin Protects against Cisplatin-Induced Stria Vascularis Damage: Possible Relation to Inhibition of Caspase-3 and PARP-1-AIF-Mediated Apoptotic Pathways

Cisplatin is an anti-cancer drug that causes oxotoxic side effects such as impairment of inner ear function and hearing loss. We aimed to investigate the effects of allicin against cisplatin-induced stria vascularis damage in mice, and to clarify the mechanism underlying the protective effects of allicin against ototoxicity. Stria vascularis injury was induced in mice by intraperitoneal injection of cisplatin, which was significantly prevented by pretreatment with allicin. Allicin not only reduced cisplatin-activated expression of cleaved caspase-3 in marginal cells, PVM/Ms (perivascular resident macrophage-like melanocytes), and basal cells of the stria vascularis, but also decreased the expression of poly(ADP-ribose) polymerase-1 (PARP-1) and apoptosis-inducing factor (AIF) nuclear translocation in the stria vascularis cells. Our results demonstrate that allicin plays an effective role in protecting stria vascularis injury induced by cisplatin by inhibiting caspase-dependent, as well as caspase-independent PARP-1-AIF-mediated apoptotic pathways. Therefore, allicin may be useful in preventing cisplatin-induced ototoxicity.