Otoprotective Effects of Stephania tetrandra S. Moore Herb Isolate against Acoustic Trauma.

Otoprotective Effects of Stephania tetrandra S. Moore Herb Isolate against Acoustic Trauma.

Yu Yan; Hu Bing; Bao Jianxin; Mulvany Jessica; Bielefeld Eric; Harrison Ryan T; Neton Sarah A; Thirumala Partha; Chen Yingying; Lei Debin; Qiu Ziyu; Zheng Qingyin; Ren Jihao; Perez-Flores Maria Cristina; Yamoah Ebenezer N; Salehi Pezhman

Journal of the Association for Research in Otolaryngology : JARO

2018

2018-12

Noise is the most common occupational and environmental hazard, and noise-induced hearing loss (NIHL) is the second most common form of sensorineural hearing deficit. Although therapeutics that target the free-radical pathway have shown promise, none of these compounds is currently approved against NIHL by the United States Food and Drug Administration. The present study has demonstrated that tetrandrine (TET), a traditional Chinese medicinal alkaloid and the main chemical isolate of the Stephania tetrandra S. Moore herb, significantly attenuated NIHL in CBA/CaJ mice. TET is known to exert antihypertensive and antiarrhythmic effects through the blocking of calcium channels. Whole-cell patch-clamp recording from adult spiral ganglion neurons showed that TET blocked the transient Ca(2+) current in a dose-dependent manner and the half-blocking concentration was 0.6 + 0.1 muM. Consistent with previous findings that modulations of calcium-based signaling pathways have both prophylactic and therapeutic effects against neural trauma, NIHL was significantly diminished by TET administration. Importantly, TET has a long-lasting protective effect after noise exposure (48 weeks) in comparison to 2 weeks after noise exposure. The otoprotective effects of TET were achieved mainly by preventing outer hair cell damage and synapse loss between inner hair cells and spiral ganglion neurons. Thus, our data indicate that TET has great potential in the prevention and treatment of NIHL.

calcium channel; hair cells; noise-induced hearing loss; spiral ganglion neurons; Stephania tetrandra; synapse; Tetrandrine

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653–668

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