Effects of Spirulina on GABA Receptor Gene Expression in Salicylate-Induced Tinnitus.

OBJECTIVES: The function of γ-amino butyric acid receptor (GR) was related with tinnitus. But, the effects of Spirulina platensis water extract (SP) on the mRNA expression of GRAβ3 in mice with tinnitus were still unclear.

METHOD: Eighteen SAMP8 mice were divided into the control group (intraperitoneal injection of saline, once per day), the tinnitus group (intraperitoneal injection of salicylate, 300 mg/kg body weight once per day), and the spirulina group [intraperitoneal injection of salicylate, 300 mg/kg body weight and oral SP supplementation (1000 mg/kg body weight) once per day]. Effects of SP on the mRNA expression of GRAβ3 in the cochlea and brain of mice were studied for 4 days.

RESULTS: Compared to the control group, the tinnitus group had significantly higher tinnitus scores and lower mRNA expression of GRAβ3 gene in the cochlear, brainstem, hippocampus and parahippocampus, temporal lobes, and the frontal lobes. On the other hand, the spirulina group had significantly lower tinnitus scores and higher GRAβ3 gene expression than the tinnitus group in all tested areas.

CONCLUSION: SP could reduce salicylate-induced tinnitus possibly via increasing the salicylate-induced down-regulation of GRAβ3 gene expression.