Protective Effect of Spirulina on Cisplatin-Induced Ototoxicity: A Functional and Histopathological Study

Objective: The purpose of this study was to evaluate the protective effect of an antioxidant and anti-inflammatory agent, "spirulina," against cisplatin-induced ototoxicity in rats. Methods: Twenty-eight adult Sprague-Dawley rats were divided into 4 groups. Before drug administration, distortion product otoacoustic emission and auditory brainstem response tests were performed. Group 1 (n =7) received 1 mg of intraperitoneal saline. Group 2 (n=7) received a single dose of intraperitoneal cisplatin at 15 mg/kg/day. Group 3 (n=7) received oral spirulina at 1000 mg/kg/day for 10 days. Group 4 (n=7) received a single i.p. dose of cisplatin at 15 mg/kg/day, followed by 10 days of oral spirulina at 1000 mg/kg/day. The final distortion product otoacoustic emission and auditory brainstem response measurements were provided 10 days after the initial drug administration. Cochleas were removed, the histochemical examination was performed by caspase-3, caspase-9, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling methods. Results: Initially, there were no significant differences in distortion product otoacoustic emission and auditory brainstem response measurements between groups. Following cisplatin treatment, the mean difference in signal to noise ratio values was lower in the cisplatin + spirulina group compared to the cisplatin-only group. The increase in auditory brainstem response thresholds was more significant in the cisplatin-only group than in the cisplatin + spirulina group. Posttreatment auditory brainstem response latencies were prolonged in cisplatin and cisplatin + spirulina groups; however, a significant difference was obtained between these 2 groups. The cisplatin + spirulina group had a lower density of apoptotic cells than the cisplatin-only group. Conclusion: Spirulina has no adverse effects on cochlear functions and may provide some protection against cisplatin-induced ototoxicity.