Protective effects of resveratrol on cisplatin-dependent inner-ear damage in rats

Cisplatin is a common chemotherapeutic agent used in many solid and hematologic malignancies. The main unwanted effect of cisplatin is ototoxicity, for which no standard treatment has been reported. The present study examined the protective efficacy of resveratrol on cisplatin-dependent ototoxicity through an experimental model. Fifteen rats were randomized into three groups. Group 1 (control group) (n = 5) received intraperitoneal (i.p.) 15 mg/kg cisplatin; group 2 (resveratrol group) (n = 5) received i.p. 100 mg/kg resveratrol, followed by i.p. 15 mg/kg cisplatin; group 3 (n = 5) served as a vehicle group and received i.p. 1 ml dimethyl sulfoxide. All rats underwent the auditory brainstem response (ABR) test before and 72 h after the treatment. Pretreatment ABR values of the groups were not significantly different. The pretreatment hearing threshold values of the groups were 30 ± 6.60 and 28.5 ± 5.29 dB in groups 1 and 2, respectively (p > 0.05). The post-ABR-I and post-ABR-IV values were, respectively, 1.41 ± 0.18 and 5.83 ± 0.16 ms in the control subjects and 1.19 ± 0.22 and 4.58 ± 0.27 ms in the study group. The ABR-I and ABR-IV durations in rats treated with resveratrol were significantly shorter (p < 0.01). A comparison of threshold values shows that the resveratrol-treated rats had significantly lower values than the control rats. After cisplatin injection, ABR I-IV intervals were compared among the groups. The ABR I-IV interval duration was 4.42 ± 0.16 ms in the control group, while the resveratrol-treated rats showed a significantly shorter ABR I-IV interval duration of 3.49 ± 0.27 ms (p < 0.001). Resveratrol attenuated cisplatin-dependent inner-ear damage, as shown by the ABR-I, ABR-IV, ABR I-IV interval, and hearing threshold values. Our results suggest that this natural antioxidant may be effectively used in reducing the unwanted effects of cisplatin on the ear physiology of patients, particularly those undergoing chemotherapy.