Çay üzümü ekstresinin ratlarda cisplatin ototoksisitesi üzerine koruyucu etkisi

Introduction/objective: Although cisplatin is a frequently used chemotherapeutic agent in head and neck cancer, the ototoxic effect of it is still a serious problem. Various antioxidant materials have been used to avoid and/or prevent this ototoxicity in literature. The protective effect of whortleberry on cisplatin ototoxicity was investigated in the current study. Materials/methods: Forty-eight male, adult (3-5 months of age) Spraque Dawley albino rats ranging in weight from 250 g to 350 g were included in the study. The rats were divided into six groups. The control group was not exposed to any injection. The other groups were consisted of rats which received only 8 doses of solvent, only 8 doses of whortleberry at 100 mg/kg dose, only a single dose of 16 mg / kg cisplatin, a single dose of 16 mg / kg cisplatin with 8 doses of whortleberry at 100 mg/kg dose and a single dose of 16 mg / kg cisplatin with 8 doses of whortleberry at 200 mg/kg dose respectively. DPOAE test was performed at the beginning and the eighth day of the study. The rats were sacrificed on the eighth day and blood samples were collected for the biochemical analysis. Total antioxidant capacity and total oxidative stress parameters were measured from these blood samples and oxidative stress index was calculated by using these data. For histological investigations, temporal bone was dissected and fixed in 2.5% glutaraldehyde solution. Following the hematoxylin-eosine staining, the findings were evaluated under light microscopy. Results: Negative effects of cisplatin were observed on both at the cellular level and on hearingfunctions in addition to increased oxidative stress in blood. The protective effect of whortleberry on cisplatin ototoxicity was observed in both groups. No significant difference was observed between the groups which received high dose whortleberry and low dose. Discussion: The antioxidant, anti-inflammatory and antiproliferative effects of whortleberry have been already reported with its high anthocyanin, flavonoid and phenolic acid content. However, there are no adequate studies in the literature about the effects of it on ototoxicity. Significant effects were observed on the protection of the hearing in the current study. Nevertheless, there is still need for further studies to determine the appropriate dosage range.