Caffeic acid phenethyl ester ameliorated ototoxicity induced by cisplatin in rats.

Caffeic acid phenethyl ester (CAPE), an active component of propolis, exhibits antioxidant properties. This experimental study was designed to determine the effect of CAPE on ototoxicity induced with cisplatin. Twenty-four adult Wistar albino rats were divided into four groups: cisplatin (n=6), saline (n=6), CAPE (n=6), and cisplatin plus CAPE (n=6). Rats were tested before and 5 days after cisplatin treatment with or without chemo protection. The Distortion Product Otoacoustic Emissions (DPOAEs) were elicited from the control and experimental animals utilizing the standard commercial Otoacoustic Emission (OAEs) apparatus. The animals in all groups were sacrificed under general anesthesia on the fifth day following last OAE measurements. For biochemical investigations, the blood samples were drawn from inferior vena cava. On day 0, the initial baseline DPOAEs measurement results presented similar values while comparing the groups in drug free phase (p>0.05). On day 5, intrasubject measurement parameters of DPgrams and I/O functions of cisplatin group were significantly deteriorated (p<0.05). The second measurements of the other groups revealed no significant differences between their DPgrams and I/O functions in all frequencies (p>0.05). Among the biochemical parameters, plasma xanthine oxidase (XO) activity was found to be more elevated in the cisplatin group than the saline group (p<0.05). CAPE led to more decreased XO activity than cisplatin (p<0.05). The results of this study show that prophylactic administration of CAPE for cisplatin ototoxicity ameliorated hearing deterioration in rats.