Protective effect of Pycnogenol on cisplatin-induced ototoxicity in rats

Context: Pycnogenol((R)), which is French maritime pine bark extract, is a potent antioxidant. It is used in medical conditions caused by oxidative stress. Cisplatin (cis-diamminedichloroplatinum II) is an antineoplastic agent. However, its serious side effects such as ototoxicity limit its usage.Objective: Antioxidants can be used to prevent ototoxicity. We investigated the effect of Pycnogenol((R)) on cisplatin-induced ototoxicity.Materials and methods: Rats were randomly assigned to four groups of five. Distortion product-evoked otoacoustic emissions (DPOAE) test was performed for each rat. The experimental groups were as follows: Control Group, Pycnogenol((R)) Group: 10mg/kg Pycnogenol((R)) intraperitoneally for 7 days, Cisplatin Group: intraperitoneally 15mg/kg single injection of cisplatin on the fifth day, Cisplatin+Pycnogenol((R)) Group: intraperitoneally 10mg/kg Pycnogenol((R)) treatment for 7 days, additionally on the fifth day, 15mg/kg single injection of cisplatin was given. On the eighth day, DPOAE was re-performed and rats were sacrificed. Apoptosis was evaluated histopathologically.Results: Mean percentage of apoptotic cells was 1.5, 3, 30 and 11% in organ of Corti and 2, 2, 40, 15% in spiral ganglion neurons in Control Group, Pycnogenol((R)) Group, Cisplatin Group and Cisplatin+Pycnogenol((R)) Group, respectively. Cisplatin Group and Cisplatin+Pycnogenol((R)) Group were significantly different when compared to Control Group histopathologically both in organ of Corti and spiral ganglion neuron (p<0.001, p=0.019, p=0.001, p=0.015). DPOAE results showed that Cisplatin+Pycnogenol((R)) Group was significantly different when compared to Cisplatin Group at 3, 6 and 8kHz (p