Antagonistic effect of Poria Cocos on ototoxicity of kanamycin in guinea-pigs

In order to prevent ototoxicity of kanamycin (KM), the effects of Poria Cocos (PC) on the ototoxicity induced by KM in guinea-pigs was observed by giving the PC decoction to guinea-pigs with comparing the difference in the general intoxicating symptom, Prayer’s reflex (PR) threshold, brainstem auditory evoked potentials (BAEPs) and the absence rate of outer hair cells in the first turn of cochlea. The results suggested that the ototoxicity of KM was retarded by PC decoction. On the 7th day after KM was given, PR threshold of 4, 6, 8 kHz in the medicated group and control group were 4.7±1.5 dB, 5.7±2.4 dB, 2.7± 1.2 dB and 10.5 ± 3.2 dB, 12.1±3.7 dB, 8.5±2.7 dB respectively. BAEPs threshold on the 13th day after KM was given, raised 22.7 ± 9.7 dB in the PC group and 51.3 ± 14.4 dB in the control group. The absence rate of outer hair cells in the first turn of cochlea were 39.4% and 67.4% respectively. The results suggested that PC might be antagonistic to the ototoxicity of KM in guinea-pigs.