Document Type : Research Paper

Authors

• H. Morovvati
• H. Najafzadeh
• R. Avizeh
• N. Khadivi Kashani

Faculty of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran

Abstract

Drug-induced ototoxicity is one of the important factors for less auditory in dogs. Aminoglycosides including gentamicin can produce ototoxicity in dogs. The oxidative stress can be related to it. Silymarin, in the seed extract of Silybum marianum, is a potent antioxidant. In present study, the effect of silymarin and vitamin E was compared on gentamaicin-induced ototoxicity. The study was done on dogs in 5 groups: group1 was kept as control and received saline. Gentamicin was prescribed in other groups once for 9 days. Vitamin E and silymarin were given in group 3 and 4, respectively. In group 5, vitamin E and silymarin were co-administrated. After 9 days, the dogs were euthanized and ear samples were collected. One ear of dogs was colored by silver nitrate and another was decalcified by decalcificative solution. The decalcified samples were routinely sectioned and colored by Hematoxillin- Eosine (H&E) and studied by light microscope. Hair cells were not determined by silver nitrate. Organ of coarti body, tectorial membrane, limbus spiral, spiral ganglion, interdental cells, supporting cells and type I and II of  hair cells were identified in samples and colored by H&E. These histological compartments were determined in control and silymarin groups. They were not observed in other groups, because gentamicin strongly destroyed cells. Thus, silymarin decreases gentamicin-induced changes in inner ear probably by its antioxidative property.

Keywords

• Gentamicin
• silymarin
• Vitamin E
• Dog
• ototoxicity