Eman I Draz1, Amany A Abdin2, Naglaa I Sarhan3, Takwa A Gabr4. 1. Department of Forensic Medicine & Clinical Toxicology, Faculty of Medicine, Tanta University, Tanta, Egypt. 2. Department of Pharmacology, Faculty of Medicine, Tanta University, Tanta, Egypt. Electronic address: amanyabdin@med.tanta.edu.eg. 3. Department of Histology, Faculty of Medicine, Tanta University, Tanta, Egypt. 4. Department of Audiology, Faculty of Medicine, Tanta University, Tanta, Egypt.
Abstract
BACKGROUND: Despite that gentamicin is a very effective aminoglycoside, its potential ototoxicity which is of irreversible nature makes a challenge and limitation for its use. This study was designed to investigate possible neurotrophic and antioxidant effects of silymarin comparable to 4-methylcatechol in protection against gentamicin-induced ototoxicity. METHODS AND RESULTS: Twenty pigmented guinea pigs were divided into four equal groups, where group I served as normal control group. The other groups received gentamicin (120 mg/kg/day, ip) for 19 days where group II given vehicle of 1% CMC, group III and group IV were pre-treated 2h before gentamicin by 4-methylcatechol (10 μg/kg, ip) and silymarin (100mg/kg, oral gavage), respectively. The main findings indicated that silymarin exhibited restoration of nerve growth factor (NGF) levels and increased tropomyosin-related kinase receptors-A (Trk-A) m-RNA expression in cochlear tissue and preservation of hair cells of organ of Corti by scanning electron microscopy (SEM) with significant decrease in auditory brainstem response (ABR) threshold compared to 4-methylcatechol. Only silymarin caused significant amelioration in oxidative stress state by reducing malondialdehyde (MDA) levels and increasing catalase activity. CONCLUSIONS: Silymarin exerts superiority over 4-methylcatechol when recommended as protective agent against gentamicin ototoxicity based on its efficient neurotrophic and antioxidant activities.
BACKGROUND: Despite that gentamicin is a very effective aminoglycoside, its potential ototoxicity which is of irreversible nature makes a challenge and limitation for its use. This study was designed to investigate possible neurotrophic and antioxidant effects of silymarin comparable to 4-methylcatechol in protection against gentamicin-induced ototoxicity. METHODS AND RESULTS: Twenty pigmented guinea pigs were divided into four equal groups, where group I served as normal control group. The other groups received gentamicin (120 mg/kg/day, ip) for 19 days where group II given vehicle of 1% CMC, group III and group IV were pre-treated 2h before gentamicin by 4-methylcatechol (10 μg/kg, ip) and silymarin (100mg/kg, oral gavage), respectively. The main findings indicated that silymarin exhibited restoration of nerve growth factor (NGF) levels and increased tropomyosin-related kinase receptors-A (Trk-A) m-RNA expression in cochlear tissue and preservation of hair cells of organ of Corti by scanning electron microscopy (SEM) with significant decrease in auditory brainstem response (ABR) threshold compared to 4-methylcatechol. Only silymarin caused significant amelioration in oxidative stress state by reducing malondialdehyde (MDA) levels and increasing catalase activity. CONCLUSIONS:Silymarin exerts superiority over 4-methylcatechol when recommended as protective agent against gentamicinototoxicity based on its efficient neurotrophic and antioxidant activities.
Authors: Lorena M Coronado; Stephania Montealegre; Zumara Chaverra; Luis Mojica; Carlos Espinosa; Alejandro Almanza; Ricardo Correa; José A Stoute; Rolando A Gittens; Carmenza Spadafora Journal: PLoS One Date: 2016-08-18 Impact factor: 3.240