The Protective Role of Silymarin and Aerobic Exercise on Gentamicin-induced Nephrotoxicity

Abstract

Dear Editor,Gentamicin (GM) is commonly used against Gram‑negative microorganisms, but the compound’s therapeutic use is mainly limited by nephrotoxicity which is observed in 10%–20% of patients treated with GM.[1] Silymarin (SM) as an antioxidant agent has anti‑inflammatory actions, and it improves structural and enzymatic changes induced by GM.[2] On the other hand, lifelong physical activity has been recommended to improve antioxidant content.[3] Thirty‑seven adult male Wistar rats (175.56 ± 2.24 g) were used in five groups as follows: Group 1 (n = 6, control group) that received vehicle dimethyl sulfoxide (DMSO) for 3 days a week during the 6 week study period and then saline was injected for 10 days. Group 2 (n = 6, GM group) that received the same regimen as Group 1 but GM (100 mg/kg/day) for 10 days instead of saline. Group 3 (n = 7, GM + SM group) that received SM (200 mg/kg/day) dissolved in DMSO for 3 days a week during the 6 week study period and then GM was injected for 10 days. Group 4 (n = 9, GM + exercise [EX]) that received DMSO for 3 days a week and treadmill EX (5 days The Protective Role of Silymarin and Aerobic Exercise on Gentamicin‑induced Nephrotoxicity Letter to Editor in week) during the 6 week study period and then GM was injected for 10 days. Group 5 (n = 9, GM + SM + EX) that received SM dissolved in DMSO for 3 days a week and EX during the 6 week study period and then GM was injected for 10 days.The rats were exposed to treadmill EX 5 sessions a week for a period of 6 weeks as described before.[4,5]The levels of serum creatinine (Cr), blood urea nitrogen (BUN), nitrite (by Griess reaction), and malondialdehyde (MDA)[5,6] were determined.The removed kidney was weighted and subjected to hematoxylin and eosin staining. Kidney tissue damage score (KTDS) was graded from 0 to 4. Independent Student’s t‑test, Mann–Whitney test for comparison between control and GM groups, and ANOVA analysis followed by least significant difference, and Kruskal–Wallis tests were employed to compare the parameters between all GM‑treated groups