Amelioration of renal cortex histological alterations by aqueous garlic extract in gentamicin induced renal toxicity in albino rats: a histological and immunohistochemical study

ABSTRACT Background: Aminoglycosides, particularly gentamicin, endure crucial antibiotics in the armamentarium for severe Gram-negative bacterial infections through their significant risk for nephrotoxicity. Co-administration of several applicant nephroprotective agents has been investigated at the preclinical level. Garlic was proved to be an oxidative stress combatant with unique antioxidant potential. Aim of the work: To assess renal cortex structural changes due to gentamicin treatment and the role of the aqueous garlic extract (AGE) in ameliorating these changes. Material and methods: Thirty-two male albino rats were assigned into four equal groups. Group I (Control group) received 0.9% NaCl solution through oral gavage in the same volume as in AGE-treated group. Group II (AGE treated group) received AGE by oral gavage at 250 mg/kg/day. Group III (Gentamicin treated group) received Gentamicin at 80 mg/kg/day intraperitoneally. Group IV (Gentamicin and AGE cotreated group) received both gentamicin and AGE. The duration of the treatment was 21 days. Specimens of renal cortex of all groups were processed for light microscopic examination. Specimens were additionally prepared for electron microscopic examination. Morphometric study and statistical analysis were performed. Results: Examination of the renal cortex in the gentamicin treated rats showed both proximal and distal tubular necrosis, vacuolation, desquamation and interstitial mononuclear cell infiltration. Masson’s trichrome staining revealed intense deposition of collagen fibers. Strong positive immunoreaction for caspase-3 was observed. Ultrastructurally, the glomerulus showed thickened basement membrane, destructed endothelium. Proximal and distal convoluted tubular cells exhibited vacuolations, distorted mitochondria and nuclear chromatin condensation with loss of microvilli. AGE ameliorated these changes. Conclusion: Aqueous garlic extract ameliorates the histological changes caused by gentamicin in the rat renal cortex.