Ameliorative effect of aqueous avocado seed extract against chromium‐induced oxidative stress and cellular damage in rabbit kidney

Abstract

The accumulation of chromium in renal tissues promotes the generation of reactive oxygen species (ROS), leading to oxidative stress, genomic and cellular harm, and ultimately necrotic and apoptotic cell death induced by free radicals. Hence, the utilization of antioxidant phytochemicals becomes crucial for cellular defense against oxidative damage. This study endeavors to explore the potential protective effects of an aqueous avocado seed extract (ASE) on rabbit kidneys exposed to chromium-induced damage. Fifteen adult rabbits were distributed into three groups: Group 1 was kept as the control. The second and third groups received a daily dose of K₂Cr₂O₇ (5 mg/kg) intraperitoneally for 2 weeks. While the third group was given an oral dose of ASE (400 mg/kg). In rabbits administered with Cr (VI), kidney homogenates showed a marked increase in Malondialdehyde (MDA) (69.3 ± 4.1 nmol/g) along with a decrease in glutathione (59 ± 5.8 nmol/mg) content and the activity superoxide dismutase (SOD) (0.5 ± 0.05 U/mg protein), glutathione peroxidase (GPx) (16.7 ± 1.1 μmol/mg protein), and catalase (CAT) (73.8 ± 3.9 U/g protein) compared to the levels in control group. Also, the gene expression data for the enzymes SOD, GPx, and CAT dropped dramatically in kidney tissue following Cr (VI) injection. Additionally, Bowman's capsule and glomerulus showed degenerative alterations in the kidney's histopathology and immunohistochemistry. ASE treatment when administered along with Cr (VI) enhanced the activity and gene expression of antioxidant enzymes and improved histopathological conditions. The findings of this study unequivocally show that avocado seed extract, which is rich in phenolic derivatives, is a potent nephroprotective agent that inhibits nephrotoxicity induced by Cr (VI) in rabbits.