Influence of ferulic acid consumption in ameliorating the cadmium-induced liver and renal oxidative damage in rats

Abstract

The aim of this study relates to the modulatory role of ferulic acid (FA) against cadmium (Cd)-induced oxidative stress in the liver and kidney of male Wistar albino rats. Cd is an extremely toxic industrial and environmental pollutant and is well known for its varied toxic clinical manifestations. FA is a derivative of curcumin and a ubiquitous phenolic compound having a wide range of therapeutic activities. In the current study, Cd (10 mg/kg) was administered subcutaneously for 15 and 30 days to induce hepato-renal toxicity. Cd concentration was found to be significantly high in Cd-intoxicated rats (liver > kidney) while the supplementation of FA (50 mg/kg) significantly reduces the Cd concentration in liver and kidney tissues. Reduced body and organ weights and food and water consumption and increased rectal temperature were noticed in Cd-treated rats while these parameters were significantly ameliorated in FA-supplemented rats. Liver and kidney damage induced by Cd was significantly revealed by the reduction in serum total protein contents (TPC) and increased activities of serum nitric oxide (NO) levels and hepato-nephrotoxicity marker enzymes, namely aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactic dehydrogenase (LDH), AST:ALT ratio, uric acid, urea, urea nitrogen, and creatinine, along with the increased levels of hepatic and renal oxidative stress markers, namely lipid peroxidation (MDA levels), lipid hydroperoxides (LOOH), protein carbonyl content (PCC), total oxidant status (TOS), and oxidative stress index (OSI) in liver and kidney tissues. In addition, the toxicity of Cd was also evidenced by a significant decrease in the levels of total thiols (TTH), total antioxidant concentration (TAC), enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)), and non-enzymatic antioxidants (reduced glutathione (GSH) and total free sulfhydryl groups (TSH)). Administration of FA significantly restored the serum total protein levels and activities of serum NO levels and hepatic and renal marker enzymes to normal levels in comparison with Cd-intoxicated rats. Furthermore, FA significantly reduced the oxidative stress markers and recuperated the levels of antioxidant defense in the liver and kidney as evidenced by native PAGE and spectrophotometric assays, correlation and regression analysis and multivariate analysis of variance (MANOVA), and inferring the antioxidant role of FA. Histopathological damage due to Cd intoxication in the liver and kidney is demonstrated as vasodilatation and congestion in central veins and sinusoids as well as around the glomerulus, infiltration of mixed inflammatory cells and peripheral hemorrhage, hemorrhagic and enlarged sinusoids, disorganization of the hepatic parenchyma, focal necrosis, swelling of hepatocytes, calcified tissue inside blood vessels, hepatocyte degeneration and vacuolization of liver cells, hyaline casts, degenerated glomerulus with wide space and detached basement membrane, distal tubule with wide lumen, deformed proximal tubules with detached brush border, and degeneration and hyalinization of glomerular tuft. But, FA significantly reduced the toxicity of Cd and protected the normal histological architecture of the liver and kidney tissues. Cd-intoxicated rats were associated with a significant upregulation of TNF-α, COX-2, and HSP70 proteins, whereas treatment with FA caused downregulation of the above inflammatory markers indicating the anti-inflammatory role of FA. Principal component analysis (PCA) and Euclidean similarity measure studies clearly indicate that the liver is more prone to Cd toxicity than the kidney and FA supplementation significantly prevents oxidative stress, augmenting antioxidative status, and regaining histological parameters of the liver and kidney to normal, indicating hepato-nephroprotective, antiradical, antioxidant, and anti-inflammatory effects of this phenolic compound.

Keywords: Antioxidant status; Cadmium toxicity; Hepato-renal enzyme markers; Histopathology; Inflammatory markers; Oxidative stress markers.