Some Biochemical and Histological Changes during Cadmium‐Induced Toxicity in Rats and the Protective Intervention of Phyllanthus nivosus Leaf Extract

Abstract

Human exposure to environmental carcinogens like Cadmium (Cd) is one of the major causes of cancer. Acute or chronic exposure induces severe toxicity in various organs, majorly through the induction of oxidative stress. Medicinal plants are sources of exogenous antioxidants which could offer protection against carcinogen-induced toxicity. The protective effect of aqueous extract of Phyllanthus nivosus leaf during cadmium-induced toxicity in rats was therefore investigated. Phytochemical composition and free radical scavenging ability of the extract were also determined. Four groups of four rats each, of an average weight of 148.02 ± 7.02g were given oral administration of 8 mg/kg of cadmium daily for seven days. The first group of Cd-exposed rats were only given 0.1 ml of distilled water while the next two groups were treated with aqueous extract of Phyllanthus nivosus at 200 and 400 mg/kg. The fourth group received 100 mg/kg of ascorbic acid. A fifth group of rats, which were not exposed to Cd received 0.1 ml distilled only. Blood samples obtained through the Jugular vein, as well as, liver and kidney samples were used for biochemical and histological examinations. Phytochemical screening revealed the presence of alkaloids, cardiac glycosides, phenols, carbohydrate, resins, balsam, saponins, tannins, flavonoids, terpenes and steroids. Quantitative phytochemical analysis showed 4.80%w/w alkaloids, 3.67%w/w phenols, 8.72%w/w tannins, 7.92%w/w flavonoids and 6.82%w/w saponins. The extract was found to display DPPH-radical scavenging activity with an IC50 value of 56.4 μg/ml as compared with 51.9 μg/ml for ascorbic acid. There was a significant reduction (P<0.05) in the activities of superoxide dismutase, catalase and levels of reduced glutathione in the liver of Cd-exposed rats. Lipid peroxidation was also increased as revealed by a significant increase in MDA concentration. Significant alterations were observed in the serum levels of liver function indices (Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and albumin). No significant change was observed in the biochemical parameters of kidney function. Nevertheless, histopathological examinations showed obvious liver and kidney injury characterized by inflamed hepatocytes around the central veins and tubular necrosis respectively. Significant improvements of these parameters were however observed in rats treated with 400mg/kg body weight of Phyllanthus nivosus leaf extract. Liver of unexposed and untreated rats showing normal hepatocytes interspersed by sinusoids (red arrows). A central vein (white star) is seen with red blood cells. Black arrows= cytoplasm, white arrows= nuclei. H&E. ×400. kidney of unexposed and untreated rat showing normal tissue architecture. The glomerular capsule (white arrows) is intact. White stars= glomerulus, black arrows= nuclei. H&E. ×400. Liver of Cd-exposed and untreated rat. Pockets of inflammatory cells (black arrows) seen amongst normal hepatocytes (white arrows). White star=Central vein containing red blood cells. H&E. ×400. Kidney of Cd-exposed and untreated rat showing severe inflammation as presented by inflammatory cells (white arrows). Black arrows= normal kidney cells. H&E. ×400 Liver of Cd-exposed rat, treated with 400mg/Kg body weight. Mild hemorrhage is observed as presented by the presence of red blood cells (black arrows) in the interstitial spaces. Cellular architecture and nuclear presentation are normal. H&E. ×100. Kidney (medulla) of Cd-exposed rat treated with 400mg/Kg body weight showing normal tissue morphology. Black arrows= collecting ducts, white arrows= nuclei of cells. H&E ×100. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.