Hepatoprotective potentials of the methanolic leaf extract of Jatropha curcas (LINN) on cadmium induced toxicity in rabbit

Abstract

This study was carried out to investigate the possible hepatoprotective potentials of methanolic leaf extract of Jatropha curcas Linn on cadmium induced hepatotoxicity and oxidative stress in rabbits. Sixteen matured rabbits were used for the study; they were divided into four groups and treated as follows: Group I (control) was treated with normal saline (0.85% w/v NaCl) at 2 ml/kg body weight per day. Group II were treated with only cadmium chloride at 1.25 mg/kg body weight per day. Groups III and IV were pre-treated with 300 mg/kg body weight per day of Jatropha curcas extract and vitamin E respectively, one hour later, cadmium chloride was administered to them at 1.25 mg/kg body weight. All the animals were treated orally for 10 days. The animals were sacrificed on day 11, blood, liver and kidneys were removed and preserved for biochemical analyses. The liver samples were digested with mixture of concentrated trioxonitrate (V) acid (HNO3) and hydrochloric acid (HCl) (1:4 v/v). Cadmium concentrations in the liver were determined by atomic absorption spectroscopy (AAS). The concentrations of total plasma protein, albumin, uric acid and the activities of hepatic marker enzymes; alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma glutamyltransferase (GGT) were determined in the plasma and liver homogenates by standard procedures. The result of phytochemical screening revealed that flavonoids, tannins, terpenoids steroids, phlobatanins and saponins were present in the extract. The analysis by atomic absorption spectroscopy of the liver revealed that there were traces of cadmium (0.01 μg/g) in the liver of animals pre-treated with vitamin E and Jatropha curcas extract while the concentration of cadmium in the liver of only cadmium group was 0.14 µg/g. Additionally, the activities of hepatic marker enzymes (AST, ALT, GGT) were elevated in cadmium only treated group but pretreatment with methanolic extract of Jatropha curcas reduced significantly (p<0.05) the activities of these enzymes. The total protein and uric acid concentrations were also significantly reduced in cadmium treated group when compared with the extract pre-treated group. Comparison of the activities of hepatic marker enzymes (ALT, AST and GGT) in vitamin E and Jatropha curcas extract pre-treated groups revealed that ALT, AST and GGT activities were not significantly different in these groups. Also, albumin and uric acid concentrations were not significantly different between the groups. The results of biochemical studies of blood samples and liver homogenates revealed significant increase in the levels of maker enzymes reflecting liver injury caused by cadmium while pre-treatment with Jatropha curcas extract reduced the activities of the enzymes. Oral administration of methanolic extract of Jatropha curcas at 300 mg/kg body weight in this study was able to reduce the hepatotoxic effects of cadmium toxicity at 1.25 mg/kg body weight. This suggests that methanolic leaf extract of Jatropha curcas might possess hepatoprotective effect. The results of this investigation has further confirmed the inherent therapeutic properties of Jatropha curcas and also justified its uses in traditional medicine to cure various ailments in