Hepatoprotective effect of Aegle marmelos (Indian bael) and Azadirachta indica(Neem) aqueous leaf extract on paracetamol induced toxicity in rats

Abstract

The present study was undertaken to assess the hepatoprotective effect of aqueous extract of leaves of Azadirachta indica at the rate of 500 mg / kg and Aegle marmelos at the rate of 1 g/kg on paracetamol induced hepatotoxicity in rats. The study was conducted using thirty two adult albino rats weighting 150-200g. The rats were divided into four groups of eight each. Animals of Group1 served as absolute control, which received 0.2 per cent gum acacia oral suspension in distilled water for 12 days. Group II animals received paracetamol (3g/kg) suspension prepared with gum acacia in distilled water for three days orally. Group III animals received A. indica aqueous leaf extract (500mg/kg) orally for 12 days and paracetamol (3g/kg) suspension on day eight, nine and ten. Group IV animals received A. marmelos aqueous leaf extract (1g/kg) orally for 12 days and paracetamol (3g/kg) suspension on day eight, nine and ten. Blood was collected from all groups before and after treatment for haematological and biochemical examination and liver was taken for biochemical and histopathological examination. The feed intake of paracetamol treated rats was reduced compared to animals group I. In A. indica and A. marmelos treated rats the feed intake was normal upto seven days and feed intake reduced after paracetamol treatment. The animals of group I showed a gradual increase in body weight. The paracetamol treated group showed reduction weight. The body weight of Group III and group IV were decreased during the experiment, being less pronounced than the paracetamol treated rats. The lipid peroxide levels were higher in paracetamol treated animals compared to the control and plant extract treated groups. A. indica at the rate of 500 mg/kg and A. marmelos at the rate of 1g/kg reduced the elevated lipid peroxide levels. The level of superoxide dismutase and catalase were lowest in the paracetamol (3g/kg) treated rats. There was increase in the activity of superoxide dismutase and catalase in the treatment groups. Serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activity were higher in the paracetamol treated group compared to the control group. There was significant reduction in levels of these enzymes in group III and group IV compared to group II. Total protein and albumin levels were lowest in the case of animals treated with paracetamol compared to the other groups. The lowered total protein and albumin levels in group II animals were significantly elevated in group III and IV animals treated with aqueous extract of A. indica and A. marmelos. The study of haematological parameters of all the groups revealed no significant changes. Gross examination of liver from control group showed normal appearance and liver of paracetamol treated animals showed greyish white areas of necrosis. Livers of A. indica and A. marmelos pretreated rats were almost normal in appearance. Histopathological examination of control group revealed normal hepatic architecture. Liver of paracetamol treated group revealed centrilobular coagulative necrosis. The liver of A. indica and A. marmelos treated rats showed normal hepatic cords, absence of necrosis, mild congestion and less degree of infiltration. The results of the present study confirmed the strong hepatoprotective activity of A. indica and A. marmelos aqueous leaf extract in paracetamol induced hepatotoxicity in rats.