Hepatoprotective and Antioxidant Activity of Dunaliella salina in Paracetamol-induced Acute Toxicity in Rats

Abstract

Paracetamol has a reasonable safety profile when taken in therapeutic doses. However, it could induce hepatotoxicity and even more severe fatal acute hepatic damage when taken in an overdose. The green alga, Dunaliella salina was investigated for hepatoprotective and antioxidant activity against paracetamol-induced liver damage in rats. Male albino Wistar rats overdosed with paracetamol showed liver damage and oxidative stress as indicated by significantly (P<0.05) increased serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total and direct bilirubin, malondialdehyde, cholesterol and nitric oxide. At the same time, there were decreased activities of serum superoxide dismutase and total antioxidant capacity compared with the control group. Treatment with D. salina methanol extract at doses of 500 and 1000 mg/kg body weight or silymarin could significantly (P<0.05) decrease the liver damage marker enzymes, total and direct bilirubin, malondialdehyde, cholesterol and nitric oxide levels and increase the activities of superoxide dismutase and total antioxidant capacity in serum when compared with paracetamol intoxicated group. Liver histopathology also showed that D. salina reduced the centrilobular necrosis, congestion and inflammatory cell infiltration evoked by paracetamol overdose. These results suggest that D. salina exhibits a potent hepatoprotective effect on paracetamol-induced liver damage in rats, which may be due to both the increase of antioxidant enzymes activity and inhibition of lipid peroxidation.

Keywords: Dunaliella salina; antioxidant; hepatotoxicity; paracetamol; reactive oxygen species.

Fig. 2

Effect of D. salina on the liver histopathological photomicrographs of the experimental groups of rats. Histopathological photomicrographs (×400) of livers of various groups stained with haematoxylin and eosin. (a) Normal architecture of rat liver, (b) Necrosis and hepatocellular fatty degeneration (eccentric nuclei) in acetaminophen intoxicated liver and congestion of portal vein and peri-portal infiltration of inflammatory cells, (c) Lesser damage of hepatocytes and low index of necrosis (centrally located nuclei) in D. salina-500 mg/kg pretreated group, (d) Minimal damage of hepatocytes and very low index of necrosis in D. salina-1000 mg/kg pretreated group and mild congestion, (e) Very lesser damage of hepatocytes and low index of necrosis in silymarin pretreated group, narrow arrows refer to inflammatory cells infiltration, wide arrows refer to congestion of portal vein.