ACETAMINOPHEN-INDUCED LIVER DAMAGE IN ALBINO RATS: EFFECTS OF PARINARI FLAVONOIDS ON SOME BIOCHEMICAL INDICES AND ANTIOXIDANT DEFENCE SYSTEM

Abstract

The present study investigated the hepatoprotective potential of flavonoid-rich fraction (FRE) of Parinari curatellifolia Planch (Chrysobalanceae) in experimental rats with a view to ascertain the validity of folkloric claims of its effectiveness in the treatment of hepatic-related disorders. Flavonoids in flavonoid rich extract from methanolic extract of Parinari curatellifolia were quantitatively identified by subjecting to high performance liquid chromatography- diode array detector (HPLC-DAD) analysis. Adult male albino rats (180-220g) were randomly assigned into nine groups (n=5) and orally administered FRE (10, 20 and 30 mg/kg body weight) or the standard hepatoprotective drugs, Silymarin (25 mg/kg) once daily for 14 consecutive days before liver damage was chemically induced through the administration of acetaminophen (2 g/kg p.o.) on the 14th day. Thereafter, hepatoprotection was assessed by analyzing liver homogenate and serum for markers of hepatotoxicity – alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ- glutamyl transferase (GGT) and lactate dehydrogenase (LDH) activities as well as prothrombin time (PT). Evaluation of biochemical indices of oxidative stress (level of lipid peroxides, activities of superoxide dismutase (SOD) and catalase) along with histological assessment of hepatic tissues were also carried out. Analysis of flavonoid-rich extract revealed the presence (mg/100 g) of kaempeferol (39.17), tricetin (33.13), quercetin (31.41), chrysin (25.57), 3-methyl quercetin (21.86), pinocembrin (20.87) and apigenin (0.14). All doses of FRE significantly (P<0.001) and dose-dependently prevented acetaminophen-induced increase in serum activities of hepatic enzymes (AST, ALT, GGT, LDH) and PT but did not adversely affect the parameter when administered alone. Furthermore, FRE (10 and 20 mg/kg) significantly (P<0.001) reduced lipid peroxidation in liver tissues, restored the activities of the antioxidant enzymes and catalase towards normal levels. Histopathology of the liver showed that PCF mitigated the toxicant-induced hepatocellular necrosis, reduced inflammatory cells infiltration and enhanced hepatocytes regeneration. The results indicated that P. curatellifolia flavonoids demonstrated remarkable hepatoprotective activity in acute liver injury caused by acetaminophen. This effect might have been mediated via the inherent free radical scavenging activity of the constituent flavonoids. The results so far indicate the hepatoprotective potential of the flavonoid rich extract of P. curatelifolia seeds.