Objective: 

Coumarins are a vast group of natural compounds and some of them possess anti-oxidant activities. The comparison of the antioxidant activity of some coumarins with various chemical molecular structures has not been investigated in previous studies. Therefore this study was aimed to investigate the hepatoprotective effect against CCl4 (carbon tetrachloride) -induced hepatic injury by coumarin (1,2-benzopyrone) and coumarin derivatives, esculetin (6,7-dihydroxycoumarin), scoparone (6,7-dimethoxycoumarin) and 4-methylumbelliferone (7-hyroxy-4-methyl) in male Sprague-Dawley rats.

Methods: 

Product of lipid peroxidation, malondialdehyde (MDA), and activities of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT) were evaluated for oxidative stress in hepatic injury. Gamma glutamyl transpeptidase (GGT), and lactate dehydrogenase (LDH) were detected in plasma as biomarkers of hepatic injury.

Results: 

Significantly elevated levels of MDA and lowered levels of SOD and CAT activities were observed in livers of rats exposed to CCl4, when compared to control values. Similarly, administration of CCl4 increased LDH and GGT levels in serum. Pre-treatment of rats with esculetin (35 mg kg-1, orally) and scoparone (35 mg kg-1, orally) significantly prevented CCl4-induced increases in MDA level and decreases in SOD and CAT activities, whereas 4-methylumbelliferone (35 mg kg-1) and coumarin (30 mg kg-1) had no effect against CCl4-induced rise in serum enzymes.

Conclusions: 

Esculetin and scoparone also showed protective properties as was evidenced in reduced LDH and GGT levels in serum. The results of this study indicate that the chemical structures of coumarins play an important role in the prevention of oxidative stress.