Evaluation of the protective effects of quercetin in biliary cirrhotic rats

Biliary cirrhosis is a chronic disease marked by the progressive destruct-tion of liver. There is no known cure for this disease; however، medications may slow its progression. The present study was designed to investigate the effect of quercetin as a plant derived flavonoid on the hepatic injury reduction of biliary cirrhotic rats.

Thirty male Sprague-Dawley rats aged 6-7 months were randomized into three groups of ten each. One group served as control (sham operated)، while the other two groups underwent a complete bile-duct ligation (BDL). Four weeks after the opera-tion، serum bilirubin، alkaline phosphatase (ALP)، alanine amino-transferase (ALT)، and aspartate amino-transferase (AST) were measured in two BDL groups to confirm the occurrence of cirrhosis. Then one of the BDL groups received placebo and the other one injected intraperitoneally with 50mg/kg of quercetin once a day for a period of four weeks. At the end of the study، hepatic enzymes and serum bilirubin were measured again. Liver species were tested for histological characteristics.

Quercetin could decrease serum level of bilirubin (7. 4±0. 9 vs. 8. 9±1. 6 mg/dL; P<0. 05)، ALP (1387±76. 9 vs. 2273±65. 3 IU/L; P<0. 001) and ALT (601. 9±38. 1 vs. 644. 8±37. 4 IU/L; P<0. 05) compared to cirrhotic group. AST was higher in cirrhotic groups compared to control both in the 4th and 8th week. However، the difference between BDL and BDL+Q groups was not statistically significant. Quercetin decreased ALT/AST ratio، as an indicator of liver damage. No significant histological changes were observed in quercetin group.

These data suggest that although quercetin did not change histological characteristics of liver، it could significantly decrease bilirubin، alkaline phosphatase and alanine amino-transferase، indicating less liver injury.