[Oil of Piper longum unsaponifiable matter prevents cholesterol gallstone formation].

To observe the effect of various doses of oil of Piper longum unsaponifiable matter (OPUM) to cholesterol gallstones in experimental mice. C57BL/6 mice (n = 60) were randomly divided into 6 groups: control group, model group, OPUM (15, 30 and 60 mg x kg(-1)) group and ursodeoxycholic acid (UDCA, 60 mg x kg(-1)) group, administered for 10 weeks. The level of serum lipid and liver function enzymes were tested. The gallbladder was removed and bile was obtained by centrifugation. Next, the levels of the bile total cholesterol (TC), phospholipid (PL) and bile acid (TBA) were measured. The indicators of lipid peroxidation were determined and cholesterol saturation index (CSI) was calculated. The liver histological changes were observed by HE staining. The results showed that serum TC, TG (triglycerides) and AST (aspartate transaminase) contents, gallbladder cholesterol crystallization and CSI increased significantly (P < 0.05). In addition, the activity of SOD decreased significantly and MDA content increased significantly in liver (P < 0.05). HE staining results showed that the hepatic cord disorder and intracellular lipid droplets increased significantly. All results indicate that lithogenic diet lead to the formation of cholesterol gallstones. In OPUM (30 and 60 mg x kg(-1)) group, serum TC, TG and AST content, gallbladder cholesterol crystallization and CSI decreased significantly, the activity of SOD increased significantly and MDA content decreased significantly. HE staining results showed that OPUM can improve the morphology of liver cell, reduce the degree of hepatic cord disorders and restore the cell morphology close to normal. The cause of OPUM prevents cholesterol gallstone formation maybe due to protect the integrity of the liver cells, lower CSI, and reduce cholesterol crystal formation and hence prevent cholesterol gallstone formation.