Fatty Acid Bile Acid Conjugates Derivatives Anti-gallstone In Vivo

Cholelithiasis is a common disease worldwide. In some developed countries the incidence rate is about 15% or above. The great majority are cholesterol gallstones. The bile contains a lot of insoluble cholesterol which comes from diet,synthesis of the body and secretion of liver. The residence time of bile in the biliary tract is measured in hours. Preavent of cholesterol crystallization during this interval may prevent the formation of gallstones. In normal, bile acid and phospholipids can dissolve biliary cholesterol and prevent cholesterol crystallization. Biliary cholesterol supersaturation has traditionally been considered the major factor determining precipitation of cholesterol crystals and gallstone formation. In some reports, ursodeoxycholic acid (UDCA) can prevent and dissolve the gallstones, but it is long course treatment and recrudescent. So it is time to find a new oral drug to therapy the gallstones.Fatty Acid Bile Acid Conjugates (FABACs) are prepared by conjugation of cholic acid at position 3 with saturated fatty acids of variable chain length using an amide bond. It is absorbed in intestinal tract and secrete into bile by liver. FABACs can prevent cholesterol crystal and resolve cholesterol gallstone. The existing Preparation method of FABACs is changing 3-hydroxy of bile acid (salt) to amino-group, then coupling saturated fatty acids by amide linkage. It irreversibly changes the specificity of bile acid molecular structure,thus affecting its ability of liver targeting and biological activity. Our modified synthetic compounds of FABACs is coupling the 24- carboxy of bile acid and carboxy of fatty acid to an amino acids (aa) .This method keeps fatty acid stability in plasma. Carboxy group of bile acid andα-COOH of aa have the same electronegativity. So it keeps biological activity of bile acid.We chose inbred gallstones-susceptible C57BL/6 male mice as model. After 12 weeks high diet food, most of them were have gallstones and fatty liver. Then the mice were reverted to a regular chow diet. Part served as control, and the others of each group were given the compound for 8 weeks. There are respectively four,eight,six,six,seven,seven mice which have gallstones in each group (EBHU18,EBHC18,EBHU20 EBHC20,3C18 and control). After all the mice sacrificed, We detected the indicators (formation of gallstone,content of gallbladder,analysis of gallstone ingredient and liver pathology). We could ascertain that most composition of gallstone is cholesterol. Compared with the control group, the weight of gallbladder content in EBHU18 group was much improved (P<0.05). The others are meaningless. The fatty liver of EBHU18,EBHU20 groups were significant compared with the control (P<0.05).This study had showed that the gallstone and fatty liver could be treated by oral administration of EBHU18.The bile acid part of new compounds is an effective liver target vector. It can improve the efficacy of the fatty acid by enterohepatic circulation. So EBHU18 can prevent the cholesterol crystal and promote metabolism of fat.In the second study, we used different doses of EBHU18 to prevent/reduce the gallstones and fatty liver. By the same material and methods,EBHU18 treated the mice with different doses. Eight weeks later, all the mice were sacrificed We detected the indicators (formation of gallstone,content of gallbladder,analysis of gallstone ingredient and liver pathology). Most of gallstones were ascertained cholesterol. There are respectively nine,five,four,eight mice which have gallstones in each group (control,low dose group,high dose group,UDCA). The gallstones and fatty liver of high doses group were significant improved (P<0.01).and that of the low dose group were improved (P<0.05). All the datas had statistical significance. In the therapeutic study , after 8 weeks treatment, There are respectively thirteen,ten,eight,twelve mice which have gallstones in each group (control,low dose group,high dose group,UDCA). Compared with the control group, the weight of gallbladder content in two dose groups were improved (P<0.05). Fatty liver of high dose group was significant improved (P<0.01). In low dose group, it is improved (P<0.05). UDCA group is improved too,but statistically meaningless. In conclusion, our study showed that EBHU18 can reduce and prevent diet-induced gallstone and fatty liver.In our studies, EBHU18 is much better than others in the prevent of gallstones and fatty live. No pathological toxicity was observed in all drug-treating groups. The compound may be of potential use in cholesterol gallstone disease in humans.