Effect Of Fenofibrate On Liver Injury With Bile Duct Ligation

ObjectiveBile duct ligation (BDL) leads to complete biliary obstruction and obstructive jaundice (OJ), causing complete blockage of cholesterol excretion and then hyperlipidemia develops. Fibrates are usually used for the treatment of dyslipidemia, which moderate high level of triglyceride (TG) and cholesterol significantly. Therefore, we infer that fenofibrate may play a good role in liver injury with obstructive jaundice. In order to further observe whether fenofibrate would do good to liver injury with OJ, which may apply to clinical treatment, this study investigated the influence of fenofibrate on serum liver function, cytokine, hepatocyte apoptosis, hepatic glycogen and collagen fiber by administration of fenofibrate at different dosage in rats with BDL.Methods1. The establishment of OJ model of ratsThe model of OJ in rats was established with BDL. Male Wistar rats were divided into 4 groups randomly (12 in each group):blank control group (A), OJ model group (B), low dose of fenofibrate group (C), high dose of fenofibrate group (D). All the groups except group A were treated with BDL. Operative procedures: Following a midline incision, the common bile duct was exposed and then ligated with 5-0 silk, abdominal incision was closed in the end. Rats in group C were given fenofibrate (30mg/kg per day) by gavage, when rats in group D were treated with fenofibrate (60mg/kg per day).2. Determination of various biochemical indicatorsAfter ripping with ether inhalation anesthesia, the blood of abdominal aorta was drawed. Serum ALT, AST, ALP, GGT, TBA levels were detected with automatic biochemistry analyzer; tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) levels were detected by Radioimmunoassay Kits.3. Determination of hepatocyte apoptosis, hepatic glycogen and collagen fiber Liver tissues were obtained after rats in each group were sacrificed to make the paraffin section. Hepatocellular apoptosis was evaluated by TUNEL; hepatic glycogen was tested by PAS; collagen fiber was tested by Masson.Results1.The general state of ratsIn the first 24 hours with BDL, the rats in group B presented the symptoms of OJ, including white feces, yellow urine, listlessness, slow response, poor diet, etal. The development of OJ symptoms in rats given fenofibrate at different doses in group C and group D delayed. Body weight changes in each group were as follows: the body weights of rats in group A after the experiment were significantly higher than before (P<0.01), while the body weights in group B after the experiment were much lower than before (P<0.01). However, there was no significant difference in terms of the body weights between after and before the experiment in Group C or D (P>0.01).2. The analysis of biochemical indexes in serum of rats2.1 Comparison of biochemical indexes between OJ rats and normal ratsAfter seven days with BDL, the biochemical indexes in serum of groups B, C and D compared with group A, it was found that the activities of ALT, AST, ALP, GGT were obviously higher than they were in group A (P<0.01). The levels of TBA, TNF-αwere significantly higher than they were in group A (P<0.01). Yet, the content of IL-1βin group B or C was significantly higher than that was in group A (P<0.01), when there was no difference between group D and group A(P>0.01).2.2 Comparison of biochemical indexes in serum of rats in each group after fenofibrate treatmentAfter drug treatment, the levels of ALT, AST, ALP, GGT, TBA, IL-1β, TNF-αin group D were significantly lower than they were in group B or group C (P<0.01) except the levels of ALT, TNF-αin group C (P>0.01). Given a low dose, the level of IL-1βwas lower than that was in group B (P<0.01), while the difference of the level of ALT, AST, ALP, GGT, TBA, TNF-αwas no remarkable (P>0.01). 3. Determination of hepatocyte apoptosis, hepatic glycogen and collagen fiber3.1 Comparison of the number of hepatocyte apoptosis in each groupAfter TUNEL staining, positive cells were violet blue. The number of hepatocyte apoptosis in group B was higher than that was in group A, C and D, with poor arranged hepatocytes. The number of hepatocyte apoptosis in group C was lower than that was in group B when hepatocytes was poor arranged but good shaped. The number of hepatocyte apoptosis in rats of group D was considerably lower than that was in rats of group B and C, and the general conditions above were also much better than they were in group B and C. Of course, the conditions of group A, which was normal group, was the best of all.Quantitative analysis results:after the common bile duct was ligated, the number of hepatocyte apoptosis in rats of group B, C and D was significantly higher than that was in rats of group A (P<0.01). After given fenofibrate at a different dose, the number of hepatocyte apoptosis in rats of group C or group D was considerably lower than that was in rats of group B (P<0.01), and the number of hepatocyte apoptosis in group D was markedly lower than that was in group C (P<0.01).3.2 Comparison of the number of hepatic glycogen granule in each groupAfter PAS staining, hepatic glycogen granule was shiny red. In group A, hepatocyte structures were intact and well arranged, with no big fissures, and PAS staining is strengthened all over in both intercellular and intracellular. However, there was a reduction of glycogen granule in group B, which had poor relativehomogeneity, with nearly intact hepatocyte structures, notably increased mesenchymes and big fissures in portal area. After drug treatment, the general conditions of group C was better than group B, and the conditions of group D was better than group C.Quantitative analysis results:after BDL, the number of hepatic glycogen granule in rats of group B, C and D was considerably lower than that was in rats of group A (P<0.01). After given a different dose, the number of hepatic glycogen granule in rats of group C or group D was markedly higher than that was in rats of group B (P<0.01), and the number of hepatic glycogen granule in group D was significantly higher than that was in rats of group C (P<0.01).3.3 Comparison of the area of collagen fiber in each groupThe positive reaction of collagen fiber was stained blue by Masson. A little collagen fiber was appropriately arranged only around central veins or small bile ducts in group A. However, collagen fiber increased markedly, and disrupted mainly around proliferative small bile ducts in group B. Compared with group B, the collagen fiber decreased and was arranged regularly around proliferative small bile ducts in group C. The collagen fiber in group D, which was distributed regularly among proliferative bile ducts, was significantly less than that was in group B and C.Quantitative analysis results:after BDL, the area of collagen fiber in rats of group B, C and D was significantly higher than that was in group A (P<0.01). After given a different dose, the area of collagen fiber in rats of group C or group D was considerably lower than that was in group B (P<0.01), and the area of collagen fiber in group D was significantly lower than that was in group C (P<0.01).ConclusionsThis study discussed the effect of fenofibrate on liver injury in OJ from histology and biochemistry points at animal experiments, and revealed that given short-term fenofibrate would markedly alleviate liver damage with a certain dose dependent effect in OJ by suppressing inflammatory response, inhabiting hepatocyte apoptosis and performing anti-hepatic fibrosis effect, etal.