The Protective Effects Of Atorvastatin On The Liver Injury Induced By Doxorubicin In Rats And Its Underlying Mechanism

Objective: Doxorubicin(Dox)is a commonly used anti-cancer drug in clinical practice and widely used in the treatment of various malignant tumors and hematological diseases.However,there are many adverse reactions including cardiotoxicity,hepatorenal damage and lipid metabolism disorders.Atorvastatin(Ato)is an HMG-CoA reductase inhibitor and is the most used hypolipidemic agent in clinics.In recent years,studies have found that statin drugs not only have obvious lipid-regulating effects,but also have the “practicality” feature of improving endothelial function,reducing inflammation,anti-oxidation and anti-platelet aggregation.However,there is no evidence that Ato has protective effects against the liver injury caused by Dox.Therefore,the purpose of this study was to establish an animal model of hepatic injury induced by Dox and to investigate the protective effects of Ato and its possible molecular mechanisms in vivo.Method: SD rats were randomly divided into four groups: control group(Con),doxorubicin group(Dox),doxorubicin+atorvastatin low-dose group 2 mg/kg(Dox+Ato low),doxorubicin+atorvastatin high-dose group6 mg/kg(Dox+Ato high).Except for the control group with normal saline,the model group was performed with the Dox injected(i.p.)at a single dose of 10 mg/kg.Then,Ato was administered intragastrically in Ato treatment groups once a day for two weeks,while the control group and Dox group were given equal volume of solvent.At the end of each week(at 8 d and 15 d after modeling),blood was collected from the medial canthus vein of each mouse to determine various biochemical indicators(ALT,AST,ALB,TP,TG,and NEFA)in the serum.At 15 d,After theanimals were euthanized by deep anesthesia,the liver and fat tissues were harvested and weighed for calculating organ coefficient.The hormone-sensitive lipase(HSL)and fatty triglyceride lipase(ATGL)activities in adipose tissue were assayed by Elisa methods.Some liver tissues were used for histopathology examination,ROS expression was determined with immunofluorescence technique,and some liver homogenates were used to measure GSH activity and MDA content.Protein expressions of Mn-SOD,NF-?B,IL-1?,FABP4,FABP3,FABP1,CPT-1,BAX,and BCL-2 were assayed by Western Blot technique.Results:1.There was no abnormality observed in food intake,body weight,and general activity in Con group within 2 weeks.Compared with the Con group,animals in Dox group showed decreased food intake and body weight(P < 0.05 or 0.01),listlessness,piloerection,and red discharge around the eyes.The animals in Ato groups(both low and high dosages)were generally better than those in Dox group,but body weight of the animal had no obvious improvement.2.Serum biochemical results showed that,in the end of first week,compared with that in Con group,the levels of ALT,AST,TG,and NEFA were all increased,and TP and ALB were decreased(P < 0.05 or 0.01)in Dox group;compared with that in Dox group,Ato 2mg/kg reduced the TG,ALT,and NEFA levels(P < 0.05 or 0.01)and had no significant effects on AST,TP,and ALB levels;In Ato 6mg/kg group,the levels of ALT,AST,TG,and NEFA in serum were decreased(P < 0.05),while the levels of TP and ALB had no obvious changes.In the second week,compared with those in Con group,the levels of ALT,AST,TG,and NEFA were all increased in Dox group(P < 0.01),and the levels of TP and ALB were decreased(P < 0.05 or 0.01).Compared with Dox group,Ato 2mg/kg group reduced serum NEFA,ALT and AST levels(P < 0.05 or 0.01),and the levels of TP,ALB,and TG had no significant changes;Ato 6mg/kg reduced serum ALT,AST,TG,and NEFA levels(P < 0.05 or0.01),and increased TP and ALB levels(P < 0.05).3.Gross and pathological examination of the liver: there was no obvious abnormality observed in the liver in Con group;while in Dox group,the liver tissue was light in appearance,tough,and blunt in the edges.Addionally,the hepatic tissue in Dox group showed a large number of inflammatory cell infiltration,hepatocyte edema,and vacuolar degeneration.Occasionally,necrosis was observed.Ato reversed the hepatic patholoical changes caused by Dox.It was shown that the color returned to normal in some animals in the high-dose group.Besides,Ato alleviated inflammatory cell infiltration and interstitial edema caused by Dox in varying degrees.4.The results of liver homogenate showed that,compared with Con group,doxorubicin decreased the GPX levels and increased the MDA levels(P < 0.05).Both Ato 2mg/kg and 6mg/kg reserved the changes of GPX and MDA caused by Dox(P < 0.05).Compared with Con group,the expression of ROS in the liver was significantly increased in Dox group.Whereas,in Ato treatment group,the ROS expression was relatively less than that of the Dox group.Western Blot results showed that,compared with Con group,the expression of Mn-SOD protein in the liver of Dox group was significantly decreased(P < 0.01).The expression of Mn-SOD in Ato low dose group was higher than that in Dox group,but there was no significant difference.The expression of Mn-SOD in Ato high dose group was significantly higher than that of Dox group(P <0.01).5.Results of adipose tissue homogenate showed that the activities of HSL and ATGL in Dox group were significantly higher than those in Con group(P < 0.01).while,both Ato 2mg/kg and 6mg/kg decreased the activities of HSL and ATGL(P < 0.05 or 0.01).6.Detection of liver tissue inflammation and apoptosis: Western Blot results showed that,compared with Con group,the content of NFNF-?B,IL-1? were increased(P < 0.01),and BAX/BCL-2 ratio increased(P < 0.05).Compared with Dox group,the content of NF-?B,IL-1?protein decreased significantly(P < 0.05)in Ato low dose group,while the ratio of il-1 and BAX/ bcl-2 decreased,but no statistical significance was observed.Compared with Dox group,the expression of NF-?B,IL-1? and the ratio of BAX/BCL-2 was significantly decreased in Ato high dose group(P < 0.05).7.Liver tissue fatty acid transport and metabolism enzyme protein expression showed that: compared with Con group,the content of FABP1,FABP4 protein in Dox group were increased significantly(P < 0.05 or0.01),CPT1 and FABP3 protein were significantly decreased(P < 0.05 or0.01);The content of FABP3 protein in Ato low dose group were significantly higher than that in Dox group;in Ato high dose group,the protein levels of CPT1 and FABP3 were significantly increased and FABP1,FABP4 were decreased,Compared with Dox group(P < 0.05).Conclusion:1.Dox can cause chronic liver injury and atrophy of adipose tissue in rats.The liver injury effect of Dox is associated with increased hepatic oxidative stress,inflammation,and apoptosis.The atrophy of adipose tissue is associated with its ability to promote lipolysis of adipose tissue.2.Ato has protective effects on liver injury induced by Dox,and this effect is related to its reduction of oxidative stress,inflammation,and apoptosis.