The Effects Of Lycopene On Nonalcoholic Fatty Liver In Rats

Objective: To explore the protective effects and the possiblemechanism of lycopene on CCl4-induced acute hepatic injury in rats. Toexplore the effects and possible mechanism of lycopene on nonalcoholicfatty liver in rats. Methods: Experiment one: Protective effects of lycopene on CCl4-induced acutehepatic injury in rats. Acute hepatic injury model was induced by CCl4. Serum activities ofaspartate aminotransferase (AST) and alanine aminotransferase (ALT), thelevel of liver index, the activities of superoxide dismutase (SOD) and thecontents of malondialdehyde (MDA) in serum and liver tissue weremeasured,hepatic pathological changes were also observed before andafter giving low-dose (10 mg·kg-1 body weight) or high-dose (20 mg·kg-1body weight) of lycopene. Experiment two: The effects of lycopene on nonalcoholic fatty liver inrats. 60 Wistar rats were divided into normal control chow group (n=12)and high-fat chow group (n=48) randomly according of body weight. Thehigh-fat chow consists of normal chow 88%, lard 10% and cholesterol 2%.2 rats of normal control group and 8 rats of high-fat chow group werekilled after giving high-fat chow 8 weeks to detect the levels ofcholesterol(CH) and triglyceride(TG) in serum and observe their hepaticpathological changes. After the fatty liver model was established, thetherapeutical experiment was executed, the rats with fatty liver wererandomly divided into 4 groups, i.e. (1) model control group fed withhigh-fat chow, (2) natural recovery group fed with normal chow, (3)low-dose lycopene-treated group fed with lycopene(10mg·kg-1 bodyweight)and normal chow, (4) high-dose lycopene-treated group fed withlycopene(20 mg·kg-1 body weight)and normal chow. All rats were killedin 4 weeks. The following parameters were detected in all groups: thelevels of body weight and liver index, the activities of aspartateaminotransferase (AST) and alanine aminotransferase (ALT) in serum; theactivities of superoxide dismutase (SOD), the contents of malondialdehyde(MDA), the levels of CH, TG, free fatty acid(FFA), low-density lipoproteincholesterol(LDL-C) and high-density lipoprotein cholesterol(HDL-C), theactivities of lipoprotein lipase(LPL), hepatic lipase (HL) andcholinesterase(CHE) in serum and liver tissues; the changes of histology,and the expression of tumor necrosis factor-α(TNF-α) and cytochromeP4502E1 (CYP2E1) in liver tissue. Results: Experiment one: Compared with CCl4-induced acute hepatic injury ofrats model group :(1) Lycopene decreased the serum activities of AST,ALT(P <0.05 or P <0.01); (2) Lycopene reduced the liver index (P <0.05); (3)Lycopene diminished significantly MDA contents (P <0.05) and increasedthe activities of SOD (P <0.05) in serum and liver tissue; (4) Degenerationand necrosis of liver tissues were abated and pathological changes wererelieved. Experiment two: Compared with the natural recovery group, thechanges of low-dose or high-dose of lycopene-treated groups are asfollows: (1) The levels of body weight and liver index were obviouslyreduced(P <0.05 or P <0.01); (2) The activities of AST and ALT in serumwere decreased (P <0.05 or P <0.01); (3) The serum and liver tissueactivities of SOD were raised (P <0.05 or P <0.01), however the contentsof MDA were diminished (P <0.05 or P <0.01); (4) The serum and livertissue levels of TG, CH, LDL-C and FFA were decreased (P <0.05); but thelevels of HDL-C were increased (P <0.05); (5) The serum and liver tissueactivities of LPL and HL were raised (P <0.05 or P <0.01); but theactivities of CHE were diminished (P <0.05 or P <0.01); (6) Theexpression of TNF-α and CYP2E1 was reduced (P <0.05 ) in liver; (7)The degree of fat deposition can be alleviated and histological changeswere improved significantly. Conclusion: Lycopene has protective effects on CCl4-induced acutehepatic injury in rats. The degeneration degree of nonalcoholic fatty livercan be alleviated by lycopene. The mechanisms possibly contribute to itsaction of antioxidation and plasma lipoprotein modulation, also associatedwith its effect of inhibiting the e...