D-柠檬烯对大鼠酒精性肝损伤脂质代谢紊乱的影响

Effect of D-Limonene on Lipid Metabolism Disorder in Rats with Alcohol-Induced Liver Damage

探讨D-柠檬烯(D-limonene)对大鼠酒精性肝损伤脂质代谢紊乱的保护作用及可能作用机制,利用持续酒精灌胃的方法建立大鼠酒精肝损伤模型,分为A、B、C、D、E、F、G共7组。A组为空白对照组,每日给予蒸馏水灌胃,前2周8 m L/(kg·d),后4周12 m L/(kg·d);B组为酒精模型组,每日灌胃体积分数为50%的乙醇,前2周8 m L/(kg·d),后4周12 m L/(kg·d);C、D、E组分别为D-柠檬烯低、中、高剂量组,每日分别灌胃D-柠檬烯100、200、400 m L/(kg·d),其中D-柠檬烯与A、B组等量的50%的乙醇混合后灌胃;F组为水和D-柠檬烯空白高剂量组,每日给予D-柠檬烯400 m L/(kg·d);G组为甘利欣药物对照组,灌胃量200 m L/(kg·d)。HE染色和电镜观察肝组织形态结构和肝组织超微结构的变化,测定血清谷丙转氨酶(alanine transaminase,ALT)、谷草转氨酶(aspartate transaminase,AST)、碱性磷酸酶(phosoporic acid,ALP)、胆碱酯酶(cholinesterase,CHE)、甘油三酯(triglyceride,TG)、胆固醇(cholesterol,CHO)、低密度脂蛋白胆固醇(low density lipoprotein-cholesterol,LDL-C)水平。结果电镜下观察到A组肝细胞结构正常,核呈圆形或椭圆,线粒体形态正常。B组肝细胞次级溶酶体数量增加,线粒体形状不规则,脂滴多。C组可见少量脂滴,高尔基体正常,线粒体清楚。D组少量脂滴,胆小管有内容物,线粒体正常。E组线粒体高尔基体正常,少量脂滴,核圆。F组细胞器无异常,少量脂滴。G组少量脂滴,偶见溶酶,体线粒体正常。B组大鼠血清ALT、AST、ALP、CHE、TG、CHO、LDL-C均高于空白对照组,差异显著(P<0.05);F组大鼠血清所测各指标与空白对照组无明显差异;而D-柠檬烯低、中、高剂量干预组和酒精模型组比较,血清所测各指标水平均有不同程度地降低,其中D-柠檬烯中、高剂量干预组血清所测各指标水平明显低于酒精模型组,差异显著(P<0.05)。结论:过量酒精摄入引起的肝组织超微结构病理损伤与升高血清ALP、CHE、ALT、AST、TG、CHO、LDL-C水平,在D-柠檬烯干预下有所减轻和降低。因此,D-柠檬烯可调节过量酒精摄入造成的脂质代谢紊乱。

Objective:This study evaluated the protective effect of D-limonene against ethanol-induced hepatic injury in rats and analyzed the associated mechanisms.Methods:The alcoholic liver disease(ALD) model of rats was established by administration of 50% alcohol.Seven groups of mice were created,namely blank control(A),alcoholic damage model(B),low-dose D-limonene(C),middle-dose D-limonene(D),high-dose D-limonene(E),high-dose D-limonene blank(F),and diammonium glycyrrhizinate(DG) control(G) groups.Group A was daily administered by gavage with distilled water at a volume of 8 m L/(kg·d) first for two weeks followed by 8 m L/(kg·d) for another four weeks,Group B was administered with 50% aqueous by the same schedule as for group A,Groups C,D and E were respectively given 100,200 and 400 m L/(kg·d) D-limonene in 50% aqueous ethanol at the same volume as that used for groups A and B,Group F was daily administered with 400 m L/(kg·d) D-limonene without alcohol-induced liver injury,and Group G was treated with 200 m L/(kg·d) of DG.HE staining and electronic microscopic evaluation were conducted for examining the morphology and ultrastructure of liver tissues.The levels of alanine transaminase(ALT),aspartate transaminase(AST),phosoporic acid(ALP),cholinesterase(CHE),triglyceride(TG),cholesterol(CHO),and low-density lipoprotein-cholesterol(LDL-C) were detected.Results:Normal liver tissue structure was observed in Group A.Many secondary lysosomes were observed in Group B.A small amount of lipid droplets was observed in Group C while Golgi was normal and mitochondria was clear.Normal mitochondria were observed in Group D.Normal mitochondria and Golgi were observed in Group E.The organelles without abnormalities were observed in Group F.Normal mitochondria were observed in Group G.Serum ALT,AST,ALP,CHE,TG,CHO and LDL-C were higher in group B than in other groups(P < 0.05);serum levels of the indicators measured were reduced in different D-limonene groups at various doses than those in alcohol model group(P < 0.05).Conclusion:D-limonene can ameliorate the damage of ultrastructure in liver tissues,reduce serum indexes caused by alcohol exposure and the body's lipids.Moreover,it has a regulatory role in lipid metabolism disorders caused by alcohol.