绿原酸对高脂饲粮诱导非酒精性脂肪肝大鼠细胞凋亡相关基因表达的影响

Effects of Chlorogenic Acid on Apoptosis-Related Gene Expressions in Rats with Non-Alcoholic Fatty Liver Disease Caused by High-Fat Diet

本试验旨在研究绿原酸(CGA)对高脂饲粮所导致的非酒精性脂肪肝(NAFLD)大鼠细胞凋亡相关基因表达的影响。将40只雄性SD大鼠随机分成对照组(NC组)、高脂饲粮模型组(HFD组)、高脂饲粮+低剂量绿原酸组[20mg/(kg·d),HFD-LC组]和高脂饲粮+高剂量绿原酸组[90mg/(kg·d),HFD-HC组],每组10只。每天称量体重,12周后处死。取血清检测谷丙转氨酶(ALT)、总胆固醇(TC)、甘油三酯(TG)、游离脂肪酸(FFA)和高密度脂蛋白胆固醇(HDL-c)、低密度脂蛋白胆固醇(LDL-c)含量;取新鲜肝脏组织制备苏木精-伊红(HE)染色切片观察病理变化情况;称量肝脏湿重,计算肝脏指数;采用半定量逆转录PCR(RT-PCR)法测定肝脏组织肿瘤坏死因子-α(TNF-α)、肿瘤坏死因子受体-1(TNFR-1)、半胱氨酸天冬氨酸蛋白酶-8(caspase-8)、半胱氨酸天冬氨酸蛋白酶-3(caspase-3)、B-细胞淋巴瘤/白血病-2原癌基因(Bcl-2)、Bcl-2相关基因(Bax)、核转录因子-κB(NF-κB)、白细胞介素-6(IL-6)的mRNA表达量。结果表明:与NC组对比,HFD组大鼠最终体重(P>0.05)、肝脏湿重(P<0.01)、肝脏指数(P<0.01)、凋亡相关因子mRNA表达量均有上升。与HFD组相比,低剂量绿原酸能够降低最终体重(P>0.05)、肝脏湿重(P<0.05)、肝脏指数(P>0.05),降低凋亡相关因子mRNA表达量;高剂量绿原酸能够降低最终体重(P<0.05)、肝脏湿重(P<0.05)、肝脏指数(P>0.05),降低凋亡相关因子mRNA表达量。切片结果显示HFD组细胞出现大量脂肪空泡,大量细胞出现凋亡形态,绿原酸能够降低脂肪性空泡的数量,改善肝细胞的生理状态,并且高剂量绿原酸作用效果更加明显。由此可见,绿原酸能够缓解高脂饮食所导致的肝细胞凋亡,改善体内的脂肪代谢,对肝脏具有保护作用。

To investigate the effects of chlorogenic acid （CGA） on the expressions of apoptosis-related genes in rats with nonalcoholic fatty liver disease （NAFLD） caused by high-fat diet. Forty male SD rats were randomly divided into 5 groups： control group （NC group）, high-fat diet model group （HFD group）, high-fat diet＋low dose CGA group [ （20 mg/（kg · d）, HFD-LC group], and high-fat diet＋high dose CGA group [ （90 mg/（ kg · d） , HFD-HC group]. Each group had 10 rats. All rats were weighed everyday and were killed after 12 weeks. Serum contents of alanine transarninase （ALT）, total cholesterol （TC）, triglyceride （TG）, free fatty acid （FFA）, high-density lipoprotein cholesterol （HDL-c） and low-density lipoprotein cholesterol （LDL-c） were detected; histological changes of the liver were examined by hematoxylin and eosin staining ; liver wet weight and hepatic index were weighed; the mRNA expression levels of tumor necrosis factor-α （ TNF-α）, tumor necrosis factor receptor-1 （ TNFR-1）, caspase-8, caspase-3, B cell lymphoma/leukemia-2 （Bcl-2）, Bcl-2 related gene （ Bax）, nuclear factor-κB （ NF-κB）, and interleukin 6 （IL-6） were assessed by semi-quantification RT-PCR. The results showed as follows： compared with NC group, final body weight （ P〉0.05）, liver wet weight （ P〈0.01 ）, hepatic index （ P〈0.01 ）, and the mRNA expression levels of apoptosis-related genes were much higher in HFD group. Compared with HFD group, final body weight （P〉 0.05）, liver wet weight （P〈0.05）, hepatic index （P〉0.05）, and the mRNA expression levels of apoptosisrelated genes were reduced after the treatment of low dose CGA; and high dose of CGA could induce more on those indices [ final body weight （ P〈0.05）, liver wet weight （ P〈0.05）, hepatic index （P〉0.05） ] than low dose CGA could do. The histological study revealed that there were a lot of fatty vacuoles, a large number of cells with apoptotic morphology. CGA dose dependently reduced the quantity of fatty vacuoles, and improve the physiological state of hepatic cells. It is concluded that CGA can reduce the chance of hepatic apoptosis caused by high-fat diet, improve fat metabolism, and has protection effects on rat liver.