目的：采用动物实验,探讨盐酸小檗碱（berberine,BBR）对高胆固醇所致肝脏损伤的保护作用。方法：将8周龄雄性C57BL/6J小鼠随机分为3组（每组10只）,分别给予普通饲料组、高胆固醇饲料组（高胆固醇组）和高胆固醇饲料加BBR治疗组（以下简称BBR组）,喂养8周后采集其肝脏和血清。采用反转录聚合酶链反应（reverse transcription polymerase chain reaction, RT-PCR）法测量小鼠肝脏相关基因mRNA的表达,并测定肝脏组织丙二醛（malondialdehyde,MDA）的含量。采用HepG2细胞系,研究BBR对高胆固醇处理下细胞内质网应激的影响。结果：与普通饲料组比较,高胆固醇组小鼠的肝脏组织中CHOP、GRP78、ATF4等内质网应激相关基因mRNA表达量增加了1倍以上（P<0.05）,Trp53、Nqo1等氧化应激相关基因的mRNA表达量分别增加了8倍、5倍（P<0.05）,肿瘤坏死因子α、白细胞介素1β等炎症因子相关基因的mRNA表达量分别增加了15倍和0.5倍（P<0.05）,而BBR组的上述基因表达与普通饲料组水平接近（P<0.05）。高胆固醇组小鼠肝脏的MDA含量增加了1倍以上（P<0.05）,而BBR可下调高胆固醇导致的肝脏MDA含量增高（P<0.05）。HepG2细胞体外实验显示,BBR可降低高胆固醇导致的内质网应激关键蛋白GRP78表达上调（P<0.05）和二氢乙啶（dihydroethidium,DHE）荧光量上调。结论：BBR可缓解高胆固醇导致的肝脏细胞内质网应激、氧化应激及炎症反应,具有一定的肝脏保护作用。
Objective: To investigate the protective effect of berberine (BBR) on liver damage under high-cholesterol diet challenge. Methods: Eight-week old male C57BL/6J mice were randomly divided into normal diet group, high cholesterol diet (1.25% cholesterol+0.5% cholic acid) group and high cholesterol diet+BBR (100 mg/kg per day by gavage) group, with 10 mice in each group. Liver and serum plasma samples were collected after 8-week feeding. Hepatic mRNA expressions of genes involved in endoplasmic reticulum stress (ER stress), oxidative stress and inflammatory cytokines were determined by real-time quantitative PCR, and content of malondialdehyde (MDA) in liver tissues was measured. HepG2 cell line was used to investigate the effect of BBR on ER stress under high cholesterol challenge. Results: Compared with normal diet group, hepatic mRNA expressions of genes in ER stress, oxidative stress and inflammatory cytokines increased significantly in high cholesterol diet group (P<0.05), and were reduced closely to levels of normal diet group by BBR treatment (P<0.05). BBR also down-regulated the increased hepatic MDA content induced by high cholesterol diet (P<0.05). Furthermore, BBR decreased the expression of GRP78, a key protein marker concerning ER stress (P<0.05), as well as the fluorescence intensity of DHE probe after high cholesterol treatment in HepG2 cells. Conclusions: BBR could effectively ameliorate hepatic ER stress, oxidative stress and inflammatory response under high cholesterol challenge, which might protect liver from damage when overloaded with cholesterol.
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