洋甘菊总黄酮通过抑制ACC/FAS/DGAT2通路减少ApoE-/-小鼠三酰甘油合成

目的： 探究洋甘菊总黄酮通过调节ACC/FAS/DGAT2通路减少ApoE^-/-小鼠三酰甘油合成的药理作用机制。方法： 用乙醇回流提取和大孔树脂分离纯化法获得洋甘菊总黄酮；高脂饲料喂养法建立ApoE^-/-小鼠高脂模型；以C57BL/6J小鼠为空白对照组，ApoE^-/-小鼠分成模型组，非诺贝特组（30 mg·kg^-1），洋甘菊总黄酮低、中、高剂量组（88，176，352 mg·kg^-1）；空白对照组和模型组分别用基础饲料和高脂饲料喂养，其余组小鼠高脂饲料喂养的同时灌胃给药干预8周。检测小鼠血清三酰甘油（TG）、总胆固醇（TC）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）水平；HE染色和油红O染色观察小鼠肝脏脂肪变性情况；免疫组化法检测二酰基甘油酰基转移酶2（DGAT2）蛋白表达水平；Western Blot法检测肝组织乙酰辅酶A羧化酶（ACC）、脂肪酸合成酶（FAS）、DGAT2蛋白表达水平。结果： 与空白对照组相比，模型组小鼠TG、TC、LDL-C、ACC、FAS、DGAT2水平均明显升高，HDL-C水平明显降低；与模型组相比，非诺贝特组和洋甘菊总黄酮各剂量组脂肪变性情况明显减轻。与模型组相比，非诺贝特组、洋甘菊总黄酮各剂量组TG、TC、LDL-C、ACC、FAS水平均明显降低，HDL-C水平明显升高；非诺贝特组和洋甘菊总黄酮中、高剂量组DGAT2水平明显降低。结论： 洋甘菊总黄酮可以抑制ApoE^-/-小鼠三酰甘油合成，改善血脂水平，可能与其下调ACC/FAS/DGAT2通路表达有关。

Total flavonoids of chamomile reducing triacylglycerol synthesis in ApoE-/-mice by inhibiting ACC/FAS/DGAT2 pathway

OBJECTIVE To explore the pharmacological mechanism of total flavonoids of chamomile reducing the triacylglycerol synthesis in ApoE^-/- mice by regulating ACC/FAS/DGAT2 pathway.METHODS The total flavonoids of chamomile were extracted by ethanol reflux and purified by macroporous resin. Hyper lipedema model of ApoE^-/-mice was established by feeding high-fat diet, and C57 BL/6 J mice were used as normal group, ApoE^-/- mice were divided into model group, fenofibrate group(30 mg·kg^-1), low, middle and high dose of total flavonoids of chamomile groups(88,176,352 mg·kg^-1). The mice in the normal group and model group were fed with basal diet and high-fat diet, respectively, and the mice in other groups were fed with high-fat diet, and corresponding drug was administered intragastrically at the same time for 8 weeks. The serum levels of triacylglycerol(TG), total cholesterol(TC), high density lipoprotein cholesterol(HDL-C) and low density lipoprotein cholesterol(LDL-C) were measured. Liver steatosis was observed by HE staining and oil red O staining. The expression level of diacylglycerol transferase 2(DGAT2) protein was detected by immunohistochemistry method. Western blot was used to analyze the protein expression levels of acetyl-CoA carboxylase(ACC), fatty acid synthase(FAS) and DGAT2 in liver tissue.RESULTS As compared to those in the normal group, the levels of TG, TC, LDL-C, ACC, FAS and DGAT2 in the model group were significantly increased, while there was a significant reduction in HDL-C level in the model group. Compared with that in the model group, hepatic steatosis in fenofibrate group and each group of total chamomile flavonoids were significantly alleviated and the levels of TG, TC, LDL-C, ACC and FAS in fenofibrate group and each group of chamomile total flavonoid were also significantly decreased, while the HDL-C level was significantly increased. The DGAT2 level in fenofibrate group and middle and high dose of total flavonoids from chamomile groups decreased significantly as compared to that in the model group.CONCLUSION Total flavonoids of chamomile inhibits the synthesis of triacylglycerol in ApoE^-/- mice and improve the lipid level of mice, which may related to the down-regulation of ACC/FAS/DGAT2 pathway.