杜仲叶提取物对高脂血症模型大鼠降脂作用及肠道菌群影响研究

Lipid-Lowering Effect of EUCOMMIAE FOLIUM Extract on Hyperlipidemia Model Rats and Its Influence on Intestinal Flora

目的:测定杜仲叶提取物最大耐受量,研究其对高脂血症模型大鼠降脂作用及肠道菌群的影响。方法:以SPF级昆明种小鼠为受试动物采用MTD法测定最大耐受量。以SD大鼠为受试动物,采用高脂高糖饲料联合猪油灌胃进行高脂血症造模,造模成功大鼠随机分为模型对照组、杜仲叶提取物3.2、5.8、10.6 g/kg组。灌胃给予杜仲叶提取物连续4 w,测定大鼠血清三酰甘油(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)及高密度脂蛋白胆固醇(HDL-C)含量,采用16S rDNA高通量测序技术对大鼠粪便DNA进行测序。结果:杜仲叶提取物最大耐受量为44.8 g/kg,折合成杜仲叶生药为213.3 g/kg。与正常对照组比较,模型对照组血清TG、TC及LDL-C含量明显升高(P<0.05);与模型对照组相比,杜仲叶提取物5.8、10.6 g/kg组血清TG含量明显降低(P<0.05),3.2 g/kg组血清TC含量明显降低(P<0.05)。模型对照组大鼠肠道菌群Alpha多样性呈现降低趋势,与正常对照组菌群结构明显分开(P<0.05),在门、属分类水平上存在菌群结构失调;与模型对照组比较,给药组肠道菌群丰富度升高,菌群结构呈现向正常对照组靠近的趋势;在门分类水平上,杜仲叶提取物10.6 g/kg组显著升高厚壁菌门丰度(P<0.01),3.2、5.8 g/kg组明显降低unidentified_Bacteria丰度(P<0.05);在属分类水平上,与正常对照组比较,模型对照组乳酸杆菌属、Prevotellaceae_NK3B31_group丰度明显降低(P<0.05),阿克曼氏菌属丰度呈现降低趋势;与模型对照组比较,杜仲叶提取物10.6 g/kg组乳酸杆菌属丰度明显升高(P<0.05),5.8 g/kg组阿克曼氏菌属丰度显著升高(P<0.01),各给药组Prevotellaceae_NK3B31_group丰度均显著升高(P<0.01)。结论:杜仲叶提取物具有降血脂作用,能够调节高脂血症所致大鼠肠道菌群结构失调。

Objective:To determine the maximum tolerable dose(MTD)of EUCOMMIAE FOLIUM extract(EFE)and study its lipid-lowering effect on a rat model of hyperlipidemia and its impact on the intestinal flora.Methods:SPF Kunming mice were used to determine the MTD.SD rats were used as the experimental animals and were induced with a high-fat and high-sugar diet combined with intragastric administration of lard to create the hyperlipidemia model.The model rats were randomLy divided into a model control group and three groups treated with EFE at doses of 10.6,5.8,and 3.2 g/kg.The rats were orally administered with the EFE for four weeks,and the serum levels of triglycerides(TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),and high-density lipoprotein cholesterol(HDL-C)were measured.High-throughput sequencing of 16S rDNA was performed to sequence the fecal DNA of the rats.Results:The MTD of EFE was determined to be 44.8 g/kg,equivalent to 213.3 g/kg of the raw medicinal materials.The serum levels of TG,TC,and LDL-C significantly increased in the model control group as compared with those in the normal control group(P<0.05).Compared with the model control group,the groups treated with EFE at doses of 10.6 and 5.8 g/kg showed a significant decrease in serum TG level(P<0.05),and the group treated with EFE at 3.2 g/kg showed a decrease in serum TC level(P<0.05).Compared with the intestinal flora in the normal control group,that of the model control group showed a decreased trend in alpha diversity and a distinct separation of microbial structure(P<0.05),indicating microbial dysbiosis at the phylum and genus levels.Compared with the model control group,the treatment groups showed increased microbial abundance and a tendency to approach the microbial structure of the normal control group.At the phylum level,the group treated with EFE at 10.6 g/kg showed a significant increase in the abundance of Firmicutes(P<0.01),and the groups treated with EFE at 5.8 and 3.2 g/kg showed a significant decrease in the abundance of unidentified_Bacteria(P<0.05).At the genus level,compared with the normal control group,the model control group showed a significant decrease in the abundance of Lactobacillus and Prevotellaceae_NK3B31_group(P<0.05),and a decreasing trend in the abundance of Akkermansia.Compared with the model control group,the group treated with EFE at 10.6 g/kg showed a significant increase in the abundance of Lactobacillus(P<0.05),and the group treated with EFE at 5.8 g/kg showed a significant increase in the abundance of Akkermansia(P<0.01).The abundance of Prevotellaceae_NK3B31_group significantly increased in all treatment groups(P<0.01).Conclusion:EFE has a lipid-lowering effect and can regulate the imbalanced intestinal flora caused by hyperlipidemia in rats.