摘要
目的:基于磷脂酰肌醇3-激酶/蛋白激酶B/过氧化物酶体增殖物激活受体α/肉毒碱棕榈酰基转移酶-1(PI3K/Akt/PPARα/CPT-1)信号通路探讨桑叶水提物对2型糖尿病(T2DM)大鼠肝脏糖脂代谢紊乱的作用及其机制。方法:高脂喂养联合腹腔注射链脲佐菌素(STZ)方法制备T2DM模型,按血糖、体质量将造模成功大鼠随机分为模型组、二甲双胍(0.2 g·kg^(-1))组和桑叶水提物(含生药4.0 g·kg^(-1))组,连续给药8周,每周相同时间测定空腹血糖。苏木素-伊红(HE)染色、油红O染色观察肝脏组织形态学和脂肪变化;生化分析法测定血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、丙氨酸氨基转移酶(ALT)和天冬氨基酸氨基转移酶(AST)水平;蛋白免疫印迹法(Western blot)检测肝脏磷酸化磷脂酰肌醇3-激酶(p-PI3K)、PI3K、磷酸化蛋白激酶B(p-Akt)、Akt、PPAR-α、CPT-1蛋白表达。结果:给药8周后,与正常组比较,模型组大鼠血糖显著升高(P<0.01);与模型组比较,桑叶水提物组大鼠血糖显著降低(P<0.01)。HE染色显示,正常组大鼠肝组织结构完整,肝细胞以中央静脉为中心呈放射状排列;模型组大鼠肝细胞损伤明显;与模型组比较,桑叶水提物组大鼠空泡变性程度显著降低,未见小胆管增生等病变。油红O染色显示,正常组大鼠肝细胞无明显脂肪变性、坏死,肝细胞几乎无脂滴;模型组大鼠肝内脂滴较正常组明显增加;桑叶给药可明显减少大鼠肝脏脂滴。模型组大鼠TC、TG、LDL-C、AST、ALT水平较正常组显著升高(P<0.01);桑叶水提物组大鼠TC、TG、LDL-C、AST、ALT水平较模型组明显降低(P<0.05,P<0.01)。Western blot结果显示,与正常组比较,模型组大鼠p-PI3K/PI3K、p-Akt/Akt、PPARα和CPT-1的蛋白表达显著降低(P<0.01);与模型组比较,桑叶水提物能明显增加p-PI3K/PI3K、p-Akt/Akt、PPARα和CPT-1的蛋白表达(P<0.05,P<0.01)。结论:桑叶水提物可改善T2DM大鼠肝脏糖代谢紊乱,降糖机制可能与调控PI3K/Akt/PPAR-α/CPT-1信号通路有关。
Objective:To investigate the effect and mechanism of Mori Folium extract on the glucose and lipid metabolism disorders in the liver of rats with type 2 diabetes mellitus(T2DM)through the phosphatidylinositol 3-kinase/protein kinase B/peroxisome proliferation-activated receptorα/carnitine palmitoyl transferase-1(PI3K/Akt/PPARα/CPT-1)signaling pathway.Method:The T2DM model was induced by the high-fat diet combined with the intraperitoneal injection of streptozotocin(STZ).The model rats were randomly divided into a model group,a metformin(0.2 g·kg^(-1))group,and a Mori Folium water extract(4.0 g·kg^(-1))group according to blood glucose and body weight.In the 8-week administration,fasting blood glucose was measured at the same time every week.The histomorphological and fat changes in the rat liver were observed by hematoxylin-eosin(HE)staining and oil red O staining.The levels of total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),high-density lipoprotein cholesterol(HDL-C),alanine aminotransferase(ALT),and aspartate aminotransferase(AST)in the serum were measured by biochemical methods.Western blot(WB)was used to quantitatively detect the protein expression of p-PI3K,PI3K,p-Akt,Akt,PPARα,and CPT-1 in the rat liver.Result:After 8-week administration,the blood glucose of rats was higher in the model group than that in the control group(P<0.01),and lower in the Mori Folium water extract group than that in the model group(P<0.01).The results of HE staining showed that the liver tissue structure of the control group was complete,and the hepatocytes were arranged radially around the central vein,while the hepatocyte injury in the model group was obvious.Compared with the model group,the Mori Folium water extract group showed improved vacuolar degeneration and no lesions such as small bile duct hyperplasia.Oil red O staining showed that there was no obvious steatosis and necrosis in the hepatocytes of rats in the control group,and no lipid droplets in the hepatocytes were observed,while the model group showed increased lipid droplets.Mori Folium significantly reduced the lipid droplets in the liver.Biochemical analysis showed that the levels of TC,TG,LDL-C,AST,and ALT in the model group were significantly higher than those in control group(P<0.01).The levels of TC,TG,LDL-C,AST,and ALT in the Mori Folium water extract group were significantly lower than those in the model group(P<0.05,P<0.01).WB showed that the protein expression of p-PI3K/PI3K,p-Akt/Akt,PPARα,and CPT-1 in the model group were lower than those in the control group(P<0.01).Mori Folium water extract could increase the protein expression of p-PI3K/PI3K,p-Akt/Akt,PPARα,and CPT-1(P<0.05 or P<0.01).Conclusion:The hypoglycemic mechanism of Mori Folium water extract may be related to the regulation of the PI3K/Akt/PPARα/CPT-1 signaling pathway.
作者
代泓钰
王敬康
王晨
石璐
段钰卉
安永铖
吕迎兰
李慧敏
程龙
何昶昊
张慧琳
黄艳
付宛鑫
刘珍清
赵保胜
DAI Hong-yu;WANG Jing-kang;WANG Chen;SHI Lu;DUAN Yu-hui;AN Yong-cheng;LYU Ying-lan;LI Hui-min;CHENG Long;HE Chang-hao;ZHANG Hui-lin;HUANG Yan;FU Wan-xin;LIU Zhen-qing;ZHAO Bao-sheng(College of Chinese Materia Medica and Life Sciences,Beijing University of Chinese Medicine,Beijing 102488,China;Beijing Research Institute of Chinese Medicine,Beijing University of Chinese Medicine,Beijing 100029,China)
出处
《中国实验方剂学杂志》
CAS
CSCD
北大核心
2022年第7期105-112,共8页
Chinese Journal of Experimental Traditional Medical Formulae
基金
国家自然科学基金项目(81973535,81773960)。
