OBJECTIVE To explore the mechanism of the active ingredient compatibility（quercetin， quercitrin and kaempferol at a mass ratio of 2∶9∶3）of Dimocarpus longan Lour. leaves（abbreviated as CDL） on ameliorating glucose and lipid metabolism disorders in type 2 diabetes mellitus （T2DM） rats. METHODS SD rats were randomly divided into blank control group， model group， metformin hydrochloride group （100 mg/kg）， and CDL high-， medium- and low-dose groups （280， 140， 75 mg/kg）， with 10 rats in each group. Rats in the blank control group were fed with standard chow， while rats in the other groups were given high-sugar and high-fat diet combined with intraperitoneal injection of streptozotocin to establish the T2DM rat model. After successful modeling， rats in each administration group were given corresponding drug solution， and rats in the blank control group and model group were intragastrically administered with equal volume of pure water， once a day， for consecutive 4 weeks. Fasting blood glucose （FBG） was detected at fixed time every week. The curves of oral glucose tolerance test （OGTT） and intraperitoneal insulin tolerance test （IPITT） were plotted， and the area under curve （AUC） was calculated. The pancreatic islet function indexes [fasting insulin （FINS）， homeostasis model assessment of insulin resistance （HOMA-IR）， insulin sensitivity index （ISI）]，blood lipid indexes [total cholesterol （TC）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）] and hepatic glycogen content were determined. The pathological morphological changes of liver and pancreatic tissues were observed. The protein and mRNA expression levels of molecules related to phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway in liver tissues were detected. RESULTS Compared with the blank control group， the FBG， AUC of IPITT curve， AUC of OGTT curve， HOMA-IR， the levels of FINS， TC， TG and LDL-C， as well as the protein and mRNA expression of phosphatase and tensin homolog， forkhead box protein O1 and glycogen synthase kinase-3β in liver tissues were significantly increased in the model group （ P ＜0.05）. ISI， the levels of HDL-C and hepatic glycogen content， along with the protein and mRNA expression of PI3K， insulin receptor substrate-1， Akt and protein expression of phosphorylated Akt in liver tissues were markedly decreased （ P ＜0.05）. In model group rats， the arrangement of hepatocytes was irregular， the overall structure of pancreatic lobules was disordered， and a large number of inflammatory cell infiltration was observed. Compared with the model group， most of the above quantitative indexes were significantly reversed in the CDL high-dose group （ P ＜0.05）， and the pathological lesions of liver and pancreas were obviously alleviated. CONCLUSIONS CDL can regulate glucose and lipid metabolism disorders， elevate insulin sensitivity and relieve insulin resistance in T2DM rats. Its mechanism may be related to the activation of the PI3K/Akt signaling pathway.

OBJECTIVE To explore the mechanism of the active ingredient compatibility（quercetin， quercitrin and kaempferol at a mass ratio of 2∶9∶3）of Dimocarpus longan Lour. leaves（abbreviated as CDL） on ameliorating glucose and lipid metabolism disorders in type 2 diabetes mellitus （T2DM） rats. METHODS SD rats were randomly divided into blank control group， model group， metformin hydrochloride group （100 mg/kg）， and CDL high-， medium- and low-dose groups （280， 140， 75 mg/kg）， with 10 rats in each group. Rats in the blank control group were fed with standard chow， while rats in the other groups were given high-sugar and high-fat diet combined with intraperitoneal injection of streptozotocin to establish the T2DM rat model. After successful modeling， rats in each administration group were given corresponding drug solution， and rats in the blank control group and model group were intragastrically administered with equal volume of pure water， once a day， for consecutive 4 weeks. Fasting blood glucose （FBG） was detected at fixed time every week. The curves of oral glucose tolerance test （OGTT） and intraperitoneal insulin tolerance test （IPITT） were plotted， and the area under curve （AUC） was calculated. The pancreatic islet function indexes [fasting insulin （FINS）， homeostasis model assessment of insulin resistance （HOMA-IR）， insulin sensitivity index （ISI）]，blood lipid indexes [total cholesterol （TC）， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， high-density lipoprotein cholesterol （HDL-C）] and hepatic glycogen content were determined. The pathological morphological changes of liver and pancreatic tissues were observed. The protein and mRNA expression levels of molecules related to phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway in liver tissues were detected. RESULTS Compared with the blank control group， the FBG， AUC of IPITT curve， AUC of OGTT curve， HOMA-IR， the levels of FINS， TC， TG and LDL-C， as well as the protein and mRNA expression of phosphatase and tensin homolog， forkhead box protein O1 and glycogen synthase kinase-3β in liver tissues were significantly increased in the model group （ P ＜0.05）. ISI， the levels of HDL-C and hepatic glycogen content， along with the protein and mRNA expression of PI3K， insulin receptor substrate-1， Akt and protein expression of phosphorylated Akt in liver tissues were markedly decreased （ P ＜0.05）. In model group rats， the arrangement of hepatocytes was irregular， the overall structure of pancreatic lobules was disordered， and a large number of inflammatory cell infiltration was observed. Compared with the model group， most of the above quantitative indexes were significantly reversed in the CDL high-dose group （ P ＜0.05）， and the pathological lesions of liver and pancreas were obviously alleviated. CONCLUSIONS CDL can regulate glucose and lipid metabolism disorders， elevate insulin sensitivity and relieve insulin resistance in T2DM rats. Its mechanism may be related to the activation of the PI3K/Akt signaling pathway.

OBJECTIVE:To optimize the hypoglycemic active parts from the leaves of Dimocarpus longan for type 2 diabetes mellitus mice,and to provide reference for material basis study of it. METHODS:Total extract was obtained from the leaves of D. longan with 95% ethanol percolation extraction. After confirming hypoglycemic effect of total extract,extract was suspended with water. Relevant extract was obtained by using petroleum ether,ethyl acetate and n-butanol in turn(respectively marked as ST,YT,ZT and WT). The model of type 2 diabetes mellitus mice was established by high glucose and high fat diet combined with STZ. Model mice were randomly divided into model group(distilled water),positive control group(metformin,0.1 g/kg), ST low-dose,medium-dose and high-dose groups(22.2,29.6,44 g/kg,calculated by crude drug,similarly hereinafter),YT low-dose,medium-dose and high-dose groups(10.7,16,32 g/kg),ZT low-dose,medium-dose and high-dose groups(10.5, 15.8,31.6 g/kg),WT low-dose,medium-dose and high-dose groups(18.5,24.6,37 g/kg),with 10 mice in each group. Other 10 normal mice were included in normal group(distilled water). Those groups were given relevant medicine intragastrically,once a day,for consecutive 28 d.The growth of mice and the change of body weight were observed and recorded. Fasting blood glucose(FBG)of mice was detected,and glucose tolerance test of mice was conducted. The contents of TC,TG,HDL-C and LDL-C in serum of mice were also determined. RESULTS:Compared with normal group,body weight and serum content of HDL-C in model group were decreased;FBG and the blood sugar after giving glucose for 0.5,1,2 h and area under glucose tolerance curve of mice were increased,and serum contents of TC,TG and LDL-C were alse increased,with statistical significance(P<0.01). compared with model group,body weight of mice in YT high-dose group after administration of 25 d was increased,FBG of mice in YT groups and ZT medium-dose,high-dose groups were decreased(P<0.05 or P<0.01);blood sugar of mice in YT medium-dose,high-dose groups and ZT high-dose group after giving glucose for 1 h as well as blood sugar of mice in YT high-dose group after giving glucose for 2 h were all decreased;area under glucose tolerance curve of mice and serum content of TC were decreased in YT groups and ZT high-dose group,while serum content of HDL-C was increased. Serum content of TG and LDL-C in YT high-dose group and ZT high-dose group as well as serum content of TG in YT medium-dose group were all decreased,serum content of HDL-C in ZT medium-dose group was increased,with statistical significance(P<0.05 or P<0.01). CONCLUSIONS:The ethyl acetate part and n-butanol part from the leaves of D. longan show good hypoglycemic effect on type 2 diabetes mellitus mice.