GPR119激动剂MBX-2982的小鼠药效学及大鼠体内药动学研究

 目的 研究GPR119激动剂MBX-2982对小鼠糖耐量的影响以及对KK-A^y小鼠各项指标的影响,评价其降糖效果,并进一步评价其在大鼠体内的吸收情况。方法 以KM小鼠评价MBX-2982单次给药后对其糖耐量的影响;以KK-A^y小鼠体重、空腹血糖、糖耐量、甘油三酯、血清胰岛素为评价指标考察其药效情况;以大鼠进行不同剂量下的药动学实验,考察灌胃给予MBX-2982混悬液和溶液的吸收情况。结果 正常小鼠糖耐量实验中,灌胃给予3、10、30 mg·kg^-1的MBX-2982后均可降低各时间点的血糖值。MBX-2982以10、30 mg·kg^-1剂量连续给药4周后,能显著降低KK-A^y小鼠的空腹血糖、降低血清甘油三酯、增加血清胰岛素水平,30 mg·kg^-1剂量还能显著降低糖耐量实验中血糖曲线下面积。大鼠0.4%羧甲基纤维素混悬液4 mg·kg^-1灌胃给药后的绝对生物利用度约为35.2%,而二甲基亚砜-蓖麻油-生理盐水=1∶1∶8溶液4 mg·kg^-1灌胃给药后的绝对生物利用度为98.2%。结论 动物实验结果显示,MBX-2982作为GPR119激动剂有很好的降糖效果,其全溶溶液的口服生物利用度远高于混悬液,接近于100%。     

Ginsenoside Re attenuates diabetes-associated cognitive deficits in rats

Objective

This study was designed to investigate the effect of ginsenoside Re (Re) on cognitive functions, oxidative stress and inflammation in streptozotocin-induced diabetic rats.

Research design and method

Diabetic rats were treated with Re (40 mg/kg) for 8 weeks, blood glucose and body weight were measured monthly and weekly, respectively. Cognitive performances were evaluated with Morris water maze. Brain was obtained for measurements of TNF-α and malondialdehyde (MDA) contents in both temporal cortex and hippocampus, blood was collected for assays of TNF-α, MDA and reduced glutathione (GSH) levels.

Results

Learning and memory abilities were significantly (both P < 0.01) impaired in diabetic rats, accompanied by the marked (all P < 0.01) elevations of TNF-α and MDA levels in temporal cortex and hippocampus. Increment of MDA and decrement of GSH in serum also occurred with significant differences (both P < 0.01). Chronic treatment with Re markedly (P < 0.05) improved the cognition of diabetic rats, evidenced by the decreased escape latency and the increased percentage of time spent in the target quadrant. Furthermore, Re treatment remarkably (P < 0.05) reduced the levels of TNF-α and MDA in both brain areas of diabetic rats. Decline of MDA level and elevation of GSH level in serum were also seen in Re-treated diabetic rats, coupled with decrease in serum glucose level, all with statistically significant differences.

Conclusions

Our findings firstly provide the first evidence that ginsenoside Re can remarkably attenuate diabetes-associated cognitive decline, secondly confirm the involvement of oxidative stress and inflammation in the development of cognitive impairment caused by diabetes, finally point toward the potential of ginsenoside Re as an adjuvant therapy to conventional anti-hyperglycemic regimens as well as diabetes-associated cognitive decline.     

艾塞那肽对2型糖尿病临床疗效观察

观察艾塞那肽对2型糖尿病患者血糖控制情况。将2010年7月～12月间应用艾塞那肽的15例2型糖尿病患者进行一般资料分析:包括年龄、糖尿病病程、空腹血糖、餐后血糖、糖化血红蛋白,甘油三酯、胆固醇、就诊时降糖药物应用药统计。对患者进行艾塞那肽5μg一日2次早晚餐前1 h皮下注射后,观察用药前后空腹血糖及餐后2 h血糖变化。结果显示用艾塞那肽后空腹血糖及餐后血糖均较用药前下降,艾塞那肽降低餐后血糖较空腹血糖程度高。艾塞那肽可短时间内有效降低空腹及餐后血糖,降低餐后血糖较空腹血糖效果好。     

Insulin deficiency induces abnormal increase in intestinal disaccharidase activities and expression under diabetic states, evidences from in vivo and in vitro study

Structural and functional alterations in the gastrointestinal tract of diabetic patients are often accompanied by increase in absorption of intestinal glucose and activities of brush-border disaccharidases. The purpose of this study was to investigate the role of insulin in regulating intestinal disaccharidases using in vivo and in vitro experiments. Streptozotocin-induced diabetic rats and normal rats received protamine zinc insulin (10 IU/kg) subcutaneously twice daily for 5 weeks. Disaccharidase activities and sucrase–isomaltase (SI) complex protein and mRNA expression in intestinal regions were assessed. In addition, Caco-2 cells were cultured in medium containing glucose, insulin or insulin plus some pharmacological inhibitors for 7 days, disaccharidase activities, sucrase–isomaltase (SI) complex and Cdx2 mRNA levels were measured. The animal experiments showed that diabetes increased intestinal disaccharidase activities, accompanied by high mRNA and protein expression of SI complex. Insulin treatment reversed the increases induced by diabetes. The cellular results showed that insulin suppressed disaccharidase activities and down-regulated SI complex and Cdx2 mRNA expression in a concentration-dependent manner. The inhibitor of MAPK signal pathway PD-98059 blocked the suppression of disaccharidase activities and expression of SI complex and Cdx2 mRNA induced by insulin. In conclusion, insulin deficiency induces abnormal increase in intestinal disaccharidase activities and expression under diabetic states. Insulin plays an essential role in regulation disaccharidase activities and expression, at least in part, via the MAPK-dependent pathway.     

Hypoglycemic activity of Thai medicinal plants selected from the Thai/Lanna Medicinal Recipe Database MANOSROI II

Ethnopharmacological relevance

Five medicinal plants including Anogeissus acuminata (Roxb. ex DC.) Gills. & Perr. (Combretaceae), Catunaregam tormentosa (Bl. ex DC.) Tirveng (Rubiaceae), Dioecrescis erythroclada (Kurz) Tirveng. (Rubiaceae), Mimosa pudica Linn. var. hispida Bren. (Fabaceae), and Rauwolfia serpentina (L). Benth. ex Kurz. (Apocyanaceae), which have been traditionally used for the treatment of diabetes mellitus and other diseases for several generations by the Thai-Lanna people in the Northern part of Thailand were investigated for their hypoglycemic activity in normoglycemic and alloxan, induced diabetic mice.

Materials and methods

The aqueous extracts of the selected five medicinal plants were tested for their phytochemicals, free radical scavenging activity and hypoglycemic activity on 18 h fasted normoglycemic and alloxan induced diabetic mice over a period of 4 h comparing with the standard anti-diabetic drugs (insulin and glibenclamide) using two way analysis of variance (ANOVA) as analytical tool. Phytochemical analysis was performed using the standard methods while 2,2-diphenyl-1-picrylhydrazine (DPPH) was used to test for free radical scavenging activities of the medicinal plant extracts.

Results

Phytochemicals detected in the extracts were glycosides, xanthones, tannins, alkaloids and saponins. Anogeissus acuminata showed the highest free radical scavenging activity with the IC₅₀ value of 11.00 μg/mL which was 4 folds of the standard ascorbic acid. Significant reduction in fasting blood glucose (FBG) levels of the normoglycemic mice was observed at 4 and 3 h with the extracts of Mimosa pudica (200 mg/kg bw) and Rauwolfia serpentina (100 mg/kg bw), and percentage decreases of 46.15 and 27.94% which were 0.76 and 1.47; 0.53 and 0.91 folds of insulin and glibenclamide, respectively. In alloxan induced diabetic mice, all extracts showed significant (p < 0.05) hypoglycemic activity, with the maximum FBG reduction of 78.96 at 100 mg/kg bw shown by Anogeissus acuminata at the 4 h. The hypoglycemic activity of Anogeissus acuminata was comparable to insulin (1.1 fold), but more potent than glibenclamide (1.76 folds).

Conclusions

Medicinal plants selected from the Thai/Lanna Medicinal Plant Recipe Database MANOSROI II showed hypoglycemic activity in normoglycemic and alloxan induced diabetic mice. This study confirmed the traditional use of these medicinal plants for the treatment of diabetes mellitus and the thiazolidiendiones mimic hypoglycemic effects of the medicinal plants was suggested.     

Assessment of antidiabetic potential of Cynodon dactylon extract in streptozotocin diabetic rats

This study was undertaken to investigate the hypoglycemic and antidiabetic effect of single and repeated oral administration of the aqueous extract of Cynodon dactylon (Family: Poaceae) in normal and streptozotocin induced diabetic rats, respectively. The effect of repeated oral administration of aqueous extract on serum lipid profile in diabetic rats was also examined. A range of doses, viz. 250, 500 and 1000mg/kg bw of aqueous extract of Cynodon dactylon were evaluated and the dose of 500mg/kg was identified as the most effective dose. It lowers blood glucose level around 31% after 4h of administration in normal rats. The same dose of 500mg/kg produced a fall of 23% in blood glucose level within 1h during glucose tolerance test (GTT) of mild diabetic rats. This dose has almost similar effect as that of standard drug tolbutamide (250mg/kg bw). Severely diabetic rats were also treated daily with 500mg/kg bw for 14 days and a significant reduction of 59% was observed in fasting blood glucose level. A reduction in the urine sugar level and increase in body weight of severe diabetic rats were additional corroborating factors for its antidiabetic potential. Total cholesterol (TC), low density lipoprotein (LDL) and triglyceride (TG) levels were decreased by 35, 77 and 29%, respectively, in severely diabetic rats whereas, cardioprotective, high density lipoprotein (HDL) was increased by 18%. These results clearly indicate that aqueous extract of Cynodon dactylon has high antidiabetic potential along with significant hypoglycemic and hypolipidemic effects.     

Correlation between serum Dickkopf-1 (DKK1) levels and coronary artery stenosis

Background and aimsTo study the correlation between the level of serum Dickkopf-1 (DKK1) and the degree of coronary artery stenosis in patients with coronary atherosclerotic heart disease.Methods and resultsIn 2018, general data and biochemical indexes of 311 patients who underwent coronary angiography were recorded. Before procedure, arterial blood was drawn and the concentrations of DKK1, retinol binding protein 4 (RBP4), plasminogen activator inhibitor (PAI-1) were measured. Based on coronary angiography results, subjects were divided into a coronary heart disease (CHD) group; and a non-coronary heart disease (non-CHD)group. The CHD group was divided into three subgroups: the low Gensini score; the middle Gensini score; and the high Gensini score subgroups. Compared with those of the non-CHD group, DKK1, RBP4 and PAI-1 of the CHD group were significantly higher, while the OC was lower.DKK1,RBP4 and PAI-1 levels of the middle and high Gensini subgroups were significantly higher, compared with that of the low Gensini subgroup. Differences between osteocalcin (OC), beta-isomerized C-terminal telopeptidase (β-CTX), and 25(OH)₂D₃ of the three subgroups were not significant.Correlation between DKK1 and the inflammatory factors, RBP4 and PAI-1, was positive. Correlation between DKK1 and β - CTX, 25(OH)₂D₃ and OC was not significant. DKK1 was a risk factor for CHD. The degree of coronary artery stenosis was related to DKK1 concentration.ConclusionsSerum DKK1 levels in coronary heart disease patients were significantly higher, and positively correlated with the degree of coronary artery stenosis. DKK1 level is an independent risk factor for coronary heart disease.