当归补血汤主要吸收成分对GK大鼠肾保护作用研究

观察当归补血汤主要吸收成分对2型糖尿病模型GK大鼠肾保护作用及可能机制。方法 UPLC-MS/MS定性定量吸收入血活性成分(ABCs),确定ABCs组成,定量1g母方中ABCs浓度。GK大鼠按血糖随机分为模型组、当归补血汤组及吸收成分（ABCs）组,每组10只,给药组分别灌胃当归补血汤（4g/kg）、吸收入血的生物活性成分（剂量相当于母方含量,即咖啡酸5.36mg/kg,芒柄花素2.68mg/kg,毛蕊异黄酮2.56mg/kg,阿魏酸1.36mg/kg,黄芪甲苷0.45mg/kg,丁苯酞0.16mg/kg,蒿本内酯0.16mg/kg）,10只普通Wistar大鼠作为空白对照,给予等量生理盐水,每日1次,连续给药28d。观察指标:①肾脏系数、尿总蛋白和尿白蛋白;②肾组织氧化应激;③病理切片观察肾脏组织形态。结果 当归补血汤及ABCs均能够改善糖尿病大鼠的肾脏肥大,显著降低糖尿病模型大鼠尿总蛋白、尿白蛋白和肾脏MDA水平（P<0.05）,显著升高肾脏总SOD活力（P<0.05）,且对肾脏组织病理形态学有保护作用;与当归补血汤组比较,ABCs作用不如汤剂显著。结论 ABCs能够代表母方当归补血汤发挥对GK大鼠的肾保护作用,机制涉及氧化应激。母方中除ABCs外,其微量元素、氨基酸、多糖等其他成分也同时发挥着药效作用。     

改变胃旁路术Roux肠袢长度对GK大鼠糖代谢改善的影响

目的研究胃旁路术(RYGB)中,不同Roux肠袢长度对GK大鼠糖代谢和激素分泌的影响。方法将GK大鼠随机分为5组,未处理组(GK-Blank)、假手术饮食对照组(GK-PF-Sham)和3组RYGB手术组。手术组根据Roux肠袢长度3 cm、12 cm和30cm分为GK-S-3 cm组、GK-S-12 cm组、GK-S-30 cm组,同时用Wistar大鼠作为正常对照。定期测量大鼠体质量;术后6个月,对各组大鼠行口服糖耐量试验、腹腔糖耐量试验和胰岛素耐量试验,并眼眶取血检测血中胰岛素及激素含量。结果 GK-S-12 cm组及GK-S-30 cm组大鼠体质量显著低于GK-Blank组,GK-S-3 cm组在各实验时间点均未观察到明显体质量下降。GK-S-30 cm组在胰岛素抵抗、口服和腹腔注射葡萄糖耐受性上,均显著优于GK-S-3 cm组与GK-Blank组。经葡萄糖灌胃,3个手术组胰岛素分泌、GLP-1水平都有明显改善,显著不同于GK-Blank组及GK-PF-Sham组。结论胃旁路手术中,通过构建不同的Roux肠袢长度,可不同程度缓解2型糖尿病病症。增加Roux袢长度,更有助于改善糖耐量,并提高胰岛素敏感性。     

Evaluation of hypoglycemic activity of total lignans from Fructus Arctii in the spontaneously diabetic Goto-Kakizaki rats

Ethnopharmacological relevance

Fructus Arctii, called “Niubangzi” in China (Great burdock achene in English), is a well-known Chinese Materia Medica. It is the dried ripe fruit of Arctium lappa L. (family Asteraceae) and was included in the Chinese pharmacopoeia for its traditional therapeutic actions. Meanwhile it has been utilized extensively in a number of classical drug formulas as a major component for the treatment of noninsulin-dependent diabetes mellitus. It has also been reported recently that the clinical use of Fructus Arctii resulted in a satisfactory hypoglycemic effect in diabetic patients. The aim of this study was to investigate hypoglycemic activity of total lignans from Fructus Arctii (TLFA) in Goto-Kakizaki (GK) rats, a spontaneous type 2 diabetic animal model, and the mechanism of its hypoglycemic activity.

Materials and methods

Male GK rats and normal Wistar rats were used in this study, GK rats fed twice daily were given TLFA (300 mg/kg) or nateglinide (50 mg/kg) orally before each meal for 12 weeks. Besides common evaluation indexes of hypoglycemic activity such as blood glucose level, oral glucose tolerance test (OGTT), glycated hemoglobin, as well as lipid metabolism parameters such as cholesterol (CHOL), triglycerides (TG), et al., in rat serum. The effects of TLFA on insulin secretion and pancreas tissue sections, the levels of serum glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and the α-glucosidase inhibitory activity of TLFA in vitro were investigated.

Results

TLFA demonstrated stable and long-lasting hypoglycemic activity in GK rats and showed significant improvement in glucose tolerance in glucose fed hyperglycemic GK rats. Both TLFA and nateglinide controlled the glycosylated hemoglobin levels of the experimental animals very well. Stimulation of insulin secretion was proved to be one of the hypoglycemic mechanism of TLFA, promoting the release of GLP-1 should be another one, and ɑ-glucosidase inhibitory activity of TLFA also contributes to its hypoglycemic activity. In this study, we didn't found that TLFA could effect the body weight of GK rats, which was also verified by the changes of biochemical parameters of blood in experimental rats.

Conclusion

The results of this study indicates that TLFA has significant hypoglycemic potential in GK rats, and it may be acting through stimulating insulin secretion, promoting the release of GLP-1, and decreasing intestinal absorption of glucose.     

Management of diabetic complications: A chemical constituents based approach

Ethnopharmacological relevance

Long term hyperglycemia leads to development of complications associated with diabetes. Diabetic complications are now a global health problem without effective therapeutic approach. Hyperglycemia and oxidative stress are important components for the development of diabetic complications. Over the past few decades, herbal medicines have attracted much attention as potential therapeutic agents in the prevention and treatment of diabetic complications due to their multiple targets and less toxic side effects. This review aims to assess the current available knowledge of medicinal herbs for attenuation and management of diabetic complications and their underlying mechanisms.

Material and methods

Bibliographic investigation was carried out by scrutinizing classical text books and peer reviewed papers, consulting worldwide accepted scientific databases (SCOPUS, PUBMED, SCIELO, NISCAIR, Google Scholar) to retrieve available published literature. The inclusion criteria for the selection of plants were based upon all medicinal herbs and their active compounds with attributed potentials in relieving diabetic complications. Moreover, plants which have potential effect in ameliorating oxidative stress in diabetic animals have been included.

Results

Overall, 238 articles were reviewed for plant literature and out of the reviewed literature, 127 articles were selected for the study. Various medicinal plants/plant extracts containing flavonoids, alkaloids, phenolic compounds, terpenoids, saponins and phytosterol type chemical constituents were found to be effective in the management of diabetic complications. This effect might be attributed to amelioration of persistent hyperglycemia, oxidative stress and modulation of various metabolic pathways involved in the pathogenesis of diabetic complications.

Conclusion

Screening chemical candidate from herbal medicine might be a promising approach for new drug discovery to treat the diabetic complications. There is still a dire need to explore the mechanism of action of various plant extracts and their toxicity profile and to determine their role in therapy of diabetic complications. Moreover, a perfect rodent model which completely mimics human diabetic complications should be developed.     

葡萄糖激酶基因逆转录病毒表达载体及包装细胞系的构建及鉴定

目的构建葡萄糖激酶(glucokinase,GK)基因逆转录病毒表达载体及稳定的产毒细胞系,为将GK基因应用于糖尿病的基因治疗打下基础.方法质粒pCMV4-GKZ1经EcoRⅠ/BamHⅠ双酶切后亚克隆至逆转录病毒载体PLXSN,构建成重组逆转录病毒表达载体PLX-GK,采用酶切及测序对重组体进行鉴定.而后脂质体转染PLX-GK至包装细胞PA317,检测培养上清病毒滴度,挑选滴度较高的稳定产毒细胞系并对其行PCR及免疫组化鉴定.结果构建了GK基因逆转录病毒表达载体PLX-GK,经酶切及序列分析证实目的基因插入位点和读码框架正确、无突变;建立了稳定产毒细胞系PA317/GK,其培养上清平均病毒滴度为6.8×105cfu/ml,最高为1.8×106cfu/ml,PCR及免疫组化证实GK基因整合入PA317/GK细胞基因组并有GK的表达.结论成功构建了携GK基因的逆转录病毒表达载体及高滴度的稳定产毒细胞系.     

蔗糖对GK/Wistar大鼠糖脂代谢及肝胰组织的影响

目的研究蔗糖对GK/Wistar大鼠糖脂代谢及其肝、胰组织的影响。方法GK和Wistar大鼠各32只,随机分为W(Wistar)组、WS(Wistar+30%蔗糖)组、G(GK)组和GS(GK+30%蔗糖)组。WS、GS组给予30%蔗糖饮水,另两组给予正常饮水。实验期间每周测定一次空腹血糖,于实验开始后的2、4、6、10周时间点处死部分动物,收集血液并分离肝脏和胰腺,测定甘油三酯、葡萄糖、总胆固醇等生化指标,常规组织病理学检测肝脏和胰腺的病理改变。结果给予蔗糖水后,随着时间的延长,WS组体重和血清TG呈升高趋势,血清TC、Glu未发现相应的趋势,胰腺、肝脏病理损伤呈加重趋势,且胰腺损伤出现时间早于肝脏;GS组除WS组的发现外,血清TC呈先降低后恢复趋势,血清Glu呈先降低后升高趋势,且胰腺损伤要比WS组出现得更早、更严重,肝脏损伤也更严重。结论蔗糖可引起或加重GK/Wistar大鼠的糖脂代谢紊乱以及肝胰组织的病理性损伤,并呈现一定的时效关系。