大明胶囊对1型糖尿病大鼠的降糖作用及机制

Glucose-lowering effects of Daming capsule in type 1 diabetic rats and its mechanisms

目的研究大明胶囊(Daming capsule,DM)对链脲佐菌素(streptozocin,STZ)诱导的1型糖尿病大鼠的血糖影响。方法将65只成年雄性Sprague-Dawley(SD)大鼠随机分为5组:DM低(50 mg·kg-1·d-1)、中(100 mg·kg-1·d-1)、高(200 mg·kg-1·d-1)剂量组、空白组及模型组。灌胃给予大鼠不同浓度的DM,空白组和模型组给予同等体积的生理盐水,每天两次。两周后,腹腔注射STZ 65 mg·kg-1建立1型糖尿病模型。STZ注射后3天、7天检测大鼠空腹血糖,1个月后检测糖耐量。苏木素-伊红(HE)染色和末端脱氧核糖核苷酸转移酶介导的缺口末端标记法(TUNEL)观察各组胰岛形态学和凋亡。结果 DM显著降低STZ诱导糖尿病大鼠的空腹血糖值并改善糖尿病大鼠的糖耐量;在STZ大鼠,HE染色显示DM升高STZ大鼠胰岛的数量;TUNEL染色结果显示DM组的胰岛β细胞凋亡较STZ模型组显著减少。结论预防性给予DM能降低STZ诱导的1型糖尿病大鼠空腹血糖并明显改善糖耐量,减少胰岛β细胞凋亡。

Objective To study the protective effects of Daming capsule （ DM） in type 1 dia-betic rats.Methods Sixty-five male sprague-dawley （SD） rats were randomly divided into 5 groups （13 rats/group）：low dose group （50 mg·kg^-1·d^-1 ）, middle dose group （100 mg·kg^-1·d^-1 ） , high dose group of DM （ 200 mg·kg^-1·d^-1 ） , control group , and diabetes group .DM group received DM twice a day via gavage for two weeks;control group and diabe-tes group received equal volume of distilled water .Rats were administered with a single intra-peritoneal （ i.p.） injection of streptozocin （ STZ） 65 mg·kg^-1 after two weeks of DM .The fasting blood glucose was measured on day 3 and 7 after STZ treatment and glucose tolerance test was performed on day 30 after STZ treatment.Hematoxylin and eosin stain （HE stain） and terminal-deoxynucleotidyl transferase mediated nick end labeling （ TUNEL ） assay were per-formed on the pancreas of the rats .Results Significant increase in the fasting blood glucose and abnormal glucose tolerance were found in the STZ-treated rats compared to controls （ P〈0.05 ） .Rats treated with different doses of DM had significant decrease in the fast blood glu-cose （ P 〈0.05 ） and profound improvement in glucose tolerance in diabetic rats .HE stain showed that DM protected pancreatic islet against STZ damage , reflected by increase of number of pancreatic islets in diabetic rats （ P〈0.05 ） .TUNEL results showed that DM attenuated ap-optosis of pancreatic β-cells compared with diabetes group .Conclusion DM decreases the fasting blood glucose level and improves glucose tolerance by at least protecting β-cells from ap-optosis in type 1 diabetic rats .