[Preliminary study on mechanisms of total saponins from Entada phaseoloides against diabetes].
OBJECTIVE
To study the effect of total saponins from Entada phaseoloides (TSEP) on islet morphology and skeletal muscle PI3K pathway-related protein expression of type 2 diabetic rats.


METHODS
Type 2 diabetic rats were induced by high-fat diet and low-dose streptozotocin and then randomly divided into 5 groups, i.e. the normal control, the model group, the positive control drug (200 mg x kg(-1) metformin), the low-dose TSEP (25 mg x kg(-1)) group and the high-dose TSEP (50 mg x kg(-1)). Three weeks later, the islet morphology of rat pancreas were observed by HE staining, and protein expressions of insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3-kinase (PI3K), protein tyrosine phosphatase-1B (PTP-1 B) and glucose transporter 4 (GLUT4) in rat skeletal muscle were detected by Western blot.


RESULTS
Compared with the modal group, TSEP administration groups showed relatively normal structures, clear pancreatic cells and intact capsula structures in pancreatic tissue pathological sections, with the number of pancreatic islets close to the normal control group. Meanwhile, above TSEP administration groups showed increased IRS-1, PI3K and GLUT4 protein expressions in their skeletal muscle tissues and decreased PTP-1B protein expression compared with the model group.


CONCLUSIONS
TSEP has an effect on protecting pancreatic tissues of type 2 diabetic rats and intervening in abnormal expression of proteins in skeletal muscle tissues.
College of Pharmacy, South-central University for Nationalities, Wuhan 430074, China.
Tao
T
Zheng
Guangwen
G
Shu
Zhanzhan
Z
Yang
Shasha
S
Mo
Yin
Y
Zhao
Zhinan
Z
Mei
D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D007887:Fabaceae / Q000737:chemistry*; D051275:Glucose Transporter Type 4 / Q000032:analysis; D007515:Islets of Langerhans / Q000187:drug effects / Q000473:pathology; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000473:pathology; D019869:Phosphatidylinositol 3-Kinases / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012503:Saponins / Q000627:therapeutic use*
D051275:Glucose Transporter Type 4; D012503:Saponins; C495694:Slc2a4 protein, rat; D019869:Phosphatidylinositol 3-Kinases