The Establishment And Application Of Anti-diabetic Drug Screening Model

OBJECTIVE To establish drug screening methods for finding natural small molecular compounds with anti-diabetic activity, in the programs of discovering new drugs with novel mechanism or novel structure.METHODS First, a cell-based glucose uptake screening model was developed by using 3T3-L1 preadipocyte for new small molecules stimulating glucose uptake as insulin. Second, another drug screening model based on reporter gene and the signal transduction of PPARγ system was established for finding new small molecular compounds with activity of improving insulin sensitivity. Last, experimental diabetes mice and rats models were prepared for confirming the hypoglycemic effects of "hit" compounds.RESULTS (1) Glucose uptake was stimulated by insulin in a dose-dependent manner. Among the 200 compounds , 41 compounds were found to have different levels of activity of promoting glucose uptake. (2) No effect of rosiglitazone maleate on the proliferation of 293T was observed. Stably transfected clones were obtained. The expression of reporter gene Luc from one of the cell clones was induced by rosiglitazone maleate in a dose-dependent manner. The speciality and stability of the developed method were good. The expression levels of Luc induced by NO.60,144 and HJ-12 were up to 2 fold. While the expression levels of Luc induced by NO. 196, QB-3 and 203 were about 1.5 fold. (3) NO.253 significantly reduced the blood glucose level in ALX induced diabetic mice, while NO.60, 144, 211 did not show the same effect. (4) NIDDM rat model was established by treating with low-dose STZ plus high sucrose-fat diet. Significant decrease of serum glucose, triglyceride and insulin level in NO.211 treated group were observed. (5) It was observed that significant decrease in blood glucose level in normal mice treated with NO.60. Significant decrease in blood glucose levels in glucose loaded mice was also observed after pre-treating with NO.60 and 253.CONCLUTION (1) The glucose uptake model was characterized as the low cost, the low quantity of sample, the high screening efficiency etc, except the poor stability and speciality. Another drug screening model was characterized as the single target, the certain mechanism and the preferable speciality and stability. There were about 80% of the mice can be induced by tail-vein injection of ALX. (2) Among the 41 compounds which with the activity of stimulating glucose...