Abstract: Objective To establish a natural Chinese herbal cytological screening method through the establishment of stably transfected 3T3-L1 cell line with the luciferase reporter gene expression plasmid containing human PPARγ2 gene promoter. Methods Firstly, the luciferase reporter gene expression plasmids containing various length PPARγ2 gene promoter sequence were constructed by using pGL3-Basic-luc and pGL3-Enhancer-luc as vector. The stably transfected 3T3-L1 cell line was stablished, and twenty-eight kinds of extracts of Chinese medical herbs (ECMH)were selected. Finally the effects of these ECMH on the luciferase expression in 3T3-L1 cells were observed. Results The luciferase expression of 3T3-L1 cells stably transfected withpGL3- Enhancer -PPARγ2 625bp-Luc plasmid was the highest,about 200 times than the background. Therefore, this cell line was selected for the following screening experiment. Our results showed that the administration of safflower ECMH(10，100, and 1000μg / mL)significantly promoted the luciferase expression of 3T3-L1 cells .it was 1.63 , 1.90 , and 2.30 (p<0.05) of no drug intervention cells. Similarity,Leaves and madder ECMH (10 ~ 1000μg / mL)also notably increased the luciferase expression of 3T3-L1 cells. The highest actions were observed, at a concentration of 1000μg / mL，which were 2.03 (p<0.01) and 2.00 times of the control group (p<0.01), respectively. Conclusions Stable transfection of 3T3-L1 cell line with pGL3- Enhancer -PPARγ2 625bp-Luc plasmid was successfully established. Using this cell line safflower,leaves,madder ECMH were found to significantly promote human PPARγ2 gene promoter activities, and they may become potential weight loss medicine in the future.

Key words: Key words: peroxisome proliferator activated receptor gamma （PPARγ2）, Extracts of Chinese Medical Herbs（ECMH）, Plasmid construction, Stable transfection, 3T3-L1 preadipocytes