In vitro Screening and Evaluation of 37 Traditional Chinese Medicines for Their Potential to Activate Peroxisome Proliferator-Activated Receptors-γ.

Background: Peroxisome proliferator-activated receptors (PPAR)-gamma is widely used as an attractive target for the treatment of type 2 diabetes mellitus. Thiazolidinediones, the agonists of PPAR gamma, has been popularly utilized as insulin sensitizers in the therapy of type 2 diabetes whereas numerous severe side-effects may also occur concomitantly. Objective: The PPAR. activation activity of different polar extracts, including petroleum ether, ethyl acetate, n-butanol, residual of ethanol, the precipitate part of water and the supernatant of water extracts, from 37 traditional Chinese medicines were systematically evaluated. Materials and Methods: HeLa cells were transiently co-transfected with the re-constructed plasmids of GAL4-PPAR gamma-ligand binding domain and pGL4.35. The activation of PPAR. by different polarity extracts were evaluated based on the PPAR. transactivation assay and rosiglitazone was used as positive control. Results: Seven medicines (root bark of Lycium barbarum, Anoectochilus sroxburghii, the rhizome of Phragmites australis, Pterocephalus hookeri, Polygonatum sibiricum, fruit of Gleditsia sinensis, and Epimedium brevicornu) were able to significantly activate PPAR gamma. Conclusion: As seven medicines were able to activate PPAR gamma, the anti-diabetic activity of them is likely to be mediated by this nuclear receptor.