In vitro activation of peroxisome proliferator activated receptor alpha by some extracts from food materials

[[abstract]]Peroxisome proliferator activated receptor a (PPAR alpha) is a ligand-dependent transcription factor that regulates the expression of genes involved in lipid metabolism and transport. Activators of PPAR alpha may be potential hypolipidemic agents, like the fibrate-type drugs. This study was therefore aimed at identifying potential hypolipidemic functional foods by screening activators of PPAR(X from food materials. CHO-K1 cells were stably transfected with vectors (pBKCMV) carrying cDNAs of a (UAS)(4)-tk-alkaline phosphatase reporter and a chimeric receptor Ga14-PPAR alpha LBD successively. Clones of cells responsive to Wy-14643, a known PPAR alpha activator were selected, characterized and used for testing the PPAR alpha activating potency of fractions extracted from food materials. Food materials were extracted with ethyl acetate and the extract (EAE) was cold-saponified and tested for the PPARct activating ability using the selected stable transfected clone of cells. 10 mu M Wy-14643 (WY) was used as the positive control. Among food materials tested, EAE of bitter gourd showed the highest activity that exceeded Wy-14643, although the activity significantly decreased after saponification. The non-saponifiable fraction of onion EAE had a high maximal fold of activation equivalent to Wy-14643, while that of peanut, lychee, ricinus seed and longan showed moderate activity. The saponifiable fraction of ricinus seed, sesame and peanut also showed moderate activity. Further investigation is needed to explore the health benefit of the PPAR alpha activating food extracts found in this Study