Obesity of many peoples all-over the world urges them to change their life style and food habits, one of these habits is the recent world-wide use of conjugated linoleic acid (CLA) as a dietary supplement in many countries to control body weight. Many studies were done on the conjugated linoleic acid addressing its role in decreasing the body weight, however many of them have conflicting results and didn't consider the effect of CLA isomers on gene expression level. This study aimed to monitor the possible mechanisms of different CLA isomers in controlling body weight and lipid oxidation at gene expression of the main lipolytic enzymes in rats. From the present results it can be concluded that the different isomers of CLA especially T10C12 isomer able to control body weight via induction of lipolysis through activation of peroxisome proliferators-activated receptor-β(PPAR-β) and its inducible enzymes as carnetine palmetoyl transferase(CPT1), hormone sensitive lipase(HSL) and lipoprotein lipase(LPL).
Key words: Body weight, CLA (Conjugated Linoleic Acid), CPT1 (carnitine palmetoyl transferase), HSL (hormone sensitive lipase), LPL (lipoprotein lipase), PPAR-β (peroxisome proliferators-activated receptor-β)