Abstract: AIM: To study the effects of naringin and naringenin on the expression of peroxisome proliferator-activated receptors δ(PPAR-δ) in peripheral blood monocyte of diet-induced obese rats. METHODS: The experimental animals were divided into normal diet control group, high-fat diet control group and high-fat diet groups treated with high or low dose of naringin and naringenin, respectively.After treated by high lipid emulsion garage except for normal diet control group, the high-fat diet rat models were established successfully.Then, vehicle (0.5%CMC) or different dosages of naringin or naringenin had been given to the rats for 8 weeks.The PPAR-δ mRNA expression was detected by reverse transcription polymerase chain reaction ( RT-PCR) , the serum levels of triglyceride, total cholesterol, high density lipoprotein-cholesterol,low density lipoprotein-cholesterol and very low density lipoprotein-cholesterol were measured respectively.RESULTS: Compared with the high-fat diet control group,the levels of triglyceride, total cholesterol, low density lipoprotein-cholesterol and very low density lipoprotein-cholesterol were decreased in high dose of naringin and naringenin groups(all P<0.01);the level of high density lipoprotein-cholesterol was increased(P<0.01);the expression of PPAR-δ mRNA in peripheral blood monocyte in high dose of naringin and naringenin groups was increased (P<0.05).The positive correlation between PPAR-δ(r=0.158, P<0.05) and triglyceride, total cholestero(r=0.147, P<0.05) were observed through correlation analysis. CONCLUSION: The high dosages of naringin and naringenin might reduce the levels of serum lipid and increase the expression of PPAR-δ in peripheral blood monocyte.

Key words: Naringin, Naringenin, Hyperlipidemia, Peroxisome proliferator-activated receptors δ