Pharmacological Actions And Mechanisms Of Pentamethylquercetin On 3T3-L1 Cells

Phytopolyphenol of flavonoids have always been highly concerned in the medicine kingdom. We synthesized pentamethyl- quercetin (PMQ) that is high purity and low price. PMQ is the derivate of Quercetin. The chemical constitution of the Quercetin is 3,5,7,3′,4′-pentalmethylquercetin, the five hydroxide group on the Quercetin are substituted with methoxy group. Polymethoxylflavonoids have obvious pharmacokinetics characteristics and pharmacodynamics advantage than Polyhydroxyflavonoids. For example they have stable chemical property; have advantage to process, deliver, store and so on... And they have high bioavailability, enhance absorption in stomach intestine, depress the first pass elimination, and keep high level of plasma concentration and last longer time. It is confirmed that they have a variety of biological activities, including anti-oxidation, inhibition of platelet aggregation, free radical scavenging, anti- inflammatory, blood pressure reduction, vasodilatation, protection of endothelium and so on.Metabolic Syndrome which is described as a group of high risk of factors such as visceral abdominal fat, improved insulin sensitivity, high blood pressure and elevated HDL. An epidemic of obesity is threatening to undermine the health of people living in Westernized societies. Obesity is a major risk factor for insulin resistance, hyperglycemia, abnormal blood lipid profiles, and hypertension, all of which contribute to cardiovascular disease leading to stroke and myocardial infarction Peroxisome proliferator-activated receptor-γ(PPAR-γ) is a key regulator of lipid metabolism and energy balance implicated in the development of insulin resistance and obesity. PPAR-γactivation promotes adipocyte differentiation and is associated with induction of lipogenic enzymes and glucoregulatory molecules. The MS rat which PPAR-γare activated and the cytokine secretion are changed can be seen in the mRNA expressed use PCR. In our experiments, we study the effects of PMQ on 3T3-L1 cells, testing the PPAR-γexpression, the cells increasing and the cell differentiation. PartⅠEffects of PMQ on 3T3-L1 Dipocytes in the mRNA Expession of PPAR-γand AdiponectinObjective: To observe the influence of PMQ on the expression of PPAR-γand adiponectin mRNA in 3T3-L1 preadipocytes. Methods: After 4 days of the differentiation of 3T3-L1 preadipocytes was induced by insulin, IBMX and DEX and PMQ (0.1, 0.3, 1, 3, 10, 30μmol·L-1) The adiponectin just has 4 PMQ groups: 0.1,0.3,1,3μmol·L-1 and rosiglitazone (1, 10μmol·L-1) were added in medium respectively. Afer 24h, cells were harvested and total RNA was isolated with TRIzol reagent (Invitrogen) in accordance with the manufacturer's instructions. RT-PCR was used to measure the expression of adiponectin mRNA. Results: 1. Compare with the control group the concentration of PMQ on 0.3μmol·L-1,1μmol·L-1,3μmol·L-1 can activate the PPAR-γin the mRNA level, and has statistical significance. And on the concentration of 1μmol·L-1 PMQ has got the highest effect. 2. The concentration from 0.1~ 3μmol·L-1PMQ have activated adiponectin expression in a dose-dependent manner. And the concentration of 0.1~ 1μmol·L-1PMQ have statistical significance. Conclusion: PMQ significantly up-regulate the mRNA expression of PPAR-γand adiponectin in 3T3-L1 cells. PMQ is about 30 fold more potent than rosiglitazone.PartⅡThe effect of PMQ on Cell Proliferation in 3T3-L1 AdipocytesObjective: To study the effects of PMQ on 3T3-1L preadipocytes proliferation. Methods: 3T3-L1 preadipocytes were cultured with or without PMQ for 24, 48, and 72 h respectively. MTT was adopted to detect the proliferation. Results: At 24 h, PMQ (0.1, 0.3, 1, 3, 10, 30, 100μmol·L-1) could not affect 3T3-L1 preadipocytes proliferation. At 48 h, 100μmol·L-1 PMQ markedly inhibit the proliferation of 3T3-L1 preadipocytes (P<0.01). At 72h, 10, 30, 100μmol·L-1 PMQ could significantly inhibit the 3T3-L1 preadipocytes proliferation. Conclusion: The effective concentration of inhibit profliration has decreased when the treatment time of PMQ prolonged (24-72 h), suggested that treatment time has significant influence on drug effect.PartⅢEffects of PMQ on the 3T3-L1 Preadipocyte DifferentiationObjective: To study the influences of PMQ on 3T3-L1 preadipocytes differentiation. Methods: After 2 days of confluence (day 0), the differentiation of 3T3-L1 preadipocytes was induced by insulin, IBMX and DEX. Afer 4 days, PMQ (0.1, 0.3, 1, 3, 10, 30, 100μmol·L-1) and rosiglitazone (1, 10μmol·L-1) were added in medium respectively. The next day, cells were harvested and stained by Oil Red O. Results: Rosiglitazone could markedly enhance the differentiation of 3T3-L1 preadipocytes. However, PMQ on the all the concentrations we have used have no effect on the 3T3-L1 adipocytes differentiation. Conclusion: the concentration of 0.1~30μmol·L-1PMQ have no significant effect on 3T3-L1 adipocytes differentiation.