Preliminary study on effect of Gegen Qinlian Decoction on enzyme activity, gene expression and methylation level of FASN in adipose tissue of rats with insulin resistance / 中国中药杂志

To investigate the effect of Gegen Qinlian Decoction(GQD) on enzyme activity, gene expression and methylation level of fatty acid synthase(FASN) in adipose tissue from rats with insulin resistance induced by high-fat diet. The 60% fat-powered high-fat diet was continuously given to male SD rats to induce the insulin resistance model. Then, they were divided into five groups randomly and administrated by gavage every day for 16 weeks with following drugs respectively: 10 mL·kg~(-1)water for control group(C) and insulin resistance model control group(IR), 1.65 g·kg~(-1)GQD per day for low-dose group(GQDL), 4.95 g·kg~(-1)GQD per day for medium-dose group(GQDM), 14.85 g·kg~(-1)GQD per day for high-dose group(GQDH), and 5 mg·kg~(-1) rosiglitazone per day for rosiglitazone group(RGN). Epididymal adipose tissue was taken to determine enzyme activity of FASN by colorimetric method, mRNA expression level of Fasn by quantitative Real-time PCR(Q-PCR) and CpGs methylation level between +313 and +582 by bisulfite sequencing PCR(BSP). These results showed that Fasn expression was significantly lowered in IR model rats compared with the control rats(P<0.01). Enzymatic activity and CpGs methylation level of Fasn in IR group showed downward trends. Low and medium-dose GQD can increase enzyme activity of FASN(P<0.05). Moreover, low-dose GQD increased the total CpGs methylation level of Fasn fragment between +313 and +582 in insulin resistance rats(P<0.05). For GQDM group, the methylation frequency of CpGs at positions +506 and +508(P<0.01) as well as the methylation frequency of CpGs on the binding sites of transcription factorzinc finger protein 161(P<0.05) were significantly increased. The methylation frequency of CpG at +442 position was positively correlated with Fasn expression(P<0.01, r=0.735), and methylation frequencies of CpGs at +345 and +366 positions were positively associated to enzyme activity of FASN respectively(P<0.05, r=0.479; P<0.01, r=0.640). In conclusion, GQD can reverse enzyme activity of FASN and methylation level of Fasn in adipose tissue of insulin resistant rats, and CpG sites at positions +506 and +508 may be the targets of GQD. The methylation level of CpGs at + 345 and + 366 sites were possibly related to FASN activity, while methylation of CpG at + 442 site may be closely correlated with mRNA level of Fasn. In addition, GQD did not significantly change mRNA expression level of Fasn, but effectively reversed enzymatic activity, suggesting that GQD may regulate the post transcriptional expression of Fasn.

Effect of Ligustri Lucidi Fructus on hepatic COX activity in normal rats and preliminary investigation of its DNA methylation mechanism / 中国中药杂志

The study aims to investigate the effect of Ligustri Lucidi Fructus on cytochrome c oxidase(COX) activity in rat hepatic tissues and explore its possible mechanism of DNA methylation. Male SD rats received aqueous extract of Ligustri Lucidi Fructus (2.0，6.0 g•kg⁻¹) by intragastric administration for 30 d. After the rats were sacrificed, hepatic tissues of rats were taken to detect COX activity, protein concentration of COX4I1, TET1 and DNMT3A protein levels, mRNA expression levels of Cox4i1, Dnmt3a and Tet1, and determine the DNA methylation frequency of Cox4i1.Results showed that both low and high doses of Ligustri Lucidi Fructus could significantly increase COX activity and concentration of COX4I1(P<0.05), with a decreasing tendency of both TET1 protein and DNMT3a protein expression； however, mRNA expression levels of Cox4i1, Dnmt3a and Tet1 were not significantly changed by Ligustri Lucidi Fructus. In addition, DNA methylation frequency of Cox4i1 in high dose group showed a declining tendency as compared with the blank control group, but without significant difference.These results indicated that Ligustri Lucidi Fructus had promotive effect on hepatic COX activity in rats, which may be achieved by increasing protein content of COX4I1. Moreover, a decreased tendency of DNMT3A protein could be one of the reasons for the lower trend of Cox4i1 methylation rate. In addition, Ligustri Lucidi Fructus may regulate the expression levels of DNMT3A and TET1 in the same direction and its mechanism is not clear.

Effect of euodiae fructus on hepatic energy metabolism-related mechanisms of reserpine-induced asthenia cold syndrome rats / 中国中药杂志

<p><b>OBJECTIVE</b>To discuss the effect of Euodiae Fructus on hepatic energy metabolism-related mechanisms of mitochondria of hepatic tissues of asthenia cold syndrome rats.</p><p><b>METHOD</b>Rats were subcutaneously injected with Reserpine to establish the model. After the oral administration with Euodiae Fructus for 12 d, the oxygen electrode method was adopted to determine the respiration efficiency. The expressions of Cox4, Atp5b, Ucp2,Pgc-1alpha, Nrf1, Tfam mRNA were assayed by using RT-PCR method.</p><p><b>RESULT</b>Euodiae Fructus 4.2 g x kg(-1) could obviously increase ST3 and RCR of asthenia cold syndrome rats, and expressions of Cox4, Ucp2 Nrf1 mRNA. It could also increase expressions of Atp5b and Pgc-1alpha mRNA, but with no statistical significance. No obvious change was observed in Tfam mRNA expression. Euodiae Fructus 4.2 g x kg(-1) could significantly increase ST3 and RCR of asthenia cold syndrome rats and Pgc-1alpha mRNA and Nrf1 mRNA expressions, and significantly decrease P/O, with no obvious impact on Cox4, AtpSb, Ucp2, Tfam mRNA expressions.</p><p><b>CONCLUSION</b>Euodiae Fructus can promote mitochondrial respiratory function and oxidative phosphorylation efficiency by improving Pgc-1alpha mRNA and Nrf1 mRNA expressions and regulating Cox4 and Atp5b mRNA in mitochondrial respiratory chain. It can also strengthen mitochondrial uncoupling respiration and add heat production by activating Ucp2 mRNA expression in liver.</p>