Regulatory effect of coptisine on key genes involved in cholesterol metabolism / 中国中药杂志

To study the effect of cholesterol and 25-OH-cholesterol on cholesterol metabolism in HepG2 cells and the effect of coptisine (Cop) extracted from Coptidis Rhizoma (CR) in reducing and regulating cholesterol. In this study, TC, TG, LDL-c and HDL-c were measured by biochemical analysis; mRNA and protein expressions of LDLR, HMGCR and CYP7A1 were detected by qRT-PCR and Western blot. According to the results, cholesterol and 25-OH-cholesterol inducing could decrease in mRNA and protein expressions of LDLR and CYP7A1, so as to increase TC and LDL-c contents. However, Cop could up-regulate mRNA and protein expressions of LDLR and CYP7A1 and down-regulate that of HMGCR, so as to reduce TC and LDL-c levels. These findings suggested that Cop has potential pharmacological activity for reducing cholesterol, and may reduce cholesterol by regulating mRNA and protein expressions of key genes involved in cholesterol metabolism, such as LDLR, CYP7A1 and HMGCR. This study laid a firm theoretical foundation for developing new natural drugs with the cholesterol-lowering activity.

Efficient and rapid liquid reduction animal model / 中国中药杂志

To investigate the practicability of establishing zebrafish lipid-lowering drug screening model and the effect of berberine (BBR) on hyperlipidemic zebrafish. Three-month-old zebrafishes were fed with 4% cholesterol for 0, 2, 4, 8, 14, 20, 25, 30 days, and the level of total cholesterol in serum was measured. Zebrafish were randomly divided into four groups: the control group, the high cholesterol diet group, the 0.01% simvastatin-treated group, the 0.1% berberine-treated group and the 0.2% berberine-treated group. The levels of total cholesterol (TC), triglyceride (TC), low density lipoprotein cholesterol (LDL-c) and high-density lipoprotein cholesterol (HDL-c) in serum were measured; the expression of hepatic HMGCR, LDLR and CYP7A1a mRNA expressions were detected by real time PCR. Oil red O staining was performed to observe the changes in fat content in the liver. According to the result, the level of serum TC in the 4% cholesterol diet group significantly was higher than that of the normal control group in a time-dependent manner and reached a stable level at the 20th day. The BBR group showed significant decreases in the levels of TC, TG and LDL-c, HMGCR mRNA expression and fat content and increases in LDLR and CYP7A1a mRNA. The hyperlipidemia zebrafish model was successfully established by feeding with 4% cholesterol for 20 days. The findings lay a foundation for further screenings on lipid-lowering drugs.

Effects of alkaloids from Coptidis Rhizoma on mouse peritoneal macrophages in vitro / 中国中药杂志

This work was mainly studied the effects of the four alkaloids from Coptidis Rhizoma on the mouse peritoneal macrophages in vitro and preliminarily discussed the regulating mechanisms. The effect of alkaloids from Coptidis Rhizoma on the vitality of macrophages was measured by the MTT assay. The effect of alkaloids on the phagocytosis of macrophages was determined by neutral red trial and respiratory burst activity was tested by NBT. The expressions of respiratory-burst-associated genes influenced by alkaloids were detected by qRT-PCR. The conformation change of membrane protein in macrophages by the impact of alkaloids was studied by fluorospectro-photometer. Results showed that the four alkaloids from Coptidis Rhizoma could increase the phagocytosis of macrophages in different level and berberine had the best effect. Berberine, coptisine and palmatine had up-regulation effects on respiratory burst activity of mouse peritoneal macrophages stimulated by PMA and regulatory activity on the mRNA expression of PKC, p40phox or p47phox, whereas the epiberberine had no significant influence on respiratory burst. Moreover, alkaloids from Coptidis Rhizoma could change the conformation of membrane protein and the berberine showed the strongest activity. The results suggested that the four alkaloids from Coptidis Rhizoma might activate macrophages through changing the conformation of membrane protein of macrophages and then enhanced the phagocytosis and respiratory burst activity of macrophages. Furthermore, the regulatory mechanism of alkaloids on the respiratory burst activity of macrophages may be also related to the expression level of PKC, p40phox and p47phox.