[Study on membrane injury mechanism of total alkaloids and berberine from Coptidis Rhizoma on Aeromonas hydrophila].

To explore the antibacterial activity and mechanism of total alkaloids and berberine from Coptidis Rhizoma on Aeromonas hydrophila, and determine the effect of total alkaloids and berberine from Coptidis Rhizoma on minimum inhibitory concentrations, permeability and fluidity of cell membrane, conformation of membrane proteins and virulence factors of A. hydrophila. The results showed that both total alkaloids and berberine from Coptidis Rhizoma had antibacterial activities on A. hydrophila, with minimum inhibitory concentrations of 62.5 and 125 mg · L(-1), respectively. Total alkaloids and berberine from Coptidis Rhizoma could increase the fluidity of membrane, change the conformation of membrane porteins and increase the permeability of bacteria membrane by 24.52% and 19.66%, respectively. Besides, total alkaloids and berberine from Coptidis Rhizoma significantly decreased the hemolysis of exotoxin and the mRNA expressions of aerA and hlyA (P < 0.05, P < 0.01), the secretion of endotoxin and the mRNA expression of LpxC (P < 0.05, P < 0.01). The results suggested that the antibacterial activity of total alkaloids and berberine from Coptidis Rhizoma on A. hydrophila may be related to the bacteria membrane injury. They inhibited the bacterial growth by increasing membrane lipid fluidity and changing conformation of membrane proteins, and reduced the secretion of virulence factors of A. hydrophila to weaken the pathogenicity.

[Comparative study of pharmacokinetics and tissue distribution of 8-cetylberberine and berberine in rats].

The concentrations of berberine (BBR) and 8-cetylberberine (8-BBR-C16) in rat plasma and tissue were determined by RP-HPLC. Both the plasma pharmacokinetics characteristic and tissue distribution differences of BBR and 8-BBR-C16 were compared to provide experimental data for the mechanism research and further drug development. After the oral administrations of BBR and 8-BBR-C16 at the dose of 80 mg x kg(-1) for rats, the pharmacokinetics result showed that compared with BBR, the C(max) and AUC(0-t), of 8-BBR-C16 increased by 2.8 times and 12.9 times respectively, t1/2 extended from 3.61 h to 11.90 h. The tissue distribution result showed that compared with BBR, the concentration of 8-BBR-C16 in various organizations increased and the retention time extended remarkably. The maximum concentration was achieved in lung and the highest concentration in it was 3 731.82 ng x g(-1). After being derived, the C(max) in plasma and bioavailability of 8-BBR-C16 increased remarkably and the circulation time in vivo extended. The drug concentration in tissue increased remarkably, and the distribution ratio changed too, with strong targeting selection in lung.

[Effect of different parts, harvesting time and processing technologies on alkaloids content of Coptis chinensis adventitious root].

OBJECTIVE: To investigate the effect of different parts, harvesting time and processing technologies on alkaloids content of Coptis chinensis adventitious root. METHODS: The content of alkaloids were analyzed by HPLC. RESULTS: The content of total alkaloids in adventitious root harvested in different time was ranged from 2.5% to 2.9%, in which that of berberine and coptisine were the highest, reaching to 1%, and that of palmatine was only 0.1%. It suggested there was no significant difference of total alkaloids at different harvesting time. Nevertheless, the difference of the alkaloids content from different parts was much significant. The content of total alkaloid of adventitious root near to rhizome was about 4%, 2 times higher than that away from rhizome (only 2%). In addition, different processing technologies would affect alkaloids content obviously. There was hardly loss of alkaloids when the fresh adventitious root was washed with water, but it would decrease alkaloids content when the dried adventitious root was washed. CONCLUSION: Medicine value of Coptis chinensis adventitious root near to rhizome is higher than that away from rhizome. And fresh Coptis chinensis adventitious root can be washed with water.

Activation of Akt and JNK/Nrf2/NQO1 pathway contributes to the protective effect of coptisine against AAPH-induced oxidative stress.

Coptisine (COP) is one of the main active constituents of Coptidis Rhizoma. Previous studies have clarified that COP possesses antioxidant activity, but its defensive effects against pathological characteristics accompanied by oxidative damage in animal models and antioxidant mechanism are still unclear. Therefore, our purpose was to confirm the antioxidant activity of COP and explore its mechanism of action. We first detected the effects of COP on intracellular reactive oxygen species (ROS), heart beating rate, lipid peroxidation and cell death in zebrafish model with AAPH-induced oxidative stress. The results showed that COP of 10µg/mL significantly reduced ROS production, the increase of heart beating rate, lipid peroxidation and cell death by 41.3%, 24.5%, 26.5% and 30.0%, respectively. In addition, COP of 0.8µg/mL also decreased ROS, increased glutathione (GSH) content and elevated activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) by 40.1%, 19.8%, 18.3% and 49.3%, respectively in HepG2 cells. Further assays were carried out to explore the mRNA expression in zebrafish and protein expression of key factors in HepG2 cells. We demonstrated that COP up-regulated phase II antioxidant enzymes NAD(P)H/quinone oxidoreductase 1 (NQO1) through activating the nuclear factor erythroid-2 related factor 2 (Nrf2). Moreover, as the upstream signalings of Nrf2, the protein kinase B (Akt) and c-Jun NH2-terminal kinase (JNK) signalings were also induced by COP. And up-regulating Nrf2-mediated NQO1 expression of COP was in Akt and JNK-dependent manner. Taken together, COP exerted its antioxidant activity against AAPH-induced toxicity involving in activating Akt and JNK/Nrf2/NQO1 pathway.

The protective effect of coptisine on experimental atherosclerosis ApoE-/- mice is mediated by MAPK/NF-κB-dependent pathway.

Coptisine is one of main bioactive compounds extracted from the traditional Chinese herbal medicine Rhizoma Coptidis. It is reported that coptisine can attenuate obesity-related inflammation and oxidant damage in Syrian golden hamsters. Therefore，coptisine may exhibit beneficial effects for the treatment of atherosclerosis (AS) due to its hypolipidemic and anti-inflammation activities. The present study investigated the anti-atherosclerotic and anti-inflammatory properties of coptisine using apoE-/- mice as AS model. The atherosclerotic plaque area of aorta, serum lipid profile and the expression of inflammatory cytokines were determined. After coptisine treatment, the serum level of TC, TG and LDL-C decreased; the serum level of IL-6, IL-1ß and TNF-α were decreased; the mRNA levels of NF-κBp65, VCAM-1, ICAM-1, IL-6 and IL-1ß in both aorta and liver were down-regulated; the p-p38 and p-JNK1/2 protein expression level were decreased. Coptisine decreased atherosclerotic plaque area significantly through both anti-inflammation and lipid lowering effect. The anti-inflammatory effect of coptisine is achieved through inhibiting activation of MAPK signaling pathways and NF-κB nuclear translocation. Therefore，the combined anti-inflammation and lipid lowering effect of coptisine attributed the decreased atherosclerotic plaque area in coptisine treated apoE-/- mice. The results of this study will afford a novel application for coptisine in the treatment of atherosclerosis and other chronic inflammatory disease.

Epiberberine reduces serum cholesterol in diet-induced dyslipidemia Syrian golden hamsters via network pathways involving cholesterol metabolism.

This study aimed to evaluate the cholesterol-lowering effect of epiberberine in dyslipidemia Syrian golden hamsters induced by high fat and high cholesterol (HFHC) diet and its regulation mechanism on some key genes involved in cholesterol metabolism. Hamsters were divided into six groups: normal control group (NC), HFHC group, simvastatin (Sim) and three doses of epiberberine group. The body weight, organs weight and serum lipid levels, as well as total cholesterol (TC) and total bile acids (TBA) levels in liver and feces were determined. Furthermore, the antidyslipidemia effect of epiberberine on key genes involved in cholesterol biosynthesis, uptake, conversion and elimination such as 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), low density lipoprotein receptor (LDL receptor), 7-alpha-hydroxylase (CYP7A1) and apical sodium dependent bile acid transporter (ASBT) were investigated. The results showed that epiberberine at high dosage significantly reduced serum TC, low density lipoprotein cholesterol (LDL-c) and TBA levels by 20.2%, 22.3% and 43.8%, respectively, and increased TBA and TC levels in feces. Epiberberine inhibited HMGCR mRNA and protein expressions and slightly reduced the protein level of ASBT, as well as dramatically up-regulated mRNA and protein expressions of CYP7A1 and LDL receptor. These findings suggested that the antidyslipidemia effects of epiberberine can be achieved via inhibiting the synthesis of cholesterol, promoting the uptake and conversion of TC in liver and increasing the excretion of TC and TBA in feces. Thus, epiberberine should be considered as one of the promising natural drugs for the treatment of dyslipidemia.

Coptisine attenuates obesity-related inflammation through LPS/TLR-4-mediated signaling pathway in Syrian golden hamsters.

It is known that obesity resulted from consumption of diets high in fat and calories and associated with a chronic low-grade inflammation. Because the fat, sterol and bile acid metabolism of male Syrian golden hamster are more similar to that of human, in the present study, high fat and high cholesterol (HFHC) induced obese hamsters were used to evaluate the anti-inflammation and hypolipidemic role of coptisine. The results showed that body weight, plasma lipid levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol (LDL-c), very low density lipoprotein-cholesterol (VLDL-c), ApoB and pro-inflammatory cytokines including TNF-α, IL-6 and lipopolysaccharide (LPS) were significantly altered in hamsters fed with HFHC diet. A strong correlation was observed between the LPS level in serum and the level of LBP and pro-inflammatory cytokines. Coptisine from the concentrations of 60 to 700 mg/L dose-dependently inhibited Enterobacter cloacae growth, which can easily induce obesity and insulin resistance. The results of endotoxin neutralization assay suggest that coptisine is capable of reducing the LPS content under inflammation status. Real time RT-PCR analyses revealed that coptisine suppressed TLR-4 in visceral fat of hamsters and decreased CD14 expression in livers of hamsters. These encouraging findings make the development of coptisine a good candidate for preventing obesity-related diseases through the LPS/TLR-4-mediated signaling pathway.

Pharmacological and safety evaluation of fibrous root of Rhizoma Coptidis.

The aim of this study was to investigated the pharmacological activities and safety of fibrous root of Rhizoma Coptidis (FRC). FRC not only protected Kunming mice from the minimal lethal dose of Escherichia coli, but also protected rabbits from hyperpyrexia induced by lipopolysaccharid (LPS). The acute toxicity study showed that oral medial lethal dose (LD50) of FRC was greater than 7000mg/kg body weight in Kunming mice. The sub-chronic toxicity study showed that the no-observed-adverse effect level (NOAEL) of FRC was 1.88g/kg body weight in Sprague-Dawley rats, whereas FRC at higher dose (3.76g/kg body weight) resulted in damage to liver and lung. Negative results were present in Ames test, mouse micronucleus test and mouse sperm abnormality test. These finding support the use of FRC in veterinary medicine.