Baicalin protects against 17α-ethinylestradiol-induced cholestasis via Sirt1/HNF-1α/FXR pathway / 中国药理学与毒理学杂志

OBJECTIVE Baicalin is a major flavonoid component of Scutellaria baicalensis, and has been used in the treatment of liver diseases for many years. However, the role of baicalin in estrogen-induced cholestasis (EIC) remains to be elucidated. This present study explored the protective effect of baicalin against estrogen-induced liver injury and further elucidated the mechanisms involved both in vivo and in vitro. METHODS We conducted a series of experiments using 17α-ethinylestradiol (EE) induced cholestatic rats and cultured HepG2 cells. Serum, bile, and liver samples were collected for biochemical and histological analyses. Bile acid composition in liver was analyzed by LC-MS/MS. The mechanisms underlying the hepatoprotective of baicalin were investigated by RT-PCR, Western blotting analyses and immunohistochemistry. RESULTS Baicalin showed obvious hepatoprotective effects in EIC rats by reducing serum bio?markers and increasing the bile flow rate, as well as by alleviating liver histology and restoring the abnormal composition of hepatic bile acids (BAs). In addition, baicalin protected against EE induced liver injury by up-regulation of the expres?sion of hepatic efflux transporters and down-regulation of hepatic uptake transporters. Furthermore, baicalin increased the expression of hepatic BA synthase (CYP27A1) and metabolic enzymes (Bal, Baat and Sult2a1) in EIC rats. We showed that baicalin significantly inhibited hepatic inflammatory responses in EIC rats through reducing elevated levels of TNF-α, IL-1β, IL-6 and NF-κB. Finally, we confirmed that baicalin maintains BA homeostasis and alleviates inflamma?tion through Sirt1/HNF-1α/FXR signaling pathway. CONCLUSION Baicalin protects against estrogen-induced cholestatic liver injury, and the underlying mechanism involved is related to activation of the Sirt1/HNF-1α/FXR signaling pathway.

Mechanism of Calculus Bovis Sativus in inhibiting hepatocyte lipid deposition based on serum pharmacology / 中国中药杂志

The aim of this paper was to investigate the molecular mechanism of Calculus Bovis Sativus( CBS) in alleviating lipid accumulation in vitro by serum pharmacology. The CBS-containing serum of mice was obtained by serum pharmacology method to evaluate its effect on the proliferation of LO2 hepatocytes. The lipid reducing effects of CBS-containing serum through Nrf2 was evaluated by fructose-induced LO2 hepatocyte steatosis model,nuclear factor erythroid 2 related factor 2( Nrf2) agonist oltipraz combined intervention,cell oil red O staining and intracellular triglyceride( TG) content. The effects of CBS-containing serum on lipid peroxidation and hepatocytes apoptosis were evaluated by reactive oxygen species( ROS) and apoptosis assay,respectively. Real-time quantitative polymerase chain reaction( PCR) was used to detect the relative expression of lipid synthesis-related genes and apoptosis-related genes.RESULTS:: showed that CBS drug-containing serum had no significant effect on LO2 hepatocyte proliferation. As compared with the model group,CBS-containing serum could effectively reduce the formation of lipid droplets in fructose-induced LO2 hepatocytes,significantly reduce intracellular TG and ROS levels,and significantly reduce hepatocyte apoptosis rate( P < 0. 05). As compared with the model group,carbohydrate responsive element binding protein( ChREBP),sterol regulatory element binding protein-1 c( SREBP-1 c),fatty acid synthase( FAS),acetyl-CoA carboxylase 1( ACC1),stearoyl-CoA desaturase 1( SCD1),Bax and caspase-3 mRNA levels were significantly reduced in CBS drug-containing serum treatment group( P<0. 05). All of the above effects could be reversed by oltipraz.In conclusion,CBS-containing serum can significantly inhibit the fructose-induced LO2 liver fat deposition,and the mechanism may be related to reducing intracellular ROS level through the Nrf2 pathway and improving intracellular peroxidation state to reduce apoptosis.

Effects of estrogen on P-Tau, ChAT and nerve growth factor protein expressions in the brain tissue of rats with Alzheimer's disease / 南方医科大学学报

<p><b>OBJECTIVE</b>To examine the effect of estrogen on the expressions of phosphorylated Tau (P-Tau), ChAT and nerve growth factor (NGF) protein in the brain tissue of rat models of Alzheimer disease (AD).</p><p><b>METHODS</b>Rat models of AD were established by injecting Aβ1-42 protein fragments in the right lateral ventricle. Two weeks later, 17β-estradiol tablets were implanted subcutaneously at the neck of the rats and maintained for 30 days. The pathological changes in the rats' brain neurons and alterations in the expressions of P-Tau, ChAT and NGF proteins were observed using HE staining and immunohistochemistry, respectively.</p><p><b>RESULTS</b>In the AD rats, neurofibrillary tangles occurred in the brain tissue, and estrogen treatment significantly reduced the formation of neurofibrillary tangles. Estrogen treatment also resulted in lowered P-Tau expression and increased ChAT and NGF protein expressions in comparison with those in the AD model rats.</p><p><b>CONCLUSION</b>Estrogen can up-regulate ChAT and NGF and down-regulate tau protein expression, thus producing obvious therapeutic effect on AD in rats.</p>

Effect of polyoxyl ether analogous surfactants on the activity of cytochromes P450 3A in rats in vivo / 药学学报

To evaluate the effects of p-octyl polyethylene glycol phenyl ether (Triton X-100), polyoxyl 35 caster oil (EL35) and polyoxyl 40 hydrogenated caster oil (RH40) on the activity of Cytochrome P450 3A (CYP3 As) in vivo. Rats were administered with saline, ketoconazole (75 mg x kg(-1) x d(-1)), Triton X-100 (30 mg x kg(-1) x d(-1)), EL35 (150 mg x kg(-1) x d(-1)) and RH40 (150 mg x kg(-1) x d(-1)) intragastrically for 5 consecutive days, and then given midazolam 10 mg x kg(-1) 20 min after the last treatment of ketoconazole or three surfactants with the same dose through duodenal administration. Pharmacokinetics parameters for midazolam and its metabolite 1'-hydroxymidazolam were estimated from the plasma concentration-time data by a noncompartmental approach. The results showed that multiple dose administration of Triton X-100, EL35 and RH40 decreased the ratios of 1'-hydroxymidazolam and midazolam AUC0-infinity from 1.14 to 0.90, 1.03 and 0.64, respectively. In contrast, multiple dose administration of ketoconazole caused the ratios of 1'-hydroxymidazolam and midazolam a significant decrease to 0.50. This study indicated that Triton X-100 and EL35 would have no inhibition on CYP3A, while RH40 had significant inhibition on CYP3A. Therefore, RH40 might be used to prepare drug formulations in pharmaceutical industry and would increase the bioavailability of some drugs transformed by CYP3As and further lead to significant clinical pharmacologic effects.