ABSTRACT
The aim of this study was to investigate the effects of polyethylene glycol (PEGs) with different molecular weights (MW: 400, 1 000, 4 000) on the pharmacokinetics of baicalin, and preliminarily analyze its mechanism. Rats were gavaged with baicalin (168 mg·kg-1) + aqueous solution or baicalin + PEGs solution and plasma samples were collected from 0 to 24 h after administration. The concentration of baicalin and its main metabolite baicalein 6-O-β-D-glucuronide (B6G) were determined at different time points by UPLC-MS/MS, and the pharmacokinetic parameters were calculated with DAS 3.0 software. The results showed that PEGs with different molecular weights could effectively increase the AUC0-t of baicalin and B6G, increase the Cmax, and prolong the t1/2, effectively increasing the concentration of baicalin and B6G in vivo. The mechanism may be by promoting the activity of uridine diphosphate glucuronosyl-transferases 1A8 (UGT1A8) and 1A9 (UGT1A9), thereby increasing the transformation rate of baicalin and B6G. The rate of metabolism of B6G was faster than that of baicalin, suggesting that PEGs had a higher affinity for UGT1A8, and PEG400 had the most significant effect. The purpose of this study was to provide a basis for the clinical safe use of baicalin and other flavonoids and the design of new dosage forms with the participation of PEGs. The animal experiment protocol in this study was approved by the Experimental Animal Ethics Committee of Guizhou Medical University.
ABSTRACT
Objective::To investigate the effect of polyethylene glycol 400 (PEG400) on rat bile excretion of baicalin and its main metabolite [baicalein 6-O-β-D-glucuronide (B6G)], and to analyze its mechanism of action. Method::Rats were randomly divided into baicalin+ water group and baicalin+ PEG400 group, the anesthesia was induced by intraperitoneal injection of 10% chloral hydrate (dose of 4 mL·kg-1) to prepare a rat bile duct intubation model. After the rats were fully awake, rats were given baicalin aqueous solution and baicalin PEG400 solution with dose of 168 mg·kg-1 for baicalin, respectively. And bile was collected from 0 h to 12 h after administration. UPLC-MS/MS was used to determine the concentration of drug excreted through bile at different time periods. Thermo Hypersil GOLD C18 column was used with acetonitrile (A)-0.1% formic acid solution (B) as the mobile phase for gradient elution (0-9 min, 90%-27%B; 9-10 min, 27%-90%B; 10-12 min, 90%B), the flow rate was 0.3 mL·min-1, the column temperature was 30 ℃, the injection volume was 5 μL. The mass spectra were obtained in positive ion mode with electrospray ionization (ESI). The effects of PEG400 on the activities and expressions in rat liver of uridine diphosphate glucuronyltransferase (UGT) 1A8 and UGT1A9 were studied in vitro incubation assay and enzyme linked immunosorbent assay (ELISA). Result::Compared with the baicalin+ water group, in the baicalin+ PEG400 group, the bile cumulative excretions of baicalin and B6G increased by 1.8 times and 2.1 times within 12 h, respectively. PEG400 increased the enzyme activities of UGT1A8 and UGT1A9 by 2.0 times and 1.5 times, and their concentrations in liver were increased by 2.2 times and 1.3 times, respectively. Conclusion::PEG400 can significantly increase the bile excretion of baicalin and its main metabolite B6G by enhancing the activities and expressions of UGT1A8 and UGT1A9, and its promoting effect on bile excretion of B6G is greater than that of baicalin, which provides a basis for the rational clinical application of PEG400 and the design of new dosage forms of flavonoids such as baicalin.
ABSTRACT
The study aimed to establish an UPLC-MS/MS method for the determination of baicalin in rat plasma,in order to study the effect of PEG400 on pharmacokinetics of baicalin and baicalein in normal and gut microbiotadysbiosis rats. Plasma was precipitated with ethyl acetate and determined by UPLC-MS/MS method,with genistein as an internal standard. In terms of specificity,linearity,range,accuracy,precision and stability,the method was suitable for the determination of baicalin in plasma. The gut microbiotadysbiosis rat model was induced through the oral administration with lincomycin hydrochloride(5 g·kg-1·d-1) for one week. Samples of plasma of rats were obtained at different time points,after the rats were administrated with baicalin,baicalin and PEG400. Baicalin in rats were detected by UPLC-MS/MS method,and pharmacokinetic parameters were calculated by DAS 3. 2. 2 software. The results showed that the β-glucosidase activity and the number of colonies in the feces of gut microbiotadysbiosis rats induced by lincomycin hydrochloride were significantly reduced. The Cmaxand AUC0-tof the baicalinand PEG400 group in the intestinal flora were significantly lower than those in the normal rat baicalin and PEG400 group. There was no significant difference in Cmaxand AUC0-tbetween the baicalin group and the baicalin+PEG400 group of gut microbiotadysbiosis rats. The Cmaxand AUC0-tof the normal rats baicalin group were significantly higher than those of the gut microbiotadysbiosis rats baicalin group and the baicalin + PEG400 group. There was no significant difference in Cmaxand AUC0-tbetween the normal rat baicalein and PEG400 group and the baicalein group. The Cmaxand AUC0-tof the baicalein group in the gut microbiotadysbiosis rats were lower than those in the normal baicalein group,but significantly higher than those in the baicalein and PEG400 group. PEG400 could increase the absorption of baicalin in normal rats,but is ineffective in gut microbiotadysbiosis rats,with no impact on the absorption of baicalein in rats.
Subject(s)
Animals , Rats , Chromatography, Liquid , Dysbiosis , Drug Therapy , Flavanones , Pharmacokinetics , Flavonoids , Pharmacokinetics , Gastrointestinal Microbiome , Polyethylene Glycols , Tandem Mass SpectrometryABSTRACT
AIM To investigate the protective effects of Miaoling Natto Capsules (MNC) on myocardial ischemia-reperfusion injury (MIR) in rats.METHODS Forty-eight healthy male Sprague-Dawley (SD) rats randomly divided into sham group,model group,positive control group (propranolol),MNC groups (low dose,medium dose,and high dose groups) underwent corresponding 7-day oral administration at a frequency of twice daily (rats of the sham group and the model group were dosed with saline water at 1 mL/100 g).Anesthetized by 8％ chloral hydrate,rat models were made by left anterior descending coronary artery ligation,30 min coronary occlusion followed by 3 h of reperfusion for ST segments and T waves monitoring,and rats in the sham group were performed opening and suture procedures.The rats had their serum levels of acetic transaminase (AST),lactate dehydrogenase (LDH),creatine kinase isoenzyme (CK-MB),cardiac troponin-Ⅰ (cTn-Ⅰ),superoxide dismutase (SOD),malondialdehyde (MDA),and tumor necrosis factor-α (TNF-α) detected,real time ECG changes monitored and myocardial infarction area assessed by TTC.RESULTS Compared with the sham group,the model group was observed with markedly elevated ST segments or high T waves rise,significantly increased activities of CK-MB,LDH,AST and the content of cTnⅠ,MDA,TNF-α,and decreased activity of SOD (P ＜ 0.01 or P ＜ 0.001).Compared with the model group,the positive control group and the low,medium and high dose MNC groups achieved controlled ST segments elevation or greater T waves amplitude,significantly decreased activities of CKMB,LDH,AST and the content of cTnⅠ,MDA,TNF-α increased activity of SOD (P ＜0.01 or P ＜0.05) and mycocardial infact range reduction (P ＜ 0.001).CONCLUSION MNC is protective to rats with myocardial ischemia-reperfusion injury.
ABSTRACT
This experiment aimed to explore and research the process of preparing baicalein and wogonin through liquid fermentation with Bacillus natto. Active enzymes of produced by B. natto was used for the biological transformation of baclin and wogonoside, in order to increase the content of the haicalein and wogonin in the scutellaria. With the content of the baicalein and wogonin as evaluating indexes, the effects of carbon source, nitrogen source, the types and suitable concentration of inorganic salt, medium pH, granularities of medical materials, liquid volume in flask, shaking speed, liquid-to-solid ratio, fermentation time on the fermentation process were studied. The optimal process conditions for liquid fermentation of scutellaria were 1.0% of peptone, 0.05% of NaCl, pH at 6, the granularities of medical materials of the scutellaria screened through 40-mesh sifter, 33% of liquid, shaker incubator speed at 200 r x min(-1), liquid-to-solid ratio of 5:1, temperature at 37 degrees C, fermentation for 6 days, baclin's conversion rate at 97.6% and wogonoside's conversion rate at 97% in the scutellaria. According to the verification test, the process was stable and feasible, and could provide data reference for the industrial production.