Development of self-microemulsifying drug delivery system for oral bioavailability enhancement of berberine hydrochloride.

The purpose of this study was to develop a self-microemulsifying drug delivery system (SMEDDS) to improve the oral bioavailability of Berberine hydrochloride (BBH), an important bioactive compound from Chinese Medicines with poor water solubility. Pseudoternary phase diagrams were constructed using oil, surfactant and co-surfactant types to identify the efficient self-microemulsification region. SMEDDS was characterized by morphological observation, droplet size, zeta-potential determination, stability, in vitro release and in vivo bioavailability study. The optimal formulation with the best self-microemulsifying and solubilization ability consisted of 40% (w/w) of ethyl linoleate and oleic acid (2:1), 35% (w/w) Tween-80 and 25% (w/w) glycerol. The SMEDDS of BBH could exhibit good stability. In vitro release test showed a complete release of BBH from SMEDDS was in 5 h. In vivo results indicated that the peak plasma concentration (C(max)) and the area under the curve (AUC(0→12 h)) of SMEDDS of BBH were higher than the commercial tablet by 163.4% and 154.2%, respectively. The relative bioavailability of SMEDDS of BBH was enhanced about 2.42-fold compared with the commercial tablet in rats. The study confirmed that the SMEDDS formulation could be used as a possible alternative to traditional oral formulations of BBH to improve its bioavailability.

Macrophage biospecific extraction and HPLC-ESI-MSn analysis for screening immunological active components in Smilacis Glabrae Rhizoma.

A cell-permeable membrane, as typified by Transwell insert Permeable Supports, permit accurate repeatable invasion assays, has been developed as a tool for screening immunological active components in Smilacis Glabrae Rhizoma (SGR). In this research, components in the water extract of SGR (ESGR) might conjugate with the receptors or other targets on macrophages which invaded Transwell inserts, and then the eluate which contained components biospecific binding to macrophages was identified by HPLC-ESI-MS(n) analysis. Six compounds, which could interact with macrophages, were detected and identified. Among these compounds, taxifolin (2) and astilbin (4) were identified by comparing with the chromatography of standards, while the four others including 5-O-caffeoylshikimic acid (1), neoastilbin (3), neoisoastilbin (5) and isoastilbin (6), were elucidated by their structure clearage characterizations of tandem mass spectrometry. Then compound 1 was isolated and purified from SGR, along with 2 and 4, was applied to the macrophage migration and adhesion assay in HUVEC (Human Umbilical Vein Endothelial Cells) -macrophages co-incultured Transwell system for immunological activity assessment. The results showed that compounds 1, 2 and 4 with concentration of 5µM (H), 500nM (M) and 50nM (L) could remarkably inhibit the macrophage migration and adhesion (Vs AGEs (Advanced Glycation End Produces) group, 1-L, 2-H and 4-L groups: p<0.05; other groups: p<0.01). Moreover, 1 and 4 showed satisfactory dose-effect relationship. In conclusion, the application of macrophage biospecific extraction coupled with HPLC-ESI-MS(n) analysis is a rapid, simple and reliable method for screening immunological active components from Traditional Chinese Medicine.

Pre-column incubation followed by fast liquid chromatography analysis for rapid screening of natural methylglyoxal scavengers directly from herbal medicines: case study of Polygonum cuspidatum.

Methylglyoxal (MGO), a very reactive metabolite of glucose, plays a pivotal role in the pathogenesis of several chronic diseases associated with diabetes, and it has been validated as an attractive target for them. In the present study, a simple and effective method, namely pre-column incubation followed by fast high performance liquid chromatography based on superficially porous particles (shell), coupled with diode array detection and tandem mass spectrometry (UHPLC-DAD-MS(n)), was proposed for rapid and high-throughput screening of natural MGO scavengers directly from the crude extract of Polygonum cuspidatum Sieb. et Zucc, a well-known traditional Chinese medicine which was used for treatment of diabetic complications. The hypothesis is that upon reaction with MGO, the peak areas of components with MGO scavenging potency in the chromatogram will be significantly reduced or disappear, and the structural characterization could be achieved by UHPLC-DAD-MS(n) hyphenated technique. First of all, 12 compounds in P. cuspidatum were well separated within shorter time (~12 min) than previous methods and identified, and two of them, i.e. 3,5,4'-trihydroxystilbene-3-O-(6″-galloyl)-glucoside (3) and emodin-8-O-(6'-malonyl)-glucoside (8) were firstly reported ingredients. After incubation with MGO, four stilbene derivatives were demonstrated to possess potential MGO trapping activities. Furthermore, it was proved that both polydatin (piceid) and resveratrol exhibited effective MGO-trapping capacity by UHPLC analysis, and they could significantly inhibit the formation of advanced glycation end products (AGEs) in the human serum albumin (HSA)-MGO assay, indicating that they were potential candidate agents for delaying and preventing diabetic complications. Additionally, MGO trapping mechanism exploration by UHPLC-MS(n) showed that the positions 2 and 4 of the A ring of stilbene were major active sites for trapping MGO to form both mono- and di-MGO adducts, however, the glucosylation of the hydroxyl group would significantly decrease the trapping efficiency. Collectively, the current work provides a very promising method for rapid discovery of natural MGO scavengers directly from complex matrices such as herbal medicines with huge resources.