AIM To modify and improve a screening assay so that it becomes more convenient, economic and adaptable in China for high throughput screening of HIV fusion inhibitors targeting gp41. METHODS The original screening method reported by Jiang et al (J Virol. Methods 1999;80:85 96) was modified by: ① using a conformation specific monoclonal antibody to replace a polyclonal antibody for coating plates; ②simplifying the procedures; ③using parts of the reagents produced in China. RESULTS The modified screening assay is simpler, more convenient, and more economic than the original assay, but its sensitivity is comparable to and specificity is a little better than the original method. CONCLUSIONS The modified screening assay is more convenient and economic and can be used in China for high throughput screening of HIV fusion inhibitors from complex sample, such as phage display peptide libraries, microorganism fermentation liquids, herbs and other natural products.

OBJECTIVETo investigate the effects of Fuzheng Huayu recipe and Huangqi tang on DMN-induced experimental liver cirrhosis in rats and explore the therapeutic characteristics of Buxu herbals on liver cirrhosis.

METHODLiver cirrhosis in rats was induced by intraperitoneally injection of DMN for 4 weeks. Cirrhotic rats were randomly divided into 4 groups: model group, and Fuzheng Huayu recipe group, Huangqi tang group, Fuzheng Huayu recipe combined with Huangqi Tang group. The rats in treatment groups were orally administered with Fuzheng Huayu recipe, Huangqi tang, Fuzheng Huayu recipe combined with Huangqi tang (1:1), respectively. Normal and model control rats were given the equivalent normal saline. The body weight, liver weight and spleen weight were observed when rats were sacrificed. Liver histology was examined by HE staining and Sirius red staining. The liver function parameters including ALT, T. Bil and Alb were determined. The SOD activity and MDA content in liver tissues were also measured. Hepatic hydroxyproline (Hyp) content was determined by Jamall's method. The expression of alpha-SMA was determined by both immunohistochemistry staining and western blot method.

RESULTCompared with normal rats, the serum ALT and T. Bil levels in model rats increased obviously, by contrast, the serum Alb level decreased. There was a significant decline of SOD activity in model rat liver tissue, while the content of MDA and Hyp increased remarkably. A severe deterioration of liver architecture, infiltration of inflammatory cells and deposition of collagen were observed in model rat liver tissue. The expression of alpha-SMA also increased significantly. Compared with model rats, the liver function, lipid peroxidation parameters, Hyp content and liver histology were all improved in the 3 treatment groups. The combined group is better than any single-use group in decreasing collagen deposition and expression of alpha-SMA.

CONCLUSIONFuzheng Huayu recipe, Huangqi tang, Fuzheng Huayu recipe combined with Huangqi tang can attenuate liver fibrosis in DMN induced rats. Fuzheng Huayu recipe combined with Huangqi tang is better than that using alone in decreasing collagen deposition. The mechanism is partially due to the better effect of Fuzheng Huayu recipe combined with Huangqi tang on inhibiting activated HSC.

Animals ; Body Weight ; drug effects ; Dimethylnitrosamine ; adverse effects ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Liver ; drug effects ; enzymology ; Liver Cirrhosis, Experimental ; chemically induced ; drug therapy ; enzymology ; physiopathology ; Organ Size ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism

To investigate the effect of schisantherin A on liver sinusoid endothelial cell function and angiogenesis. Different dosages (0-40 μmol•L⁻¹) of schisantherin A were incubated 24 h with SK-HEP-1 cells, and the toxicity of SK-HEP-1 cells was assayed by MTT method. The proliferation of SK-HEP-1 cells were induced by the vascular endothelial growth factor (VEGF), with receptor tyrosine kinase inhibitor sorafenib as the control, at the same time, set up the control group, 2, 20 μmol•L⁻¹ schisantherin A were incubated with SK-HEP-1 cells, cell proliferation was analyzed by EdU DNA cell proliferation kit. Fluorescence probe method was used to assay the intracellular NO levels and NOS activity. Tube formation was observed using cell migration and a matrigel tube formation assay. Rat aortic ring assay was performed to observe the sprouting vessels from aortic ring. The fluorescence vessels, the number of functional blood vessels, and intersegmental vessel changes of transgenic zebrafish were also observed. Compared with control group, the proliferation of SK-HEP-1 cells induced by VEGF increased and and the level of NO and NOS activity induced; compared with model group, 2, 20 μmol•L⁻¹ schisantherin A and sorafenib inhibited the proliferation of SK-Hep-1 cells induced by VEGF, and reduced the level of NO and NOS activity. At the dosage of 20 μmol•L⁻¹, schisantherin A attenuated the migration and tube formation of SK-HEP-1 cells induced by VEGF, and also inhibition the formation of rat aortic rings and intersegmental vessel changes of transgenic zebrafish, and significantly reduce the number of vessels in zebrafish. Schisantherin A has potential effects on function of endothelial cell proliferation and angiogenesis.

Microemulsions are promising drug delivery systems for the oral administration of poorly water-soluble drugs. However, the evolution of microemulsions in the gastrointestinal tract is still poorly characterized, especially the structural change of microemulsions under the effect of lipase and mucus. To better understand the fate of microemulsions in the gastrointestinal tract, we applied small-angle X-ray scattering (SAXS) and fluorescence resonance energy transfer (FRET) to monitor the structural change of microemulsions under the effect of lipolysis and mucus. First, the effect of lipolysis on microemulsions was studied by SAXS, which found the generation of liquid crystalline phases. Meanwhile, FRET spectra indicated micelles with smaller particle sizes were generated during lipolysis, which could be affected by CaCl, bile salts and lecithin. Then, the effect of mucus on the structural change of lipolysed microemulsions was studied. The results of SAXS and FRET indicated that the liquid crystalline phases disappeared, and more micelles were generated. In summary, we studied the structural change of microemulsions in simulated gastrointestinal conditions by SAXS and FRET, and successfully monitored the appearance and disappearance of the liquid crystalline phases and micelles.