Comparison of the Inhibitory Potential of Bavachalcone and Corylin against UDP-Glucuronosyltransferases

Bavachalcone and corylin are two major bioactive compounds isolated from Psoralea corylifolia L., which has been widely used as traditional Chinese medicine for many years. As two antibiotic or anticancer drugs, bavachalcone and corylin are used in combination with other drugs; thus it is necessary to evaluate potential pharmacokinetic herb-drug interactions (HDI) of the two bioactive compounds. The aim of the present study was to compare the effects of liver UDP-glucuronosyltransferase (UGT) 1A1, UGT1A3, UGT1A7, UGT1A8, UGT 1A10, and UGT2B4 inhibited by bavachalcone and corylin. 4-Methylumbelliferone (4-MU) was used as a nonspecific “probe” substrate. Bavachalcone had stronger inhibition on UGT1A1 and UGT1A7 than corylin which did not inhibit UGT1A1, UGT1A3, UGT1A7, UGT1A8, UGT1A10, and UGT2B4. Data fitting using Dixon and Lineweaver-Burk plots demonstrated the noncompetitive inhibition of bavachalcone against UGT1A1 and UGT1A7-mediated 4-MU glucuronidation reaction. The values of inhibition kinetic parameters (Ki) were 5.41 μM and 4.51 μM for UGT1A1 and UGT1A7, respectively. The results of present study suggested that there was a possibility of UGT1A1 and UGT1A7 inhibition-based herb-drug interaction associated with bavachalcone and provided the basis for further in vivo studies to investigate the HDI potential between bavachalcone and UGT substrates

The R Protein of SARS-CoV: Analyses of Structure and Function Based on Four Complete Genome Sequences of Isolates BJ01-BJ04

The R (replicase) protein is the uniquely defined non-structural protein (NSP) responsible for RNA replication, mutation rate or fidelity, regulation of transcription in coronaviruses and many other ssRNA viruses. Based on our complete genome sequences of four isolates (BJ01-BJ04) of SARS-CoV from Beijing, China, we analyzed the structure and predicted functions of the R protein in comparison with 13 other isolates of SARS-CoV and 6 other coronaviruses. The entire ORF (open-reading frame) encodes for two major enzyme activities, RNA-dependent RNA polymerase (RdRp) and proteinase activities. The R polyprotein undergoes a complex proteolytic process to produce 15 function-related peptides. A hydrophobic domain (HOD) and a hydrophilic domain (HID) are newly identified within NSP1. The substitution rate of the R protein is close to the average of the SARS-CoV genome. The functional domains in all NSPs of the R protein give different phylogenetic results that suggest their different mutation rate under selective pressure. Eleven highly conserved regions in RdRp and twelve cleavage sites by 3CLP (chymotrypsin-like protein) have been identified as potential drug targets. Findings suggest that it is possible to obtain information about the phylogeny of SARS-CoV, as well as potential tools for drug design, genotyping and diagnostics of SARS

Development of a novel PCV2 and PCV3 vaccine using virus-like vesicles incorporating Venezuelan equine encephalomyelitis virus-containing vesicular stomatitis virus glycoprotein

Porcine circovirus disease (PCV) causes substantial economic losses in the pig industry, primarily from porcine circovirus type 2 (PCV2) and porcine circovirus type 3 (PCV3). Novel vaccines are necessary to prevent and control PCV infections. PCV coat proteins are crucial for eliciting immunogenic proteins that induce the production of antibodies and immune responses. A vaccine platform utilizing Semliki Forest virus RNA replicons expressing vesicular stomatitis virus glycoprotein (VSV-G), was recently developed. This platform generates virus-like vesicles (VLVs) containing VSV-G exclusively, excluding other viral structural proteins. In our study, we developed a novel virus-like vesicle vaccine by constructing recombinant virus-like vesicles (rVLVs) that also express EGFP. These rVLVs were created using the RNA replicon of Venezuelan equine encephalomyelitis (VEEV) and New Jersey serotype VSV-G. The rVLVs underwent characterization and safety evaluation in vitro. Subsequently, rVLVs expressing PCV2d-Cap and PCV3-Cap proteins were constructed. Immunization of C57 mice with these rVLVs led to a significant increase in anti-porcine circovirus type 2 and type 3 capsid protein antibodies in mouse serum. Additionally, a cellular immune response was induced, as evidenced by high production of IFN-γ and IL-4 cytokines. Overall, this study demonstrates the feasibility of developing a novel porcine circovirus disease vaccine based on rVLVs