Objective:The protective effects of grape procyanidins (GPC) on free radical induced endothelial cell damage were investigated. Methods:Human umbilical vein vascular endothelial cells (ECV304) were cultured in GPC of different doses. Oxidative injury was caused by Fenton system, and MTT method was used to test cell proliferation when cells were cultured 12, 24, 36, 48 h, respectively, MDA and SOD in cells were also determinated 30 min after Fenton system was added. Results: GPC protected cell proliferation damage induced by OH. When GPC doses increased, the protective effects were . enhanced, while MDA level and apoptosis rate of 100?g/ml GPC group both decreased (P

To express Pleurocidin in Escherichia coli and to enhance the secretory efficiency of the fusion protein, the gene encoding Pleurocidin was ligated with Cherry DNA sequence via blunt-end ligation. Then this fusion gene was cloned into pET22b (+) vector and the recombinant plasmid was transformed into E. coli BL21 (DE3). Lactose was used to induce expression of fusion protein. The recombinant plasmid pET22b (+) -CP was successfully constructed and high-level expression of fusion protein was induced with lactose. Statistics showed that addition of glycine after 16 h of induction significantly enhanced the secretory efficiency of the fusion protein. After hydrolysis of the fusion protein by diluted hydrochloric acid and some further purification steps, r-Pleurocidin was obtained with antibacterial activity against E. coli DH5α and Bacillus subtilis BS168. In conclusion, the fusion protein was expressed in E. coli and biologically active r-Pleurocidin was obtained after hydrochloric acid cleavage and purification.
Animals ; Cloning, Molecular ; Escherichia coli ; metabolism ; Fish Proteins ; biosynthesis ; Flounder ; Recombinant Fusion Proteins ; biosynthesis

The febrile respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become the focus of global attention. Up to now, the infection has been continuing to spread all over the world and it is urgent to develop specific drugs for SARS-CoV-2. Finding effective and safe drugs which are already available in the market for treating coronavirus disease 2019 (COVID-19) is one of the main strategies to solve the problem in time. As quinoline alkaloids against malaria, chloroquine and hydroxychloroquine have been proved to have the anti-SARS-CoV-2 activity. Quinoline alkaloids are expected to be important drugs for the treatment of COVID-19. In this article, the research and application of chloroquine and hydroxychloroquine are reviewed from the aspects of pharmacokinetics, drug interaction, clinical research progress, treatment plan optimization and resolution of optical enantiomers. The possible problems are summarized in order to provide reference for further research and clinical application of quinoline alkaloids in the treatment of COVID-19.