Effect of Pien Tze Huang against EV71 / 中国中药杂志

This study aims to investigate the inhibitory effect of Pien Tze Huang(PZH) on enterovirus 71(EV71). To be speci-fic, chemiluminescence method was adopted to evaluate the toxicity of PZH to African green monkey kidney(Vero) cells and human rhabdomyosarcoma(RD) cells, and cytopathic effect(CPE) method to assess the inhibition on EV71-GFP reporter virus and EV71 C4 wild-type virus. The results showed that PZH had low cytotoxicity to Vero cells and RD cells, with the half-maximal cytotoxic concentration(CC_(50)) of about 0.691 3-0.879 2 mg·mL~(-1) for the two. In addition, PZH can effectively inhibit the replication of EV71 within the non-cytotoxic concentration range, and dose-dependently alleviate the cytopathic changes caused by virus infection, with the half-maximal effective concentration(EC_(50)) of 0.009 2-0.106 3 mg·mL~(-1). On the basis of the above results, the green fluorescent protein(GFP), indirect immunofluorescence assay(IFA), and median tissue culture infective dose(TCID_(50)) were employed to assess and verify the anti-EV71-GFP and anti-EV71 C4 activity of PZH. The results demonstrated that PZH can dose-dependently lower the expression of GFP by EV71-GFP and structural protein VP-1 by EV71 C4 and decrease the production of progeny infectious viruses. The EC_(50) of PZH for EV71-GFP and EV71 C4 was about 0.006 0-0.006 2 mg·mL~(-1) and 0.006 6-0.025 6 mg·mL~(-1), respectively. This study suggested that PZH may exert antiviral activity by acting on EV71 and interfering with the expression of VP-1. At the moment, there is still a lack of specific anti-EV71 drugs. This study proposed a new idea for the symptomatic treatment of EV71 infections such as hand-foot-mouth disease and verified an effective drug for the treatment of EV71 infections.

Immunogenicity of single-dose HBsAg-PLGA controlled release microspheres in mice / 药学学报

<p><b>AIM</b>To investigate the level of immune response and the immune mechanism of the single-dose hepatitis B surface antigen (HBsAg)-poly (d, l)-lactide-co-glicolide acid (PLGA) microspheres in BALB/c mice.</p><p><b>METHODS</b>Three kind of HBsAg-PLGA microspheres, HBsAg-PLGA50/50-COOH microspheres, HBsAg-PLGA75/25 microspheres and HBsAg-PLGA50/50 microspheres, were prepared by double emulsion microencapsulation technique used three kinds of PLGA with different L/G ratio. The single-dose of HBsAg-PLGA microspheres was subcutaneously injected into BALB/c mice at the dose of 7.5 microg HBsAg per mouse. The conventional aluminum-adjuvant vaccine was subcutaneously injected at 0, 1 and 2 month as positive control. In certain time interval, the induced immune level of total antibody was detected by enzyme linked immunosorbent assay (ELISA). For subclass of IgG antibody and cytokines studies, the dose of HBsAg was 2.5 microg per mouse.</p><p><b>RESULTS</b>The HBsAg-PLGA microspheres could successfully induce a humoral immune response in BALB/c mice. Compared with the conventional aluminum-adjuvant vaccine, the antibody response of the HBsAg-PLGA50/50-COOH microspheres was significantly lower than the group received three injections of aluminum-adjuvant vaccine (P < 0.01) except for a higher priming response during the early 6 weeks. The results were ascribed to the relatively rapid degradation charactics of PLGA50/50-COOH polymer. The immune response for the HBsAg-PLGA50/50 microspheres and HBsAg-PLGA75/25 microspheres were comparable to the group administered with aluminum-adjuvant vaccine (P > 0.05) which was due to the sustained degradation of PLGA50/50 and PLGA75/25 polymer.</p><p><b>CONCLUSION</b>The HBsAg-PLGA microsphere is a promising candidate for the controlled delivery of a vaccine which does not require multiple injections.</p>