RESUMO
Objective: To observe the effects of steroidal saponin YB16 of Ypsilandra thibetica on cell apoptosis of A549 human lung cancer cells, and explore the mechanism of apoptosis. Methods: Cells were cultured in vitro and treated with different concentration of YB16; The proliferation of A549 cells was examined by MTT method; Cells fluorescence changes of A549 were examined by acridine orange (AO) and JC-1 staining; PI, Annexin V-FITC/PI double staining, and JC-1 staining were examined by flow cytometry. Intracellular level of reactive oxygen (ROS) was determined by DCFH-DA assay, the expression of YB16 on apoptosis-related proteins was examined by Western blotting. Results: Steroidal saponin YB16 of Y. thibetica could inhibit A549 cells growth significantly with dose-effect relationship (P < 0.05); With the increasing of drug concentration, cell morphology changed significantly compared with the control group; Cell apoptosis rate increased with the different concentration of YB16 (P < 0.05); Mitochondrial membrane potential decreased significantly; ROS level of cells was increased with a significant difference (P < 0.05). Apoptotic protein, such as Bcl-2 expression of anti-apoptotic protein, was decreased, and the expression of pro-apoptotic protein Bax and cleaved caspase-3 was increased treated by YB16 after 24 h (P < 0.05). Conclusion: Steroidal saponin YB16 of Y. thibetica could inhibit the cell proliferation, reduce the mitochondrial membrane potential, enhance ROS level of A549 cells, and promote apoptosis. Therefore, it has a good anti-tumor activity.
RESUMO
<p><b>OBJECTIVE</b>To determine whether or not enterovirus 71 (enteroviurs 71, EV71) may induce autophagy and affect the production and release of EV71 after the treatment of autophagy inhibitor.</p><p><b>METHODS</b>Western blots were performed to examine the conversion of LC3-I to LC3- II and the degradation of P62 after the RD-A cells were infected with EV71. CCID50 was determined by checking the virus titer in the supernatant of cells that treated with autophagy inhibitor 3-MA.</p><p><b>RESULTS</b>EV71 infection enhances the type conversion of LC3 and degradation of P62. The infectious virus particles were decreased after the treatment of 3-MA.</p><p><b>CONCLUSION</b>EV71 infection could induce cell autophagy and the autophagy might contribute to the production and release of infectious EV71 particles.</p>
Assuntos
Humanos , Adenina , Farmacologia , Antivirais , Farmacologia , Autofagia , Linhagem Celular Tumoral , EnterovirusRESUMO
<p><b>OBJECTIVE</b>To compare the sensitivity and specificity of four kits for detection of anti-severe acute respiratory syndrome (SARS)-CoV IgG in sera of SARS patients.</p><p><b>METHODS</b>Anti-SARS-CoV IgG was detected in 99 serial sera from 18 SARS patients and in 123 negative reference sera, using two enzyme linked immunosorbent assays (EIA No. A and No. B) and two indirect immunofluorescence assays (Australian IFA and Euroimmun IFA).</p><p><b>RESULTS</b>Anti-SARS-CoV IgG was not detected in sera collected from SARS patients at the first week after onset by any of the four kits, however, it was detectable in sera obtained at the second week of illness by EIA No. B, and two IFA, but not by EIA No. A, with the positive rates of 57.1% (4/7), 57.1% (4/7) and 42.9% (3/7), respectively. The anti-SARS-CoV IgG was first determined in sera on the 9th day by Euroimmun IFA, 12th day by EIA No. B, 13th day by Australian IFA, and 16th day by EIA No. A. The positive rates of antibody on the 3rd week after onset were 84.2% (16/19), 94.7% (18/19), 78.9% (15/19) and 52.6% (10/19) respectively. They were identical since the 4th week after the disease onset. Through detection of 123 negative reference sera, the specificity of EIA No. A and two IFA was 100%, with exception of 94.9% for EIA No. B.</p><p><b>CONCLUSION</b>The sensitivity and specificity of the two IFAs were relatively higher than that of the two EIAs. The quality of the two homemade EIAs should be improved.</p>