[Antagonism of baicalin on cell cyclical distribution and cell apoptosis in A549 cells infected with influenza A (H1N1) virus].
ABSTRACT To observe the inhibitive effect of Baicalin against influenza A H1N1 virus infection in epithelial cell line A549, the cell proliferation and cytotoxicity were assayed by MTT, the cell cycle and the apoptosis were analyzed by flowcytometer using PI staining, the morphology of cellular nucleolus was observed by Hoechst 33258 staining and the effects of activation on caspase 3 and caspase 8/9 were also detected by immunofluorescent staining with a fluorescence microscope. The results showed that Baicalin exerted an inhibitive effect on CPE after influenza A H1N1 virus infection. The FACS with PI staining showed that the cell cycle of the infected cell was arrested at S phase, the Baicalin-treated group decreased S phase cell ratio and subG0 phase peak in comparison with the control (P < 0.05) and significantly promoted cell proliferation (# P < 0.05). Hoechst33258 staining suggested that Baicalin protected the cellular nucleolus against the influenza virus-induced apoptosis. Observation under the immunofluorescent microscope suggested that the activities of caspase-8 and caspase-3 were enhanced at 36 h post the influenza virus infection, but 100 microg/mL Baicalin suppressing the activation of caspase-8 and caspase-3 rather than that of caspase-9. In summary, this research confirmed that Baicalin inhibited the influenza A H1N1 virus strain infection in vitro, the drug obviously protected cells from apoptosis damages through regulating cell cycle and suppressed the activation of caspase-8 and caspase-3. The down-regulation was significant and showed a dose-dependent relationship.
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ABSTRACT: Background These experiments were employed to explore the mechanisms underlying baicalin action on Candida albicans. Methodology and Principal Findings We detected the baicalin inhibition effects on three isotope-labeled precursors of 3H–UdR, 3H-TdR and 3H-leucine incorporation into Candida albicans using the isotope incorporation technology. The activities of Succinate Dehydrogenase (SDH), cytochrome oxidase (CCO) and Ca2+-Mg2+ ATPase, cytosolic Ca2+ concentration, the cell cycle and apoptosis, as well as the ultrastructure of Candida albicans were also tested. We found that baicalin inhibited 3H–UdR, 3H-TdR and 3H-leucine incorporation into Candida albicans (P<0.005). The activities of the SDH and Ca2+-Mg2+ ATPase of Candida albicans in baicalin groups were lower than those in control group (P<0.05). Ca2+ concentrations of Candida albincans in baicalin groups were much higher than those in control group (P<0.05). The ratio of Candida albicans at the G0/G1 stage increased in baicalin groups in dose dependent manner (P<0.01). There were a significant differences in the apoptosis rate of Candida albicans between baicalin and control groups (P<0.01). After 12-48h incubationwith baicalin (1 mg/ml),Candida albicans shown to be markedly damaged under transmission electron micrographs. Innovation and Significance Baicalin can increase the apoptosis rate of Candida albicans..These effects of Baicalin may involved in its inhibiting the activities of the SDH and Ca2+-Mg2+ ATPase, increasing cytosolic Ca2+ content and damaging the ultrastructure of Candida albicans.Biochemical and Biophysical Research Communications 08/2014; 451(1). DOI:10.1016/j.bbrc.2014.07.040 · 2.28 Impact Factor