RESUMO
An entomopathogenic bacterial strain SCQ1 was isolated from silkworm (Bombyx mori) and identified as Serratia marcescens via 16S rRNA gene analysis. This strain produces a red pigment that causes acute septicemia of silkworm. The red pigment of strain SCQ1 was identified as prodigiosin analogue (PGA) with various reported biological activities. In this study, we found that low concentration of PGA showed significant anticancer activity in human lung adenocarcinoma A549 cells, but has little effect in human bone marrow stem cells, in vitro. By exposure to different concentrations of PGA for 24 h, morphological changes and the MTT assay showed that A549 cell line was very sensitive to PGA, with IC(50) value about 2.2 mg/L. Early stage of apoptosis was detected by flow cytometry while A549 cells were treated with PGA for 4 and 12 h, respectively. The proportion of dead cells was increased with treatment time or the concentrations of PGA, but it was inversely proportional to that of apoptotic cells. These results indicate that PGA obtained from strain SCQ1 induces apoptosis in A549 cells, but the molecular mechanisms of cell death are complicated, and the S. marcescens strain SCQ1 may serve as a source of the anticancer compound, PGA.
Assuntos
Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Apoptose , Neoplasias Pulmonares/tratamento farmacológico , Prodigiosina/isolamento & purificação , Prodigiosina/farmacologia , Serratia marcescens/química , Animais , Bombyx/microbiologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Humanos , Concentração Inibidora 50 , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Serratia marcescens/classificação , Serratia marcescens/isolamento & purificação , Serratia marcescens/metabolismo , Sais de Tetrazólio/metabolismo , Tiazóis/metabolismo , Fatores de TempoRESUMO
Although garlic has been used in Chinese traditional medicine for its medical properties for thousands of years, investigations into its mode of action are relatively recent. The purpose of this study was to evaluate the in vitro anti-fungal efficacy of the active principle of garlic, pure allicin and polybutylcyanoacrylate (PBCA) nanoparticles (NPs) loaded with allicin. Pure allicin was prepared by reacting synthetic alliin with a stabilized process of the garlic enzyme alliinase. PBCA NPs were prepared by emulsion polymerization method and pure allicin was wrapped into it. The in vitro efficacy of pure allicin and PBCA-allicin NPs to Candida albicans, Cryputococcus neoformans, Trichophyton rubum, Microsporum gypseum, M. canis and Epidermophyton floccosum was examined and evaluated by MIC and MFC. The MIC of PBCA-allicin NPs to C. albicans (2.93 x 10(-2)mg/ml), T. rubum (1.46 x 10(-2)mg/ml) and E. floccosum (1.46 x 10(-2)mg/ml) was significantly lower than that of pure allicin (5.86 x 10(-2)mg/ml, 2.93 x 10(-2)mg/ml, 2.93 x 10(-2)mg/ml, respectively); accordingly, the MFC of PBCA-allicin NPs to C. albicans (5.86 x 10(-2)mg/ml), T. rubum (2.93 x 10(-2)mg/ml), E. floccosum (2.93 x 10(-2)mg/ml) and M. canis (2.93 x 10(-2)mg/ml) also decreased dramatically. These favourable results indicated that pure allicin has stronger in vitro anti-fungal efficacy to six tested fungi than alliinase and alliin. Moreover, it has improved significantly after pure allicin being wrapped into PBCA NP, which may be due to the NP's good prolonged release effect and nano-scale dimensions.
