木犀草素对金黄色葡萄球菌的抑菌活性及其机制

【目的】研究木犀草素对金黄色葡萄球菌的抑制活性及其机制。【方法】利用2,3,5-氯化三苯基四氮唑(TTC)染色,细胞膜渗透性测定,SDS-PAGE蛋白谱变化,4′,6-二脒基-2-苯基吲哚(DAPI)荧光染色法等对木犀草素的抑菌活性及其机制进行研究。【结果】木犀草素能影响金黄色葡萄球菌细胞膜的通透性,木犀草素作用16h,菌体可溶性蛋白总量减少64.54%,DNA含量减少48.44%,RNA含量减少39.35%,木犀草素的浓度为1.6mg/mL时,拓扑异构酶I和II的活性可完全被抑制。【结论】木犀草素有明显的抑菌活性,其抑菌机制主要是通过抑制DNA拓扑异构酶的活性,进而影响菌体核酸及蛋白质的合成来实现的。

Antibacterial activity and mechanism of Luteolin on Staphylococcus aureus

Abstract: [Objective] To investigate the antibacterial activity and mechanism of luteolin on Staphylococcus aureus. [Methods] The antibacterial activity and mechanism experiments were carried out by using 2, 3, 5-triphenyl tetrazolium chloride (TTC), determining membrane penetrability, the change of SDS-PAGE protein spectra and 4'6-diamidino-2-phenylindole (DAPI) staining assay. [Results] Luteolin could affect the membrane permeability of Staphylococcus aureus, but not destroy the membrane integrity directly. After treated with luteolin for 16 hours, the total content of proteins decreased to 64.54%, the quantity of both DNA and RNA reduced to 48.44% and 39.35% respectively. The activity of DNA topoisomerase I and II was inhibited completely by 1.6 mg/mL luteolin. [Conclusion] Luteolin showed obvious antibacterial activity against Staphylococcus aureus. The antibacterial mechanism of luteolin is that it could inhibit the activity of DNA topoisomerase I and II, which resulted in some decrease in the nucleic acid and protein synthesis.