柠檬提取物抑菌、杀灭病毒作用机制研究

Study on bacteriostatic and antiviral mechanism of lemon extract

目的观察柠檬提取物对细菌生物膜的消除作用,对柠檬提取物抑制多重耐药金黄色葡萄球菌的机制进行初步研究,以及对环境中富集的病毒消除作用的研究。方法采用高分子滤膜法制备金黄色葡萄球菌生物膜后,加入柠檬提取物分别作用1、2和3 h,通过细菌菌落计数判定不同生物膜的细菌存活数;采用SDS-PAGE电泳法,观察在柠檬提取物作用下菌体蛋白质的变化;EcoR I酶切金黄色葡萄球菌DNA,观察酶切图谱的改变;在低渗环境下动态观察柠檬提取物在不同作用时间对细菌细胞壁的影响;通过柠檬提取物对病毒作用后RNA量的变化,说明柠檬提取物具有杀灭病毒的作用。结果柠檬提取物对生物膜中的细菌具有杀菌作用,且随作用时间的延长而逐渐增强;柠檬提取物对细菌蛋白质的组成和表达量均有一定影响,同时细菌DNA的EcoR I酶切图谱发生改变;柠檬提取物作用15 min时细菌呈现明显的胞壁缺损现象,即细菌个体胀大,呈现大球形;经柠檬提取物作用后,RNA病毒被杀灭。结论结果显示柠檬提取物对耐药金黄色葡萄球菌所形成的生物膜具有明显抑制作用;在柠檬提取物作用下,菌体蛋白合成量发生改变,同时对细菌的DNA和细胞壁有明显的影响。柠檬提取物处理病毒悬液后,病毒RNA量显著减少,说明病毒RNA结构被破坏。

Objective To observe the effect of lemon extract on eliminating bacterial biomembrane, explore its inhibitive mechanism on multi-drug resistant strain of Staphylococcus aureus, and its function on eliminating virus concentrate from environmental sample. Method Staphylococcus aureus biomembrane was prepared by high polymer filtration method, then added with lemon extract at 1 h, 2 h, and 3 h respectively. The survival number of bacterium with different biomem- brane was calculated via bacterial colony count; also the change of tropina evoked by lemon extract was analyzed by SDS- PAGE electrophoresis. The DNA extracted from Staphylococcus aureus was cut by EcoR I and the change of cleavage map was evaluated. The effects of lemon extract on bacterial cell wall under low osmotic pressure at 5,10 and 15 min were observed respectively; the virus-eliminating effect were analyzed by comparing RNA band intensity in agarose gel. Result The results demonstrated that the lemon extract had bactericidal effect on the germs inside biomembrane, and this bactericidal effect increased gradually along with incubation time （1.6 × 10^7CFU/ml, 2.5 × 10^6 CFU/ml and 5.6 × 10^4 CFU/ml respectively）. The lemon extract had a certain effect on the composition and expression of bacterioprotein, and the cleavage map of bacterial DNA by EcoR I was altered. Damage to the cell wall of bacteria was observed after 15 min of treatment with lemon extract. Viruses were eliminated after treatment with lemon extract. Conclusion Lemon extract possesses significant inhibitive effect on Staphylococcus aureus biomembrane. It can change the quantity of tmpina synthesized and has a certain effect on DNA and cell wall of bacteria.. Lemon extract can also effectively eliminating the viruses concentrated from enviromnent.