【摘要】 目的:研究苎麻叶不同溶剂萃取物对甲型流感病毒(H1N1)的体外抑制作用和抗氧化活性,以扩大苎麻植物的药用部位并开发天然抗病毒、抗氧化药物。方法:取苎麻叶以95%乙醇提取,分别用水加热溶解醇提物浸膏,再以不同溶剂分别萃取,制得苎麻叶石油醚相、三氯甲烷相、乙酸乙酯相、正丁醇相、水相萃取物。考察50～400μg/mL的苎麻叶水相萃取物对犬肾细胞(MDCK)的毒性作用;以利巴韦林为阳性对照,采用甲型流感病毒(H1N1)攻击MDCK细胞,并采用Western blotting法检测相同质量浓度的苎麻叶石油醚相、三氯甲烷相、乙酸乙酯相、正丁醇相、水相萃取物溶液(均为100μg/mL),不同质量浓度的苎麻叶水相萃取物溶液(50、100、200、400μg/mL)以及不同质量浓度的利巴韦林溶液(0.31、0.63、1.25μg/mL)对病毒感染的细胞中核蛋白(NP)表达水平。以维生素C为阳性对照,采用羟基自由基(·OH)清除试验、DPPH自由基清除试验和还原试验考察各相萃取物的体外抗氧化活性。结果:苎麻叶水相萃取物质量浓度在400μg/mL以内时对MDCK细胞无毒性;苎麻叶石油醚相、三氯甲烷相、乙酸乙酯相、水相萃取物质量浓度在100μg/mL时均能显著降低甲型流感病毒(H1N1)感染的细胞中NP蛋白表达水平(P<0.01);而不同质量浓度(50～400μg/mL)的水相萃取物均能显著降低NP蛋白表达水平(P<0.01),且呈一定浓度依赖趋势;其石油醚相和乙酸乙酯相萃取物的抗氧化活性与维生素C较为接近。结论:苎麻叶水相萃取物具有较好的体外抗甲型流感病毒(H1N1)作用;其石油醚相和乙酸乙酯相萃取物表现出较好的体外抗氧化活性。更多还原

【Abstract】 OBJECTIVE:To study the in vitro inhibitory effects and antioxidant activity of different solvent extracts of Boehmeria nivea leaves against influenza A virus(H1N1),and to expand the medicinal parts of B. nivea and develop natural antiviral and antioxidant drugs. METHODS:The leaves of B. nivea were extracted with 95% ethanol. The ethanol extract was dissolved by water heating,and extracted with different solvents to obtain petroleum ether phase,trichloromethane phase,ethyl acetate phase,n-butanol phase and aqueous phase extracts of B. nivea leaves. The toxicity of aqueous extract of B. nivea leaves(50-400 μg/mL)on Madin-Darby canine kidney(MDCK)cell line was investigated. Using ribavirin as positive control,MDCK cells were attacked by influenza A virus(H1N1). Western blotting assay was used to detect the expression of nucleoproteins(NP)in viral infected cells after treated with same concentrations of petroleum ether phase,trichloromethane phase,ethyl acetate phase,n-butanol phase and aqueous phase extracts of B. nivea leaves(100 μg/mL),different concentrations of aqueous phase extract solution of B. nivea leaves(50,100,200,400 μg/m L)and different concentrations of ribavirin solution(0.31,0.63,1.25 μg/m L).Using vitamin C as a positive control,hydroxyl radical(·OH)scavenging test,DPPH radical scavenging test and reduction test were used to investigate in vitro antioxidant activity of the extracts. RESULTS:Aqueous phase extract of B. nivea leaves with concentration less than 400 μg/mL was nontoxic to MDCK cells. The petroleum ether phase,trichloromethane phase,ethyl acetate phase and aqueous phase extracts at 100 g/mL could significantly reduce the expression of NP protein in influenza A virus(H1N1)infected cells(P<0.01). Different concentrations(50-400 μg/mL) of aqueous extract could significantly reduce the protein expression of NP(P<0.01)in concentration-dependent manner. The in vitro antioxidant activity of petroleum ether phase and ethyl acetate phase was similar to that of vitamin C. CONCLUSIONS:B. nivea leaves extract have better anti-influenza A virus(H1N1)effects in vitro,and the extracts of petroleum ether phase and ethyl acetate phase show good antioxidant activity in vitro.更多还原