硫异维甲类化合物A2对结核分枝杆菌抗菌效果的观察

Antibacterial effect of sulfur heteroarotinoid A2 on Mycobacterium tuberculosis in vitro and in vivo

目的评价硫异维甲类化合物(SHetA2)在体内外对结核分枝杆菌(MTB)的抗菌效果。方法(1)采用试管法,将SHetA2(2.5μg/ml、5.0μg/ml、10.0μg/ml、20.0μg/ml)分别加入苏通培养基内后,加入等量MTB标准菌株H37RV菌液[1mg/ml,每支接种0.1ml,含106菌落形成单位(CFU)细菌],于37℃培养2周,测定SHetA2的最小抑菌浓度(MIC)。(2)将76只无特定病原体(SPF)级昆明小鼠采用雾化吸入感染装置构建肺结核感染模型,最终纳入60只建模成功的小鼠。采用数字表法随机将小鼠分为对照组、异烟肼组、SHetA2组,每组20只,分别采用生理盐水、异烟肼、SHetA2进行治疗。治疗45d后,观察各组小鼠体征及体质量变化、肺组织细菌载荷量计数及组织病理学变化。结果(1)体外实验结果显示,SHetA2对MTB标准菌株H37RV的MIC为10μg/ml。(2)体内抗结核实验显示,治疗45d后,对照组小鼠体质量为(27.21±2.85)g,明显低于异烟肼组[(37.98±3.09)g]和SHetA2组[(38.28±3.43)g],差异有统计学意义(F=4.05,P=0.023);异烟肼组与SHetA2组比较,小鼠体质量差异无统计学意义(q=0.10,P=0.998);对照组小鼠肺组织重度病变的构成比(80.0%,16/20)明显高于异烟肼组(15.0%,3/20)和SHetA2组(10.0%,2/20),差异有统计学意义(χ^2=32.18,P<0.01);对照组小鼠肺脏感染细菌数量[经对数转换(lg10CFU/ml)]为7.01±1.23,明显高于异烟肼组(2.59±0.87)和SHetA2组(2.25±0.94),差异有统计学意义(F=6.71,P=0.002);而异烟肼组与SHetA2组比较,差异无统计学意义(q=0.33,P=0.970)。结论SHetA2在体内外均对MTB有抗菌作用,或可成为新的抗结核化学药物的候选。

Objective To evaluate the antibacterial effect of sulfur heteroarotinoid A2(SHetA2)on Mycobacterium tuberculosis(MTB)in vitro and in vivo.Methods(1)SHetA2 with different doses(2.5μg/ml,5.0μg/ml,10.0μg/ml,and 20.0μg/ml)was added to Sutong medium in test tube,followed by the addition of the equal volume of MTB standard strain H37RV solution(1 mg/ml,0.1 ml/each inoculation,containing 106 CFU).After cultured at 37℃for 2 weeks,the minimum inhibitory concentration(MIC)of SHetA2 was determined.(2)Seventy-six specific pathogen free Kunming mice were inoculated with nebulizer inhalation device to establish tuberculosis infection model.Sixty mice were modeled successfully and randomly divided into control group,isoniazid group,and SHetA2 group in equal numbers(n=20),accordingly,the mice were treated with saline,isoniazid,and SHetA2,respectively,in different groups.After 45 days of treatment,the changes in physical signs,body weight,lung tissue bacterial load,and histopathology were observed.Results(1)In vitro results showed that MIC of SHetA2 against standard strain MTB H37RV was 10μg/ml.(2)In vivo anti-tuberculosis experiments showed that after 45 days of treatment,the body weight of the control group was(27.21±2.85)g,which was significantly lower than those of isoniazid group((37.98±3.09)g)and SHetA2 group((38.28±3.43)g),with statistically significant difference(F=4.05,P=0.023).The difference of body weight between the isoniazid group and SHetA2 group(q=0.10,P=0.998)was not statistically significant.In the control group,the ratio of severe lung lesions(80.0%,16/20)was significantly higher than those of isoniazid group(15.0%,3/20)and SHetA2 group(10.0%,2/20),with statistically significant difference(χ^2=32.18,P<0.01).Lung bacterial load(lg10 CFU/ml)of control group was 7.01±1.23,which was obviously higher than those of isoniazid group(2.59±0.87)and SHetA2 group(2.25±0.94),with statistically significant difference(F=6.71,P=0.002);while no statistically significant difference was found between the isoniazid group and SHetA2 group(q=0.33,P=0.970).Conclusion SHetA2 has a considerable antibacterial effect on MTB both in vivo and in vitro,which may be a candidate for new anti-tuberculosis drugs.