一种新型抗菌肽APNT-6的溶血性和急性毒性评价

摘要

研究了一种以抗菌脂肽类物质surfactin、iturin和fengycin为主要成分的新型抗菌肽APNT-6的体外溶血和小鼠口服急性毒性,为食品应用安全性提供初步评估.将抗菌肽作100倍稀释置于兔血琼脂平板上的牛津杯中观察溶血情况；结果显示,经100倍稀释的抗菌肽在体外对血细胞有较强的溶血毒性.将60只小鼠按雌雄各半随机分成6组,分别以8、40、200、l000、5000 mg每千克体重剂量的抗菌肽对小鼠进行一次性灌胃,7d内观察小鼠毒性体征并测定相关指标.结果表明,当小鼠被给予该抗菌肽5000 mg/kg剂量时,观察7d无任何毒性反应,说明高剂量的抗菌肽经口服在小鼠体内不能达到有效溶血浓度,其口服半数致死剂量(LD50)大于5000 mg/kg小鼠体质量,急性毒性评级属实际无毒级.根据以上结果可知,新型抗菌肽APNT-6在体外有溶血毒性但经口服对小鼠没有急性毒性作用.%In this paper, the hemolytic and mice acute oral toxicity of a new antibacterial peptide APNT-6 with antibacterial lipopeptide surfactin, iturin and fengycin as the main components was evaluated. At first, hemolytic activity of the antibacterial peptide was studied in vitro; a 100-fold dilution of the antibacterial peptide was added to an Oxford cup placed on rabbit blood agar plate, after 37 °C overnight, the hemolytic activity was determined. The results showed that, 100-fold dilution of the antibacterial peptide in the Oxford cup formed 32 mm hemolytic circle on the plate medium, indicating that it has a strong hemolytic toxicity in vitro that is possible barriers to actual use. Meanwhile, a study for acute oral toxicity of the antibacterial peptide in mice was conducted, 60 male and female Kunming mice were randomly divided into six groups, with normal saline as a control, each group of mice was respectively fed 8, 40, 200, 1 000 and 5 000 mg/kg of the antibacterial peptide dose at one-time, within 7 d, observing toxicity body signs and death situation of mice and determining feed intake, water intake, weight gain and organ index, and examining pathological changes for the abnormal organs. The results showed that in each dose group of mice death and any signs of poisoning were not seen. The oral median lethal dose (LD50) is greater than 5 000 mg/kg body weight; feed intake and water intake of each group mice have no significant change; except that the highest dose group had slightly lower weight gain, there were no significant differences in weight gain between the other groups and the control group; the spleen, kidney, lung and cardiac index of each group had no statistically significant differences and liver index of more than 1 000 mg/kg dose group was higher compared with the control group; mice organs and tissues of each dose group have no obvious pathological changes. These results suggest that high doses of the antibacterial peptide by oral administration can not achieve an effective hemolytic concentration in mice; in accordance with the acute toxic standard of disinfectant, it really has no toxicity, and that oral administration of the antibacterial peptide in mice does not constitute significant acute toxic effects. Based on the above results, it can be concluded that the new antibacterial peptide APNT-6 has strong hemolytic toxicity in vitro, but no acute oral toxicity in mice.