Bourinbaiar A S, Lee C H
Metatron, Inc, New York, NY 10003 USA.
Contraception. 1996 Dec;54(6):367-72. doi: 10.1016/s0010-7824(96)00205-3.
Gramicidin, a linear polypeptide with antiviral and antimicrobial properties, was compared in vitro with a commonly used spermicidal detergent-nonoxynol-9 (N9). The inhibition of sperm functions was evaluated by computer-assisted semen analysis (CASA) for sperm motility, in cervical mucus penetration assay, and by colorimetric tetrazolium salt and lactate dehydrogenase release assays routinely employed for testing the toxicity of drugs. The effective 100% inhibitory concentration (IC100) of gramicidin in a 2-min sperm immobilization assay by CASA was equal to 4 micrograms/ml, whereas IC100 of N9 was equal to 200 micrograms/ml. The presence of 0.1% of chelating agent, EDTA, reduced IC100 of gramicidin to 10 ng/ml, while less than a twofold enhancement in N9 activity was observed upon combination with EDTA. Likewise, the gramicidin/EDTA combination was 100,000 times more potent than N9/EDTA in the sperm penetration assay. Quantitative toxicity tests confirmed that gramicidin is a potent spermostatic rather than spermicidal agent. Further development of a gramicidin/EDTA formulation is warranted as a nontoxic topical contraceptive with activity against viral and microbial sexually transmitted diseases (STDs).
短杆菌肽是一种具有抗病毒和抗菌特性的线性多肽，在体外将其与常用的杀精洗涤剂壬苯醇醚-9（N9）进行了比较。通过计算机辅助精液分析（CASA）评估精子活力、宫颈黏液穿透试验以及通过常用于测试药物毒性的比色四氮唑盐和乳酸脱氢酶释放试验来评估精子功能的抑制情况。在通过CASA进行的2分钟精子固定试验中，短杆菌肽的有效100%抑制浓度（IC100）等于4微克/毫升，而N9的IC100等于200微克/毫升。存在0.1%的螯合剂乙二胺四乙酸（EDTA）时，短杆菌肽的IC100降至10纳克/毫升，而与EDTA联合使用时，N9的活性增强不到两倍。同样，在精子穿透试验中，短杆菌肽/EDTA组合比N9/EDTA有效100,000倍。定量毒性试验证实短杆菌肽是一种有效的精子静止剂而非杀精剂。作为一种对病毒性和微生物性传播疾病（STD）具有活性的无毒局部避孕药，进一步开发短杆菌肽/EDTA制剂是有必要的。
