[Effect of nitrofurylpropenylidene benzhydrazides against trichomonads, bacteria, yeasts and fungi with particular consideration of the results in the Ames test and host-mediated assay].

11 out of 13 N-[3-[5-nitrofuryl-(2)-propenylidene)]-benzhydrazides described by us showed an in vitro activity against T. vaginalis almost equivalent to or approaching that of the standard substances metronidazole and tinidazole. One compound was markedly more effective; two compounds exhibited much weaker activity than the two reference substances. In the model of the T. foetus infection of mice, only two compounds came close to the chemotherapeutic effect of tinidazole when administered orally. The other compounds were less effective. Metronidazole showed an activity 10 times weaker than that of tinidazole in this animal model. The in vitro efficacy of the most active substances a and d on T. foetus infection paralleled the bacteriostatic effect against different species of bacteria. In comparison, d was more effective than a against T. vaginalis, 2 Candida strains and M. tuberculosis. In the Ames test, 5 out of the 13 described N-[3-[5-nitrofuryl-(2)-propenylidene))]-benzhydrazides proved mutagenic in test strains TA 98 and TA 100; this was the case also in strain TA 1537 for the microbiologically most promising compound a. Because of liver damage observed in the test on toxicity, the substance was not taken up in clinical studies. It is interesting to note that these substances were not found to be mutagenic in the host-mediated assay. No signs of chromosome breaks were observed for substances a and n in the micronucleus test. The relevance of these findings was discussed. Statistical procedures were described for both the Ames test and the host-mediated assay.