Investigation of serum minimal inhibitory concentrations of some benzimidazole, imidazole and benzothiazole derivatives and their effects on liver and renal functions

In previous studies many benzimidazole, imidazole and benzothiazole derivat ives had been synthesized and their antimicrobial activities were tasted in vitro conditions. Four of these compounds showed minimal inhibitory concen trations (MIC) of 5-25 mu g/ml against standard strains and clinical isolat es. In order to determine whether these four compounds can be used for ther apeutic purpose, their serum MIC values and side effects on hepatic and ren al functions were determined. Different concentrations of the compounds wer e tested on Wistar rats. Compound 1 was administered orally, intramuscularl y and intravenously; compounds 2, 3 and 4 were given orally and intramuscul arly. Blood samples were taken 4 and 24 h after administration of the compo unds. Serum MIC Values were investigated by bioassay and serum levels of bi ochemical parameters by autoanalyzer. None of the tested compounds showed a ntimicrobial activity at their serum concentrations. Although creatinine ac tivity was found at normal levels in all experiments, compounds 1 and 2 cau sed a significant increase in blood urea nitrogen (BUN) level. The values o f aspartate aminotransferase and/or alanine aminotransferase and/or alkalin e phosphatase which are characteristic for liver function were generally fo und at high levels. According to these results, it can be concluded that th e tested compounds caused damage in liver and biliary tracts without antimi crobial activity by their serum concentrations.