Potencial antifúngico e citotóxico de ácidos graxos e oximas.

Abstract

The secretion of extracellular phospholipases and proteinases of Candida has been described as a relevant virulence factor of human infections. Aliphatic fatty acids have antimicrobial properties, but the mode by which they act in the virulence factors of microorganisms, such as Candida, is still unclear. The oximes have a long history in organic synthesis and medicinal chemistry. Moreover, there are few reports about their toxicity. Current study investigated the in vitro antifungal activity, exoenzyme production and cytotoxicity of some aliphatic fatty acids and their esters derivatives and ten oximes against the Candida species. The MIC and MFC of aliphatic medium-chain fatty acids, methyl and ethyl esters and oximes were performed by the CLSI M27-A3 method. The influence of these compounds in the inhibition of the production of hydrolytic enzymes, phospholipase and proteinase by Candida was also investigated. Lauric acid was the fatty acid with the best result on MIC against Candida species although its esters derivatives showed no activity. The inhibition of phospholipase was more significant than proteinase production by Candida. Oximes showed a great ability to inhibit phospholipase with 50% reduction in most cases. However, tested compounds for proteinase did not affect the enzyme. Current results showed a great reduction in phospholipase production which suggests that compounds of this class may interfere with the invasion of the host and disease growth. The fatty acids showed 80% cell viability in MIC concentrations, as in the concentrations which presented anti-enzymatic effect. Therefore, the potential use of these fatty acids and oximes could be the base for more antimicrobial tests.