Screening of antifungal and antibiofilm activity of Brazilian plant extracts exhibiting selective activity against Cryptococcus neoformans

Abstract

Extracts derived from plants have long been recognized as having potential antimicrobial activity and their use has contributed immensely to the pharmacotherapy of infectious diseases. In a biomedical context of increasing microbial resistance to traditional drugs and persistence due to biofilm, new bioactives with proven antifungal and antibiofilm activities emerge as resourceful options to get past these problems. In this work, we tested the capacity of 45 extracts derived from seeds of Amazonic and Southern Brazilian plants to inhibit the formation and/or to eradicate the preformed biofilm of Cryptococcus neoformans and Candida albicans - common pathogens of severe systemic infections. Minimal inhibitory concentration (MIC) was also carried out. Our study identified one selective extract with a rate of biofilm eradication superior to 80% and no activity against planktonic cells of C. neoformans. This may shed light to a plant-derived extract with no antifungal activity but with the ability to affect formed biofilm, which induces less resistance by the yeast.