Atividade anticriptocócica de Xylosma prockia (Turcz.) Turcz.: investigação de alvos moleculares em Cryptococcus neoformans por meio de linhagens mutantes

Abstract

Opportunistic fungal infections have increased globally, especially among immunocompromised individuals, representing a significant public health challenge. Cryptococcosis stands out due to its high morbidity and mortality in HIV patients, as well as the limitations of current therapies, including toxicity and increasing resistance to polyenes and azoles. In this context, plant species such as Xylosma prockia (Turcz.) Turcz. emerge as potential sources of novel antifungal compounds. Previous studies by our group demonstrated that leaf extracts exhibit activity against Cryptococcus neoformans, Cryptococcus gattii, and Candida parapsilosis. This study aimed to investigate the metabolic pathways involved in the anticryptococcal activity of the ethyl acetate fraction (EAF) obtained from X. prockia leaves, using a mutant strain library of C. neoformans ATCC K99. The minimum inhibitory concentration (MIC) was determined by broth microdilution in 96-well plates, according to CLSI guidelines, using the wild-type strain as a control. The EAF exhibited antifungal activity, with MIC values ranging from 15.6 to 31.25 μg/mL. Comparative analysis between mutant and wild-type strains revealed changes in susceptibility profiles associated with specific genes, indicating the involvement of distinct metabolic pathways. Increased sensitivity was observed in mutants related to mitochondrial energy metabolism, indicating impairment of cellular energy production. Alterations in mutants associated with plasma membrane integrity indicate destabilization of this structure. Mutants related to proline metabolism demonstrated the involvement of oxidative stress mechanisms. Additionally, changes observed in mutants with deletions in genes involved in polysaccharide capsule biosynthesis indicate an impact on virulence factors. In conclusion, the ethyl acetate fraction of X. prockia exhibits significant antifungal activity, associated with the modulation of pathways related to mitochondrial energy metabolism, plasma membrane integrity, oxidative stress, and capsule biosynthesis, reinforcing its potential as a source of promising bioactive molecules. Further studies, particularly in vivo, are required to validate these findings.