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Aim: This study evaluated the antifungal efficacy of gentian violet (GV) in an experimental vulvovaginal candidiasis (VVC) model. Materials & methods: In vitro susceptibility and cytotoxicity assays were performed to validate the antifungal potential and safety of GV. The antifungal efficacy was then evaluated in vivo through comparative analysis of the fungal burden following treatment with GV or nystatin, as well as assessment of the vaginal tissue by histology and electron microscopy. Results: GV demonstrated a safe antifungal profile against C. albicans , with a significant decrease in fungal burden and an improvement in the inflammatory process evaluated histologically. Conclusion: The results of this study motivate further assessment of GV as a promising alternative for VVC therapy.

Aim: To study the behavior of Candida albicans in women with vulvovaginal candidiasis (VVC), recurrent VVC (RVVC) and asymptomatic (AS), regarding adhesion on HeLa cells and their ability to express secreted aspartic proteinases ( SAP ) genes, agglutinin-like sequence ( ALS ) genes and HWP1 . Materials & methods: The adhesion of Candida albicans to HeLa cells was evaluated by colony-forming units, and the expressed genes were evaluated by qRT-PCR. Results: AS and VVC isolates showed greater ability to adhere HeLa cells when compared with RVVC isolate. Nevertheless, RVVC isolate exhibited upregulation of a large number of genes of ALS and SAP gene families and HWP1 gene. Conclusion: The results demonstrated that RVVC isolate expressed significantly important genes for invasion and yeast-host interactions.

Aim: To compare the pathogenesis of vulvovaginal candidiasis by three Candida species in diabetic mice. Materials & methods: Estrogenized and diabetic mice were challenged with C. albicans , C. tropicalis and C. glabrata . Results: Diabetic animals infected with C. albicans and C. tropicalis maintained the highest fungal burden, despite of high levels of proinflammatory cytokines (IL-6 and TNF-α), respectively. For C. glabrata , the results were similar in diabetic and nondiabetic groups. Conclusion: C. tropicalis was as invasive as C. albicans , and both were more effective than C. glabrata . This ability was attributed to filamentation, which may be stimulated by glucose levels from vaginal fluid. In addition, the high burden may be attributed to the apparent immunological inefficiency of the diabetic host.

Aim: A structural model of chorismate synthase (CS) from the pathogenic fungus Candida albicans was used for virtual screening simulations. Methods: Docking, molecular dynamics, cell growth inhibition and protein binding assays were used for search and validation. Results: Two molecules termed CS8 and CaCS02 were identified. Further studies of the minimal inhibitory concentration demonstrated fungicidal activity against Paracoccidioides brasiliensis with a minimal inhibitory concentration and minimal fungicidal concentration of 512 and 32 μg·ml -1 for CS8 and CaCS02, respectively. In addition, CaCS02 showed a strong synergistic effect in combination with amphotericin B without cytotoxic effects. In vitro studies using recombinant CS from P. brasiliensis showed IC 50 of 29 μM for CaCS02 supporting our interpretation that inhibition of CS causes the observed fungicidal activity.

Aim:  17 new 4-methoxynaphthalene- N -acylhydrazones were synthesized in order to evaluate their biological action against important pathogens. Methods:   In vitro susceptibility assays of compounds were performed against Paracoccidioides brasiliensis and Mycobacterium tuberculosis . Results: Compounds 4a , 4b and 4k were the most potent against P. brasiliensis , two with minimum inhibitory concentrations of ≤1 μg ml -1 and exhibited pharmacological synergy with amphotericin B. The compounds also showed activity against M. tuberculosis , with 4c and 4k being the more promising. Compound 4k showed good synergistic antimycobacterium activity with ethambutol. None of the compounds tested showed toxicity. Conclusion: We highlight the compound 4k , as a potential agent for the treatment of patients co-infected with paracoccidioidomycosis and tuberculosis.

Aim: Novel 4-methoxy-naphthalene derivatives were synthesized based on hits structures in order to evaluate the antifungal activity against Paracoccidioides spp., Methods: Antifungal activity of compounds was evaluated against P. brasiliensis and most promising compounds 2 and 3 were tested against eight clinically important fungal species., Results: Compound 3 was the more active compound with MIC 8 to 32 μg.ml -1 for Paracoccidioides spp without toxicity monkey kidney and murine macrophagecells. Carbohydrazide 3 showed good synergistic antifungal activity with amphotericin B against P. brasiliensis specie. Titration assay of carbohydrazide 3 with PbHSD enzyme demonstrates the binding ligand-protein. Molecular dynamics simulations show that ligand 3 let the PbHSD protein more stable., Conclusion: New carbohydrazide 3 is an attractive lead for drug development to treat paracoccidioidomycoses.