Cleison Leite

Background: Vulvovaginal candidiasis (VVC) is a significant public health concern characterized by increasing incidence and challenges in treatment. However, most studies investigating Candida spp. virulence factors and antifungal susceptibility predominantly rely on in vitro assays. While these assays are highly reproducible, they do not accurately replicate the complex vaginal microenvironment. To address this limitation, we developed an ex vivo model using porcine vaginal mucosa and a physiologically relevant volume of simulated vaginal fluid (SFV) to better mimic human vaginal conditions. Methods: Biofilm formation and fluconazole activity were assessed using the reference strain Candida albicans ATCC 90028 and two clinical isolates associated with VVC. Results were expressed as colony-forming units (CFU) and directly compared with in vitro assays conducted in Sabouraud dextrose broth (SDB) and SVF. Results: CFU analysis revealed that the ex vivo vaginal mucosa model supported more robust biofilm development, with counts ranging from 6.67 × 10⁷ to 7.20 × 10⁷ CFU/mL, compared to the in vitro SDB assay (3.58 × 10⁷ to 4.5 × 10⁷ CFU/mL). This suggests enhanced fungal growth under tissue-based conditions. Moreover, fluconazole achieved greater biofilm eradication in the ex vivo model (>70%) compared to the in vitro SDB assay (≤34.50%), which may indicate increased antifungal activity within a physiologically relevant environment. Conclusions: The ex vivo vaginal mucosa model offers a physiologically relevant platform for supporting C. albicans biofilm development and serves as a valuable alternative for preclinical screening of antifungal agents.

Background: Skin infections caused by Staphylococcus aureus represent a major public health concern, and plant extracts, such as those from Cochlospermum regium, have emerged as promising therapeutic alternatives. Methods: This study developed carbopol-based gel formulations containing ethanolic leaf extracts of C. regium (CRG 0.5% and 1%) and evaluated their physicochemical stability, antibacterial activity against S. aureus and a methicillin-resistant wound isolate, antioxidant potential, and biocompatibility. Results: Both CRG 0.5% and 1% were physically stable and maintained antibacterial activity for up to 90 days at 8 °C, while at 25 °C only CRG 1% retained activity throughout the evaluation period. In ex vivo pig skin assays, CRG 1% reduced methicillin-resistant S. aureus contamination by 99%, outperforming the conventional topical antibacterial agent (neomycin + bacitracin), which achieved 66% inhibition. The extract also exhibited high antioxidant activity without mutagenic or hemolytic effects. Although phenolic and flavonoid contents decreased over time, CRG 1% preserved adequate levels for therapeutic application. Conclusions: These findings indicate that CRG 1% has potential as a stable, safe, and effective alternative for the treatment of topical infections, particularly those caused by methicillin-resistant S. aureus.

A series of 2‐nitroimidazole‐1,2,3‐triazole sulfonamide hybrid analogs were designed using medicinal chemistry approaches, such as bioisosterism, molecular hybridization, Topliss tree decision, and Craig plot. A total of 24 compounds were synthesized via click chemistry in satisfactory yields. Overall, analogs 15 a‐x exhibited relevant in vitro anti‐trypanosomatid activity against amastigote forms of T. cruzi and without cytotoxic effect on LLC–MK2 cells. Analogs 15 b (R₁=4‐Cl−Ph; IC₅₀=1.63 μM, SI=>30.65), 15 m (R₁=3,4‐di‐Cl−Ph; IC₅₀=0.63 μM, SI=>78.96), and 15 s (R₁=Ph‐4‐O−Ph; IC₅₀=0.63 μM, SI=>79.90) demonstrated pronounced antitrypanosomal activity, more active than the reference drug, benznidazole and with good selectivity indexes. Furthermore, analog 15 b (R₁=4‐Cl−Ph; IC₅₀=0.5 μM, SI=>100) exhibited an outstanding antileishmanial activity against amastigote forms of Leishmania (L.) amazonensis and impressive selectivity index, comparable to the reference compound amphotericin B. The mutagenicity of compounds 15 b and 15 m were evaluated against Salmonella typhimurium strains (TA98, TA100 and TA102). Compound 15 b exhibited mutageniticy only at a concentration of 500 μg/plate for the TA100 strain, whereas compound 15 m was considered non‐mutagenic. These findings suggest that 2‐nitroimidazoles‐1,2,3‐triazole sulfonamide hybrid analogs are promising anti‐trypanosomatid candidates for future in vivo studies.