Invasive and superficial infections caused by the Candida species result in significant global morbidity and mortality. As the pathogenicity of these organisms is intimately intertwined with host immune response, therapies to target both the fungus and host inflammation may be warranted. Structural similarities exist between established inhibitors of the NLRP3 inflammasome and those of fungal acetohydroxyacid synthase (AHAS). Therefore, we leveraged this information to conduct an in silico molecular docking screen to find novel polypharmacologic inhibitors of these targets that resulted in the identification of 12 candidate molecules. Of these, compound 10 significantly attenuated activation of the NLPR3 inflammasome by LPS + ATP, while also demonstrating growth inhibitory activity against C. albicans that was alleviated in the presence of exogenous branched chain amino acids, consistent with targeting of fungal AHAS. SAR studies delineated an essential molecular scaffold required for dual activity. Ultimately, 10 and its analog 10a resulted in IC50 (IL-1β release) and MIC50 (fungal growth) values with low μM potency against several Candida species. Collectively, this work demonstrates promising potential of dual-target approaches for improved management of fungal infections.
Keywords: AHAS; Candida; NLRP3; antifungal; dual-target; inflammasome.