Synergistic Antifungal Activity of PIT and ITZ Against Varied Aspergillus Species via Affecting The Ergosterol Content and Intracellular Drug Retention.

Abstract

Aspergillus species are a significant cause of aspergillosis, with invasive pulmonary aspergillosis (IPA) being particularly severe and often fatal. The increasing resistance to azole antifungals and limited treatment options highlight the need for new therapeutic strategies. This study explores the synergistic effects of pitavastatin (PIT), a statin, combined with itraconazole (ITZ) against various Aspergillus species. In vitro assessments included plate inoculation, liquid medium incubation, and microscopic observation of spore germination, alongside ergosterol content analysis, intracellular itraconazole retention, and rhodamine 6G (Rh6G) uptake and efflux assays. The PIT and ITZ combination exhibited significant synergistic antifungal activity against Aspergillus flavus, Aspergillus niger, Aspergillus terreus, and Aspergillus fumigatus. The synergistic mechanism was attributed to decreased ergosterol levels, increased intracellular itraconazole retention, reduced spore germination, and abnormal hyphal formation in fungal cells. An in vivo Galleria mellonella infectious model demonstrated reduced mortality in larvae treated with the drug combination compared to those treated with ITZ alone. These findings suggest that the PIT and ITZ combination enhances antifungal effects against Aspergillus species, potentially offering a novel therapeutic strategy for IPA treatment. Further clinical trials are warranted to explore the potential of this drug combination in treating aspergillosis.