Allicin can effectively treat Aspergillus fumigatus by inhibiting the germination of conidia via oxidative stress.

Aspergillus fumigatus (A. fumigatus) infection is still a threat to human health, but the use of existing drugs is limited due to resistance, side effects and expensive. Allicin has been shown to be effective against microbial infection; however, little is known about the effect of allicin on A. fumigatus. Here, the MIC of allicin against A. fumigatus was 2 μg/ml, within a range of 2–16 μg/ml against 35 other A. fumigatus clinical isolates; moreover, allicin even exhibited activity against the strains that were resistant to AmB or VRC. Additionally, allicin (6, 3 and 1.5 mg/kg) exerted a dose-dependent therapeutic effect on A. fumigatus-infected mice by significantly improving survival, reducing fungal load and lung damage. Furthermore, after 6 h of incubation, the allicin treatment subsequently reduced the A. fumiga spore diameter, with diameters of 3.57, 2.54 and 2.6 μm in the control group, 1 MIC, and 2 MIC allicin groups, respectively, and inhibited the formation of spores during the expansion phase, thus interfering with spore germination. Finally, through transcriptomic and proteomic analyses, the genes, proteins, and pathways associated with oxidative stress were found to be increased and activated. Moreover, the measurement of reactive oxygen species also verified that there was more oxidative damage after allicin treatment in a concentration-dependent manner. These results confirmed that allicin has good anti-A. fumigatus efficacy, and that its mechanism of action occurs through the induction of greater oxidative damage to inhibit the germination of conidia into the swollen phase. Allicin maybe become a new type of anti-A. fumigatus therapeutic.