The therapeutic effect of 5-nitro-8-hydroxyquinoline on Aspergillus fumigatus: results from in vitro and in vivo models of invasive aspergillosis.

Aspergillus fumigatus is an important opportunistic pathogen. In the immunocompromised people, A. fumigatus infection can cause invasive aspergillosis, which is characterized by high incidence rate and high mortality. However, due to the limited availability of anti-fungal drugs and the continuous emergence of drug-resistant strains, the treatment of A. fumigatus infection is facing enormous challenges. 5-nitro-8-hydroxyquinoline (NQ) is an ancient antibiotic and pharmaceutical intermediate and fungicide, which is not only exhibits good antibacterial activity on against drug-resistant Staphylococcus aureus, Candida spp., but also has good biofilm eradication on activity against Pseudomonas aeruginosa, Acinetobacter baumannii. However, it is not known whether NQ has anti-A. fumigatus infection effects in vivo. This study evaluates the in vitro and in vivo activity of NQ against A. fumigatus. The results showed that NQ not only had a good anti-A. fumigatus effect, but also promoted the phagocytosis and killing ability of alveolar macrophages to A. fumigatus. In addition, we found that intraperitoneal injection of NQ significantly reduced the diffuse infection degree of A. fumigatus and the fungal burden in mice tissues, and increased the secretion of IL-2, IL-6, IL-10 in the blood. NQ exerted a good anti-fungal effect. In summary, these results confirm that NQ may be a potential anti-fungal drug for treating A. fumigatus infection.