In vitro investigation of antifungal efficacy of diclofenac sodium salt against Aspergillus spp. strains causing food spoilage: a drug repurposing approach

Fungal species especially Aspergillus spp. causes contamination in food causing food spoilage. Aspergillus flavus is the most common fungal pathogen which secrets highly poisionous secondary metabolite aflatoxin which is toxic to mammals. So, to identify a compound which can control contamination of A. flavus of food is necessary and challenging. Drug repurposing is an alternative which is less time consuming and economical. Current study aimed to investigate potential of NSAID drug-diclofenac sodium for its antifungal potency. Isolation of Aspergillus species causing food contamination were carried out by the suspension-dilution technique and inoculation on agar medium from peanuts. Antifungal efficacy of diclofenac was conducted using the agar plate and liquid dilution methods. The inhibitory effect of diclofenac sodium was found significantly on A. flavus and A. niger in concentration dependent manner. The mycelial was significantly reduced at concentration of 300 µg/ml diclofenac for both A. flavus and A. niger strains. The MIC50 was achieved at 300 and 1200 µg/ml for A. flavus and A. niger respectively in liquid medium. Our findings suggest diclofenac can be used effectively to control food spoilage caused by Aspergillus species. Keywords: Diclofenac sodium, Aspergillus spp, Drug repurposing, Mycelium inhibition