Withania somnifera seed oil exhibits antibiofilm properties against drug-resistant Candida auris clinical isolate through modulation in cell permeability.

AIM: Candida auris, fast evolving drug-resistant fungus, poses an imminent global health threat. Alternative drug-resistance nonevoking treatment options are necessary. This study explored the antifungal and antibiofilm efficacies of Withania somnifera seed oil extracted using super critical CO2 (WSSO) against clinically isolated Fluconazole-resistant C. auris and its putative mode-of-action. METHODS AND RESULTS: Effects of WSSO on C. auris were tested by broth microdilution method, with observed IC50 at 5.96 mg ml-1. Time-kill assay revealed that WSSO is fungistatic. Mechanistically, ergosterol binding and sorbitol protection assays showed that C. auris cell membrane and cell wall are the targets for WSSO. Lactophenol: Cotton-Blue: Trypan-Blue staining confirmed loss of intracellular contents by WSSO treatment. Candida auris biofilm formation was disrupted by WSSO (BIC50: 8.52 mg ml-1). Additionally, WSSO exhibited dose and time-dependent mature biofilm eradication property with 50% efficacies at 23.27, 19.28, 18.18, and 7.22 mg ml-1 over 24, 48, 72, and 96 h, respectively. Biofilm eradication by WSSO was further substantiated through scanning electron microscopy. Standard-of-Care Amphotericin B, at its break-point concentration, (2 µg ml-1) was found to be inefficient as an antibiofilm agent. CONCLUSIONS: WSSO is a potent antifungal agent effective against planktonic C. auris and its biofilm.

Anu taila, an herbal nasal drop, suppresses mucormycosis by regulating host TNF-α response and fungal ergosterol biosynthesis.

AIM: The intractable, mucormycosis, caused by Mucorales primarily targets immunocompromised individuals. The first-line therapy, intravenous liposomal amphotericin B and surgical debridement of necrotic tissue, is contraindicative in individuals with compromised kidneys. This invokes a pressing need to identify safer treatment options. METHODS AND RESULTS: The antifungal effect of the classical nasal drop, Anu taila, against Mucor spp. was investigated through microbiological, cytological, analytical chemical (HPLC and GS-MS/MS) and scanning electron microscopic (SEM) approaches. Anu taila-pretreated spores germinated late, resulting in reduced infectivity, observed as milder monocytic immune response. Conversely, Anu taila-pretreated human THP-1 cells exhibited an improved immune response against Mucor spores, through TNF-α. Repeated Anu taila application rapidly abolished fungal microarchitectures than amphotericin B, evident from swift replacement of hyphae, sporangiophores and sporangia with fused biomass, in the SEM images. HPLC analysis showed that Anu taila treatment significantly reduced overall ergosterol content in Mucor biomass. Anu taila also downregulated sterol-C5-desaturase-coding ERG3 gene, crucial for ergosterol biosynthesis and resultant structural integrity, in Mucor spp. CONCLUSION: Taken together, Anu taila was found effective against Mucor spp., with both prophylactic and curative implications, which is attributable to the phytochemical composition of this classical nasal drop. SIGNIFICANCE AND IMPACT STATEMENT: The potential remedial effects of a classical nasal drop against an obdurate and challenging fungal infection are identified.