Investigation of the Antimicrobial and Antioxidant Activities of the Ethanol Extract of Amanita muscaria

Characterized by its bright red cap adorned with white spots, Amanita muscaria is not only visually distinctive but also of considerable pharmaceutical interest due to its diverse array of biologically active compounds. Rich in metabolites such as muscimol, ibotenic acid, phenolic compounds, and polysaccharides, this species has been regarded as a potential source of antioxidant and antimicrobial agents. In light of the growing global challenge of antibiotic resistance, the exploration of natural sources has gained increasing significance, with fungal species emerging as promising alternatives. Different concentrations of the A. muscaria extract were tested against 12 reference, 11 multidrug-resistant (MDR), 13 clinical, and 6 food-isolated microorganisms. Disk diffusion assays revealed that the extract produced inhibition zones ranging from 7 to 10 mm, particularly against Listeria monocytogenes, Pseudomonas fluorescens, Enterococcus faecium, and Staphylococcus aureus. The minimum inhibitory concentration (MIC) values ranged between 310 and 5,080 µg/mL, while the minimum bactericidal concentrations (MBCs) were generally above 10,000 µg/mL, indicating a predominantly bacteriostatic effect. The relatively weak activity observed against Gram-negative bacteria was attributed to the diffusion-limiting properties of their lipopolysaccharide outer layer. Antioxidant capacity was assessed using the DPPH radical scavenging assay, in which the extract was compared with ascorbic acid. At 1000 µg/mL, A. muscaria exhibited 97.05% inhibition, comparable to that of ascorbic acid (94.67%), and demonstrated stronger radical scavenging potential at lower concentrations (EC₅₀ = 33.5 µg/mL). These findings suggest that while the antimicrobial potential of A. muscaria is limited, its antioxidant activity is remarkably high. The results highlight the potential of this species as a valuable natural source of antioxidant compounds and indicate that its antimicrobial efficacy may be enhanced through the isolation of active constituents, combination strategies, or nanoparticle-based approaches.