Inhibitory Effects and Mechanisms of <i>Athyrium multidentatum</i> Against <i>Staphylococcus aureus</i> and <i>Bacillus</i> cereus

Athyrium multidentatum, a perennial herb used as a traditional wild vegetable, has antioxidant and anti-inflammatory activities, but its full bioactivity spectrum remains unstudied. To expand its application, this study explored its inhibition capacity against foodborne bacteria, aiming to identify candidates for natural antimicrobial preservatives and provide a basis for comprehensive utilization. A. multidentatum extract (AME) was analyzed for flavonoid profile via LC-MS. Its antibacterial activity was assessed by determining minimum inhibitory concentration (MIC) using the 2,3,5-triphenyltetrazolium chloride assay. AME's effects on bacterial cell membrane permeability, respiratory inhibition, and metabolic pathways were analyzed via conductivity measurements, spectrophotometry, SDS-PAGE, and scanning electron microscopy. AME exhibited inhibitory effects against Staphylococcus aureus and Bacillus cereus, with MIC values of 4 mg/mL for S. aureus and 8 mg/mL for B. cereus. The extract increased leakage of alkaline phosphatase, electrolytes, nucleic acids, and proteins (indicating disrupted cell permeability) and inhibited bacterial respiration, mainly by disrupting the glycolysis pathway. Thus, A. multidentatum shows potential for developing natural antimicrobials and food preservatives.