Red onion wastes (ROW) are valuable sources of bioactive metabolites with promising antimicrobial effects. Methicillin-resistant Staphylococcus aureus (MRSA) infections are a growing risk in hospitals and communities. This study aims to investigate the in vitro and in vivo antibiofilm activities of the acidified ethanolic extract of red onion scales (RO-T) and its fractions against an MRSA vaginal colonization model. The RO-T extract, as well as its anthocyanin-rich fraction (RO-P) and flavonoid-rich fraction (RO-S), recorded a promising antibacterial activity against highly virulent strains of bacteria (MRSA, Acinetobacter baumannii, Escherichia coli and Pseudomonas aeruginosa). RO-S showed the highest antibacterial activity (MBC of 0.33 ± 0.11 mg/mL) against MRSA USA300 and significantly eradicated its biofilm formation with an IC₅₀ of 0.003. Using a rat model, in vivo assessment on all samples, which were formulated as a hydrogel, revealed a significant reduction of MRSA bacterial load recovered from an infected vagina compared to that of the negative control group (NCG). RO-T extract and vancomycin groups recorded the highest antibacterial activity with a bacterial load 2.998 and 3.358 logs lower than the NCG, respectively. The histopathological investigation confirmed our findings. RO-T and RO-S were standardized for their quercetin content. Finally, ROW offers a new potent antibiofilm agent mostly due to its high quercetin content.

Biopriming is a seed-level biotechnological intervention with considerable potential to enhance the nutritional, phytochemical, and functional attributes of cereal grains. In this study, microbial biopriming was investigated as a targeted approach to modulate the phytochemical composition, antioxidant capacity, and neuroprotective efficacy of barley-derived extracts. Germinated barley extract (GBE) was comparatively evaluated against two bioprimed derivatives produced by inoculating barley seeds with Bacillus subtilis (GBB) and Aspergillus niger (GBF) prior to germination. Comprehensive physicochemical characterization was performed using chromatographic and spectroscopic profiling, and functional efficacy was evaluated through in vitro antioxidant assays and in vivo assessment using a monosodium glutamate (MSG)-induced attention-deficit/hyperactivity disorder-like rat model. The GBB exhibited the most pronounced bioactivity, characterized by marked enrichment in phenolic acids and B-complex vitamins, particularly vitamins B2, B9, and B12. This enhanced compositional profile was associated with significant improvements in locomotor activity and spatial memory, restoration of neurotransmitter homeostasis, attenuation of oxidative stress and neuroinflammatory signaling, and activation of autophagy-associated survival pathways. This study identifies B. subtilis biopriming as a promising and sustainable method for amplifying the neuroprotective properties of germinated barley, advocating its development as a functional food ingredient derived from cereals.