In Vitro and In Vivo Antibiofilm Activity of Red Onion Scales: An Agro-Food Waste

• Published in: Molecules (Basel, Switzerland) Switzerland), 2023-01, Vol.28 (1), p.355
• Main Authors: Ali, Nermeen B, El-Shiekh, Riham A, Ashour, Rehab M, El-Gayed, Sabah H, Abdel-Sattar, Essam, Hassan, Mariam
• Format: Article
• Language: English
• Subjects: Acidification; Agricultural wastes; agro-waste; Allium cepa; Analysis; Anthocyanin; Anthocyanins; antibacterial; Antibacterial activity; Antibiotics; Antimicrobial activity; Antimicrobial agents; Bacteria; Bacterial infections; Bioactive compounds; Biofilms; Blood vessels; Care and treatment; Coliforms; Colonization; Complications and side effects; Composition; Drug resistance; Edema; Environmental aspects; Flavonoids; Food waste; Food wastes; Health aspects; Illnesses; In vivo methods and tests; Metabolites; Methicillin; Microorganisms; MRSA; Onions; Pathogens; Pseudomonas aeruginosa; Public health; Quercetin; standardization; Staphylococcus aureus; Staphylococcus aureus infections; Staphylococcus infections; Vagina; vaginal colonization; Vancomycin
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28010355

Red onion wastes (ROW) are valuable sources of bioactive metabolites with promising antimicrobial effects. Methicillin-resistant (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, , and ). 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 IC 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.