Antimicrobial Effect of Moringa oleifera Leaves Extract on Foodborne Pathogens in Ground Beef

E, R G, Paul SFD, R. M. Targeting beta-lactamase activity with Oxacyclohexadecan-2-one in carbapenem-resistant uropathogenic E. coli: A molecular simulation approach

Urinary tract infections caused by uropathogenic Escherichia coli (E. coli) are a global health concern, with rising rates and antibiotic resistance demanding novel treatments. Therefore, in this study, we explored the potential of Oxacyclohexadecan-2-one obtained from Moringa oleifera (M. oleifera) seed, as antibacterial agent against three majorly prevalent carbapenemase-producing E. coli proteins, blaNDM-1 (New Delhi metallo-betalactamase-1), blaNDM-5 (New Delhi metallo-betalactamase-5) and blaOXA-48 (Oxacillinase-48) from the strains Ecw3, EC-114 and T20 respectively. The ethanolic extract of M. oleifera seed was subjected to GC-MS, identifying 135 compounds. PyRx virtual screening, identified the top 10 ligands for each protein following the Rule of 5 and ProTox classes V and VI, with Oxacyclohexadecan-2-one (PubChem ID: 235414) showing best binding affinity across all 3 proteins with an optimized dose (LD50) of 5000mg/kg. Hence, molecular docking was carried out for ligand 235414 along with Imipenem, belonging to the same class V toxicity class with an optimized dose (LD50) of 5000mg/kg. Imipenem is a commonly used FDA drug to treat UTIs, which served as the control in the study. Oxacyclohexadecan-2-one showed higher binding affinity for the beta-lactamase proteins with a docking score of -6.45 kcal/mol, -6.05 kcal/mol and -7.34 kcal/mol compared to -3.41 kcal/mol, -3.99 kcal/mol and -6.36 kcal/mol of Imipenem for NDM-1, NDM-5 and OXA-48 respectively. Dynamic Simulation was performed for 100 ns for Oxacyclohexadecan-2-one and Imipenem bound protein complexes to determine the stability, fluctuations, compactness, bond interaction, solvent accessibility area, free energy landscape and the binding free energy. The results of molecular docking and dynamics were promising for the Oxacyclohexadecan-2-one, suggesting its potent inhibitory effect against the beta-lactamase producing proteins.

Ultrasound-assisted extraction of bioactive compounds from Moringa oleifera leaves for beef patties preservation: Antioxidant and inhibitory activities, half-life, and sensory attributes

This study aims to examine employing ultrasound-assisted extraction of bioactive components from Moringa oleifera leaves and apply them in beef patties preservation, as well as antioxidant and inhibitory activities and sensory qualities. The study included studying the chemical content and minerals of the M. oleifera leaves, preparation of aqueous and alcoholic extracts using an ultrasound device, then exploring the extraction yield. The results proved that the extraction yield by ultrasound using ethanol at 80% was the highest, reaching 19.22%. The total phenols in the ultrasonic extract with moringa leaves aqueous extract (AMEUS) amounted to 120,755 mg/mL. Since the AMEUS exhibited the highest value of 68.308 mg/mL calic acid - eight phenolic compounds discovered by HPLC - the total content of flavonoids was also calculated. The inhibitory and antioxidant effects of moringa leaf extracts are well documented. We monitored the changes in chemical indicators, such as the value of peroxide and thiobarbituric acid, as well as the percentage of free fatty acids and physical characteristics, such as water-carrying capacity, pH, and pigments, for storage periods 0, 4, 8, and 12 days after adding AMEUS to beef patties at a concentration of 0.5%. The patties were kept under refrigeration at 4 ± 1°C during this time. The values of peroxide number, thiobarbituric acid, free fatty acid, and metmyoglobin pigment were decreased in the beef patties treated with the AMEUS. However, they increased continuously during the cryopreservation period, and there was a significant increase in water-holding capacity (WHC) when the beef patties were treated with AMEUS. The results also showed that adding AMEUS to beef patties improved their qualitative characteristics.

Impact of Fermentation on the Phytochemical Content and Biological Properties of Moringa oleifera Lam. Shoot Teas

This work examined the variation in chemical and biological properties of Moringa oleifera Lam. shoot (MOS) teas prepared under different degrees of fermentation, viz: non-fermented, semi-fermented and fermented. The chemical composition was ascertained via FTIR, GC-MS, total phenolic and total flavonoid content. Also determined were the biological properties, including antioxidant, antimicrobial and alpha-amylase inhibitory activities. The data confirmed that MOS teas were rich in phenolic and flavonoid compounds, with fermented MOS tea displaying the highest phenolic and flavonoid contents. With respect to antioxidant property, all tea extracts exhibited good radical scavenging activities against DPPH⋅, ABTS⋅+ and NO⋅, and the radical scavenging capacity was in the order of non-fermented>semi-fermented>fermented MOS teas. The same trend was also observed for the antimicrobial activities against Staphylococcus aureus and Staphylococcus epidermidis. In contrast, the fermented MOS tea exhibited better α-amylase inhibitory activity compared to the non-fermented and semi-fermented MOS teas.