Comparative Phytochemical Characterization and Antibacterial Activityof Ethanol and Aqueous Extracts of Moringa peregrina and Moringaoleifera against Multidrug-Resistant Bacteria

INTRODUCTION: The increase of Multidrug-Resistant (MDR) bacteria continues to complicate antimicrobial therapy and motivates and investigates alternative bioactive sources. Moringa peregrina and Moringa oleifera contain diverse phytochemicals associated with antimicrobial activity and therefore represent candidates for experimental evaluation. METHODS: Ethanol and aqueous leaf extracts were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS). These were evaluated against Methicillin-Resistant Staphylococcus aureus (MRSA), Vancomycin-Resistant Enterococcus (VRE), Carbapenemresistant K. pneumoniae (CRKP), and Carbapenem-resistant Pseudomonas aeruginosa (CRPA) using agar well diffusion, Minimum Inhibitory Concentration (MIC), and Minimum Bactericidal Concentration (MBC) assays. Ultrastructural changes were examined by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). RESULTS: FTIR showed the presence of hydroxyl, carbonyl, and aromatic groups. GC-MS found sterols, fatty acids, terpenoids, and glycosides as the main parts. The ethanol extract of M. peregrina was the best at killing bacteria, especially MRSA and CRKP. It had a Zone of Inhibition (ZI) up to 10 mm, a Minimum Inhibitory Concentration (MIC) of 0.5-1.4 mg/mL, and a Minimum Bactericidal Concentration (MBC) of 1.4-2.1 mg/mL. The water extract of M. oleifera worked best against CRKP and VRE, with a ZI of 11.5 mm, MIC of 0.9 mg/mL, and MBC of 1.8 mg/mL. The electron microscope revealed structural alteration following the treatment. SEM analysis demonstrated bacterial surface deformation, while TEM observation indicated membrane disruption accompanied by cytoplasmic disorganization; these findings indicate cellular damage associated with extracted exposure. DISCUSSION: Phytochemical polarity has a significant impact on antimicrobial potency, as seen by the varying antibacterial responses seen in solvent extracts. The potent effect of M. peregrina ethanol extract on MRSA and CRKP indicates that terpenoids, fatty acids, and lipid-soluble sterols may cause membranetargeted disruption. On the other hand, the wider inhibitory spectrum of M. oleifera aqueous extract against VRE and CRKP suggests that polar glycosides, phenolics, and cardenolide-type substances aid in the disruption of cell walls. SEM and TEM imaging confirmed that extract exposure leads to profound ultrastructural collapse, including membrane rupture, cytoplasmic leakage, and loss of intracellular organization, supporting a mechanism of direct structural assault rather than metabolic inhibition. As a whole, the observations support continued investigation of Moringa-derived phytochemicals as experimentally relevant antimicrobial sources and provide methodical insight for future validation studies. CONCLUSION: M. peregrina and M. oleifera extracts demonstrate selective antibacterial activity against MDR pathogens, with ethanol extracts favoring Gram-positive and aqueous extracts showing broader activity. These findings highlight Moringa phytochemicals as promising complementary agents in the fight against antibiotic resistance, warranting further in vivo and synergistic studies.