Evaluation of Bioactive Compounds and Antibacterial Potentials of Moringa oleifera and Aloe vera Leaves Against Escherichia coli and Klebsiella pneumoniae

Abstract

ABSTRACT

The growing resistance of pathogens to standard antibiotics has increased the search for alternative treatments derived from medicinal plants, particularly those rich in bioactive phytochemicals. This study investigated the phytochemical constituents and antibacterial efficacy of Moringa oleifera and Aloe barbadensis Miller (Aloe vera) leaf extracts against Escherichia coli and Klebsiella pneumoniae, two bacteria commonly associated with gastroenteritis. The leaves of both plants were collected from Gombe State, Nigeria, and subjected to cold maceration using distilled water and ethanol as the solvents. Standard qualitative techniques were employed for phytochemical analysis, and antibacterial properties were evaluated using the disk diffusion method. Results revealed that Moringa oleifera aqueous and ethanol extracts contained flavonoids, saponins, tannins, alkaloids, and glycosides, with ethanol extracts exhibiting a higher abundance. Aloe vera aqueous extracts contained flavonoids, alkaloids, phenols, saponins, and glycosides, while the ethanol extracts contained all except steroids, including tannins. Antibacterial testing demonstrated that both plants possessed inhibitory effects on the test organisms, with ethanol extracts producing higher zones of inhibition. The highest antibacterial activity was observed with ethanol extracts of Moringa oleifera (23 mm against E. coli) and Aloe vera (20 mm against E. coli) at 100 mg/ml, suggesting a dose-dependent response. These findings confirm the presence of medicinally valuable phytochemicals in both plants and support their traditional use for treating bacterial infections. The enhanced activity of the ethanol extracts indicates the superior ability of the solvent to extract the active constituents. This study underscores the therapeutic potential of Moringa oleifera and Aloe vera, emphasizing the need for further investigation of the isolation and characterization of specific antibacterial compounds for pharmaceutical applications.

Keywords: Phytochemicals, antibacterial activity, Moringa oleifera, Aloe vera, Escherichia coli and Klebsiella pneumoniae.