Synthesis and antimicrobial activities of a metallic oxide nanoparticle complex of Moringa oleifera leaves extracts against selected microorganisms

Abstract

This research work aimed at synthesizing and investigating the antimicrobial activities of a metallic oxide nanoparticle complex of Moringa oleifera leaves extracts against some microorganisms. Moringa oleifera leaves were washed, dried and blended. They were extracted with distilled water and ethanol using standard methods. The nanoparticle was synthesized by coordinating with manganese oxide. The physicochemical properties were determined following standard procedures. The phytochemical screening was carried out by standard methods. The antibacterial activities were done using agar well diffusion method. Antifungal activity was carried out following the plate technique. The leaves extract had a 75% yield and melting point of 116 °C while the nanoparticle had a yield of 60% and melted at 78 °C with pH of 3.46. The molar conductance of the nanoparticle revealed at 10.6 Ω⁻¹cm²mol⁻¹. The ethanolic extract of the leaves showed the presence of alkaloids, tannin, steroids and saponins. The ethanolic extract of M. oleifera exhibited the highest antibacterial activity of 33.05±0.10 mm against Bacillus subtilis while its antifungal activity revealed the highest inhibition of 48.40±0.53 mm at 30 mg/mL against Aspergillus niger. Staphylococcus aureus had a zone of inhibition of 19.00±0.16^a using the aqueous extract. The ethanolic extract of M. oleifera nanoparticles showed antibacterial and antifungal activity against B. megaterium and A. niger with a zone of inhibition of 49.21±0.32 mm and 50.35±0.29 mm respectively while the aqueous extract showed antibacterial activity against S. aureus with a zone of 26.00±0.38mm. As it was concluded ethanolic extract in both leaves extract and its nanoparticle, possessed higher antibacterial and antifungal activities than the aqueous extract.