Kolanut-mediated magnesium oxide nanostructures for biomedical applications: Antimicrobial, antioxidant, larvicidal, anticoagulant and thrombolytic activities

Abstract

This study was aimed at using hot water extracts of pod (KP), seed (KS), leaf (KL) and seed shell (KSS) of Cola nitida (kola nut) for the synthesis of nano-sized magnesium oxide and evaluation for biomedical applications. The nano-sized MgO were biosynthesized for the first time using kola nut extracts and characterized by UV–visible spectroscopy, Fourier transform infra-red spectroscopy (FTIR), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and energy-dispersive X-ray (EDX). The antimicrobial, antioxidant, larvicidal, anticoagulant and thrombolytic activities of the nano-sized MgO were evaluated. The crystalline polygonal-shaped nano-sized MgO absorbed maximally in the range of 270–280 nm and FTIR spectra indicated the involvement of phenolic compounds and proteins in their biosynthesis. At 40 µg/ml, nano-sized MgO showed growth inhibition of 41.2–79.3% against eight multi-drug resistant strains of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Klebsiella granulomatis, and inhibition of 60.2–88.4% on Rhizopus stolonifer, Trichoderma longibrachiatum, Aspergillus flavus and Aspergillus fumigatus. DPPH scavenging activities of 26.1–90.4% were obtained for 1–40 µg/ml of MgO nanostructures, while mortality of 13.33–100% against anopheline larvae was achieved at 30 µg/ml. The nanostructures also prevented blood coagulation and completely dissolved preformed blood clots within 10 min which is herein reported for the first time. This report has shown that Cola nitida can be employed for sustainable synthesis of nano-sized MgO with potent biomedical applications.