Green Synthesis of Magnesium and Potassium Hydroxide Nanoparticles from Garcinia Kola Heckel Stem-Bark and Their Preliminary Cytotoxic and Antioxidant Activities

Abstract

Green synthesis of nanoparticles from medicinal plants has become a focus point in the search for healing and other benefits for mankind. This work is aimed at synthesizing, characterizing and determining the preliminary cytotoxic and antioxidant properties of magnesium and potassium hydroxide nanoparticles using aqueous Garcinia kola stem-bark extract. Magnesium and potassium hydroxide nanoparticles were synthesized using 50% Garcinia kola stem-bark aqueous extract. The nanoparticles were characterized using Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, UV-visible spectrophotometry X-ray diffraction (XRD) spectroscopy, Energy-Dispersive X-ray spectroscopy (EDX) and Scanning Electron Microscopy (SEM). The preliminary cytotoxic and antioxidant investigations were carried out using the brine shrimp lethality bioassay and Thin Layer Chromatography (TLC) bio-autography with DPPH (1, 1-diphenyl-2- picrylhydrazyl) respectively. The magnesium and potassium hydroxide nanoparticles (GbMgN and GbKN) were synthesized from aqueous G. kola extract (GbAQ). FT-IR detected O-H stretch (3231 cm^-1, 3384 cm^-1), C=C stretch (1640 cm^-1, 1580 cm^-1) and C-O stretch (1066 cm^-1, 1364 cm^-1) in GbMgN and GbKN respectively. FTIR of the GbAQ extract showed O-H stretch (3260 cm^-1), C-H stretch (2937 cm^-1) and aromatic C=C stretch (1606 cm^-1,1513 cm^-1, 1401 cm^-1), UV-visible data gave λ_max=270 nm for GbMgN and λ_max230 nm for GbKN which is consistent with magnesium and potassium nanoparticles. XRD study revealed the crystalline groups of GbMgN and GbKN, EDX analysis showed the percentage elemental compositions and the morphological assessment from SEM analysis confirmed that the nanoparticles are of different shapes. The average grain size of the synthesized nanoparticles was calculated to be 52.80 nm and 36.29 nm respectively for GbMgN and GbKN The bioassay results showed both nanoparticles have cytotoxic activity. The Mg-nanoparticles and the aqueous extract showed DPPH scavenging activities. The results suggested GbMgN and GbKN as possible sources of new drugs in the management of cancer and other inflammatory conditions.