Abayomi Gideon Adeyemo

The essential oils of Syzygium aromaticum, Monodora myristica, and Xylopia aethiopica have been used widely in Africa for medicinal purposes. This work is aimed at finding out the combined medicinal efficacy of the three essential oils. The crude EOs were extracted by the hydrodistillation method. The chemical components were determined by GC-MSanalysis. The phytochemicals, antidiabetic, anti-inflammatory, and antioxidant activities were determined by standard analytical methods. The GC-MS analysis indicated eugenol (75.08%) as the major component in the EO of S. aromaticum, isocaryophyllene (29.36%) in the EO of M. myristica, isospathulenol(8.67%) in the EO of X. aethiopica, and eugenol (34.25%) in the blend of the EOs. The phytochemicals in all the EOs and the blend were at varying values. α-amylase and α-glucosidase inhibition showed that the EO blend with an IC50 value of 1250.69 µg/mL and 1080.56 µg/mL, respectively, had the highest inhibition compared with other EOs. S. aromaticum had the highest activity against the anti-inflammatory indicators. The least inhibitory activity for DPPH was recorded with M. myristicaEO. S. aromaticum recorded the highest inhibitory efficacy against ABTS and nitric oxide assays ,respectively. The blend recorded the highest inhibitory activity against lipid peroxidation, with an IC50 value of 827.22 µg/mL. The findings demonstrated that the crude EOs and the blend exhibited medicinal activities. However, the EO blend had higher potency.

The phytotoxic effect of essential oil from African nutmeg (Monodora myristica) seeds on growth of tomato (Solanum lycopersicum L)., maize (Zea mays), and cowpea (Vigna unguiculata) was examined. Essential oil from the seeds of M. myristica was extracted by hydrodistillation. The essential oil’s composition was examined by gas chromatography-mass spectrometry (GC-MS). The phytotoxicity of the essential oil formulation at different concentrations for five days was evaluated on the leaves and roots. The activity was ascertained by estimating the shoots’ and the roots’ lenght. The result of GC-MS showed α–phellandrene (43.2%) as the essential oil's main constituent. The essential oil reduced the growth of the root and shoot of tomato, maize, and cowpea. At 4 mL/L treatment, the percentage inhibition of roots ranged from 63.8 to 75.4% after five days, while that of the shoot was 100% after three days. A varying toxicity was reported on the leaves of the seedlings of the plants after 24 hours. Phytotoxic was more potent on the leaves of cowpea and lowest in tomato. Phototoxic activity was also noted when essential oil was administered to the Seedling’s roots. The three species showed notable phytotoxicity when exposed to the essential oil of M. myristica.

Synergetic and antagonistic medicinal activities of crude and fractionated essential oil from the seed of Monodora myristica were investigated. The crude essential oil was extracted by steam distillation and then subjected to column chromatography; three fractions (N1, N2, and N3) were obtained. To identify the components, gas chromatography and mass spectrometry (GC-MS) investigation was utilized. The phytochemical parameters were determined by standard analytical methods. 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were used to evaluate the antioxidative capacity. and, the anti-diabetic activity was performed using α-amylase and α-glucosidase assay. The Agar diffusion method was used to determine the antibacterial activities. The GC-MS analysis indicated p-cymene (21.12%) as the major component of the crude essential oil. The antioxidant activity using DPPH varied from 614 to 704 µg/mL, while the ABTS activity ranged between 281-342 µg/mL. The α-amylase assay showed fraction N1 with IC50 value of 3.21 µg/mL, while for α-glucosidase assay, fraction N2 with IC50 2.15 µg/mL recorded the least value. The minimum inhibitory concentration values for the crude extract and all the fractions against the strains of bacteria ranged from 6 to 12.5 mg/mL Both crude extract and fractionated essential oil showed antioxidant, anti-diabetic and antibacterial activities.