Radical Scavenging Capacity and Efficacy of Myristica fragrans (Nutmeg) Metabolites on Cladosporum herbarum of Food Origin

Aim: To determine radical scavenging capacity and efficacy of Myristica fragrans metabolites on fungi of food origin.

Study of Design: Pretreatment and processing of Myristica fragrans, solvent extraction technique, phytochemical screening, radical scavenging activity, total phenolic concentration assay, essential oil extraction and evaluation of antifungal activity.

Place and Duration of Study: Microbiology Unit, Department of Biological Sciences, College of Natural and Applied Sciences, Fountain University Osogbo, Osun State, Nigeria between October, 2015 and July, 2016.

Methodology: Crude extract of Myristica fragrans seed was obtained using organic solvent (distilled water, ethyl acetate and ethanol) with solvent extraction technique and preliminary phytoconstituents was determined. The essential oil was extracted by hydrodistillation technique and isolated with petroleum ether. Metabolites present in the essential oil were quantified using Gas Chromatography Flame Ionization Detection (GCFID). Antifungal activity of Myristica fragrans oil and crude extract were investigated using agar well diffusion method. Folin-Ciocalteu and 2,2, diphenyl picryl hydrazyl (DPPH) radical scavenging assays were employed to determine total phenolic content and antioxidant activity respectively.

Results: Preliminary phytochemical screening of Myristica fragrans seed revealed the existence of alkaloid, phenols, flavonoids, terpenes, saponins, glycosides, tannins, steroids and phenolic compounds. The percentage yield of Myristica fragrans oil extracted was 3.25%. Thirty-six metabolites were quantified in Myristica fragrans essential oil using GCFID among which are sabinene (26.58%), myristicin (13.55%), alpha-pinene (11.84%), terpinene-4-ol (9.35%), limonene (5.74%), safrole (5.40%), alpha-terpineol (4.51%), alpha-myrcena (3.82%), gama- terpinene (3.71%), alpha-terpinolene (3.19%), pinene-2-ol (1.84%), elimicin (1.27%) and isoeugenol (1.13%) respectively. Highest scavenging and antifungal activities were observed in ethyl acetate extract of Myristica fragrans compared to Beta-carotene and antifungal drug (Fluconazole) used as control at varying concentrations.

Conclusion: Presence of thirty-six different phytoconstituents (metabolites) in Myristica fragrans essential oil poses the potential of providing useful drugs for treating food-borne infection and reduction of oxidative stress in the body other than its general uses as spices and flavoring agent.