Antimicrobial Activity of Fractioned Components from Dacryodes edulis: Invitro Study

Abstract

Introduction: The history of the relationship between man and plants is as old as creation and man has used plants for different purposes including food and medicines. In this dispensation, man has been able to classify plants into food and medicinal plants and has also discovered that solution to his health problem comes from nature. Objectives: The antibacterial activities of the dichloromethane (DCM) and aqueous (AQU) fractions of acetone extract of Dacryodes edulis leaf were investigated against both Gram positive and Gram negative bacterial organisms made up of locally isolated and standard strains. Materials and Methods: About 1 kg of the powdered leaves of D. edulis was extracted at room temperature (25-27oC) using 75% acetone for 3 days. The mixture was then filtered and the filtrate was dried in vacuo using a rotary evaporator (insert the make and model). The crude extract was successfully partitioned using organic solvents in order of their polarity, that is, n-Hexane, DCM, n-Butanol, Ethylacetate. The sensitivity testing of the extracts against the organisms was determined using agar-well diffusion method as described by Irobi et al. [1]. Results: DCM and aqueous (AQU) fractions possessed closely related broad spectrum antibacterial activities and greater activity than the control standard antibiotics (Streptomycin and Ampicillin). The zones of inhibition exhibited by AQU fraction ranged between 20 and 30 mm while that of DCM fraction ranged between 22 and 32 mm. On the other hand, the zones of inhibition observed for the standard antibiotics, streptomycin ranged between 10 and 20 mm and ampicillin between 11 and 27 mm. The MIC and MBC of both fractions had range values between 0.78 and 6.25 mg/mL, evaluation of phytochemical composition of D. edulis revealed alkaloid (30.63 mg/g), terpenoid (19.72 mg/g), saponins (10.54 mg/g), tannin (9.14 mg/g), flavonoid (6.51 mg/g) and glycoside (6.29 mg/g) which are very significant antibacterial agents in medicinal plants. Conclusion: This work indicates that the two fractions had better antibacterial potentials than the standard antibiotics used.