Antimicrobial and antioxidant activities of ethanolic stem bark and root extracts of Khaya ivorensis A Chev. (Meliaceae)

Abstract

Plants of the genus Khaya (Meliaceae) are traditionally used to relieve ear infection, fever, malaria. The main objective was to evaluate the antimicrobial and the antioxidant activity of the ethanolic of extracts stem back and root of Khaya ivorensis. Plants were extracted by ethanol. The antimicrobial activity was assayed against some Gram-negative bacteria (Klebsiella pneumonia ATCC 70603, Haemophilus influenza ATCC 49247), Gram-positive bacteria ( Staphylococcus aureus ATCC 43300, Staphylococcus aureus BAA-917, Enterococcus faecalis ATCC 51299 ) and fungal (Candida albicans ATCC NR-2450,Candida albicans 141S, Candida albicans NR- 2450, Candida glabrata 44B, Candida parapsilosis 153B, Candida krusei) by determining the Minimum Inhibitory Concentration (MIC) and the antioxidant activity by determining the inhibition concentration IC50 using DPPH, FRAP and ABTS methods. The phytochemical screening of K. Ivorensis showed the presence of alkaloids, flavonoids, tannins, saponins, steroids and triterpenoids. The ethanolic extracts of stem back and root showed significant activity against two Gram-positive strains (S. aureus BAA-917 and S. areus ATCC 43300) with MIC ranging 0.3125 to 0.625 mg/mL and two fungal strains (C. albicans 141S and C. krusei) with MIC 0.625 mg/mL. The extract had the greatest scavenging activity with IC50 ranging 2.08, 4.48 µg/mL and 2.78 µg/mL in ABTS and DPPH assays respectively. These results suggest that extracts from K. Ivorensis possess antimicrobial and antioxidant activities and therefore justifies their usage in traditional medicine for the treatment of various diseases.