ABSTRACT

The ethanol, aqueous/water and ethyl acetate extracts of the leaves of Acalypha wilkesiana Musaica were subjected to phytochemical and antibacterial studies. The phytochemical studies showed the presence of alkaloid, saponin, tannin, phenol, flavonoid and hydrogen cyanide (HCN) in varying concentrations from the different extracts. The recorded concentrations were as follows; Aqueous extract (alkaloid = 0.97 ± 0.01, saponin 0.71 ± 0.02, tannin = 0.25 ± 0.01, phenol = 0.18 ± 0.01, flavonoid = 0.22 ± 0.01, HCN 3.74 ± 0.33), Ethanol extract (alkaloid = 1.83 ± 0.01, saponin = 0.41 ± 0.02, tannin = 0.87 ± 0.01, phenol 0.30 ± 0.02, flavonoid = 0.27 + 0.01, HCN = 1.11 ± 0.02) and Ethyl acetate extract (alkaloid = 0.99 ± 0.02, saponin = 0.19 ± 0.02, tannin = 0.11 ± 0.01, phenol 0.24 ± 0.01, flavonoid = 0.25 ± 0.01, HCN = 0.00 + 0.00). The antibacterial activity of the leaves of A. wilkesiana Musaica ethanol, aqueous and ethyl acetate extracts and its fine derivative fractions were tested on Methicillin resistant Staphylococcus aureus strains from clinical sources using the Mueller Hinton Agar (MHA) and the zone of inhibition recorded. The mean zone of inhibition recorded was; aqueous extract (16.72 mm), ethanol extract (14.46 mm) and ethyl acetate extract (13.06 mm). Results showed that the extracts had inhibitory action on the MRSA and the performance of the extracts against the MRSA on average was close to that of the commercial antibiotic, Vancomycin (18.28 mm). The aqueous extract was more potent than the ethanol and the ethyl acetate extracts having 9 1.47% while, the other two had 79.19% and 7 1.52% respectively. The MIC of the different extracts against the test organisms was also determined. The MIC recorded for the aqueous and ethanol extract was 75 mg/mL having an inhibition diameter of 2.3 mm and 3.0mm respectively and MBC was 100 mg/mL. For ethyl acetate, the MIC was 100 mg/mL with inhibition diameter of 1.3 mm and MBC was recorded at 125 mg/mL. These results show that the aqueous and ethanol extracts of this plant are more effective than the ethyl acetate extract and is also indicative that the plant extracts could be put to effective pharmacological applications.