Evaluation Of The Antibacterial, Antioxidant And Bioactive Properties Of Leaf And Root Bark Extract Of Newbouldia Leavis

ABSTRACT

Methanol, Chloroform and N-Hexane fractions of Newbouldia leavis root bark and leaf extract were analyzed in-vitro for their antibacterial, antioxidant and phytochemical properties against resistant bacteria isolate from infected wound. The antibacterial activity of the plant extracts were evaluated against Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli using agar well diffusion method. It was observed that methanol extract of the plant leaf had the highest activity against E. coli with the mean zone of inhibition diameter of 17.67±0.67mm. While the least was N-Hexane and chloroform leaf extracts of the plant against Staph. aureus and E. coli respectively with a mean zone of inhibition diameter of 12.00 ± 0.00 mm each. Broth dilution method was used to determine the Minimum Inhibitory Concentration (MIC) in which methanol leaf extract against E. coli and Pseudomonas aeruginosa, N-hexane root extract against E. coli and chloroform root extract against Staph. aureus were observed at 25mg/ml while others were in 50 and 100 mg/ml. Minimum Bactericidal Concentration (MBC) of the extracts   against the three test organisms were almost at the double concentration of the MIC. Antioxidant screening was done employing 2.2’- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and Ferric reducing antioxidant power method- at the range of 25 – 400 µg/mL concentration in triplicate. The antioxidant activity shows positive results in most of the extracts. Their activities increased as the concentration increased with methanol leaf extract showing the highest activity, almost the same with the standard (ascorbic acid). The GC-MS analysis showed 17,32,18,16 and 22 compounds from methanol leaf extract, N-Hexane leaf extract, Chloroform leaf extract, Methanol root extract and Chloroform root extract of N. leavis respectively. The high bioactive activity of the methanol leaf extract is majorly due to the presence of Carbamodithioic acid, 5-Chlorovaleric acid, 1-Methylverbenol, Methylverbenol ether, arachidonic acid semicarbamide, N-Desmethyl Tapentadol, benzonitril, cyclopentene butylperoxy- phtalan present only in this extract. The study shows that the plant had broad spectrum in activity which justified the traditional use of this plant in treatment of wound and other bacterial infections.