Antibacterial Potentials of Methanol Extract of Acalypha wilkesiana Leaves on Selected Foodborne Pathogens

Abstract

Acalypha wilkesiana is one of the weed plants with many potential metabolites that are important medicinally. This study aimed to investigate the antibacterial activity of A. wilkesiana methanol leaves extract against some food-borne pathogens and identify its metabolites. The agar well diffusion method was used to study the growth inhibition of four (4) bacterial species; Staphylococcus aureus, Bacillus cereus, Salmonella spp, and Escherichia coli with an initial concentration of 250 µg/ml methanol leaves extract of A. wilkesiana and final concentration of 2000 µg/ml. The agar well diffusion revealed that concentrations of 2000 µg/ml were more effective than other concentrations of the extracts, (S. aureus 20+2.45), Salmonella spp; (20+0.82) B. cereus (19+3.27), and E. coli (18+4.16). The liquid chromatography mass spectrophotometer profile of the extract carried out showed the presence of important metabolites such as Scopoletin (7-hydroxycoumarins), (6beta,8betaOH)-6,8-Dihydroxy-7(11)-eremophilen-12,8-olide (Terpene lactones), Pyrethrin I (Pyrethrins), Quercetin (Flavonols), Quercitrin (Flavonoid-3-O-glycosides), Malonamic acid and succinamic acid among others. These identified metabolites were reported to have many medical importance. Therefore, the activities observed may be as a result of these metabolites.   A. wilkesiana leaves could be explored further in the treatment of gastrointestinal disorders.