Antioxidant activity and antimicrobial properties of Entada leptostachya and Prosopis juliflora extracts

Background:  Natural phytoconstituents produced by plants for their sustenance have been reported to reduce disease. Objectives:  This study determined the phytoconstituents, antioxidant and antimicrobial activity of crude methanolic extracts of  Entada leptostachya  and  Prosopis juliflora  extracts. Methodology:  Antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl and β-carotene assays; the total phenolic and flavonoid were estimated using Folin–Ciocalteau and aluminium chloride, whereas antimicrobial activity was determined using the zone of inhibition method. Results:  Screening of the extracts revealed the presence of terpenoids, flavonoids, saponins and phenols. Fourier transform infrared spectra of the extracts revealed presence of hydrogen bonded –OH functional group.  E. leptostachya  barks had the highest antioxidant activity followed by  P. juliflora  roots,  E. leptostachya  roots and  P. juliflora  leaves [μg/mL].  Prosopis juliflora  (roots) had the highest bleaching effect, whereas  E. leptostachya  (barks) had the lowest bleaching effect. The total flavonoids were determined to be 0.15 ± 0.02 mg/g, 1.18 ± 0.18 mg/g, 0.39 ± 0.05 mg/g and 0.64 ± 0.03 mg/g for  E. leptostachya  roots,  E. leptostachya  barks,  P. juliflora  leaves and  P. juliflora  roots extracts, respectively. The total phenols were determined to be 0.93 ± 0.18 mg/g, 2.69 ± 0.41 mg/g, 0.62 ± 0.08 mg/g and 0.62 ± 0.08 mg/g for  E. leptostachya  roots,  E. leptostachya  barks,  P. juliflora  roots and  P. juliflora  leaves extracts. All plant extracts exhibited moderate activity against the growth of selected microorganisms. Conclusion:  Antimicrobial and antioxidant activity of the two plants was as a result of secondary metabolites found in the crude extracts.