Phytochemical Content, Radical Scavenging and Antibacterial Properties of Aqueous Extract of Jatropha curcas Linn Leaves

Abstract

This study investigated phytochemical content, radical scavenging and antibacterial activities of aqueous extract of leaves of Jatropha curcas Linn. Quantitative phytochemical analyses of alkaloids, phenols, tannins and flavonoids contents were carried out; radical scavenging activity was assessed using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical and hydrogen peroxide inhibition assays while Disc diffusion and Agar well (ditch) diffusion methods were used for antibacterial activity against Klebsiella pneumonia, Escherichia coli, Pseudomonas aeruginosa, Staphilococcus aureus and Proteus species at 62.5, 125, 250 and 500 mg/mL. The extract contained alkaloids (1.600 ± 0.58 %), tannins (0.121 ± 0.00 mg/mL), phenols (0.463 ± 0.06 mg/mL) and flavonoids (0.672 ± 0.00 mg/mL), and showed radical scavenging activities against DPPH (IC50 = 21.24) and hydrogen peroxide (15.67 mg/mL) which were less than that of Butylated hydroxyanisole (BHA); IC50 = 3.92 (DPPH) and 6.19 mg/mL (hydrogen peroxide) respectively. It also showed antibacterial activity against Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa at 250 and 500 mg/ml (MIC = 125 mg/mL), which were resistant to ampicillin, chloxacillin and erythromycin, and the extract was inactive against Staphilococcus aureus and Proteus species at these concentrations, though all were sensitive to gentamycin. This shows that the aqueous extract of leaves of Jatropha curcas Linn may possess some of the folkloric properties claimed. Keywords: Jatropha curcas; Euphorbiaceae; aqueous extract; antibacterial activity; radical scavenging activity