In vitro Antibacterial Activity and Phytochemical Screening of Crude Extracts from Jatropha curcas Linn.

摘要

Aims: This study aims at investigating the antibacterial activity of crude methanolic and aqueous extracts of leaves and root barks of Jatropha curcas against Gram-positive and Gram-negative bacteria isolated from urinary tract infections (UTIs) and to confirm the effective use of this plant against the uropathogenic strains in traditional medicine in Democratic Republic of Congo (D.R.C). Study Design: Laboratory experimental tests; Extraction of J. curcas leaf and root bark, susceptibility tests (zones of inhibition) and minimum inhibitory concentration (MIC) determination and phytochemical screening and high performance liquid chromatography (HPLC) analysis. Place and Duration of the Study: Department of Phytobiology, Department of Biotechnology and Department of Microbiology, General Atomic Energy Commission. Regional Center of Nuclear Studies of Kinshasa P.O BOX 868 Kin. XI DRC during October and November 2011. Methodology: Fresh leaves and root barks of J. curcas were collected, oven- dried at 45oC, powdered and extracted with water and methanol. The aqueous extracts were lyophilized. Agar disc diffusion method was used to test antibacterial activity of the crude extracts of J. curcas against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Citrobacter diversus isolated from UTIs. The extracts were subjected to phytochemical tests. HPLC method was used to screen phenolic compounds. Results: The crude extracts exhibited a significant antibacterial activity against four of seven tested bacterial isolates. MIC values ranged from 1.0 to 7.5 mg/L. The extracts phytochemical screening revealed the presence of saponins, tannins, alkaloids, steroids and flavonoids. The presence of phenolic compounds was screened by HPLC analysis. Conclusion: The inhibitory effects of the crude extracts from leaves and root barks against uropathogenic strains have justified the usefulness of J. curcas for the treatment of UTIs and sexually transmitted Infections (STIs) in traditional medicine of D.R.C.