Abstract

PHYTOCHEMICAL INVESTIGATION, ANTIBACTERIAL AND ANTIOXIDANT ACTIVITIES OF THE ROOT EXTRACTS OF RUTA CHALEPENSIS

Zelalem Abdisa* and Temesgen Ababu

ABSTRACT

Objective: Ruta chalepensis is an evergreen shrub that belongs to the family Rutaceae and reported to have antibacterial, anti-rheumatic, repellent activity, antioxidant activities and also traditionally used for treatment of snake bites, headaches and wounds. The objective of the present work was to study the chemical constituents, antibacterial and antioxidant activities of the root of Ruta chalepensis. Method: The powdered root of Ruta chalepensis was successively extracted using n-hexane, chloroform, acetone and methanol. Phytochemical screening was conducted using standard procedures. Antibacterial activity was evaluated against four human pathogenic bacteria namely Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella typhimurium using the agar disc diffusion technique. The DPPH radical scavenging assay was employed to test the antioxidant activity of the plant. Isolation of compound was performed using silica gel column chromatographic method. Result: Phytochemical screening test revealed the presence of alkaloids, flavonoids, saponins, tannins, phenolic compounds and glycosides in the root of Ruta chalepensis. The maximum inhibition zone (20 mm) was exhibited by acetone extract followed by chloroform extract (18 mm), both against Escherichia coli compared to Gentamicin (28 mm) indicating the significance of this plant against bacteria. The methanol crude extract inhibited DPPH by 94% at 0.5 mg/ml showing the potential of this plant as a natural antioxidant. The chloroform extract after silica gel column chromatographic separation has led to isolation of one pure furanocoumarin derivative, named 6-(2-methylbut-3-en-2-yl)-7H-furo[3,2-g]chromen-7-one (Chalepensin).

Keywords: Chalepensin, Radical scavenging activity, Rutaceae, Ruta chalepensis.