Preliminary Phytochemical Screening, Antioxidant and Antimicrobial Activities of the Aqueous, Methanol, Acetone, and Hexane Fractions of Centaurea cyanoides Wahlenb

Centaurea cyanoides Wahlenb aqueous, methanol, acetone, and hexane fractions has been evaluated for their phytochemical constituents, antioxidant and antibacterial activities. The fractions of were studied in order to support its use in the traditional medicine. Antioxidant activity was assessed employing 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging method. Antimicrobial activity was tested using broth microdilution method and agar dilution method. All fractions were contained proteins, amino acids, carbohydrate, reducing sugars, volatile oil, phytosterols and alkaloids. Whereas Methanol fraction contained flavonoids (91.35±1.75 mg QUE/g), phenols (96.32±2.2 mg of GAE/g) and tannins (93.2±2.22 mg CaE/g) beside the earlier mentioned phytochemicals. Antioxidant activity for methanol fraction showed the highest activity (IC50=3.16±1.70 μg/ml) followed by aqueous fraction (IC50=16.59±1.89 μg/ml), hexane fraction (IC50=23.98±1.94 μg/ml) and acetone (IC50=42.65±2.13 μg/ml). All fractions exhibited remarkable potential antimicrobial activities. The methanolic fraction of C. cyanoides possesses high content of flavonoids, tannins and phenols, the plant demonstrated potential antioxidant and powerful antimicrobial activities.