Antioxidant Activity of Some Common Plants

Authors: NOOMAN A. KHALAF, ASHOK K. SHAKYA, ATIF AL-OTHMAN, ZAHA EL-AGBAR, HUSNI FARAH

Abstract: The methanolic crude extracts of some commonly used medicinal plants were screened for their free radical scavenging properties using ascorbic acid as standard antioxidant. Free radical scavenging activity was evaluated using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) free radical. The overall antioxidant activity of green tea (Camellia sinensis Linn.) was the strongest, followed in descending order by black tea (Camellia sinensis Linn.), Eugenia caryophyllus (Spreng.) Bullock and Harrison, Piper cubeba Linn., Zingiber officinale Roscoe and Piper nigrum Linn. Trigonella foenum graecum Linn. and Elettaria cardamomum (Linn.) Maton showed weak free radical scavenging activity with the DPPH method. All the methanolic extracts exhibited antioxidant activity significantly. The IC_{50} of the methanolic extracts ranged between 6.7 ± 0.1 and 681.5 ± 8.4 µg/ml and that of ascorbic acid was 8.9 ± 0.1 µg/ml. The study reveals that the consumption of these spices would exert several beneficial effects by virtue of their antioxidant activity.

Keywords: Camellia sinensis Linn., Zingiber officinale Roscoe, Trigonella foenum-graecum Linn., Eugenia caryophyllus (Spreng.) Bullock and Harrison, Piper nigrum Linn., Elettaria cardamomum (Linn.) Maton, Piper cubeba Linn., antioxidant, DPPH, free radical scavenging activity

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