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 picrylhydrazyl (DPPH) free radical. | Turk J Biol 32 (2008) 51-55 © TÜB‹TAK Antioxidant Activity of Some Common Plants Nooman A. KHALAF, Ashok K. SHAKYA, Atif AL-OTHMAN, Zaha EL-AGBAR, Husni FARAH Faculty of Pharmacy and Medical Sciences, Al-Ahliyya Amman University, Amman-19328 - JORDAN Received: 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-picrylhydrazyl (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 IC50 of the methanolic extracts ranged between ± and ± µg/ml and that of ascorbic acid was ± µg/ml. The study reveals that the consumption of these spices would exert several beneficial effects by virtue of their antioxidant activity. Key Words: 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 Baz› Bitkilerin Antioksidant Aktiviteleri Özet: Çok s›k kullan›lan baz› t›bbi bitkilerin metanolik ham özütleri ile serbest radikal süpürme aktivitelerii standart antioksidant olarak askorbik asit kullan›larak incelenmifltir. Serbest radikal süpürücü aktivite için 1,1-difenil-2-pikril-hidrazil serbest radikali kullan›lm›flt›r. Antioksidant aktivitesi en yüksek, yeflil çayda (Camellia sinensis .
