Antioxidant and vasorelaxant activities of flavonoids from Amygdalus lycioides var. horrida

Abstract

Amygdalus lycioides var. horrida (Spach) Browicz (Rosaceae), also known as Prunus lycioides (Spach.) Schneid., is an endemic Iranian species of the genus Amygdalus. In Iranian traditional medicine, the aerial parts and roots of A. lycioides are used in the treatment of diabetes. Six flavonoids, i.e. quercetin 3-O-rhamnoside (1), luteolin 7-O-rhamnoside (2), isorhamnetin 3-O-rutinoside (3), kaempferol 3-O-rhamnoside (4). apigenin (5), and naringenin (6), have been isolated from the aerial parts of this plant. The structures of these compounds were elucidated by UV, MS, and NMR spectroscopic data analyses. While the antioxidant activity of these compounds was assessed by the 2,2-diphenyl-1-picryl-hydrazy) (DPPH) assay, the vasorelaxant effect was determined using the rat aortic vascular smooth muscle. Compounds 1-6 displayed significant antioxidant activity, with the RC(50) values ranging from 0.0033 to 0.5186 mg/ml. Compound 2 showed a considerable vasorelaxant activity on rat aortic vascular smooth muscle in a dose-dependent manner.