Screening of the antioxidant potential of the leaves and flowers from Rosa horrida Fischer

Abstract

Rosa species are widely distributed in Turkey. Ethanolic extracts from flowers and leaves of R. horrida, one of the 25 species of Rosa used as a traditional Turkish medicine as tonic, diuretic, expectorant, stomachic and for the treatment of dyspepsia, diarrhea and nephritis were tested in vitro for their ability to scavenge DPPH·, ABTS·+ and superoxide radicals, reduce Fe (III) to Fe (II) and to inhibit peroxidation of phophatidylcholine liposomes induced with ascorbate/Fe (III) in order to establish a relashionship between their antioxidant potency and the content of phenolic compounds. Flowers and leaves extracts showed high DPPH radical scavenging activity as shown by the lowest value of EC50, indicating the strong hydrogen-donating ability. The extracts showed similar metal chelation ability in Fe2+-ferrozin test, reducing power and ability to scavenge ABTS·+ radical cation as shown by the small differences of the EC50 values, since the EC50 values were found to be highest in TBA test, suggesting that the extracts were less effective in protection of liposomes from lipid peroxidation. The activities correlated well with total phenolic and flavonoid contents, indicating that the extracts may play an important role in chemical protection from oxidative damage by possessing endogenious antioxidants, such as phenolics and flavonoids. Key words: Rosa horrida, leaves, flowers, polyphenol content, antioxidant potential.