Abstract
Vasorelaxant and antioxidant activities are important in the therapy for cardiovascular
diseases. We aimed at investigating the vasorelaxant and antioxidant activities of
six xanthones isolated from Brazilian medicinal plants. Xanthone (1), 1-hydroxyxanthone (2), 4-hydroxyxanthone (3), 1-hydroxy-8-methoxyxanthone (4), 1,3-dihydroxy-7-methoxyxanthone (5) and 2,6,8-trihydroxy-1-methoxyxanthone (6) induced concentration-dependent vasorelaxant effects in endothelium-intact mice
aortic rings. The presence of a hydroxy group in position 1 seemed to decrease the
vasodilator effect while a hydroxy in position 4 and an increased number of hydroxy
groups improved the vasorelaxatory potential of xanthones. All xanthones showed antioxidant
activity but their potencies did not correlate with the vasodilator effect. Our results
suggest that the tested xanthones are potentially vasorelaxant and antioxidant compounds
but the two activities are not interrelated.
Key words
xanthones - vasorelaxation - antioxidant effect - aorta
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Steyner F. Cortes
Department of Pharmacology
Instituto de Ciências Biológicas
Universidade Federal de Minas Gerais
31270–901 Belo Horizonte MG
Brazil
Phone: +55-31-3409-2726
Fax: +55-31-3409-2695
Email: sfcortes@icb.ufmg.br
