RESUMO
In this investigation, the screening of two furanocoumarins; 5,8- dimethoxypsoralen (1) and heraclinin (2), isolated from the methanol root-extracts of Tamus communis L for their antioxidant activity and xanthine oxidase inhibitory effect was carried out, using different assays such as DPPH free radical scavenging effect, ß- carotene / linoleic acid, xanthine oxidase (XO) inhibition and in addition to blood total antioxidant capacity. Results revealed that the two compounds have significant DPPH radical scavenging activity and effective inhibition of linoleic acid oxidation in a dose-dependent manner; 5,8-dimethoxypsoralen exhibited the highest activity with an I% = 72.69 ± 1.88%. These results indicate that the isolated compounds inhibit xanthine oxidase activity and scavenge superoxide radicals with heraclinin (2) as the more potent xanthine oxidase inhibitor, and 5,8-dimethoxypsoralen (1) as the more effective on cytochrome c reduction, the two tested compounds can effectively protect erythrocytes against hemolytic injury induced by AAPH. These results are promising for further studies of the biological and pathological effects of these natural products.
Assuntos
Furocumarinas/isolamento & purificação , Furocumarinas/farmacologia , Extratos Vegetais/farmacologia , Tamus/química , Xantina Oxidase/antagonistas & inibidores , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Furocumarinas/química , Furocumarinas/classificação , Extratos Vegetais/química , Raízes de Plantas/químicaRESUMO
In this study, the screening of five anthraquinones (purpurin, xanthopurpurin, rubiadin, kermisic acid and flavokermisic acid), for their free radical scavenging and antioxidant effects was carried out, using three complementary methods. DPPH (2,2'-diphenyl-1-picrylhydrazyl) revealed that purpurin has a scavenging effect with IC50 = 3.491 ± 0.014 µg/ml. Results of ß-carotene/linoleic acid assay showed that kermisic and flavokermisic acids have significant inhibition of lipid peroxidation with I % = 76.1 ± 1.5% and 68.6 ± 2.5%, respectively. In addition, the ferrous ion chelating test showed that only purpurin, with small concentrations, interferes in a dose dependant manner with the formation of Fe2+-ferrozine complex. These results are promising for further studies of the biological and pathological effects of these natural products.