Xanthine oxidase inhibitory properties of Czech medicinal plants

Aim of the study: To investigate in vitro xanthine oxidase inhibitory properties of plants traditionally used in Czech Republic and Central-East Europe region for gout, arthritis or rheumatism treatment. Materials and methods: Methylene chloride-methanolic and two ethanolic extracts of 27 plant species were screened for in vitro xanthine oxidase inhibitory activity using a spectrophotometric method. Results: Around 50% of the species exhibited some degree of xanthine oxidase inhibitory properties at 200 mu g/mL, showing a moderate correlation (r=0.59) with total phenol content. The most active were methylene chloride-methanolic extracts of Populus nigra and Betula pendula, with IC(50) of 8.3 and 25.9 mu g/mL, respectively, followed by 80% ethanolic extract of Caryophyllus aromaticus and Hypericum perforatum, both under 50 mu g/mL. Conclusions: Populus nigra and Betula pendula were identified as species with the highest xanthine oxidase inhibitory potential in our study. This correlates with the ethnobotanical data on their use in Central European folklore and provides the basis for further investigation on these plants. (C) 2010 Elsevier Ireland Ltd. All rights reserved.