Xanthine Oxidase Inhibitory Activity of Extracts Prepared from Polygonaceae Species

The xanthine oxidase (XO) inhibitory activity of aqueous and organic extracts of 27 selected species belonging in five genera ( Fallopia , Oxyria , Persicaria , Polygonum and Rumex ) of the family Polygonaceae occurring in the Carpathian Basin were tested in vitro . From different plant parts (aerial parts, leaves, flowers, fruits and roots), a total of 196 extracts were prepared by subsequent extraction with methanol and hot H 2 O and solvent–solvent partition of the MeOH extract yielding n ‐hexane, chloroform and 50% MeOH subextracts. It was found that the chloroform subextracts and/or the remaining 50% MeOH extracts of Fallopia species ( F. bohemica , F. japonica and F. sachalinensis ), Rumex species ( R. acetosa , R. acetosella , R. alpinus , R. conglomeratus , R. crispus , R. hydrolapathus , R. pulcher , R. stenophyllus , R. thyrsiflorus , R. obtusifolius subsp. subalpinus , R. patientia ) and Polygonum bistorta , Polygonum hydropiper , Polygonum lapathifolium and Polygonum viviparum demonstrated the highest XO inhibitory activity (>85% inhibition) at 400 µg/mL. The IC 50 values of the active extracts were also determined. On the basis of the results, these plants, and especially P. hydropiper and R. acetosella , are considered worthy of activity‐guided phytochemical investigations. Copyright © 2014 John Wiley & Sons, Ltd.