title: Xanthine oxidase inhibitory activity of Vietnamese medicinal plants.
abstract: Among 288 extracts, prepared from 96 medicinal plants used in Vietnamese traditional medicine to treat gout and related symptoms, 188 demonstrated xanthine oxidase (XO) inhibitory activity at 100 microg/ml, with 46 having greater than 50% inhibition. At 50 microg/ml, 168 of the extracts were active, with 21 possessing more than 50% inhibition. At 25 microg/ml, 146 extracts exhibited inhibitory activity, with 8 showing over 50% inhibition, while 126 extracts presented activity at 10 microg/ml, with 2 having greater than 50% inhibition. The MeOH extracts of Artemisia vulgaris, Caesalpinia sappan (collected at the Seven-Mountain area), Blumea balsamifera (collected in Lam Dong province), Chrysanthemum sinense and MeOH-H(2)O extract of Tetracera scandens (Khanh Hoa province) exhibited strong XO inhibitory activity with IC(50) values less than 20 microg/ml. The most active extract was the MeOH extract of the flower of C. sinense with an IC(50) value of 5.1 microg/ml. Activity-guided fractionation of the MeOH extract led to the isolation of caffeic acid (1), luteolin (2), eriodictyol (3), and 1,5-di-O-caffeoylquinic acid (4). All these compounds showed significant XO inhibitory activity in a concentration-dependent manner, and the activity of 2 was more potent (IC(50) 1.3 microM) than the clinically used drug, allopurinol (IC(50) 2.5 microM).
authors.affiliation: Institute of Natural Medicine, Toyama Medical and Pharmaceutical University, 2630-Sugitani, Toyama 930-0194, Japan.
authors.forename: Mai Thanh Thi
authors.initials: MT
authors.lastname: Nguyen
authors.forename: Suresh
authors.initials: S
authors.lastname: Awale
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tezuka
authors.forename: Quan Le
authors.initials: QL
authors.lastname: Tran
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Kadota
mesh_terms: D031202:Chrysanthemum / Q000737:chemistry; D008518:Medicine, East Asian Traditional; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*; D014744:Vietnam; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
chemical_list: D010936:Plant Extracts; D014969:Xanthine Oxidase