QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: jpet.105.092684v1 316/1/169    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yu, Z. Articles by Cheng, C. H. K. Search for Related Content PubMed PubMed Citation Articles by Yu, Z. Articles by Cheng, C. H. K. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Medline Plus Health Information Antioxidants

ABSORPTION, DISTRIBUTION, METABOLISM, AND EXCRETION

The Dual Actions of Morin (3,5,7,2',4'-Pentahydroxyflavone) as a Hypouricemic Agent: Uricosuric Effect and Xanthine Oxidase Inhibitory Activity

Department of Biochemistry, The Chinese University of Hong Kong, Shatin, Hong Kong, China

Hyperuricemia is associated with a number of pathological conditions such as gout. Lowering of elevated uric acid level in the blood could be achieved by xanthine oxidase inhibitors and inhibitors of renal urate reabsorption. Some natural compounds isolated from herbs used in traditional Chinese medicine have been previously demonstrated to possess xanthine oxidase inhibitory activities. In the present investigation, morin (3,5,7,2',4'-pentahydroxyflavone), which occurs in the twigs of Morus alba L. documented in traditional Chinese medicinal literature to treat conditions akin to gout, was demonstrated to exert potent inhibitory action on urate uptake in rat renal brush-border membrane vesicles, indicating that this compound acts on the kidney to inhibit urate reabsorption. Lineweaver-Burk transformation of the inhibition kinetics data demonstrated that the inhibition of urate uptake was of a competitive type, with a K_i value of 17.4 µM. In addition, morin was also demonstrated to be an inhibitor of xanthine oxidase. Lineweaver-Burk analysis of the enzyme kinetics indicated that the mode of inhibition was of a mixed type, with K_i and K_ies values being 7.9 and 35.1 µM, respectively. Using an oxonate-induced hyperuricemic rat model, morin was indeed shown to exhibit an in vivo uricosuric action, which could explain, in part at least, the observed hypouricemic effect of morin in these rats. The potential application of this compound in the treatment of conditions associated with hyperuricemia was discussed.

Address correspondence to: Dr. Christopher H. K. Cheng, Department of Biochemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China. E-mail: chkcheng{at}cuhk.edu.hk

This article has been cited by other articles:

				Z. Yu, W. P. Fong, and C. H. K. Cheng Morin (3,5,7,2',4'-Pentahydroxyflavone) Exhibits Potent Inhibitory Actions on Urate Transport by the Human Urate Anion Transporter (hURAT1) Expressed in Human Embryonic Kidney Cells Drug Metab. Dispos., June 1, 2007; 35(6): 981 - 986. [Abstract] [Full Text] [PDF]