Biology:Xanthine oxidase inhibitor
A xanthine oxidase inhibitor is any substance that inhibits the activity of xanthine oxidase, an enzyme involved in purine metabolism. In humans, inhibition of xanthine oxidase reduces the production of uric acid, and several medications that inhibit xanthine oxidase are indicated for treatment of hyperuricemia and related medical conditions including gout.[1] Xanthine oxidase inhibitors are being investigated for management of reperfusion injury.
Xanthine oxidase inhibitors are of two kinds: purine analogues and others. Purine analogues include allopurinol, oxypurinol,[2] and tisopurine. Others include febuxostat,[3] topiroxostat, and inositols (phytic acid and myo-inositol[citation needed]).
In experiments, numerous natural products have been found to inhibit xanthine oxidase in vitro or in model animals (mice, rats). These include three flavonoids that occur in many different fruits and vegetables: kaempferol, myricetin, and quercetin.[4][5] More generally, planar flavones and flavonols with a 7-hydroxyl group inhibit xanthine oxidase.[6] An essential oil extracted from Cinnamomum osmophloeum inhibits xanthine oxidase in mice.[7] The natural product propolis from selected sources inhibits xanthine oxidase in rats; the specific substance responsible for this inhibition has not been identified, and the generality of these findings is unknown.[8] An extract of leaves of Pistacia integerrima also inhibits xanthine oxidase at a level that appears to merit further research.[9]
In folk medicine the tree fern Cyathea spinulosa (formerly Alsophila spinulosa) has been used for gout, but its most active component, caffeic acid, is only a weak inhibitor of xanthine oxidase.[10]
References
- ↑ "Therapeutic Effects of Xanthine Oxidase Inhibitors: Renaissance Half a Century after the Discovery of Allopurinol". Pharmacol. Rev. 58 (1): 87–114. March 2006. doi:10.1124/pr.58.1.6. PMID 16507884.
- ↑ "Involvement of uric acid transporter in increased renal clearance of the xanthine oxidase inhibitor oxypurinol induced by a uricosuric agent, benzbromarone". Drug Metabolism and Disposition 33 (12): 1791–5. December 2005. doi:10.1124/dmd.105.006056. PMID 16135657.
- ↑ "Febuxostat, a novel nonpurine selective inhibitor of xanthine oxidase: a twenty-eight-day, multicenter, phase II, randomized, double-blind, placebo-controlled, dose-response clinical trial examining safety and efficacy in patients with gout". Arthritis and Rheumatism 52 (3): 916–23. March 2005. doi:10.1002/art.20935. PMID 15751090.
- ↑ "Antioxidant and prooxidant properties of flavonoids". Fitoterapia 82 (4): 513–523. 2011. doi:10.1016/j.fitote.2011.01.018. PMID 21277359.
- ↑ "Effects of flavonols on the generation of superoxide anion radicals by xanthine oxidase and stimulated neutrophils". Archives of Biochemistry and Biophysics 395 (1): 49–56. November 2001. doi:10.1006/abbi.2001.2562. PMID 11673865.
- ↑ "Inhibition of xanthine oxidase by flavonoids". Bioscience, Biotechnology, and Biochemistry 63 (10): 1787–90. October 1999. doi:10.1271/bbb.63.1787. PMID 10671036.
- ↑ "Essential oil from leaves of Cinnamomum osmophloeum acts as a xanthine oxidase inhibitor and reduces the serum uric acid levels in oxonate-induced mice". Phytomedicine 15 (11): 940–5. August 2008. doi:10.1016/j.phymed.2008.06.002. PMID 18693097. http://ntur.lib.ntu.edu.tw//bitstream/246246/177305/1/20.pdf.
- ↑ "プロポリスのキサンチンオキシダーゼ活性阻害作用及び血漿尿酸値低下作用 [Xanthine oxidase inhibitory activity and hypouricemia effect of propolis in rats]" (in Japanese). Yakugaku Zasshi 125 (3): 315–21. March 2005. doi:10.1248/yakushi.125.315. PMID 15738631.
- ↑ "Pharmacological basis for use of Pistacia integerrima leaves in hyperuricemia and gout". J Ethnopharmacol 117 (3): 478–82. May 2008. doi:10.1016/j.jep.2008.02.031. PMID 18420362.
- ↑ "Xanthine oxidase inhibitors from the leaves of Alsophila spinulosa (Hook) Tryon". Journal of Enzyme Inhibition 8 (1): 61–71. 1994. doi:10.3109/14756369409040777. PMID 7539070.
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