Uric acid inhibits L-DOPA-CU(II) mediated DNA cleavage.
It has been proposed that considerable DNA damage may be caused by endogenous metabolites produced during the body's normal metabolic processes. We have previously shown that L-DOPA, in the presence of Cu(II) leads to oxidative DNA breakage in vitro. Uric acid is considered to be a naturally occuring antioxidant and is present in plasma at a relatively high concentration. In this paper we report that uric acid inhibits L-DOPA-Cu(II) mediated DNA cleavage at concentrations similar to or lower than those found in plasma. Xanthine, which is the structural analogue of uric acid is a more potent inhibitor of the reaction. Uric acid was also shown to directly quench the generation of hydroxyl radicals by L-DOPA-Cu(II). The results have been discussed in relation to the putative protective role of uric acid against endogenous DNA damage by oxygen radicals.
Singh
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Department of Biochemistry, Faculty of Life Sciences, A.M.U., Aligarh, India.
Farhan Asad
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Hadi
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SM
D000818:Animals; D002417:Cattle; D019457:Chromosome Breakage; D003300:Copper / Q000378:metabolism*; D004247:DNA / Q000187:drug effects / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects*; D004278:DNA, Superhelical / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D017665:Hydroxyl Radical / Q000378:metabolism; D007980:Levodopa / Q000378:metabolism*; D008353:Mannitol / Q000494:pharmacology; D010084:Oxidation-Reduction; D010957:Plasmids / Q000187:drug effects / Q000378:metabolism; D013890:Thiourea / Q000494:pharmacology; D014527:Uric Acid / Q000494:pharmacology*; D019820:Xanthine / Q000494:pharmacology
D004278:DNA, Superhelical; D019820:Xanthine; D014527:Uric Acid; D017665:Hydroxyl Radical; D008353:Mannitol; D007980:Levodopa; D003300:Copper; D004247:DNA; D013890:Thiourea