Fw: Dr Bounous's Response

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Debbie

Here is Dr Bounous's response

"The correlation or consequence of the finding is difficult to evaluate because we must deal instead with the physiologic concentration of iron and anti - oxidant. In addition we must keep in mind that reduced glutathione is the most potent anti hydroxyl reducing agent so it becomes irrelevant even if the rather dubious data presented are true that is that GSH and ascorbic acid enhance the pro oxidant activity of iron".

> A caution here about use of iron with glutathione precursors, & c.>> Biochim Biophys Acta 1997 Aug 29;1336(2):295-302> Comparative studies of enhanced iron-mediated production of hydroxylradical> by glutathione, cysteine, ascorbic acid, and selected catechols.> Nappi AJ, Vass E> Department of Biology, Loyola University Chicago, IL 60626, USA.>> A sensitive electrochemical detection system was employed together with a> specific salicylate hydroxylation assay to comparatively assess theeffects> of various substances on the iron-mediated generation of the hydroxyl> radical (.OH). Hydroxyl radical production was found to be enhanced> significantly by reduced glutathione, cysteine, ascorbic acid, andselected> catechols, but not by mannitol, melatonin or tyramine. The data showedthat> over the range of concentrations examined, the augmented effects were> linearly proportional to the amount of added reductant for a given amountof> iron in the system. The pro-oxidant activity of thiols and ascorbatereduced> and recycled iron providing both hydrogen peroxide (H2O2) and catalytic> ferrous ions for augmented .OH production by the Fenton reaction. The> enhanced production of .OH by catechols resulted from their oxidationeither> by molecular oxygen or ferric ions, with the accompanying formation of> semiquinones, superoxide anion and H2O2. These data caution against> therapeutic applications of thiols and ascorbate for ameliorating> oxy-radical-induced tissue damage in environments where free redox-active> metal ions may be present to function both as foci for site-specific> peroxidative activity, and as catalysts to promote the pro-oxidant> properties of certain endogenous reductants, thereby elevating rather than> diminishing .OH levels.>>>>> ------------------------------------------------------------------------> Looking for Airfare deals?> Visit Expedia.com for limited time offers> 1/5205/10/_/378/_/961132070/> ------------------------------------------------------------------------>> Get HUGE info at http://www.cures for cancer.ws, and post your own links there.Unsubscribe by sending email to cures for cancer-unsubscribeegroups or byvisiting http://www.bobhurt.com/subunsub.mv>