Note on Nonenzymatic Reduction

The reason I mentioned nonenzymatic reduction, as something the authors of those articles might have meant (articles on cytotoxic effects at 20-50 mM extracellular ribose), is that the researchers found these extreme effects on glutathione depletion. Those extreme effects don't seem like the effects one would expect to see as a result of metabolic effects. That type of thing tends to be caused by redox cycling of reactive quinones or sulfhydryl groups with transition metals (like iron), in Fenton-type reactions, etc. I still think the research is valid, though, and the issue would really be the potential for glycolysis to occur, in response to ribose or xylitol, in the face of existing adenine (and guanine) nucleotide depletion, in cells with crippled mitochondrial activity (such as following prolonged ischemia), or in cells with constitutively absent or low oxidative capacity (such as mature red blood cells).