ALA versus Dithiol-based Chelating Agents (DMPS, DMSA)

The ability of ALA to bind inorganic mercury from rabbit renal tissue was compared to glutathione and the chelators 2,3-dimercaptopropane-1-sulfonate (DMPS), meso-2,3-dimercapto-succinicacid (DMSA), penicillamine, and ethylenediaminetetra acetic acid (EDTA) (Figure 3). (69)

[FIGURE 3 OMITTED]

DMPS was the most efficient chelator, removing 86 percent of the mercury in three hours, with DMSA being the next-most efficient, removing 65 percent of the mercury. In the same time period, penicillamine removed 60 percent, glutathione removed 50 percent, ALA removed 35 percent, and EDTA removed 20 percent. Only the levels reached by DMSA and DMPS, however, were statistically significantly different from baseline (p<0.05). Therefore, the effect of ALA and glutathione may show only a trend or an apparent effect and are not comparable to DMPS and DMSA. Although the actual effect of a chelator or heavy metal-complexing agent cannot be determined in a three-hour time period, and acute doses of 10 mg/kg of inorganic mercury would be considered highly toxic in an adult human, there is evidence from this study that ALA is a less efficient binder of inorganic mercury than the recognized chelating agents, DMSA and DMPS. All of the substances were used at a concentration of 10 mM, a level difficult to reach with ALA oral supplementation.