Heavy Metal Detoxification
Novel and Emerging Therapies
Toxicogenomics. While elevated blood levels of metals are associated with adverse health outcomes, they are not necessarily indicative of clinical metal toxicity. Similarly, metal toxicities can occur in some individuals below levels that are predicted to be “safe.” Toxicogenomics, the study of gene expression changes by toxin exposure, may prove to be a useful tool for more sensitive and quick metal toxicity assessment. Several laboratories have already identified specific gene expression patterns in specific tissues arising from environmentally significant toxic metals (such as decreased expression of cytochrome P450 detoxification enzymes in response to arsenic exposure or induction of protective heat shock proteins by cadmium) (Yoon 2008).
New chelation therapies. Current chelation therapy uses chemical chelators that have several adverse effects, such as kidney overload, cardiac arrest, mineral deficiency, and anemia. This has motivated the search for safer heavy metal chelators, which have desirable properties, high specificity for metal toxins, and low affinity for nutritionally essential metals. Interesting candidates include polygamma-glutamic acid-coated superparamagnetic nanoparticles (Inbaraj 2012) and magnetic chitosan/graphene oxide composites (Fan 2013), which are both highly selective for lead. Magnetic chelators have the additional advantage that they can be magnetically directed to specific organs of interest (Inbaraj 2012).