Neurotoxins
SYNOPSIS
Children with ASD have higher urinary levels of mercury and lead.
TITLE
Altered urinary porphyrins and mercury exposure as biomarkers for autism severity in Egyptian children with autism spectrum disorder
CITATION
Khaled EM, Meguid NA, Bjørklund G, et al. Metabolic Brain Disease 2016. DOI 10.1007/s11011-016-9870-6.
SUMMARY
Results of this case-control study showed that children with ASD had higher urinary levels of mercury and lead as well as porphyrins that are characteristic of mercury toxicity as compared to non-ASD control children. Porphyrins are complex molecules that are processed in the body through a series of chemical reactions. Mercury poisons the enzymes that are needed in the process, causing a buildup in the body of excess levels of specific porphyrins. The porphyrins for mercury toxicity also correlated with autism severity in ASD patients.
TAGS
SYNOPSIS
Thimerosal reduces people’s ability to make all-important vitamin B12 compounds that help the body detoxify and control inflammation—and B12 deficiencies and severely impaired detoxification are hallmarks of autism.
TITLE
Alternatively spliced methionine synthase in SH-SY5Y neuroblastoma cells: Cobalamin and GSH dependence and inhibitory effects of neurotoxic metals and thimerosal
CITATION
Waly M, Power-Charnitsky V-A, Hodgson N, … Deth R. Oxidative Medicine and Cellular Longevity. 2016, Article ID 6143753.
SUMMARY
Thimerosal inhibited cellular production of cobalamin necessary for detoxification and amelioration of oxidative stress. This caused lower methionine synthase activity and an impaired methylation capacity. Autistic subjects in general show cobalamin deficiencies and severely impaired methylation.
TAGS
SYNOPSIS
Thimerosal exposure led to the death of neuroblastoma and liver cells due to inhibition of thioredoxin-based cellular metabolism. This is similar to neuronal damage associated with autistic disorder.
TITLE
Toxicological effects of thiomersal and ethylmercury: Inhibition of the thioredoxin system and NADP+-dependent dehydrogenases of the pentose phosphate pathway
CITATION
Juan Rodrigues, Vasco Branc, Jun Lu, Arne Holmgren, Cristina Carvalho. Toxicology and Applied Pharmacology, 286 (2015) 216–223.
SUMMARY
This study demonstrates that Thimerosal and especially Ethylmercury affect specifically the antioxidant thioredoxin cycle and the production of NADPH by impairing the oxidative branch of the pentose phosphate pathway, therefore showing that Trx, TrxR, G6PDH and 6PGDH are important molecular targets for these mercurial compounds. The impairment of these enzymes originates detrimental effects which are especially relevant to the central nervous system.
TAGS
SYNOPSIS
Many heavy metals increase the apparent toxicity of low levels of mercury.
TITLE
Mercury toxicity: Genetic susceptibility and synergistic effects
CITATION
Haley BE. Medical Veritas. 2005;2:535–542.
SUMMARY
This article discusses mercury intoxication and several normally appearing factors that increase the susceptibility to mercury toxicity. Boys with autism represent a subset of the population that is more susceptible to the toxic effects of mercury and thimerosal because they are not efficient excretors of these toxic materials. Research confirms that a lead-toxic person would be more susceptible to mercury toxicity than a healthy, non-toxic person. Researchers routinely observe that many heavy metals increase the apparent toxicity of low levels of mercury. In other words, the synergistic effects of other heavy metals, diet, antibiotics, etc. on mercury toxicity make it impossible to define a “safe level of mercury exposure.”