Treatments for Autism Spectrum Disorder Based on Glutathione Level Regulation

This paper reviews and conclude current treatment of ASD basing on elevation of glutathione (GSH) level. Gamma-glutamyl cysteine ligase (GCL) is the enzyme involved in rate limiting step in GSH synthesis. Lack of GCL and substrate cysteine is observed in ASD patients, which will reduce GSH synthesis. Accumulation of another substrate, glutamate will further inhibit GSH synthesis. Reduce in GSH level leads to decrease in GSH/oxidised GSH (GSSG) ratio, which breaks balance of redox reactions. Current treatments mainly rely on enhance of rate limiting step reaction or rebalancing of GSH and glutamate. Oral GSG bypasses GCL by delivering short peptide glutamyl-cysteine into body. Insulin-like growth factor 1 (IGF-1) increase the expression of GCLM to increase GCL level. N-acetylcysteine (NAC) treatment increases uptake of cystine into cells and oxidise it into cysteine in cells, and export glutamate out of cells at same time to prevent the inhibition. The efficiency of all these treatments has been tested clinically, which show their potential in curing ASD also flaws needed to be improved.