Glutathione: Master Antioxidant, Reducing Oxidative Stress, and Detoxification How Mast Cells Contribute to Autoimmune Brain Disorders Mast Cell Activation Syndrome and Its Impact on the Lymphatics Mast cells are hypersensitive immune cells that release histamine and other inflammatory mediatorsoften in response to oxidative stress, environmental toxins, and immune imbalance. Many patients with MCAS have low levels of glutathione.