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. 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. Ways to Address Perinatal Mast Cell Activation and Focal Brain Inflammation, including Response to SARS CoV 2, in Autism Spectrum Disorder Olive leaf extract (OLE) reduces mast cell mediated allergic inflammation ScienceDirect