Homogentisic acid is an orally active, blood-brain barrier-permeable amyloidogenic compound that functions as both an amyloid component and a pigment precursor. Accumulation of homogentisic acid downregulates tight junction proteins (such as claudin-5, occludin, ZO-1) and impairs blood-brain barrier integrity. Homogentisic acid and its oxidation product benzoquinone acetic acid not only induce the aggregation and fibrosis of multiple proteins (such as Abeta1-42, alpha-synuclein, SAA, Transthyretin (TTR), atrial natriuretic peptide), but also trigger oxidative stress, damage to the Wnt/beta-catenin pathway, and neurotoxicity, leading to ochronosis pigment deposition and synaptic dysfunction. At specific concentrations, homogentisic acid exerts no cytotoxicity or genotoxicity on human peripheral blood lymphocytes, and even counteracts the genotoxicity induced by Irinotecan (HY-16562). Homogentisic acid serves as an important tool molecule for investigating the mechanisms of diseases including ochronosis, secondary amyloidosis, Alzheimers disease, and colorectal cancer[1][2][3][4][5][6][7][8].
