Methoxatin disodium salt (Pyrroloquinolinequinone disodium salt)

Pyrroloquinoline quinone (PQQ) is a quinone and redox enzyme cofactor that has been found in a variety of bacteria and has diverse biological activities.^1,2,3,4,5 It inhibits fibril formation by the amyloid proteins amyloid-β (1-42) (Aβ42) and mouse prion protein when used at a concentrations of 100 and 300 μM.¹ PQQ stimulates cell proliferation, reduces glutamate-induced production of reactive oxygen species (ROS), necrosis, and caspase-3 activity, and increases activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) in neural stem and progenitor cells.² It inhibits LPS-induced production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) and suppresses LPS-induced expression of the pro-inflammatory mediators iNOS, COX-2, TNF-α, IL-1β, IL-6, MCP-1, and MIP-1α in primary microglia.⁶ In vivo, PQQ (3 and 10 mg/kg) reduces Iba-1 expression, a marker of microglial activation, in the cerebral cortex and hippocampal dentate gyrus in mice. PQQ decreases the number of hepatic cells positive for α-smooth muscle actin (α-SMA) and reduces collagen deposition and hepatic hydroxyproline levels in a mouse model of liver fibrosis.⁴ It also decreases serum glucose and total cholesterol levels, increases brain SOD, CAT, and GPX activities, and decreases brain lipid hydroperoxide levels in mice with diabetes induced by streptozotocin .⁵

1.Kim, J., Kobayashi, M., Fukuda, M., et al.Pyrroloquinoline quinone inhibits the fibrillation of amyloid proteinsPrion4(1)26-31(2010) 2.Guan, S., Xu, J., Guo, Y., et al.Pyrroloquinoline quinone against glutamate-induced neurotoxicity in cultured neural stem and progenitor cellsInt. J. Dev. Neurosci.4237-45(2015) 3.Yang, C., Yu, L., Kong, L., et al.Pyrroloquinoline quinone (PQQ) inhibits lipopolysaccharide induced inflammation in part via downregulated NF-κB and p38/JNK activation in microglial and attenuates microglia activation in lipopolysaccharide treatment micePLoS One9(10)e109502(2014) 4.Jia, D., Duan, F., Peng, P., et al.Pyrroloquinoline-quinone suppresses liver fibrogenesis in micePLoS One10(3)e0121939(2015) 5.Kumar, N., and Kar, A.Pyrroloquinoline quinone ameliorates oxidative stress and lipid peroxidation in the brain of streptozotocin-induced diabetic miceCan. J. Physiol. Pharmacol.93(1)71-79(2015) 6.Yang, Y., Kuwano, T., Lagor, W.R., et al.Lipidomic analyses of female mice lacking hepatic lipase and endothelial lipase indicate selective modulation of plasma lipid speciesLipids49(6)505-515(2014)