PMX-205 is a cyclic hexapeptide that acts as a potent antagonist of C5a receptor (C5aR; IC50= 31 nM).1It is orally active and blocks inflammatory signaling and symptoms in animal models of colitis and allergic asthma.2,3PMX-205 is also brain penetrant and reduces neuroinflammation and neurodegeneration in an animal model of Alzheimer's disease.4 1.March, D.R., Proctor, L.M., Stoermer, M.J., et al.Potent cyclic antagonists of the complement C5a receptor on human polymorphonuclear leukocytes. Relationships between structures and activityMol. Pharmacol.65(4)868-879(2004) 2.Jain, U., Woodruff, T.M., and Stadnyk, A.W.The C5a receptor antagonist PMX205 ameliorates experimentally induced colitis associated with increased IL-4 and IL-10Br. J. Pharmacol.168(2)488-501(2013) 3.Staab, E.B., Sanderson, S.D., Wells, S.M., et al.Treatment with the C5a receptor/CD88 antagonist PMX205 reduces inflammation in a murine model of allergic asthmaInt. Immunopharmacol.21(2)293-300(2014) 4.Fonseca, M.I., Ager, R.R., Chu, S.-H., et al.Treatment with a C5aR antagonist decreases pathology and enhances behavioral performance in murine models of Alzheimer's diseaseJ. Immunol.183(2)1375-1383(2009)
DOPAL is an aldehyde product of the oxidative deamination of dopamine by monoamine oxidase.[1] It can be further oxidized to 3,4-dihydroxyphenylacetic acid (DOPAC) by aldehyde dehydrogenase (ALDH) and, to a lesser extent reduced to 3,4-dihydroxyphenyl ethanol (DOPET). DOPAL is toxic to neurons.[2],[3] It can also oligomerize and precipitate α-synuclein, an event associated with Parkinson's disease.[2] Mice lacking cytosolic and mitochondrial forms of ALDH display increased levels of DOPAL as well as neurodegeneration and motor dysfunction characteristic of Parkinson’s disease.[4]