THE PUTATIVE ESSENTIAL NUTRIENT PYRROLOQUINOLINE QUINONE IS NEUROPROTECTIVE IN A RODENT MODEL OF HYPOXIC ISCHEMIC BRAIN INJURY/

Pyrroloquinoline quinone is a ubiquitous redox cofactor and putative e ssential nutrient in mammals. Pyrroloquinoline quinone has recently be en demonstrated to depress N-methyl-D-asparate induced electrical resp onses and is neuroprotective in vitro. In addition, pyrroloquinoline q uinone has been demonstrated to act as a free radical scavenger in mam malian tissues. In this study, we demonstrate a neuroprotective effect of pyrroloquinoline quinone in an in vivo cerebral hypoxia/ischemia m odel in the rodent. Significant reduction in infarct size resulted fro m pyrroloquinoline quinone pretreatment and also when pyrroloquinoline quinone was administered following induction of hypoxia/ischemia. The neuroprotective effect was not dependent on change in core or cranial temperatures, as there was no difference between temperature measurem ents in pyrroloquinoline quinone-treated and vehicle-treated controls. No changes in electroencephalographic activity were observed at neuro protective doses. These findings suggest that pyrroloquinoline quinone may represent a novel class of quinoid reagents of potential use in t he treatment of neurological disorders that involve excitotoxicity. Th is study demonstrates a protective effect of the novel essential nutri ent pyrroloquinoline quinone on brain injury in a rodent model of cere bral hypoxia/ischemia. Pyrroloquinoline quinone was neuroprotective wh en administered before and even after the insult, and did not appear t o have significant neurobehavioral side effects. Pyrroloquinoline quin one represents a new class of agents with potential use in the therapy of stroke.