Allopurinol reduces severity of delayed neurologic sequelae in experimental carbon monoxide toxicity in rats.

•Allopurinol ameliorated cognitive deficits in rats after CO exposure.•Allopurinol decreased TNF-α, ICAM-1 and HMGB1 protein in the cerebral cortex and hippocampus.•Allopurinol reduced neuronal death in the cerebral cortex and hippocampus.•Allopurinol prevented microglial activation in the cerebral hippocampus and corpus callosum.•Allopurinol reduced demyelination in the corpus callosum and the hippocampus in rats after CO exposure.