A compound found in dark chocolate has been found to protect the brain from ischemic damage by increasing cellular signals that are known to protect neurons from damage. Sylvain Doré, Ph.D., and colleagues at Johns Hopkins University School of Medicine induced an ischemic stroke in two groups of mice, one group of which had been fed a single dose of the flavanol epicatechin. Results showed that the mice that had been given epicatechin suffered significantly less brain damage than those who had not been given the compound. Additionally, epicatechin also appeared to limit further brain damage when given to mice 3.5 hours after inducing a stroke. Assays of neuronal cell cultures confirmed that epicatechin protects neurons against oxidative damage. Further studies suggest that this is conferred through activation of the transcriptional factor Nrf2 and an increase in the heme oxygenase 1 (HO1) enzyme, both of which are pathways that are known to protect neurons from damage.