Neuroinflammatory response to experimental stroke is inhibited by eriodictyol.

BACKGROUND: Cerebral ischemia is a common disease and one of the most common causes of death and disability worldwide. The lack of glucose and oxygen in neuronal tissue leads to a series of inflammatory events, culminating in neuronal death. Eriodictyol is a flavonoid isolated from the Chinese herb Dracocephalum rupestre that has been proven to have anti-inflammatory properties. HYPOTHESIS/PURPOSE: Thus, the present study was designed to explore whether eriodictyol has neuroprotective effects against the neuronal damage, motor and memory deficits induced by permanent middle cerebral artery occlusion (pMCAO) in mice. STUDY DESIGN: Animals were orally treated with eriodictyol (1, 2 and 4mg/kg) or vehicle (saline) 30min before pMCAO, 2h after, and then once daily for the following five days. METHODS: The parameters studied were neuronal viability, brain infarcted area; sensorimotor deficits; exploratory activity; working and aversive memory; myeloperoxidase (MPO) activity; TNFα, iNOS and GFAP immunoreactivity. RESULTS: The treatment with eriodictyol prevented neuronal death, reduced infarct area and improved neurological and memory deficits induced by brain ischemia. The increase of MPO activity and TNF-α, iNOS and GFAP expression were also reduced by eriodictyol treatment. CONCLUSION: These findings demonstrate that eriodictyol exhibit promising neuroprotection effects against the permanent focal ischemia cerebral injury in the mice experimental model and the underlying mechanisms might be mediated through inhibition of neuroinflammation.

Rosmarinic acid prevents against memory deficits in ischemic mice.

Polyphenols have neuroprotective effects after brain ischemia. It has been demonstrated that rosmarinic acid (RA), a natural phenolic compound, possesses antioxidant and anti-inflammatory properties. To evaluate the effectiveness of RA against memory deficits induced by permanent middle cerebral artery occlusion (pMCAO) mice were treated with RA (0.1, 1, and 20mg/kg/day, i.p. before ischemia and during 5 days). Animals were evaluated for locomotor activity and working memory 72 h after pMCAO, and spatial and recognition memories 96 h after pMCAO. In addition, in another set of experiments brain infarction, neurological deficit score and myeloperoxidase (MPO) activity were evaluates 24h after the pMCAO. Finally, immunohistochemistry, and western blot, and ELISA assay were used to analyze glial fibrillary acidic protein (GFAP), and synaptophysin (SYP) expression, and BDNF level, respectively. The working, spatial, and recognition memory deficits were significantly improved with RA treatment (20mg/kg). RA reduced infarct size and neurological deficits caused by acute ischemia. The mechanism for RA neuroprotection involved, neuronal loss suppression, and increase of synaptophysin expression, and increase of BDNF. Furthermore, the increase of MPO activity and GFAP immunireactivity were prevented in MCAO group treated with RA. These results suggest that RA exerts memory protective effects probably due to synaptogenic activity and anti-inflammatory action.