Protections of pinocembrin on brain mitochondria contribute to cognitive improvement in chronic cerebral hypoperfused rats

To study effects of pinocembrin, a natural compound extracted from propolis, on cognitive ability impaired by chronic cerebral hypoperfusion in rats, and if it did so, to investigate its effects on brain mitochondria. Rat chronic cerebral hypoperfasion was achieved by permanent bilateral common carotid arteries ligation, with regional cerebral blood flow evaluated. Cognitive ability was tested by Mortis water maze task. Production of reactive oxygen species and origin targets including mitochondria membrane potential, respiratory chain complex 1, complex III activities and mitochondria swelling degree were evaluated. Cytochrome oxidase was determined on its expression level by western blotting. Pinocembrin alleviated cognitive impairments in Morris water maze and decreased mitochondria reactive oxygen species production, in accordance with its improvements on complex I activity, membrane potential level, mitochondria swelling degree and cytochrome oxidase deficits. Pinocembrin could improve rat cognitive impairments induced by chronic cerebral hypoperfusion, contributed to its protections on brain mitochondria structure and function. (c) 2006 Published by Elsevier B.V.