Bacterial melanin improves cognitive impairment induced by cerebral hypoperfusion in rats.

The effect of bacterial melanin (BM) solution on learning and memory impairment induced by chronic cerebral hypoperfusion in rats was studied. Male rats were injected intramuscularly with BM solution on the second day after bilateral permanent occlusion of the common carotid artery. Rats received 6 mg/ml (170 mg/kg) BM and performed significantly better in cognition tests compared with controls. The present findings demonstrate that the beneficial effects of BM injection on cognitive functions may be due to preventing neuropathological alterations, suppressing the inflammation process, stimulating vascularization and inhibiting oxidative damage. Obtained data suggest that BM has therapeutic potential for the treatment of neurodegeneration caused by ischemia.