Minocycline Improves Memory by Enhancing Hippocampal Synaptic Plasticity and Restoring Antioxidant Enzyme Activity in a Rat Model of Cerebral Ischemia-Reperfusion.

Stroke is a common neurological disease with a relatively high mortality rate and disabilities worldwide. More than half of the patients who have had an episode of stroke suffer from the impairment of sensorimotor function and language problems as well as learning and memory disorders. Oxidative stress plays an important role in memory impairment following brain ischemia. Hence, the application of antioxidant agents could be beneficial in managing memory deficits after stroke. Minocycline is a tetracycline antibiotic that is used for the treatment of infectious diseases; it can also function as a potent antioxidant medication. Hence, we hypothesized that minocycline could attenuate memory impairment after brain ischemia. We examined this hypothesis in a rat model of brain ischemia. In this model, the main arteries that supply the brain with oxygenated blood were occluded to induce brain ischemia in the rats. Then, minocycline was administered to the rats, which were subjected to brain ischemia. Seven days later, memory function in the rats was evaluated. The results showed that minocycline could enhance the activity of antioxidant enzymes in the brain, which physiologically fight off oxidative stress. This property of minocycline protects brain cells against ischemic injury and thereby increases the transmission of neuronal signals from one cell to another cell in the memory centers in the brain. These effects ultimately increase the memory function of rats, which was evident in the behavioral memory test. Overall, the study results suggest that minocycline can be considered a memory enhancer drug in patients who suffer from learning and memory disorders following a stroke.