The Effect of Garlic on Cognition

Animal models of cognitive impairment and severe behavioral abnormalities (irritability, impaired communication, inability to process sensory information, and restlessness) have high levels of oxidative stress which are thought to cause programmed cell death (apoptosis) in the brain. Interestingly, a study by Jeong et al. found that ethyl acetate from garlic may help improve mice behavior and protect against cognitive impairment caused by oxidative stress through its antioxidant activities.[4] The researchers exposed PC12 cells (brain cells of mice) to amyloid beta (sticky, abnormal protein plaques) for two hours in order to obtain a 144% increase in oxidative stress levels. Pretreatment of the PC12 cell samples by ethyl acetate fraction from aged garlic extract significantly prevented the increase in oxidative stress, suggesting that it has potent antioxidant activities. To assess the neuroprotective effects of ethyl acetate, the researchers fed a group of mice with freeze-dried ethyl acetate fraction from aged garlic extract for 3 weeks and injected them with amyloid beta to induce memory impairment. The researchers observed that the mice performed better in Y maze test, a behavioral test that measures the willingness of rodents to explore new environments. The mice was able to perform successive entries into the three arms of the maze, suggesting that ethyl acetate fraction from aged garlic extract attenuated both memory and cognitive impairment induced by amyloid beta.