Protective effects of protocatechuic acid against cognitive impairment in an amyloid beta-induced Alzheimer's disease mouse model

In this study, we investigated the protective effects of protocatechuic acid (PA) against cognitive impairment in an amyloid-beta (A beta)-induced Alzheimer's disease (AD) mouse model. PA was administered orally for 14 days at 100 and 200 mg/kg/day. To examine effects on cognition, we conducted behavior tests including the T-maze test, novel object recognition, and the Morris water maze test. In addition, we measured lipid pemxidation, nitric oxide (NO) production, and inflammation-related protein expression in mice tissues. The PA-administered group showed more use of novel routes, better novel object recognition, and learning and memory ability compared to the A beta(25-35)-injected mice in the behavior tests. The results indicated that the administration of higher PA protected against cognitive impairment. In addition, the PA-administered groups showed significantly decreased lipid peroxidation and NO production in the brain, kidney, and liver tissues. Furthermore, the PA-administered groups showed attenuated A beta(25-35)-induced neuroinflammation by downregulating inflammatory mediators, inducible nitric oxide synthase and cyclooxygenase-2 in the brain. The results of the present study suggest that PA may be a protective agent against AD.