Neuroprotective Effects of D-(-)-Quinic Acid on Aluminum Chloride-Induced Dementia in Rats

OBJECTIVE: The present study was designed to evaluate the neuroprotective effects of D-(-)-quinic acid on aluminum chloride- (AlCl(3)-) induced neurobehavioral and biochemical changes in rats. This study showed the behavioral and biochemical effects of D-(-)-quinic acid on rats with particular emphasis on the hippocampus and frontal cortex which are associated with memory. MATERIALS AND METHODS: Chronic administration of aluminum chloride at a dose of 175 mg/kg, p.o. for a period of 25 days markedly increased the level of acetylcholinesterase (AChE) activity and reduced the levels of antioxidant enzymes in the brain. Two doses of D-(-)-quinic acid (200 mg/kg and 400 mg/kg) were selected based on previous safety/toxicity studies and administered orally from the 26th day to the 36th day of the trial. Behavioral parameters were assessed using the Morris water maze test and an actophotometer in rats. Biochemical parameter content and histology of brain tissue were assessed on the final day of the experiment. RESULTS: D-(-)-Quinic acid (200 mg/kg and 400 mg/kg) orally administered alongside AlCl(3) rescued AChE activity and the behavioral impairments caused by aluminum. There was significant inhibition of MAO-B in D-(-)-quinic acid-treated rats. Histopathological studies in the hippocampus and cortex of the rat brain also supported that D-(-)-quinic acid markedly reduced the toxicity of AlCl(3) and preserved the normal histoarchitecture pattern of the hippocampus and cortex. These results indicate that D-(-)-quinic acid can reverse memory loss caused by aluminum intoxication by attenuating AChE activity and rescuing the deleterious effect of AlCl(3).