Effect of curcumin on memory impairment: A systematic review

Background: Memory impairment (MI) is one of the most common complaints of people referred to physicians for proper diagnosis. In addition, the prevalence of neurodegenerative lesions like Alzheimer is generally on the increase. Thus far, numerous laboratory studies have been conducted to evaluate the effect of curcumin on the improvement of MI. Purpose: The aim of this study was to review the efficacy of curcumin on MI in animal studies. Methods: Keywords related to memory and curcumin were searched in PubMed, Web of Science, and Scopus databases based on MeSH; and articles published until July 2017 were later extracted. Then the articles (full text or abstract) were examined based on the inclusion and exclusion criteria. The present study evaluated articles that did not include specific pathologies such as Alzheimer. Results: A total of 90 articles met the inclusion criteria but only 25 articles underwent final review. The minimum and maximum dosages of curcumin were 5 and 480 mg/kg respectively. Curcumin was administered over the period of 1-84 days. The results of 24 articles showed that curcumin moderates short-term and long-term MI in various laboratory models such as aging, acute and chronic stress, anxiety, smoking, benzodiazepine and anticonvulsant consumption, and other conditions associated with increased oxidative stress. Conclusion: The findings of this study revealed that curcumin moderated or reversed MI in rodents and did not have a placebo effect. Accordingly, curcumin can play a preventive and therapeutic role in MI.