Eriobotrya japonica improves cognitive function in healthy adolescents: A 12-week, randomized double-blind, placebocontrolled clinical trial

Eriobotrya japonica Lindley, a subtropical plant in the family Rosaceae, has been used as a folk medicine in Asia, which is known to contain various phytochemicals and have neuroprotective and anti-oxidant effects. In this study, the efficacy and safety of ethanol extract from leaves of Eriobotrya japonica Lindley (ELEJ) were investigated for improvement of cognitive function in healthy Korean adolescents by conducting a randomized clinical trial. Eighty subjects from 16-19 years of age with normal cognitive function were randomly assigned to receive either ELEJ (750 mg, twice a day) or placebo in this 12 week, double-blind and placebo-controlled trial. Neuropsychological assessments including Korean-Mini Mental State Examination (K-MMSE) as primary outcome, Rey-kim memory test, brief cognitive rating scale, prospective and retrospective memory questionnaire, spielberger state-trait anxiety inventory and blood brain-derived neurotrophic factor (BDNF) as secondary outcomes were used to assess the cognitive function. Intake of ELEJ for 12 week significantly increased both the total score and the score of the K-MMSE compared with placebo (p = 0.043, p = 0.014, respectively). There were no significant differences in the changes of other neuropsychological assessment scores between the two groups. There was no observed adverse event related to the ingestion of ELEJ. This result suggest that ELEJ supplementation safely improves cognitive function, especially memory, in healthy Korean adolescents in a safe manner as shown by the increase in the score of K-MMSE. Further studies exploring whether ELEJ is effective for the treatment of cognitive impairment are warranted.