The Efficacy and Underlying Mechanism of Moxibustion in Preventing Cognitive Impairment: A Systematic Review of Animal Studies.

Cognitive impairment is age-related and manageable only with early diagnosis and prevention. Moxibustion is widely accepted in East Asia as useful for preventing cognitive impairment. This systematic review of animal studies was conducted to verify the efficacy of moxibustion in preventing cognitive impairment and to elucidate the underlying mechanism. Randomized controlled animal trials that established the efficacy of moxibustion in preventing cognitive impairment were included in the analysis. Results of behavioral tests and the signaling pathways elucidated were extracted and a meta-analysis was conducted with the behavioral test results. The risk of bias was evaluated using 9 items, and reporting quality was evaluated using the ARRIVE (Animal Research: Reporting In Vivo Experiments) Guidelines Checklist. Ten trials involving 410 animals met the inclusion criteria. All studies reported the benefit of moxibustion in preventing cognitive deficits caused by Alzheimer's disease (AD). Among five studies using the Morris water maze test, a significant effect of moxibustion in decreasing the escape time was reported in three studies, increasing the crossing times in four studies, and prolonging the dwelling time in two studies. The effects of moxibustion were demonstrated to be mediated by an increase in the activity of neurotrophins and heat shock protein, modulation of the cell cycle, and suppression of apoptosis and inflammation. However, considering the small number of included studies, the lack of studies investigating entire signaling pathways, and a high risk of bias and low reporting quality, our results need to be confirmed through more detailed studies.