Efficacy and mechanisms of Icariin in the treatment of Alzheimer's disease: a systematic review and meta-analysis of a preclinical study.

Alzheimer's disease (AD) is a neurodegenerative condition that predominantly affects elderly individuals, characterised by progressive cognitive dysfunction, memory impairment and behavioural changes. Icariin (ICA), the primary active ingredient of the traditional Chinese medicine Epimedium spp., has demonstrated significant potential in the treatment of neurological disorders. Nevertheless, the precise mechanisms through which it exerts its anti-AD effects remain to be elucidated. And this meta-analysis aimed to discuss the mechanisms by which ICA exerts its anti-AD effects and the differences in the efficacy of different doses of ICA by evaluating behavioral indicators and biochemical characteristics. A total of 31 pre-clinical studies were included, and the results showed that ICA treatment significantly improved cognitive dysfunction in animal models of AD in terms of resistance to neurotoxic substances, inhibition of oxidative stress, anti-inflammation, inhibition of apoptosis, modulation of neuronal autophagy, and protection of nerves to promote regeneration. Furthermore, 68 mg/kg of ICA was identified as the most effective doses in terms of improving cognition. However, further research is required, incorporating studies of higher quality and larger sample sizes, in addition to clinical trials, in order to verify the efficacy and safety of this approach in neurological disorders.