Chicoric acid enhanced brain cholesterol efflux and reduced Aβ pathology via LXR-ABCA1 signaling in Alzheimer's models

Alzheimer's disease (AD) is one of the most pressing public health challenges in an aging world. However, effective therapeutic strategies are still lacking. Imbalance in lipid homeostasis is a key driver of AD. Given the established link between dysregulated lipid metabolism and amyloid-beta (Aβ) aggregation, we investigated whether chicoric acid (CA), a dietary polyphenol with reported lipid-modulating properties, could mitigate Aβ pathology by modulating lipid metabolism in 5xFAD transgenic mice. In the brain, we found that CA upregulated the expression of liver X receptor Beta (LXR-β) and ATP-binding cassette transporter A1 (ABCA1) in 5xFAD mice. Through this pathway, it promoted apolipoprotein E (ApoE) lipidation and enhanced the expression of Aβ-clearance proteins (IDE and LRP1). Notably, in the periphery, CA reshaped the gut microbiota in 5xFAD mice, which reduced serum neurotoxic bile acid levels and preserved the integrity of the peripheral Aβ clearance system. Together, our study first demonstrated that CA globally regulated lipid homeostasis to alleviate Aβ pathology by coordinating cerebral cholesterol efflux with peripheral bile acid metabolism. The findings facilitated exploring active compounds from traditional Chinese medicine that may reduce Aβ deposition by targeting lipid metabolism pathways.