Exploring the Impact of 3-O-Methylquercetin on Wnt/β-Catenin Pathway Activity and Its Potential in Neural Processes.

Background: The Wnt/β-catenin signaling pathway plays a pivotal role in embryonic development, maintenance of the central nervous system, and the formation of neuronal circuits. Disruption of this pathway is closely associated with oncogenesis and neurodegenerative diseases, notably Alzheimer's disease. Flavonoids such as quercetin derivatives have emerged as promising neuroprotective agents. This study investigates the impact of 3-O-methylquercetin (3OMQ), a methylated quercetin metabolite, on Wnt/β-catenin signaling and its potential relevance in neurodegenerative disease models. Methods: The ability of 3OMQ to modulate Wnt/β-catenin activity was analyzed using a luciferase-based reporter assay in both neural and non-neural cell lines. Cell viability assays evaluated cytotoxicity at various concentrations. We mapped 3OMQ activity within the pathway using targeted cell signaling experiments. Docking and molecular dynamics simulations suggested glycogen synthase kinase 3β (GSK3β) as a putative target of 3OMQ. Finally, we employed a mouse model of acute amyloid-β oligomer (AβO) toxicity to assess the in vivo effects of 3OMQ on spatial memory and Wnt-related gene expression. Results: We compared the flavonoids quercitrin, quercetin, and 3-O-methylquercitrin (3OMQ) with pharmacologically active compounds in a gene reporter assay (TOPFLASH) using Wnt-sensitive RKO cells treated with Wnt3a-conditioned medium. XAV-939 and PNU-74654 showed inhibitory activity, while BIO, CHIR99021, quercitrin, and 3OMQ enhanced the Wnt/β-catenin pathway. Notably, 3OMQ potentiated this pathway at concentrations 5-10 times lower than quercitrin and outperformed 1 μM BIO at 10 μM without cytotoxicity, highlighting its remarkable potency. Mechanistically, 3OMQ acts downstream of initial membrane activation and upstream of the β-catenin destruction complex. Consistently, molecular docking indicates a strong interaction with GSK3, a central regulator of the pathway. In adult mice, 3OMQ administration prevented AβO-induced recognition memory deficits and favored normalization of Wnt-related gene expression. Conclusions: These findings identify 3OMQ as a potent positive modulator of the Wnt/β-catenin pathway, with both in vitro and in vivo neuroprotective effects. Targeting Wnt signaling with compounds such as 3OMQ holds promise for maintaining neuronal health and developing therapeutic strategies for neurodegenerative conditions.