Alzheimer's disease (AD) is a progressive neurodegenerative disorder affecting millions of people worldwide, with a major socio-economic impact. The limitations of current therapies and the associated adverse effects drive interest in natural compounds with therapeutic potential. Mansorine (MA), a coumarin compound extracted from Mansonia gagei, is known for its antioxidant and anti-inflammatory properties. The aim of this study was to evaluate the effects of mansorine on memory, using zebrafish (Danio rerio) as a preclinical model for AD.

To induce an AD-like amnesia model, fish were exposed to okadaic acid (OKA, 10 nM) for 4 days. Animals were divided into six groups (n = 10/group): control (DMSO), galantamine (GAL, 1 mg/L), OKA, and OKA co-treated with MA at 1, 3, or 6 μg/L. Mansorina was administered for 7 days, every 3 days during water exchange. Cognitive functions were assessed by Y-maze tests (spatial memory and locomotor activity) and novel object recognition (NOR). Data were analyzed with ANOVA and Tukey testing (GraphPad Prism 9, p < 0.05).

Treatment with OKA significantly impaired spatial memory and object recognition (p < 0.0001), while GAL reversed these deficits. Coadministration of MA (3 and 6 μg/L) significantly improved cognitive performance (p < 0.001 – p < 0.00001), increasing the exploration of the novel arm and novel object. MA also stimulated locomotor activity.

Conclusion: Mansorina can counteract OKA-induced cognitive deficits, posessing neuroprotective and cholinergic function restorative potential.