Fabrication of astaxanthin‐loaded nanoparticles and their neuroprotective effects on C6 cell lines

Astaxanthin (AST), a well‐known carotenoid primarily extracted from the green microalgae Haematococcus pluvialis, exhibits notable pharmacological properties, including anticancer, antioxidation, anti‐inflammatory, and neuroprotective effects. However, its practical application in pharmaceuticals, food, and cosmetics is hindered by its limited water solubility and poor bioavailability. To address these challenges, this study aims to fabricate astaxanthin‐loaded nanoparticles and evaluate their neuroprotective potential. Nanoparticles of astaxanthin were synthesized by the freeze‐drying method using the surfactants Tween 80 and lecithin, the β‐cyclodextrin encapsulating agent. The nanoparticles possessing high AST loading (up to 9.6 wt%) had a spherical shape with an average particle size of 98 nm and negative surface potentials (ζ = −36.8 mV). The neuroprotective effects of the astaxanthin nanoparticles were thoroughly determined. Nanoastaxanthin (NA) exhibited excellent dispersibility and stability in aqueous solutions, thereby remarkably improving its absorption into the C6 glial cell line. Furthermore, nanoastaxanthin protected C6 cells against Aβ25‐35‐induced neurotoxicity by inhibiting the activity of acetylcholinesterase and the expression of genes (iNOS, COX, TNF‐α, and IL‐6) involved in the inflammatory pathway. In general, these results suggest that nanoparticles of astaxanthin in this work may be appropriate ingredients for functional foods.