The Astaxanthin Aggregation Pattern Greatly Influences Its Antioxidant Activity: A Comparative Study in Caco-2 Cells

Area of Science:

• Biomaterials Science
• Nanotechnology
• Antioxidant Research

Background:

• Astaxanthin, a potent antioxidant, can form unstable aggregates.
• Understanding astaxanthin aggregate properties is crucial for its application.
• Molecular aggregation significantly alters astaxanthin's biological and chemical characteristics.

Purpose of the Study:

• To fabricate and characterize water-dispersible astaxanthin H- and J-aggregates using a DNA/chitosan nanocomplex.
• To compare the antioxidant efficacy of H- and J-aggregates in biological and in vitro systems.
• To investigate the cytoprotective effects of astaxanthin aggregates against oxidative stress.

Main Methods:

• Fabrication of astaxanthin H- and J-aggregates stabilized by DNA/chitosan nanocomplex (H-ADC and J-ADC).
• Characterization using UV-Vis spectrophotometry, FTIR, and Raman spectroscopy.
• Evaluation of antioxidant activity via DPPH and hydroxyl radical scavenging assays and assessment of cytoprotective effects on H2O2-treated Caco-2 cells.

Main Results:

• H-ADC and J-ADC were successfully synthesized, with H-ADC exhibiting smaller particle size.
• Astaxanthin H-aggregates demonstrated significantly higher antioxidant activity and free radical scavenging efficiency compared to J-aggregates and monomers.
• H-aggregates provided a superior cytoprotective effect by enhancing intracellular reactive oxygen species scavenging.

Conclusions:

• Astaxanthin H-aggregates possess enhanced antioxidant properties and cytoprotective capabilities.
• DNA/chitosan nanocomplexes are effective in stabilizing water-dispersible astaxanthin aggregates.
• Precise design of carotenoid aggregates, like H-aggregates, can lead to more efficient utilization of their antioxidant potential.