Chondroitin sulfate based nanocomplex for enhancing the stability and activity of anthocyanin

To improve the structural stability of the potent antioxidant anthocyanin (ATC), a nanocomplex was fabricated from intermolecular stacking between chondroitin sulfate (CS) and ATC using a simple complexing method in water, without inputting high energy or an organic solvent. The physicochemical properties of the nanocomplex were evaluated at various feed weight ratios of CS/ATC. The most stable nanocomplex was obtained at a CS/ATC weight ratio of 10/1 (WR10). The ATC loading content and loading efficiency were 6.3 and 99%, respectively. Its diameter was approximately 300 nm with unimodal size distribution. The intermolecular stacking state of WR10 was maintained up to 1 μg/ml of ATC, whereas an intermolecular stacking state formed by ATC alone was easily dissociated below 16 μg/ml of ATC. The structural stability of ATC in WR10 was 8 times higher than that of free ATC at 37 °C. Moreover, the complex effectively protected the ATC degradation by hydroxyl molecules under high pH (above 9) conditions. Finally, cancer cell growth suppression activity was measured to determine the in vitro free radical scavenger ability of ATC. The WR10 strongly suppressed the Hela cell growth compared with ATC alone. Therefore, we conclude that the CS/ATC nanocomplex has a potential for use as a carrier for stable antioxidants or water-soluble drugs via intermolecular stacking. These nanocomplexes would prove useful for applications in the food and pharmaceutical industries.