(PTFS08-01-26) Prebiotic Chitosan Nanoparticles Enhance Tart Cherry Anthocyanin Delivery and Attenuate Diet-Induced Obesity in Mice

Objectives: Tart cherry juice (TCJ) is rich in anthocyanins (ACNs), bioactive compounds with anti-inflammatory and gut health-promoting properties. To address their low bioavailability, we developed prebiotic chitosan-based nanoparticles (Tnano) to adsorb ACNs from TCJ and previously validated their anti-adipogenic effects in vitro. Here, we further developed alginate hydrogel shell to protect Tnano structure from the acidic gastric environment (Alg-Tnano). After confirming the sustained-release properties of Alg-Tnano, we hypothesized that Alg-Tnano would exhibit improved anti-obesity effects compared with TCJ in a mouse model.

Methods: Six-week-old male and female C57BL/6J mice (n=5) were fed a low-fat diet (LFD, 10% kcal from fat), high-fat diet (HFD, 46% kcal from fat), or HFD supplemented with alginate-encapsulated void nanoparticles (Alg-Vnano), TCJ, or Alg-Tnano (23.4 mg ACNs/kg diet, equivalent to TCJ) for 12 weeks. Body weight and food intake were recorded weekly. Body composition, glucose tolerance tests (GTT), and metabolic phenotyping were assessed before study termination. After euthanasia, colon length and weight were measured.

Results: In females, compared with LFD-fed mice, mice receiving HFD and Alg-Vnano showed about 12% higher body weight, whereas TCJ and Alg-Tnano reduced body weight by 9.5% and 13.3% (p=0.02), respectively. Compared with TCJ, Alg-Tnano further reduced body weight and fat mass by 4.7% (p=0.07) and 10%, suggesting enhanced anti-obesity efficacy; with no differences observed in male mice. Additionally, both TCJ and Alg-Tnano improved glucose clearance in females, as evidenced by reductions in GTT AUC of 11% and 17.8% (p=0.048), respectively. Alg-Tnano sex-independently reduced the respiratory exchange ratio, indicating increased lipid oxidation. Lastly, Alg-Vnano and Alg-Tnano groups exhibited increased colon length in both sexes, suggesting intestinal benefits of chitosan as a prebiotic component.

Conclusions: These findings suggest that a nano-delivery system enhances the metabolic benefits of tart cherry ACNs and represent a promising nano-nutrition strategy for improving the efficacy of polyphenol-rich functional foods in obesity management. Further analyses of adipose tissue, colon histology, and gut microbiota are ongoing.

Funding Sources: USDA 2023-67017-39555