In Vivo Antioxidant Effects of Proanthocyanidin Microencapsulated Yogurt Tablets in D-galactose-induced Aging Mice

To develop proanthocyanidin microencapsulated yogurt tablets with antioxidant properties, providing a new avenue for the development of proanthocyanidin-based products. Methods: The optimal formulation of the proanthocyanidin microencapsulated yogurt tablets was determined through single-factor experiments and response surface optimization. The nutritional composition and shelf life of the yogurt tablets were assessed. The short-term memory of mice was evaluated using the step-down test and the dark avoidance test. A D-galactose (D-gal)-induced aging mouse model was established, with groups including the control group, model group, positive control group, high, medium, and low Maillard reaction dose groups, the non-Maillard reaction group, the proanthocyanidin group, and the non-proanthocyanidin group, each consisting of 10 mice. After 42 days of intervention, the activities of glutathione peroxidase (GSH-Px) and total superoxide dismutase (T-SOD), as well as the malondialdehyde (MDA) content in the serum, liver, and brain tissues of the mice were measured. Additionally, cell morphology of liver and brain tissues was observed, and the effects of proanthocyanidin microencapsulated yogurt tablets on the D-gal-induced aging mouse model were comprehensively analyzed. Results: The optimal formulation of the proanthocyanidin microencapsulated yogurt tablets was found to be as follows: 70.5% fermented milk powder, 20.0% proanthocyanidin microcapsules, 5.1% maltodextrin, 3.8% milk powder, and 0.6% silica. The high-dose Maillard reaction group (MH: 202.5 mg/10 g) of proanthocyanidin microencapsulated yogurt tablets (ME-MRPs-PC) significantly prolonged the latency period of aging mice and reduced error frequency (P<0.05, P<0.01). In terms of physiological indices, the MH group extremely significantly increased serum GSH-Px (P<0.01) and SOD activity (P<0.01), while decreasing MDA levels (P<0.05, P<0.01). In the liver tissue of MH group mice, some cells exhibited apoptosis, vacuolation, and were infiltrated by inflammatory cells, while most cells were tightly and orderly arranged. In brain tissue, some neurons showed vacuolation and nuclear pyknosis and hyperchromasia, while the majority of cells were closely and orderly arranged. Conclusion: Proanthocyanidin microencapsulated yogurt tablets have potential anti-aging effects, likely through improving oxidative stress and maintaining physiological functions to delay the aging process.