Modulatory Effect of the Alfalfa Polysaccharide Fraction II on Cyclophosphamide-Induced Immunosuppression in Mice.
TL;DR
Alfalfa polysaccharide fraction II (APS-II) exerts a protective effect on mice with CTX-induced immunosuppression, laying the scientific foundation for its development as an immunomodulatory ingredient in functional foods and dietary supplements.
Abstract
This study investigated the protective effects of alfalfa polysaccharide fraction II (APS-II) on immunosuppression induced by cyclophosphamide (CTX) in mice. APS-II was extracted using ultrasound-assisted enzymatic extraction method and purified by DEAE-52 cellulose chromatography. Its structural characteristics, including molecular weight (Mw), monosaccharide composition, and thermal stability, were analyzed. A CTX-induced immunosuppressed mouse model was established to evaluate the effects of APS-II on immune organ indices, serum cytokines, antioxidant indicators in liver and spleen tissues, and intestinal microbiota. Results showed that APS-II, with main Mw of 28.05 kDa, consisted of glucose, galactose, mannose, arabinose, glucuronic acid, and rhamnose in the molar ratio of 8.04:1.22:1.18:0.92:1:0.06. Treatment with medium and high doses of APS-II significantly restored thymus and spleen indices (p < 0.05), increased serum cytokine levels of interleukin-2 (IL-2), interleukin-1 beta (IL-1β), and interferon-gamma (IFN-γ) (p < 0.05), and ameliorated spleen and thymus histopathology. Antioxidant parameters of total antioxidant capacity (T-AOC), catalase (CAT), and glutathione (GSH) were elevated, and malondialdehyde (MDA) was reduced, reaching significance at the high dose (p < 0.05). Additionally, APS-II reshaped the gut microbiota by increasing Bacteroidota abundance and reducing the Firmicutes/Bacteroidota ratio (p < 0.05), enriching Muribaculaceae and Lactobacillus (p < 0.01), while decreasing potentially pathogenic Rikenellaceae. In conclusion, APS-II provides significant protection against CTX-induced immunosuppression and holds promise as a functional food ingredient for immune health. PRACTICAL APPLICATIONS: Alfalfa polysaccharide fraction II (APS-II) exerts a protective effect on mice with CTX-induced immunosuppression, laying the scientific foundation for its development as an immunomodulatory ingredient in functional foods and dietary supplements.