Effects of mogrosides and Astragalus polysacharin combination on antioxidant capacity of mouse skeletal muscle

【Objective】To explore the effect of mogrosides combined with Astragalus polysacharin on improving the antioxidant capacity of skeletal muscle in mice，and to reveal its synergistic mechanism，so as to provide theoretical basis for the development of mogrosides and Astragalus polysacharin as green and safe new feed additives for improving the antioxidant capacity of skeletal muscle and meat quality in livestock and poultry.【Method】Forty SPF KM mice were randomly divided into four groups：the control（CK）group，the mogrosides（MOG）group，the Astragalus polysacharin （APS）group，and the mogrosides + Astragalus polysacharin combination（MOG+APS）group，with 10 mice in each group. The drug was administered by oral gavage，the mice in the MOG group were given 200 mg/kg mogrosides daily， the mice in the APS group were given 200 mg/kg Astragalus polysacharin daily，the mice in the MOG+APS group were given 200 mg/kg mogrosides + 200 mg/kg Astragalus polysacharin daily，and the mice in the CK group were given 0.1 ml of normal saline daily for 4 weeks. After the administration，the organs of mice were collected to calculate the organ index，the antioxidant enzyme activities in serum and skeletal muscle were determined，and the expression changes of antioxidant-related genes and Keap1/Nrf2 signaling pathway-related genes in skeletal muscle of mice were detected by real-time fluorescence quantitative PCR.【Result】Compared with CK group，the average daily feed intake，average daily gain and organ index of MOG group，APS group and MOG+APS group had no significant changes（P>0.05）. The content of malondialdehyde（MDA）in serum and gastrocnemius muscle of mice in MOG group，APS group and MOG+APS group was significantly decreased compared to that in CK group（P<0.05，the same below），while the activities of glutathione peroxidase（GSH-Px）and superoxide dismutase（SOD）were significantly increased. The content of MDA in serum and gastrocnemius muscle of mice in MOG+APS group was significantly decreased compared to that in MOG group and APS group，while the activities of GSH-Px and SOD were significantly increased. Compared with the MOG group and APS group，the relative expression of GSH-Px and SOD genes in the gastrocnemius muscle of MOG+APS group showed significant upward trend，the relative expression of NF-E2-related factor 2 gene（Nrf2）was significantly increased by 19.02% and 20.10% respectively，while the relative expression of Kelch-like epichlorohydrin-related protein 1 gene （Keap1）was significantly decreased by 29.92% and 24.20% respectively.【Conclusion】Mogrosides and Astragalus polysacharin combination can activate Keap1/Nrf2 signaling pathway，up-regulate SOD and GSH-Px genes expression，increase antioxidant enzyme activity，and enhance the antioxidant capacity of skeletal muscle in mice. It is indicated that mogrosides and Astragalus polysacharin can be used as green and safe new feed additives to improve the antioxidant capacity of skeletal muscle and meat quality of livestock and poultry.