This study aimed to investigate the protective effect of enzymatically modified stevia (EMS) on C2C12 cell-based model of dexamethasone (DEX)-induced muscle atrophy to provide baseline data for utilizing EMS in functional health products. C2C12 cells with DEX-induced muscle atrophy were treated with EMS (10, 50, and 100 μg/mL) for 24 h. C2C12 cells were treated with EMS and DEX to test their effects on cell viability and myotube formation (myotube diameter and fusion index), and analyze the expression of muscle strengthening or degrading protein markers. Schisandra chinensis Extract, a common functional ingredient, was used as a positive control. EMS did not show any cytotoxic effect at all treatment concentrations. Moreover, it exerted protective effects on C2C12 cell-based model of DEX-induced muscle atrophy at all concentrations. In addition, the positive effect of EMS on myotube formation was confirmed based on the measurement and comparison of the fusion index and myotube diameter when compared with myotubes treated with DEX alone. EMS treatment reduced the expression of muscle cell degradation-related proteins Fbx32 and MuRF1, and increased the expression of muscle strengthening and synthesis related proteins SIRT1 and p- Akt/Akt. Thus, EMS is a potential ingredient for developing functional health foods and should be further evaluated in preclinical models.

Materials and Methods
    실험재료 및 시약
    C2C12 세포 배양 및 분화
    XTT assay를 이용한 세포 생존율 측정
    Jenner-Giemsa 염색 및 fusion index 측정
    Myotube diameter 측정
    Western blot 분석
    통계처리
Results and Discussion
    DEX 유도 근위축 모델링 확립
    EMS 및 SE의 독성평가
    세포 보호 효과 평가
    Fusion index 측정
    Myotube diameter 측정
    단백질 발현량 측정
Acknowledgement
국문요약
Conflict of interests
ORCID
References

• 오건(강원대학교 식품환경융합학과) | Geon Oh (Agricultural and Life Sciences Research Institute, Kangwon National University)
• 최선일(강원대학교 농업생명과학연구원) | Sun-Il Choi (Agricultural and Life Sciences Research Institute, Kangwon National University)
• 한웅호(강원대학교 식품환경융합학과) | Xionggao Han (Agricultural and Life Sciences Research Institute, Kangwon National University)
• 문효(강원대학교 식품환경융합학과) | Xiao Men (Agricultural and Life Sciences Research Institute, Kangwon National University)
• 이세정(강원대학교 식품환경융합학과) | Se-Jeong Lee (Agricultural and Life Sciences Research Institute, Kangwon National University)
• 임지현(강원대학교 식품환경융합학과) | Ji-Hyun Im (Agricultural and Life Sciences Research Institute, Kangwon National University)
• 이호성((주)산돌식품) | Ho-Seong Lee (Sandol Food Co., Ltd, Hongcheon, Korea)
• 정형동((주)산돌식품) | Hyeong-Dong Jung (Sandol Food Co., Ltd, Hongcheon, Korea)
• 라문진((재)홍천메디칼허브연구소) | Moon Jin La (Hongcheon Institute of Medicinal Herb, Hongcheon, Korea)
• 권민희((재)홍천메디칼허브연구소) | Min Hee Kwon (Hongcheon Institute of Medicinal Herb, Hongcheon, Korea)
• 이옥환(강원대학교 식품환경융합학과, 강원대학교 농업생명과학연구원) | Ok-Hwan Lee (Department of Food Biotechnology and Environmental Science, Kangwon National University, Agricultural and Life Sciences Research Institute, Kangwon National University) Corresponding author