Yu-Ting Tseng1, Wan-Hsuan Chang1, Chih-Cheng Lin1, Fang-Rong Chang2, Pao-Chu Wu3, Yi-Ching Lo4. 1. Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan. 2. Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan. 3. School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung, Taiwan. 4. Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan; Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 80708, Taiwan. Electronic address: yichlo@kmu.edu.tw.
Abstract
BACKGROUND: Liuwei dihuang (LWDH), a widely used traditional Chinese herbal medicine, has been noticed for its potential on the improvement of diabetic complications including diabetic nephropathy and diabetic encephalopathy. However, whether LWDH can improve the effects of diabetic skeletal muscle atrophy has not yet been reported. PURPOSE: The present study aimed to investigate the protective effects and mechanisms of the water extract of Liuwei dihuang (LWDH-WE) on skeletal muscle in cellular and animal models of diabetic muscle atrophy. STUDY DESIGN: The muscle protective effects of LWDH-WE on diabetic muscle atrophy and weakness were examined in methylglyoxal (MG)-treated C2C12 myotubes and streptozotocin (STZ)-treated C57BL/6 mice, respectively. METHODS: C2C12 myoblasts were differentiated by differentiation medium to form myotube structures. C2C12 myotubes were pre-treated with LWDH-WE 1 h before MG treatment. Diabetic mice were induced by single intraperitoneal injection of STZ (150 mg/kg) in C57BL/6 mice. Cell viability was determined by MTT and LDH assays. Protein expressions were detected by western blots. Morphological changes of cells were observed by an inverted microscope. Mitochondria membrane potential and reactive oxygen species (ROS) production were measured by flow cytometry. Muscle strength was evaluated by measuring grip strength of mice. RESULTS: In C2C12 myotubes, LWDH-WE attenuated MG-induced cellular death and oxidative damage accompanied with improving mitochondrial membrane potential, inhibiting NADPH oxidase (Nox) activation, and ROS production. Moreover, LWDH-WE could attenuate MG-induced atrophy of C2C12 myotubes accompanied with regulating protein synthesis (IGF-1R, Akt, mTOR) and protein degradation (FoxO3a, atrogin-1, MuRF-1) signals. In STZ-induced diabetic mice, LWDH-WE improved body weight and skeletal muscle mass of mice. LWDH-WE also enhanced muscle strength of STZ-induced diabetic mice. Furthermore, LWDH-WE enhanced the improvement of insulin on gastrocnemius muscle mass and grip strength in STZ-treated mice. CONCLUSION: LWDH-WE possesses skeletal muscle protection via reducing oxidative damage and regulating protein synthesis and degradation pathways in MG-induced atrophy of C2C12 myotubes. We also reveal the novel protection of LWDH-WE against STZ-induced reduction of muscle mass and muscle strength in mice.
BACKGROUND: Liuwei dihuang (LWDH), a widely used traditional Chinese herbal medicine, has been noticed for its potential on the improvement of diabetic complications including diabetic nephropathy and diabetic encephalopathy. However, whether LWDH can improve the effects of diabetic skeletal muscle atrophy has not yet been reported. PURPOSE: The present study aimed to investigate the protective effects and mechanisms of the water extract of Liuwei dihuang (LWDH-WE) on skeletal muscle in cellular and animal models of diabetic muscle atrophy. STUDY DESIGN: The muscle protective effects of LWDH-WE on diabetic muscle atrophy and weakness were examined in methylglyoxal (MG)-treated C2C12 myotubes and streptozotocin (STZ)-treated C57BL/6 mice, respectively. METHODS: C2C12 myoblasts were differentiated by differentiation medium to form myotube structures. C2C12 myotubes were pre-treated with LWDH-WE 1 h before MG treatment. Diabeticmice were induced by single intraperitoneal injection of STZ (150 mg/kg) in C57BL/6 mice. Cell viability was determined by MTT and LDH assays. Protein expressions were detected by western blots. Morphological changes of cells were observed by an inverted microscope. Mitochondria membrane potential and reactive oxygen species (ROS) production were measured by flow cytometry. Muscle strength was evaluated by measuring grip strength of mice. RESULTS: In C2C12 myotubes, LWDH-WE attenuated MG-induced cellular death and oxidative damage accompanied with improving mitochondrial membrane potential, inhibiting NADPH oxidase (Nox) activation, and ROS production. Moreover, LWDH-WE could attenuate MG-induced atrophy of C2C12 myotubes accompanied with regulating protein synthesis (IGF-1R, Akt, mTOR) and protein degradation (FoxO3a, atrogin-1, MuRF-1) signals. In STZ-induced diabeticmice, LWDH-WE improved body weight and skeletal muscle mass of mice. LWDH-WE also enhanced muscle strength of STZ-induced diabeticmice. Furthermore, LWDH-WE enhanced the improvement of insulin on gastrocnemius muscle mass and grip strength in STZ-treated mice. CONCLUSION:LWDH-WE possesses skeletal muscle protection via reducing oxidative damage and regulating protein synthesis and degradation pathways in MG-induced atrophy of C2C12 myotubes. We also reveal the novel protection of LWDH-WE against STZ-induced reduction of muscle mass and muscle strength in mice.
Authors: Zi-Yang Yi; Lin Chen; Yan Wang; Dan He; Di Zhao; Shui-Han Zhang; Rong Yu; Jian-Hua Huang Journal: Acta Diabetol Date: 2022-07-20 Impact factor: 4.087