Protective Effect of Edible Insects against H₂O₂-induced Oxidative Damages in Skeletal Muscle Cells

다국어 초록 (Multilingual Abstract)

Oxidative stress caused by the excessive production of reactive oxygen species (ROS) is an important initiating factor in various chronic diseases. ROS are generated by muscle contraction and physical exercise in skeletals. Continuous high-intensity exercises generate high levels of ROS, which promote a skeletal muscle contractile dysfunction resulting in muscle damages and/or muscle fatigues. Edible insects contatin abundant protein of a high biological value with good amino acid profiles and high levels of digestibility. Furthermore, edible insects are a potential source of a variety of micronutrients such as minerals and vitamins. Edible insects are known to exhibit antioxidant, hepatoprotective, and antidiabetic activities. However, few investigations have reported the protective effect of edible insects on H₂O₂-induced oxidative stress in skeletal muscle cells. The aim of this study was to investigate the protective effect of edible insects on H₂O₂ induced oxidative stress in C2C12 muscle cells.
The contents of total polyphenolics and flavonoids in edible insects were significantly higher in Oxya chinensis sinuosa. Edible insects showed significant protective effect on H₂O₂-induced cell damages in C2C12 cells. Furthermore, H₂O₂-induced ROS generation was markedly attenuated by pretreatment of edible insects, demonstrating that edible insects are to be a potent ROS scavenger. Edible insects significantly decreased lactate dehydrogenase and creatine kinase activity in media. Moreover, edible insects increased the protein and mRNA levels of MyHC, a marker of myscle differentiation, and increased the size of the diameter of myotubes, thereby affecting the the increase of muscle hypertrophy. These results indicate that edible insects protect skeletal muscle cells from H₂O₂-induced oxidative damages and therefore have the potential for use in health functional foods.

목차 (Table of Contents)

• I. Introduction 1
• 1. Edible insects 1
• 2. Skeletal muscle 3
• 3. Oxidative stress 5
• 4. Objective 6
• Ⅱ. Meterials and methods 7
• 2.1. Chemicals 7
• 2.2. Preparation of edible insect extracts 8
• 2.3. Determination of antioxidant activities 10
• 2.4. Determination of total polyphenolic and flavonoid contents 11
• 2.5. Cell culture 12
• 2.6. Cell viability 12
• 2.7. Measurement of intracellular reactive oxygen species (ROS) 13
• 2.8. Determination of glutathione (GSH) and lipid peroxidation 14
• 2.9. Determination of lactate dehydrogenase and creatine kinase activity 15
• 2.10. Western blot assay 15
• 2.11. Total RNA isolation and quantitative real-time PCR 16
• 2.12. Measurement of muscle hypertrophy 17
• 2.13. Statistical analysis 17
• Ⅲ. Results and Discussion 18
• 3.1. Determination of antioxidant activities in edible insects 18
• 3.2. Determination of antioxidant compounds in edible insects 20
• 3.3. Effect of edible insects viability and protective effect against H2O2-induced cell damages in C2C12 myoblasts 22
• 3.4. Effect of edible insects on ROS production in myoblasts 24
• 3.5. Effect of edible insects on GSH depletion in myoblasts 2
• 3.6. Effect of edible insects on lipid peroxidation in myoblasts 28
• 3.7. Effect of edible insects viability and protective effect against H2O2-induced cell damages in C2C12 myotubes 30
• 3.8. Effect of edible insects on ROS production in myotubes 32
• 3.9. Effect of edible insects on lactate dehydrogenase and creatine kinase activity 34
• 3.10. Effect of edible insects on MyHC mRNA and protein expression 36
• 3.11. Effect of edible insects on muscle hypertrophy 38
• Ⅳ. Conclusions 40
• Ⅴ. References 41
• SUMMARY IN KOREAN 48