진피(陳皮)의 항산화 활성 및 L6 근육세포에서 당대사에 미치는 영향 = Antioxidant Activity of Citrus Peel and Effect on its Glucose Metabolism in L6 Rat Skeletal Muscle Cells

다국어 초록 (Multilingual Abstract)

Objectives : This study aimed to effects antioxidant activity of citrus peel extract (CPE) and effect on its glucose metabolism in L6 rat skeletal muscle cells.
Methods : Antioxidative activities were evaluated by using 10 kinds of natural materials, and total polyphenol and flavonoid contents were examined. The L6 muscle cells toxicity of CPE was examined by MTT assay. Expression of glucose-related genes in L6 muscle cells by CPE treatment was analyzed by real-time PCR and western blotting.
Results : The IC₅₀ values of DPPH and ABTS free radical scavenging activity of CPE were (15.47 ± 0.26 ㎍/㎖ and 12.07 ± 1.23 ㎍/㎖, respectively), effectively clearing DPPH and ABTS. CPE showed total polyphenol and flavonoid contents (20.30 ± 0.38 and 64.20 ± 0.52, respectively). The selected CPE were used in experiments using an effective concentration that is not toxic in L6 muscle cells. We investigated insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3-kinase regulatory (PI3KR), Akt, and glucose transporter 4 (GLUT4). mRNA analysis by realtime PCR showed no significant difference, but CPE-treated cells showed a tendency to increase in concentrationdependent manner. However, analysis of protein expression of Akt and GLUT4 by western blotting showed that CPE treatment significantly increased concentration dependent (p<0.001).
Conclusions : As a result, citrus peel extract with high antioxidant activity regulates glucose metabolism in L6 muscle cells. Therefore, CPE can be a potential treatment for the treatment of diabetes.