1. Extract of white sweet potato tuber against TNF-α-induced insulin resistance by activating the PI3K/Akt pathway in C2C12 myotubes
- Author
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Chiao Ming Chen, Yu Chih Chang, Viola Varga, Shu Chi Mu, Sing Chung Li, and Lie-Fen Shyur
- Subjects
0301 basic medicine ,Glucose uptake ,030209 endocrinology & metabolism ,Plant Science ,Biology ,C2C12 myotube ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Insulin resistance ,Downregulation and upregulation ,medicine ,Phosphatidylinositol ,Protein kinase B ,PI3K/AKT/mTOR pathway ,White sweet potato ,Glucose transporter ,Botany ,medicine.disease ,Molecular biology ,030104 developmental biology ,chemistry ,2-NBDG ,PI3K/Akt pathway ,QK1-989 ,biology.protein ,Original Article ,GLUT4 - Abstract
Background White sweet potato (WSP; Ipomoea batatas L. Simon No. 1) has many potential beneficial effects on metabolic control and diabetes-related insulin resistance. The improvement of insulin resistance by WSP tuber extracts on glucose uptake were not investigated in C2C12 myoblast cells. Results WSP tuberous ethanol extract (WSP-E) was partitioned with ethyl-acetate and water to obtain ethyl-acetate layer (WSP-EA) and water layer (WSP-EW). The WSP-EA shows the highest total phenolic contents and highest antioxidant activity by Folin-Ciocalteu and (2,2-diphenyl-1-picryl-hydrazyl-hydrate, DPPH) assay, respectively. After low concentration horse serum on differentiation inducement of C2C12 myoblasts into mature myotubes, the cells were treated with TNF-α to induce insulin resistance. WSP-EA and WSP-EW extracts increased the uptake of fluorescence glucose analogue (2-[N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino]-2-deoxy-d-glucose, 2-NBDG) in a dose-dependent manner as examined by flow cytometry. The WSP-EA enhanced glucose uptake by activation of phosphorylation of IR (pIR), IRS-1 (pIRS-1) and Akt (pAkt) involved in PI3K (phosphatidylinositol 3-kinase)/protein kinase B (Akt) pathway, also upregulated glucose transporter 4 (GLUT4) expression in myotubes. Conclusions WSP-EA enhanced the glucose uptake in C2C12 myotubes through upregulating the PI3K/Akt pathway. The in vitro data reveal that WSP tuber extracts has potential applications to improve insulin resistance in diabetes.
- Published
- 2021