The ethyl acetate fraction of corn silk exhibits dual antioxidant and anti-glycation activities and protects insulin-secreting cells from glucotoxicity. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Chang, Chia-Chuan; Yuan, Wei; Roan, Hsiao-Yuh; Chang, Jia-Ling; Huang, Hsiu-Chen; Lee, Yu-Ching; Tsay, Huey; Liu, Hui-Kang
• Is Part Of: BMC complementary and alternative medicine. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 11
• Publication Date: 2016-12
• Subjects: Stigmata Maydis (corn silk) -- Glucotoxicity -- Methylglyoxal -- Advanced glycation end products -- Reactive oxygen species -- β-cell failure; Alternative medicine -- Periodicals; Complementary Therapies -- Periodicals; 615.505
• DOI: 10.1186/s12906-016-1382-8
• Languages: English
• ISSNs: 1472-6882

Abstract

Abstract Background In this study, we aimed to develop a Stigmata Maydis (corn silk) fraction with dual bio-activities against oxidative stress and protein glycation to protect β-cells from diabetes-induced failure. Methods Corn silk fractions were prepared by partition and chemically characterised by thin-layer chromatography. Free radical scavenging assay, glycation assay, and cell-based viability test (neutral red) were employed to decide the best fraction. Cell death analysis was executed by annexin V/ Propidium iodide staining. Cell proliferation was measured by WST-1. Finally, β-cell function was evaluated by β-cell marker gene expression (RT-PCR) and acute insulin secretion test. Results Four corn silk fractions were prepared from an ethanolic crude extract of corn silk. In vitro assays indicate ethyl acetate fraction (YMS-EA) was the most potent fraction. YMS-EA also attenuated the hydrogen peroxide- or methylglyoxal-induced induction of reactive oxygen species, reduction of cell viability, and inhibition of cell proliferation. However, YMS-EA was unable to prevent hydrogen peroxide-induced apoptosis or advanced glycation end-products-induced toxicity. Under hyperglycemic conditions, YMS-EA effectively reduced ROS levels, improved mRNA expression of insulin, glucokinase, and PDX-1, and enhanced glucose-stimulated insulin secretion. The similarity of bioactivities among apigenin, luteolin, and YMS-EA indicated that dual activities of YMS-EA might be derived from those compounds. Conclusions We concluded that YMS-EA fraction could be developed as a preventive food agent against the glucotoxicity to β-cells in Type 2 diabetes.