Kim EJ, Kim J, Lee MY, Sudhanva MS, Devakumar S, Jeon YJ. Silymarin Inhibits Cytokine-Stimulated Pancreatic Beta Cells by Blocking the ERK1/2 Pathway.
Biomol Ther (Seoul) 2014;
22:282-7. [PMID:
25143805 PMCID:
PMC4131525 DOI:
10.4062/biomolther.2014.072]
[Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 06/19/2014] [Accepted: 06/24/2014] [Indexed: 12/11/2022] Open
Abstract
We show that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibits cytokine mixture (CM: TNF-α, IFN-γ, and IL-1β)-induced production of nitric oxide (NO) in the pancreatic beta cell line MIN6N8a. Immunostaining and Western blot analysis showed that silymarin inhibits iNOS gene expression. RT-PCR showed that silymarin inhibits iNOS gene expression in a dose-dependent manner. We also showed that silymarin inhibits extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) phosphorylation. A MEK1 inhibitor abrogated CM-induced nitrite production, similar to silymarin. Treatment of MIN6N8a cells with silymarin also inhibited CM-stimulated activation of NF-κB, which is important for iNOS transcription. Collectively, we demonstrate that silymarin inhibits NO production in pancreatic beta cells, and silymarin may represent a useful anti-diabetic agent.
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