1. Polysaccharides from Portulaca oleracea L. regulated insulin secretion in INS-1 cells through voltage-gated Na + channel.
- Author
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Hu Q, Niu Q, Song H, Wei S, Wang S, Yao L, and Li YP
- Subjects
- Animals, Cell Line, Cell Survival drug effects, Cell Survival physiology, Dose-Response Relationship, Drug, Insulin-Secreting Cells drug effects, Membrane Potential, Mitochondrial drug effects, Membrane Potential, Mitochondrial physiology, Plant Extracts isolation & purification, Polysaccharides isolation & purification, Sodium Channel Blockers isolation & purification, Sodium Channel Blockers pharmacology, Insulin metabolism, Insulin-Secreting Cells metabolism, Plant Extracts pharmacology, Polysaccharides pharmacology, Portulaca, Voltage-Gated Sodium Channels physiology
- Abstract
The present study was undertaken to determine the involvement of voltage-gated Na
+ channel (VGSC) and other mechanism related to insulin secretion in polysaccharides from Portulaca oleracea L. (POP)-induced secretion of insulin from insulin-secreting β-cell line cells (INS-1) cells. Our results showed that the concentration of insulin both in culture medium and inside INS-1 cells were increased under the existing of different concentration of glucose by POP or TTX, respectively. However, the effect POP on insulin secretion and production were blocked by TTX, a VGSC blocker. Meanwhile, POP improved the mitochondrial membrane potential (Δψm), increased adenosine triphosphate (ATP) production, depolarized cell membrane potential (MP) and increased intracellular Ca2+ levels ([Ca2+ ]i ). Furthermore, POP treatment increased the expression level of Nav1.3 and decreased the expression level of Nav1.7. TTX treatment decreased the expression level of Nav1.3 and Nav1.7 . On the other hand, POP also elevated the survival of INS-1 cells. These results suggested that POP induced-secretion/production of insulin in INS-1 cells were mediated by VGSC through its change of function and subunits expression and subsequent VGSC- dependent events such as change of intracellular Ca2+ releasing, ATP metabolism, cell membrane and mitochondrial membrane potential, and also improvement of INS-1 cell survival. Meanwhile, our data indicated the potentiality of developing POP to be a drug for diabetes treatment and VGSC as a therapeutic target in diabetes treatment is valuable to be investigated further., (Copyright © 2018. Published by Elsevier Masson SAS.)- Published
- 2019
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