RedLiriope platyphyllastimulated the insulin secretion through the regulation of calcium concentration in rat insulinoma cells and animal models

Abstract

The aim of this study was to investigate the effects of Red L. platyphylla (RLP) on calcium and glucose levels during insulin secretion. To achieve this, alteration of insulin and calcium concentrations was measured in rat insulinoma-1 (INS-1) cells and animal models in response to RLP treatment. In INS-1 cells, maximum secretion of insulin was detected upon treatment with 200 µg/mL of RLP for 20 min. Nifedipine, an L-type calcium channel blocker, effectively inhibited insulin secretion from INS-1 cells. Regarding calcium levels, the maximum concentration of intracellular calcium in INS-1 cells was obtained by treatment with 100 µg/mL of RLP, whereas this level was reduced under conditions of 200 µg/mL of RLP. Further, RLP-treated INS-1 cells showed a higher level of intracellular calcium than that of L. platyphylla (LP), Korea White Ginseng (KWG), or Korea Red Ginseng (KRG)-treated cells. This RLP-induced increase in intracellular calcium was abrogated but not completely abolished upon treatment with 40 µM nifedipine in a dose-dependent manner. Furthermore, the insulin level was dramatically elevated upon co-treatment with high concentrations of glucose and RLP, whereas it was maintained at a low level in response to glucose and RLP co-treatment at low concentrations. In an animal experiment, the serum concentration of calcium increased or decreased upon RLP treatment according to glucose level compared to vehicle treatment. Therefore, these results suggest that insulin secretion induced by RLP treatment may be tightly correlated with calcium regulation, which suggests RLP is an excellent candidate for diabetes treatment.

Ginsenoside Rg3 prevents INS-1 cell death from intermittent high glucose stress

“…Rg3 could enhance insulin secretion through the activation of ATP sensitive KC channels and AMPK signaling pathways and stimulated elevation of intracellular calcium concentrations. 8,21 There are some studies about the anti-apoptotic effects of ginseng on pancreatic b cells. They attenuated pancreatic b cell death against free fatty acids, cytokines, palmitate and sustained high glucose.…”

Beneficial effects of ethanol extracts of RedLiriope platyphyllaon vascular dysfunction in the aorta of spontaneously hypertensive rats

“…Several previous approaches have shown the novel functions of RLP on improvement of human disease after its preparation using a steaming process [ 11 ]. Aqueous extract of RLP (AEtRLP) treatment induced down-regulation of glucose, stimulation of insulin secretion, activation of the insulin receptor signaling pathway and Glucose transporter 2 (GLUT2) and 3 expression in INS cells and streptozotocin-induced diabetic mice [ 11 , 12 ]. Moreover, OLETF rats treated with AEtRLP showed dramatic alterations in insulin secretion and fatty acid metabolism.…”

Precautionary effects of RedLiriope platyphyllaon NGF secretion and Aβ42 deposition under the preclinical stage of Alzheimer's disease in Tg2576 mice

“…Furthermore, study about the effects of AEtRLP9 in type II diabetic model, OLETF rats, showed a significant increase of insulin secretion and adiponectin concentration, a decrease of fatty liver formation and recovery of β-oxidation genes in fat tissue [ 3 ]. Moreover, the intracellular calcium concentration was also higher in AEtRLP9 treated INS-1 cells than in an LP-treated group, although this elevation was abrogated in response to administration of 40 mM nifedipine in a dosedependent manner [ 4 ].…”