Mediation of β-endorphin by ginsenoside Rh2 to lower plasma glucose in streptozotocin-induced diabetic rats
Journal
Planta Medica
Journal Volume
72
Journal Issue
1
Pages
9-13
Date Issued
2006
Author(s)
Abstract
We investigated the plasma glucose-lowering mechanism(s) of Rh2, a ginsenoside derived from Panax ginseng, in rats with streptozotocin-induced diabetes (STZ-diabetic rats). After intravenous injection over 120 min into fasting STZ-diabetic rats, Rh2 decreased plasma glucose in a dose-dependent manner. In parallel to the lowering of plasma glucose, an increase of plasma β-endorphin-like immunoreactivity was observed. In addition, naloxone and naloxonazine at doses sufficient to block opioid μ-receptors inhibited the plasma glucose-lowering action of Rh2 in genetically wild-type, diabetic mice. In contrast, Rh2 failed to lower plasma glucose in opioid μ-receptor knockout diabetic mice. An increase in gene expression at both the mRNA and protein levels of glucose transporter subtype 4 (GLUT 4) was observed in soleus muscle obtained from STZ-diabetic rats treated with Rh2 three times daily for one day; this increase in expression was absent when opioid μ-receptors were blocked. In conclusion, our results suggest that ginsenoside Rh2 may lower plasma glucose in STZ-diabetic rats based on an increase in β-endorphin secretion that activates opioid μ-receptors thereby resulting in an increased expression of GLUT 4. ? Georg Thieme Verlag KG Stuttgart.
SDGs
Other Subjects
beta endorphin; ginsenoside; ginsenoside Rh 2; glucose; glucose transporter 4; messenger RNA; mu opiate receptor; naloxonazine; naloxone; unclassified drug; animal experiment; animal model; animal tissue; article; controlled study; diabetes mellitus; dose response; drug mechanism; gene expression; ginseng; glucose blood level; immunoreactivity; knockout mouse; male; nonhuman; rat; receptor upregulation; soleus muscle; streptozocin diabetes; wild type; Animals; beta-Endorphin; Blood Glucose; Diabetes Mellitus, Experimental; Ginsenosides; Glucose Transporter Type 4; Male; Mice; Panax; Phytotherapy; Rats; Rats, Wistar; Receptors, Opioid, mu; Streptozocin; Animalia; Panax ginseng
Type
journal article