Facilitating effects of berberine on rat pancreatic islets through modulating hepatic nuclear factor 4 alpha expression and glucokinase activity.
World J Gastroenterol
; 14(39): 6004-11, 2008 Oct 21.
Article
em En
| MEDLINE
| ID: mdl-18932278
ABSTRACT
AIM:
To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism.METHODS:
Primary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations (1, 3, 10 and 30 micromol/L) of berberine or 1 micromol/L Glibenclamide (GB) for 24 h. Glucose-stimulated insulin secretion (GSIS) assay was conducted and insulin was determined by radioimmunoassay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha (HNF4alpha) was determined by reverse transcription polymerase chain reaction (RT-PCR). Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4alpha in the islets. Glucokinase (GK) activity was measured by spectrophotometric method.RESULTS:
Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 mumol/L. Both mRNA and protein expressions of HNF4alpha were up-regulated by berberine in a dose-dependent manner, and GK activity was also increased accordingly. However, GB demonstrated no regulatory effects on HNF4alpha expression or GK activity.CONCLUSION:
Berberine can enhance GSIS in rat islets, and probably exerts the insulinotropic effect via a pathway involving HNF4alpha and GK, which is distinct from sulphonylureas (SUs).
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Base de dados:
MEDLINE
Assunto principal:
Berberina
/
Extratos Vegetais
/
Ilhotas Pancreáticas
/
Fator 4 Nuclear de Hepatócito
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Glucoquinase
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
China