Insulin sensitizing and insulinotropic action of berberine from Cortidis rhizoma.
Our preliminary study demonstrated that 70% ethanol Cortidis Rhizoma extracts (CR) had a hypoglycemic action in diabetic animal models. We determined whether CR fractions acted as anti-diabetic agent, and a subsequent investigation of the action mechanism of the major compound, berberine ([C(20)H(18)NO(4)](+)), was carried out in vitro. The 20, 40 and 60% methanol fractions from the XAD-4 column contained the most insulin sensitizing activities in 3T3-L1 adipocytes. The common major peak in these fractions was berberine. Treatment with 50 microM berberine plus differentiation inducers significantly reduced triglyceride accumulation by decreased differentiation of 3T3-L1 fibroblasts to adipocytes and triglyceride synthesis. Significant insulin sensitizing activity was observed in 3T3-L1 adipocytes which were given 50 microM berberine plus 0.2 nM insulin to reach a glucose uptake level increased by 10 nM of insulin alone. This was associated with increased glucose transporter-4 translocation into the plasma membrane via enhancing insulin signaling pathways and the insulin receptor substrate-1-phosphoinositide 3 Kinase-Akt. Berberine also increased glucose-stimulated insulin secretion and proliferation in Min6 cells via an enhanced insulin/insulin-like growth factor-1 signaling cascade. Data suggested that berberine can act as an effective insulin sensitizing and insulinotropic agent. Therefore, berberine can be used as anti-diabetic agent for obese diabetic patients.
Ko
Byoung-Seob
BS
Department of Quality Inspection and Examination, Korea Institute of Oriental Medicine, Daejun 305-390, Korea.
Choi
Soo Bong
SB
Park
Seong Kyu
SK
Jang
Jin Sun
JS
Kim
Yeong Eun
YE
Park
Sunmin
S
D041721:3T3-L1 Cells; D000818:Animals; D001599:Berberine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D047468:Immunoprecipitation; D007328:Insulin / Q000494:pharmacology / Q000502:physiology*; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry*; D015398:Signal Transduction; D014280:Triglycerides / Q000097:blood
D007328:Insulin; D010936:Plant Extracts; D014280:Triglycerides; D001599:Berberine