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Berberine promotes glucose consumption independently of AMP-activated protein kinase activation.

Xu M, Xiao Y, Yin J, Hou W, Yu X, Shen L, Liu F, Wei L, Jia W - PLoS ONE (2014)

Bottom Line: We found that in HepG2 hepatocytes and C2C12 myotubes, berberine significantly increased glucose consumption and lactate release in a dose-dependent manner.To test the effect of berberine on oxygen consumption, extracellular flux analysis was performed in Seahorse XF24 analyzer.These results suggest that berberine and metformin promote glucose metabolism by stimulating glycolysis, which probably results from inhibition of mitochondrial respiratory chain complex I, independent of AMPK activation.

View Article: PubMed Central - PubMed

Affiliation: Shanghai Clinical Center for Diabetes, Shanghai Clinical Center for Metabolic Diseases, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.

ABSTRACT
Berberine is a plant alkaloid with anti-diabetic action. Activation of AMP-activated protein kinase (AMPK) pathway has been proposed as mechanism for berberine's action. This study aimed to examine whether AMPK activation was necessary for berberine's glucose-lowering effect. We found that in HepG2 hepatocytes and C2C12 myotubes, berberine significantly increased glucose consumption and lactate release in a dose-dependent manner. AMPK and acetyl coenzyme A synthetase (ACC) phosphorylation were stimulated by 20 µmol/L berberine. Nevertheless, berberine was still effective on stimulating glucose utilization and lactate production, when the AMPK activation was blocked by (1) inhibition of AMPK activity by Compound C, (2) suppression of AMPKα expression by siRNA, and (3) blockade of AMPK pathway by adenoviruses containing dominant-negative forms of AMPKα1/α2. To test the effect of berberine on oxygen consumption, extracellular flux analysis was performed in Seahorse XF24 analyzer. The activity of respiratory chain complex I was almost fully blocked in C2C12 myotubes by berberine. Metformin, as a positive control, showed similar effects as berberine. These results suggest that berberine and metformin promote glucose metabolism by stimulating glycolysis, which probably results from inhibition of mitochondrial respiratory chain complex I, independent of AMPK activation.

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Effects of berberine on AMPK pathway, glucose consumption and lactate release in the presence of compound C.Cells were preincubated with compound C (10 µmol/L) for 30 min, then treated with 20 µmol/L berberine or 10 mmol/L metformin in serum-free DMEM with 0.25% BSA and 15 mM D-glucose for 24 h. Whole cell lysate protein was used to measure the phosphorylation of AMPK (pAMPK) and ACC (pACC) by Western blot in HepG2 hepatocytes and C2C12 myotubes (A). Effects of berberine and metformin on glucose consumption were checked in HepG2 (B) and C2C12 (C) cells; effects of berberine and metformin on lactate release were checked in HepG2 (D) and C2C12 (E) cells. Increasing rates of lactate release stimulated by berberine and metformin in the presence or absence of compound C in HepG2 (F) and C2C12 (G) cells were calculated. Results are shown as means ± SEM from at least three independent experiments; ***P<0.001 vs. control in corresponding group.
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pone-0103702-g006: Effects of berberine on AMPK pathway, glucose consumption and lactate release in the presence of compound C.Cells were preincubated with compound C (10 µmol/L) for 30 min, then treated with 20 µmol/L berberine or 10 mmol/L metformin in serum-free DMEM with 0.25% BSA and 15 mM D-glucose for 24 h. Whole cell lysate protein was used to measure the phosphorylation of AMPK (pAMPK) and ACC (pACC) by Western blot in HepG2 hepatocytes and C2C12 myotubes (A). Effects of berberine and metformin on glucose consumption were checked in HepG2 (B) and C2C12 (C) cells; effects of berberine and metformin on lactate release were checked in HepG2 (D) and C2C12 (E) cells. Increasing rates of lactate release stimulated by berberine and metformin in the presence or absence of compound C in HepG2 (F) and C2C12 (G) cells were calculated. Results are shown as means ± SEM from at least three independent experiments; ***P<0.001 vs. control in corresponding group.

Mentions: To determine whether berberine-stimulated glucose consumption and lactate release involved activation of AMPK pathway, the effect of compound C, an AMPK inhibitor, on berberine-stimulated glucose consumption and lactate release were measured. HepG2 hepatocytes and C2C12 myotubes were incubated for 30 min with 10 µmol/L compound C, following treatment with berberine or metformin for 24 h. As shown in Fig. 6A, compound C fully blocked berberine or metformin-induced ACC phosphorylation, and decreased phosphorylation level of AMPK, suggesting it had inhibited AMPK activity in HepG2 hepatocytes and C2C12 myotubes. With treatment of compound C, berberine and metformin still increased glucose consumption by 78.6% and 91.3% (P<0.001, P<0.001) in HepG2 cells (Fig. 6B), 71.6% and 60.3% (P<0.001, P<0.001) in C2C12 cells, respectively (Fig. 6C).


Berberine promotes glucose consumption independently of AMP-activated protein kinase activation.

Xu M, Xiao Y, Yin J, Hou W, Yu X, Shen L, Liu F, Wei L, Jia W - PLoS ONE (2014)

Effects of berberine on AMPK pathway, glucose consumption and lactate release in the presence of compound C.Cells were preincubated with compound C (10 µmol/L) for 30 min, then treated with 20 µmol/L berberine or 10 mmol/L metformin in serum-free DMEM with 0.25% BSA and 15 mM D-glucose for 24 h. Whole cell lysate protein was used to measure the phosphorylation of AMPK (pAMPK) and ACC (pACC) by Western blot in HepG2 hepatocytes and C2C12 myotubes (A). Effects of berberine and metformin on glucose consumption were checked in HepG2 (B) and C2C12 (C) cells; effects of berberine and metformin on lactate release were checked in HepG2 (D) and C2C12 (E) cells. Increasing rates of lactate release stimulated by berberine and metformin in the presence or absence of compound C in HepG2 (F) and C2C12 (G) cells were calculated. Results are shown as means ± SEM from at least three independent experiments; ***P<0.001 vs. control in corresponding group.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4114874&req=5

pone-0103702-g006: Effects of berberine on AMPK pathway, glucose consumption and lactate release in the presence of compound C.Cells were preincubated with compound C (10 µmol/L) for 30 min, then treated with 20 µmol/L berberine or 10 mmol/L metformin in serum-free DMEM with 0.25% BSA and 15 mM D-glucose for 24 h. Whole cell lysate protein was used to measure the phosphorylation of AMPK (pAMPK) and ACC (pACC) by Western blot in HepG2 hepatocytes and C2C12 myotubes (A). Effects of berberine and metformin on glucose consumption were checked in HepG2 (B) and C2C12 (C) cells; effects of berberine and metformin on lactate release were checked in HepG2 (D) and C2C12 (E) cells. Increasing rates of lactate release stimulated by berberine and metformin in the presence or absence of compound C in HepG2 (F) and C2C12 (G) cells were calculated. Results are shown as means ± SEM from at least three independent experiments; ***P<0.001 vs. control in corresponding group.
Mentions: To determine whether berberine-stimulated glucose consumption and lactate release involved activation of AMPK pathway, the effect of compound C, an AMPK inhibitor, on berberine-stimulated glucose consumption and lactate release were measured. HepG2 hepatocytes and C2C12 myotubes were incubated for 30 min with 10 µmol/L compound C, following treatment with berberine or metformin for 24 h. As shown in Fig. 6A, compound C fully blocked berberine or metformin-induced ACC phosphorylation, and decreased phosphorylation level of AMPK, suggesting it had inhibited AMPK activity in HepG2 hepatocytes and C2C12 myotubes. With treatment of compound C, berberine and metformin still increased glucose consumption by 78.6% and 91.3% (P<0.001, P<0.001) in HepG2 cells (Fig. 6B), 71.6% and 60.3% (P<0.001, P<0.001) in C2C12 cells, respectively (Fig. 6C).

Bottom Line: We found that in HepG2 hepatocytes and C2C12 myotubes, berberine significantly increased glucose consumption and lactate release in a dose-dependent manner.To test the effect of berberine on oxygen consumption, extracellular flux analysis was performed in Seahorse XF24 analyzer.These results suggest that berberine and metformin promote glucose metabolism by stimulating glycolysis, which probably results from inhibition of mitochondrial respiratory chain complex I, independent of AMPK activation.

View Article: PubMed Central - PubMed

Affiliation: Shanghai Clinical Center for Diabetes, Shanghai Clinical Center for Metabolic Diseases, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.

ABSTRACT
Berberine is a plant alkaloid with anti-diabetic action. Activation of AMP-activated protein kinase (AMPK) pathway has been proposed as mechanism for berberine's action. This study aimed to examine whether AMPK activation was necessary for berberine's glucose-lowering effect. We found that in HepG2 hepatocytes and C2C12 myotubes, berberine significantly increased glucose consumption and lactate release in a dose-dependent manner. AMPK and acetyl coenzyme A synthetase (ACC) phosphorylation were stimulated by 20 µmol/L berberine. Nevertheless, berberine was still effective on stimulating glucose utilization and lactate production, when the AMPK activation was blocked by (1) inhibition of AMPK activity by Compound C, (2) suppression of AMPKα expression by siRNA, and (3) blockade of AMPK pathway by adenoviruses containing dominant-negative forms of AMPKα1/α2. To test the effect of berberine on oxygen consumption, extracellular flux analysis was performed in Seahorse XF24 analyzer. The activity of respiratory chain complex I was almost fully blocked in C2C12 myotubes by berberine. Metformin, as a positive control, showed similar effects as berberine. These results suggest that berberine and metformin promote glucose metabolism by stimulating glycolysis, which probably results from inhibition of mitochondrial respiratory chain complex I, independent of AMPK activation.

Show MeSH
Related in: MedlinePlus