Chlorogenic acid chases glucose into muscle cells

Chlorogenic acid is a prominent component of coffee and supplements that contain Green Coffee Bean extract. The compound might be suitable for use in bodybuilding, slimming and endurance sports supplements, according to a study done at the National University of Singapore. Chlorogenic acid increases muscle cells’ insulin sensitivity and chases glucose into these cells.

Chlorogenic acid [structural formula shown here] is a prominent component of coffee and supplements that contain Green Coffee Bean extract. The compound might be suitable for use in bodybuilding, slimming and endurance sports supplements, according to a study done at the National University of Singapore. Chlorogenic acid increases muscle cells’ insulin sensitivity and chases glucose into these cells.

Chlorogenic acid is found in much of the food we eat. In fact, it’s probably the phenol we consume the most of. One cup of coffee easily contains more than 100 mg of the stuff, so the total daily intake of heavy coffee drinkers amounts to grams. For an overview of other postings by this website on chlorogenic acid click here.

Drinking coffee protects against type-2 diabetes, and nutritionists suspect that this protective effect is partly due to chlorogenic acid.

Pharmacologists at the National University of Singapore wanted to find out more about the effect of chlorogenic acid on the way insulin works, so they did a series of experiments using muscle cells from overweight mice that had type-2 diabetes.

The figure below shows that in the overweight mice in the control group [DC] less glucose found its way to the soleus muscle than in the slim mice [Lean]. Administering chlorogenic acid boosted the glucose uptake, certainly when combined with insulin. Chlorogenic acid only became toxic for the muscle cells when the concentration was higher than 2 millimoles.

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When the researchers sabotaged the AMPK enzyme with AMPK-siRNAs, the effect disappeared. When they didn’t do this, the activity of AMPK increased as the chlorogenic acid concentration increased. The researchers were able to show that chlorogenic acid activated the glucose transporter GLUT4 via AMPK. GLUT4 activation also takes place after physical exertion.

The researchers suspect that chlorogenic acid – whether in the form of regular food, super foods or supplements – is useful for type-2 diabetes sufferers, although “further experiments” are needed, they write, “to support our hypothesis that chlorogenic acid increases peripheral glucose disposal in skeletal muscle and therefore lowering fasting blood glucose”.

We’d take this a step further and envisage a future where chlorogenic acid is used in carbohydrate supplements for endurance athletes, calorie-rich post-workout products with fast sugars for strength athletes, and diet products for people who want to lose weight in an intelligent way.

Chlorogenic acid stimulates glucose transport in skeletal muscle via AMPK activation: a contributor to the beneficial effects of coffee on diabetes.

Ong KW, Hsu A, Tan BK.

Source

Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.

Abstract

Chlorogenic acid (CGA) has been shown to delay intestinal glucose absorption and inhibit gluconeogenesis. Our aim was to investigate the role of CGA in the regulation of glucose transport in skeletal muscle isolated from db/db mice and L6 skeletal muscle cells. Oral glucose tolerance test was performed on db/db mice treated with CGA and soleus muscle was isolated for 2-deoxyglucose transport study. 2DG transport was also examined in L6 myotubes with or without inhibitors such as wortmannin or compound c. AMPK was knocked down with AMPK?1/2 siRNA to study its effect on CGA-stimulated glucose transport. GLUT 4 translocation, phosphorylation of AMPK and Akt, AMPK activity, and association of IRS-1 and PI3K were investigated in the presence of CGA. In db/db mice, a significant decrease in fasting blood sugar was observed 10 minutes after the intraperitoneal administration of 250 mg/kg CGA and the effect persisted for another 30 minutes after the glucose challenge. Besides, CGA stimulated and enhanced both basal and insulin-mediated 2DG transports in soleus muscle. In L6 myotubes, CGA caused a dose- and time-dependent increase in glucose transport. Compound c and AMPK?1/2 siRNA abrogated the CGA-stimulated glucose transport. Consistent with these results, CGA was found to phosphorylate AMPK and ACC, consistent with the result of increased AMPK activities. CGA did not appear to enhance association of IRS-1 with p85. However, we observed activation of Akt by CGA. These parallel activations in turn increased translocation of GLUT 4 to plasma membrane. At 2 mmol/l, CGA did not cause any significant changes in viability or proliferation of L6 myotubes. Our data demonstrated for the first time that CGA stimulates glucose transport in skeletal muscle via the activation of AMPK. It appears that CGA may contribute to the beneficial effects of coffee on Type 2 diabetes mellitus.

PMID: 22412912 [PubMed – indexed for MEDLINE] PMCID: PMC3296733

Source: http://www.ncbi.nlm.nih.gov/pubmed/22412912  
  

 

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