Effect of pycnogenol^® on glucose transport in mature 3T3‐L1 Adipocytes

Abstract

Pycnogenol, a procyanidins-enriched extract of Pinus maritima bark, possesses antidiabetic properties, which improves the altered parameters of glucose metabolism that are associated with type 2 diabetes mellitus (T2DM). Since the insulin-stimulated antidiabetic activities of natural bioactive compounds are mediated by GLUT4 via the phosphatidylinositol-3-kinase (PI3K) and/or p38 mitogen activated protein kinase (p38-MAPK) pathway, the effects of pycnogenol were examined on the molecular mechanism of glucose uptake by the glucose transport system. 3T3-L1 adipocytes were treated with various concentrations of pycnogenol, and glucose uptake was examined using a non-radioisotope enzymatic assay and by molecular events associated with the glucose transport system using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The results show that pycnogenol increased glucose uptake in fully differentiated 3T3-L1 adipocytes and increased the relative abundance of both GLUT4 and Akt mRNAs through the PI3K pathway in a dose dependent manner. Furthermore, pycnogenol restored the PI3K antagonist-induced inhibition of glucose uptake in the presence of wartmannin, an inhibitor of the PI3K. Overall, these results indicate that pycnogenol may stimulate glucose uptake via the PI3K dependent tyrosine kinase pathways involving Akt. Further the results suggest that pycnogenol might be useful in maintaining blood glucose control.

Modulating Effects of Pycnogenol® on Oxidative Stress and DNA Damage Induced by Sepsis in Rats

“…The studies indicate that Pyc components are highly bioavailable. Pyc is a procyanidin‐enriched extract of Pinus pinaster bark, and it consists of a variety of flavonoids, which are known as potent antioxidants (Lee et al ., ). Uniquely, Pyc displays greater biologic effects as a mixture than its purified components do individually, indicating that the components interact synergistically (Masquelier et al ., ; Packer et al ., ).…”

Rutin potentiates insulin receptor kinase to enhance insulin-dependent glucose transporter 4 translocation

“…Recent reports have indicated that gallic acid can increase GLUT4 translocation via the Akt-insulin-independent pathway, up-regulation of PPAR-␥ expression [24,26], and decreasing the oxidative stress-related diabetic complications [33]. Most previous studies on the normoglycemic effects of other natural compounds are primarily focused on the antioxidant effect [33], GLUT4 translocation [36,37], glucose uptake [24,38], Akt [37][38][39], and AMPK [40,41] regulation to enhance insulin sensitivity. Rutin, a well-known flavonoid in many food plants, enhances Akt phosphorylation and improves insulin resistance [14,15].…”

The Ameliorative Effects of Pycnogenol^® on Liver Ischemia-Reperfusion Injury in Rats

“…It is a procyanidin-enriched extract of Pinus pinaster bark consisting of a variety of flavonoids, which are known as potent antioxidants. 38 PYC ® shows various beneficial health effects against different types of diseases. 17 PYC ® has been extensively used in Europe as a dietary food supplement.…”