TY - JOUR
T1 - Effects of a grapeseed procyanidin extract (GSPE) on insulin resistance
AU - Montagut Pino, Gemma
AU - Bladé, Cinta
AU - Blay, Mayte
AU - Fernández-Larrea, Juan
AU - Pujadas, Gerard
AU - Salvadó, M. Josepa
AU - Arola, Lluis
AU - Pinent, Monserrat
AU - Ardévol, Anna
N1 - MEDLINE® is the source for the MeSH terms of this document.
PY - 2010/10
Y1 - 2010/10
N2 - Flavonoids are beneficial compounds against risk factors for metabolic syndrome, but their effects and the mechanisms on glucose homeostasis modulation are not well defined. In the present study, we first checked the efficacy of grapeseed procyanidin extract (GSPE) for stimulating glucose uptake in insulin-resistant 3T3-L1 adipocytes. Results show that when resistance is induced with chronic insulin treatment, GSPE maintain a higher stimulating capacity than insulin. In contrast, when dexamethasone is used as the resistance-inducing agent, GSPE is less effective. Next we evaluated how effective different GSPE treatments are at improving glucose metabolism in hyperinsulinemic animals (fed a cafeteria diet). GSPE reduced plasma insulin levels. The lower dose (25 mg GSPE/kg body weight per day) administered for 30 days improved the HOmeostasis Model Assessment-insulin resistance index. This was accompanied by down-regulation of Pparg2, Glut4 and Irs1 in mesenteric white adipose tissue. Similarly, a chronic GSPE treatment of insulin-resistant 3T3-L1 adipocytes down-regulated the mRNA levels of those adipocyte markers, although cells were still able to respond to the acute stimulation of glucose uptake.In summary, 25 mg/kg body weight per day of GSPE has a positive long-term effect on glucose homeostasis, and GSPE could be targeted at adipose tissue, where it might directly stimulate glucose uptake. This work also highlights the need to carefully consider the bioactive dose, since a higher dose does not necessarily correlate to a greater positive effect.
AB - Flavonoids are beneficial compounds against risk factors for metabolic syndrome, but their effects and the mechanisms on glucose homeostasis modulation are not well defined. In the present study, we first checked the efficacy of grapeseed procyanidin extract (GSPE) for stimulating glucose uptake in insulin-resistant 3T3-L1 adipocytes. Results show that when resistance is induced with chronic insulin treatment, GSPE maintain a higher stimulating capacity than insulin. In contrast, when dexamethasone is used as the resistance-inducing agent, GSPE is less effective. Next we evaluated how effective different GSPE treatments are at improving glucose metabolism in hyperinsulinemic animals (fed a cafeteria diet). GSPE reduced plasma insulin levels. The lower dose (25 mg GSPE/kg body weight per day) administered for 30 days improved the HOmeostasis Model Assessment-insulin resistance index. This was accompanied by down-regulation of Pparg2, Glut4 and Irs1 in mesenteric white adipose tissue. Similarly, a chronic GSPE treatment of insulin-resistant 3T3-L1 adipocytes down-regulated the mRNA levels of those adipocyte markers, although cells were still able to respond to the acute stimulation of glucose uptake.In summary, 25 mg/kg body weight per day of GSPE has a positive long-term effect on glucose homeostasis, and GSPE could be targeted at adipose tissue, where it might directly stimulate glucose uptake. This work also highlights the need to carefully consider the bioactive dose, since a higher dose does not necessarily correlate to a greater positive effect.
UR - http://www.scopus.com/inward/record.url?scp=77954747643&partnerID=8YFLogxK
U2 - 10.1016/j.jnutbio.2009.08.001
DO - 10.1016/j.jnutbio.2009.08.001
M3 - Article
C2 - 19962298
AN - SCOPUS:77954747643
VL - 21
SP - 961
EP - 967
JO - Journal of Nutritional Biochemistry
JF - Journal of Nutritional Biochemistry
SN - 0955-2863
IS - 10
ER -