Grape Powder Extract Beneficial for Diabetes

GREENSBORO, N.C.Grape powder extract (GPE) attenuated lipopolysaccharide (LPS)-mediated inflammation in macrophages, possibly by decreasing the activation of mitogen activated protein kinases (MAPKs), nuclear factor kappa B (NF-B) and activator protein-1 (AP-1); and GPE decreased the capacity of LPS-stimulated macrophages to inflame adipocytes and cause insulin resistance, according to a study published in the International Journal of Obesity (2010;34:800808).Obesity-associated inflammation is characterized by an increased abundance of macrophages in white adipose tissue,, leading to the production of inflammatory cytokines, chemokines and prostaglandins  that can cause insulin resistance.

Researchers investigated the effect of GPE pretreatment on LPS-mediated activation of MAPKs, NF-B and AP-1, and induction of inflammatory genes in human macrophages; and the effect of GPE pretreatment of macrophages on inflammation and insulin resistance in primary human adipocytes incubated with LPS-challenged macrophages-conditioned medium.

Pretreatment of macrophages with GPE attenuated LPS-induction of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and IL-1beta; chemokines, such as IL-8 and interferon-gamma inducible protein-10 (IP-10); and a marker of PG production, cyclooxygenase-2 (COX-2). GPE also attenuated LPS activation of MAPKs, NF-B and AP-1 (c-Jun). Using LPS-challenged macrophages-conditioned medium, GPE pretreatment attenuated macrophages-mediated inflammatory gene expression, activation of an NF-B reporter and suppression of insulin-stimulated glucose uptake in human adipocytes.