Lunasin inhibited αVβ3 integrin-mediated proinflammatory markers and downregulated Akt-mediated NF-κB pathways through interaction with αVβ3 integrin.

Sulfonylureas are a class of drugs commonly used in the management of non-insulin-dependent diabetes mellitus. Their therapeutic action results primarily from their ability to inhibit ATP-sensitive potassium (K ATP ) channels in the plasma membrane of pancreatic ␤ cells and thereby stimulate insulin release. A key question is whether an endogenous ligand for the K ATP channel exists that is able to mimic the inhibitory effects of sulfonylureas. We describe here the cloning of the cDNA encoding human ␣-endosulfine, a 13-kDa peptide that is a putative candidate for such a role. ␣-Endosulfine is expressed in a wide range of tissues including muscle, brain, and endocrine tissues. The recombinant protein displaces binding of the sulfonylurea [ 3 H]glibenclamide to ␤ cell membranes, inhibits cloned K ATP channel currents, and stimulates insulin secretion. We propose that endosulfine is an endogenous regulator of the K ATP channel, which has a key role in the control of insulin release and, more generally, couples cell metabolism to electrical activity.

Cardiovascular disease (CVD) is the leading cause of death in the United States. Diet influences risk factors associated with CVD and atherosclerosis, a major vascular disease that arises from inflammation. Lunasin, a peptide derived from plant foods such as soybeans, contains a unique Arg-Gly-Asp cell-adhesion motif and inhibits the pathways involved in the inflammatory cascade. The objective was to determine the mechanism by which lunasin is internalized into human THP-1 macrophages, investigate the expression of endocytic membrane proteins in inflammatory conditions and to identify the pathways involved. While lipopolysaccharide (10 nM), vitronectin (130 nM) and a combination of these two molecules enhanced lunasin uptake and increased basal αVβ3 integrin expression, lunasin reduced αVβ3 expression by 25.5, 26.8 and 49.2%, respectively. The pretreatment of cells with brefeldin A (71 µM), an inhibitor of protein trafficking, inhibited lunasin internalization by up to 99.8%. Lunasin increased caveolin-1 expression by up to 204.8%, but did not modulate clathrin. The pretreatment of macrophages with nystatin (54 µM), an inhibitor of caveolae-dependent endocytosis, reduced lunasin internalization. The presence of amantadine (1 mM) and amiloride (1 mM), inhibitors of clathrin-mediated endocytosis and macropinocytosis, abolished lunasin cell entry. Lunasin elicited a transient reduction in intracellular levels of Ca2+ in LPS-induced macrophages. The results suggest that internalization of lunasin into macrophages is amplified in inflammatory conditions and is primarily mediated by endocytic mechanisms that involve integrin signaling, clathrin-coated structures and macropinosomes. Lunasin may be responsible for attenuation of CVD risk factors by interacting with pathways involved in endocytosis and inflammation.

Scope We studied the impact of dietary supplementation with licorice root components on diet-induced obesity, fat accumulation and hepatic steatosis in ovariectomized C57BL/6 mice as a menopause model. Materials and Methods We evaluated the molecular and physiological effects of dietary licorice root administered to ovariectomized C57BL/6 mice as root powder (LRP), extracts (LRE) or isolated isoliquiritegenin (ILQ) on reproductive (uterus and mammary gland) and non-reproductive tissues important in regulating metabolism (liver, perigonadal, perirenal, mesenteric and subcutaneous fat). Quantitative outcome measures including body weight, fat distribution (MRI), food consumption, bone density and weight (DXA) and gene expression were assessed by the degree of restoration to the premenopausal health state. We characterized histological (H&E and oil red O staining) and molecular properties (expression of certain disease markers) of these tissues, and correlated these with metabolic phenotype as well as blood levels of bioactives. Conclusions Although LRE and ILQ provided some benefit, LRP was the most effective in reducing body weight gain, overall fat deposition, liver steatosis, and expression of hepatic lipid synthesis genes following ovariectomy. Our data demonstrate that licorice root provided improvement of multiple metabolic parameters under conditions of menopausal low estrogen and high-fat diets without stimulating reproductive tissues.