Isoflavonoids and peptides from meju, long-term fermented soybeans, increase insulin sensitivity and exert insulinotropic effects in vitro.

Objective: Although soybeans have been shown to alleviate metabolic syndromes, fermented soybeans may have even greater effects. We investigated the antidiabetic effects of meju, a soy food that is fermented up to 2 mo, and the mechanism by which it exerts its effects.

Methods: Meju was prepared by a traditional fermentation process: soybeans were fermented outdoors for 20 or 60 d.

Central infusion of leptin improves insulin resistance and suppresses beta-cell function, but not beta-cell mass, primarily through the sympathetic nervous system in a type 2 diabetic rat model.

Aims: We investigated whether hypothalamic leptin alters beta-cell function and mass directly via the sympathetic nervous system (SNS) or indirectly as the result of altered insulin resistant states.

Main Methods: The 90% pancreatectomized male Sprague Dawley rats had sympathectomy into the pancreas by applying phenol into the descending aorta (SNSX) or its sham operation (Sham). Each group was divided into two sections, receiving either leptin at 300ng/kgbw/h or artificial cerebrospinal fluid (aCSF) via intracerebroventricular (ICV) infusion for 3h as a short-term study.

Glyceollins, one of the phytoalexins derived from soybeans under fungal stress, enhance insulin sensitivity and exert insulinotropic actions.

Glyceollins are a category of phytoalexins that are produced by soybeans under fungal stress, but their effects on glucose homeostasis remain unknown. We hypothesized that glyceollins play an important role in glucose homeostasis by regulating glucose utilization in adipocytes and improving beta-cell function and survival. Glyceollins improved insulin-stimulated glucose uptake in 3T3-L1 adipocytes without activating the peroxisome proliferator-activated receptor-gamma agonist.

Exendin-4 potentiates insulinotropic action partly via increasing beta-cell proliferation and neogenesis and decreasing apoptosis in association with the attenuation of endoplasmic reticulum stress in islets of diabetic rats.

Exendin-4, a long-acting glucagon-like peptide-1-receptor agonist, is known to enhance beta-cell function, but the active mechanism by which it modulates beta-cell mass still remains unclear. We investigated what the long-term effects of exendin-4 (300 pmol/kg body weight per day) on beta-cell function and mass would be in 90% pancreatectomized (Px) Sprague Dawley rats; half of whom were intraperitoneally injected with streptozotocin (STZ, 20 mg/kg body weight) and half of whom were not. Exendin-4 improved glucose tolerance by elevating serum insulin levels in both STZ-treated and untreated Px rats.

Olanzapine, not resperidone, exacerbates beta-cell function and mass in ovariectomized diabetic rats and estrogen replacement reverses them.

The effect of risperidone and olanzapine on beta-cell function and mass was investigated in 90% pancreatectomized and ovariectomized female rats, of which some were treated with estrogen replacement and some were not. Ovariectomized diabetic rats were divided into two groups: one group received daily estrogen replacement (30 mug 17beta-estradiol/kg body weight) and the other group received a vehicle. Each group was further divided into three subgroups and orally given either a placebo, risperidone (0.

Huang-Lian-Jie-Du-Tang supplemented with Schisandra chinensis Baill. and Polygonatum odoratum Druce improved glucose tolerance by potentiating insulinotropic actions in islets in 90% pancreatectomized diabetic rats.

We investigated to determine what effects, if any, the respective water extracts of Radix scutellariae (RS), Fructus schisandrae chinensis (FSC), Huang-Lian-Jie-Du-Tang (HLJDT), and HLJDT supplemented with FSC, and Rhizoma Polygonati odorati (HLJDT-M) would have on glucose tolerance by modulating glucose-stimulated insulin secretion, beta-cell mass, and morphometry in 90% pancreatectomized (Px) diabetic rats fed high-fat diets. Through the elevation of intracellular cAMP levels, FSC RS, HLJDT, and HLJDT-M increased insulin secretion in Min6 cells and GLP-1 secretion in NCI-H716 cells. After an 8-week period of treatment, it was found that HLJDT-M improved glucose tolerance in an oral glucose tolerance test in Px rats.

Exendin-4 and exercise improve hepatic glucose homeostasis by promoting insulin signaling in diabetic rats.

Recently, it has been reported that a long-acting glucagon-like peptide-1 (exendin-4) and physical exercise improve hepatic insulin action in diabetic rats. However, this phenomenon remains poorly understood. We investigated the long-term effect that exendin-4 and exercise had on hepatic insulin resistance through the modulation of hepatic and/or hypothalamic insulin signaling in 90% pancreatectomized diabetic rats fed 40% energy fat diets.

Kochujang, a Korean fermented red pepper plus soybean paste, improves glucose homeostasis in 90% pancreatectomized diabetic rats.

Objectives: Red pepper and soybeans have been reported to modulate energy and glucose metabolism. However, the antidiabetic effect of kochujang, the fermented product of red pepper plus soybeans, has not been studied. We examined whether kochujang affected insulin secretion from beta-cells and/or peripheral insulin resistance in 90% pancreatectomized diabetic rats fed high-fat diets.

Long-term intracerebroventricular infusion of insulin, but not glucose, modulates body weight and hepatic insulin sensitivity by modifying the hypothalamic insulin signaling pathway in type 2 diabetic rats.

Background/aims: It has been reported that the short-term injection of insulin and glucose into the hypothalamus modulates body weight and hepatic glucose production in non-diabetic rats. However, the effect of hypothalamic insulin and glucose on peripheral glucose metabolism in diabetic animals remains uncertain. We investigated how intracerebroventricular (ICV) infusion of insulin and glucose modified body weight and peripheral glucose homeostasis in 90% pancreatectomized rats that exhibited symptoms of mild and non-obese type 2 diabetes.

Can splenocytes enhance pancreatic beta-cell function and mass in 90% pancreatectomized rats fed a high fat diet?

Aims: Recent studies have shown that splenocytes may act as a possible neogenic source with regard to beta-cells in rodent diabetic models. Accordingly, we sought to determine whether splenocytes played an important role in promoting beta-cell function and mass among type 2 diabetic rats with and without spleen.

Main Methods: We randomly divided female 90% pancreatectomized (Px) Sprague Dawley rats into three groups: splenectomy (SPX), splenectomy plus the injection of male splenocytes (SPI), and no splenectomy (NSP).

Ginsenosides Rb1 and Rg1 suppress triglyceride accumulation in 3T3-L1 adipocytes and enhance beta-cell insulin secretion and viability in Min6 cells via PKA-dependent pathways.

Ginseng root is known to induce anti-diabetic activity, but the key components involved are unknown. We investigated which major ginsenosides in ginseng enhanced glucose homeostasis by in vitro studies. Rb1 and Rg1 reduced the triglyceride accumulation in 3T3-L1 adipocytes by activating PKA with increased intracellular cAMP.