5,7-Dimethoxy-3-(2'-hydroxybenzyl)-4-chromanone inhibits α-glucosidase in vitro and alleviates postprandial hyperglycemia in diabetic mice.

This study was designed to investigate the inhibitory activities of 5,7-dimethoxy-3-(2'hydro-xybenzyl)-4-chromanone (5,7-D chromanone) isolated from Portulaca oleracea L. on carbohydrate digesting enzymes and its ability to improve postprandial hyperglycemia in streptozotocin-induced diabetic mice. 5,7-D chromanone strongly inhibited α-glucosidase and α-amylase (half-maximal inhibitory concentration, IC50; 15.03 ±â€¯2.59 µM and 12.39 ±â€¯2.16 µM, respectively). The inhibitions were more effective than acarbose, which was the positive control. The increase in blood glucose level after ingesting starch was more significantly alleviated in the 5,7-D chromanone ingested group than in the control group of diabetic mice. In the control group, blood glucose levels were 24.64 ±â€¯1.73, 27.22 ±â€¯1.58, and 26.37 ±â€¯1.41 mM, and in the 5,7-D chromanone ingested group were 23.87 ±â€¯1.10, 23.38 ±â€¯1.32, and 21.42 ±â€¯1.36 mM at 30, 60, and 120 min, respectively. In addition, the area under the curve of blood glucose significantly declined with 5,7-D chromanone ingestion in diabetic mice. The results indicate that 5,7-D chromanone can help lower postprandial hyperglycemia by inhibiting carbohydrate digesting enzymes.

Polyphenol-Rich Fraction of Brown Alga Ecklonia cava Collected from Gijang, Korea, Reduces Obesity and Glucose Levels in High-Fat Diet-Induced Obese Mice.

Ecklonia cava (E. cava) is a brown alga that has beneficial effects in models of type 1 and type 2 diabetes. However, the effects of E. cava extracts on diet-induced obesity and type 2 diabetes have not been specifically examined. We investigated the effects of E. cava on body weight, fat content, and hyperglycemia in high-fat diet- (HFD) induced obese mice and sought the mechanisms involved. C57BL/6 male mice were fed a HFD (60% fat) diet or normal chow. After 3 weeks, the HFD diet group was given extracts (200 mg/kg) of E. cava harvested from Jeju (CA) or Gijang (G-CA), Korea or PBS by oral intubation for 8 weeks. Body weights were measured weekly. Blood glucose and glucose tolerance were measured at 7 weeks, and fat pad content and mRNA expression of adipogenic genes and inflammatory cytokines were measured after 8 weeks of treatment. G-CA was effective in reducing body weight gain, body fat, and hyperglycemia and improving glucose tolerance as compared with PBS-HFD mice. The mRNA expression of adipogenic genes was increased, and mRNA expression of inflammatory cytokines and macrophage marker gene was decreased in G-CA-treated obese mice. We suggest that G-CA reduces obesity and glucose levels by anti-inflammatory actions and improvement of lipid metabolism.

Libanoridin inhibits the mast cell-mediated allergic inflammatory reaction.

BACKGROUND AND AIM: Corydalis heterocarpa is a biennial herb in South Korea, with spikes of yellow flowers. It has been used for as a folk medicine to cure travail and spasm. However, studies on this herb and its secondary metabolites have rarely been reported. In the present study, we isolated secondary metabolite libanlibanoridin from Corydalis heterocarpa. We have also examined the effect of libanoridin on the inflammatory cytokines production in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore, A2318 stimulated human mast cell line, HMC-1. PMA plus A23187 significantly increased interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha production compared to media control (P < 0.05). RESULTS: We report that treatment with libanlibanoridin can inhibit PMA plus A23187-induced IL-1beta, IL-6, IL-8, and TNF-alpha production in a concentration-dependent manner with IC50 of 0.002, 1.38, 1.48, and 0.36 mug/ml, respectively. Maximal inhibition rates of IL-1beta, IL-6, IL-8, and TNF-alpha production by libanlibanoridin were about 117.5%, 86.22%, 86.41%, and 90.74%, respectively. libanoridin inhibits the mRNA expression of IL-1beta, IL-6, IL-8, and TNF-alpha. libanoridin also inhibits the expression of cyclooxygenase-2. CONCLUSION: These results indicate that libanlibanoridin may be helpful in regulating mast cell-mediated allergic inflammatory response.

Anti-inflammatory effect of Columbianetin on activated human mast cells.

In the present study, we extracted Corydalis heterocarpa with various solvents in order to find the bioactive constituents that demonstrated anti-inflammatory effects. We isolated the active compound, Columbianetin. Anti-inflammatory effect of Columbianetin has been reported but the precise effects of Columbianetin in experimental models have remained unknown. In the present study, we investigate the effect of Columbianetin on the production of histamine, interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor (TNF)-alpha and expression of cyclooxygenase-2 (COX-2) by using the human mast cell line (HMC-1). Various concentrations of Columbianetin were treated before the activation of HMC-1 cells with phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore, A23187. PMA plus A23187 significantly increased IL-1beta, IL-6, IL-8, and TNF-alpha production compared with media control (p<0.05). We also show that the increased cytokines IL-1beta, IL-6, IL-8, and TNF-alpha level was significantly inhibited by Columbianetin in a dose-dependent manner (p<0.05). Maximal inhibition rates of IL-1beta, IL-6, IL-8, and TNF-alpha production by Columbianetin were about 102.6%, 101.1%, 95.8%, and 103.9%, respectively. Columbianetin inhibited expression of COX-2. In addition, the effect of Columbianetin was investigated on the histamine release from HMC-1 stimulated by substance P, which promotes histamine release. Columbianetin also inhibited the histamine release by substance P. In conclusion, these results indicate that Columbianetin may be helpful in regulating mast cell-mediated allergic inflammatory responses.

Induction of apoptosis by KI0477959 through activation of caspase-3 in human leukemia cell line, HL-60 cells.

KI0477959 (Herbkines) has been used for the purpose of development of physical strength in wasting diseases, like cancer. In the present study, apoptosis-inducing activities of butanol fraction of KI0477959 were studied in human leukemia cell line, HL-60 cells. KI0477959 increased cytotoxicity but had less effect on human peripheral blood mononuclear cells. KI0477959-induced apoptosis was accompanied by activation of caspase-3 and specific proteolytic cleavage of poly-ADP-ribose polymerase. Increased apoptosis was reduced by treatment with p38 and extracellular signal-regulated protein kinase (ERK) inhibitors. These results suggest that KI0477959 induces apoptosis through activation of caspase-3, p38, and ERK in HL-60 cells.

Hypolipidemic effect of Salicornia herbacea in animal model of type 2 diabetes mellitus.

To control blood glucose level as close to normal is a major goal of treatment of diabetes mellitus. Hyperglycemia and hyperlipidemia are the major risk factors for cardiovascular complications, the major cause of immature death among the patients with type 2 diabetes. The purpose of this study is to determine the hypoglycemic and hypolipidemic effects of Salicornia herbacea in animal model of type 2 diabetes and to investigate the possible mechanisms for the beneficial effects of S. herbacea. S. herbacea was extracted with 70% ethanol and desalted with 100% ethanol. Three week-old db/db mice (C57BL/KsJ, n=16) were fed AIN-93G semipurified diet or diet containing 1% desalted ethanol extract of S. herbacea for 6 weeks after 1 week of adaptation. Fasting plasma glucose, triglyceride, and total cholesterol were measured by enzymatic methods and blood glycated hemoglobin (HbA(1C)) by the chromatographic method. Body weight and food intake of S. herbacea group were not significantly different from those of the control group. Fasting plasma glucose and blood glycated hemoglobin levels tended to be lowered by S. herbacea treatment. Consumption of S. herbacea extract significantly decreased plasma triglyceride and cholesterol levels (p<0.05). The inhibition of S. herbacea extract against yeast alpha-glucosidase was 31.9% of that of acarbose at the concentration of 0.5 mg/mL in vitro. The inhibitory activity of ethanol extract of S. herbacea against porcine pancreatic lipase was 59.0% of that of orlistat at the concentration of 0.25 mg/mL in vitro. Thus, these results suggest that S. herbacea could be effective in controlling hyperlipidemia by inhibition of pancreatic lipase in animal model of type 2 diabetes.