Anti-diabetic effect of black ginseng extract by augmentation of AMPK protein activity and upregulation of GLUT2 and GLUT4 expression in db/db mice.

BACKGROUND: Black ginseng (Panax ginseng C. A. Meyer), three to nine times-steamed and dried ginseng, has biological and pharmacological activities. In this study, the anti-diabetic effects of the black ginseng ethanol extract (GBG05-FF) in typical type 2 diabetic model db/db mice were investigated. METHODS: The effect of GBG05-FF in Type 2 diabetic mice was investigated by their blood analysis, biological mechanism analysis, and histological analysis. RESULTS: The mice group treated with GBG05-FF showed decreased fasting blood glucose and glucose tolerance compared to that of the nontreated GBG05-FF group. In the blood analysis, GBG05-FF decreased main plasma parameter such as HbA1c, triglyceride, and total-cholesterol levels related to diabetes and improved the expression of genes and protein related to glucose homeostasis and glucose uptake in the liver and muscle. The histological analysis result shows that GBG05-FF decreased lipid accumulation in the liver and damage in the muscle. Moreover, GBG05-FF increased the phosphorylation of the AMPK in the liver and upregulated the expression of GLUT2 in liver and GLUT4 in muscle. Therefore, the mechanisms of GBG05-FF may be related to suppressing gluconeogenesis by activating AMPK in the liver and affecting glucose uptake in surrounding tissues via the upregulation of GLUT2 and GLUT4 expression. CONCLUSION: These findings provided a new insight into the anti-diabetic clinical applications of GBG05-FF and it might play an important role in the development of promising functional foods and drugs from the viewpoint of the chemical composition and biological activities.

Black ginseng extract exerts anti-hyperglycemic effect via modulation of glucose metabolism in liver and muscle.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng (Panax ginseng C. A. Meyer, Araliaceae) has been used as a traditional medicine for thousands of years for the treatment of a wide variety of diseases, including diabetes. Processed ginseng named Black ginseng exhibits more potent biological activities than white and red ginseng. The aim of this study was to investigate the effects of black ginseng extract (GBG05-FF) on hyperglycemia and glucose tolerance in streptozotocin (STZ)-induced diabetic mice. MATERIALS AND METHODS: Black ginseng was produced by a repeated steaming and drying process, subsequent extraction with 70% ethanol, filtration, and lyophilization. The effect of GBG05-FF on glucose uptake and related protein expression and phosphorylation were determined in C2C12 cells. Furthermore, we evaluated the anti-diabetic effects of GBG05-FF in STZ-induced diabetic mice. RESULTS: GBG05-FF significantly (p<0.05) increased glucose uptake in C2C12 myotubes via AMPK, Sirt1 and PI3-K pathway. In addition, GBG05-FF improved the fasting blood glucose levels and glucose tolerance in STZ-induced diabetic mice. GBG05-FF decreased blood parameters such as glycated hemoglobin, triglyceride and total cholesterol. Quantitative RT-PCR assay revealed that in the STZ-induced diabetic mice treated with GBG05-FF, the expression of hepatic genes involved in gluconeogenesis (phosphoenolpyruvate carboxykinase (PEPCK), glucose 6-phosphatase (G6Pase)), glycogenolysis (liver glycogen phosphorylase (LGP)) and glycogenesis (glycogen synthase (GS)) was suppressed, while the expression of the genes involved in glucose uptake (glucose transporter (GLUT) 1, GLUT4) and ß-oxidation (acyl-CoA oxidase (ACO), carnitine palmitoyl transferase 1a (CPT1a), mitochondrial medium chain acyl-CoA dehydrogenase (MCAD)) in muscle were increased. GBG05-FF delayed diabetes-associated muscle atrophy by activating mTOR. The major bioactive compounds including ginsenoside Rg1, Rg3(S), Rg3(R), Rg5, Rk1 and Rh4 were evaluated for glucose uptake effect in C2C12 myotubes; the data indicated that Rh4 significantly (p<0.05) increased glucose uptake. CONCLUSION: Collectively, the results suggested that GBG05-FF is a potentially useful agent for treatment of diabetes by increasing glucose uptake.

Induction of apoptosis by thiosulfinates in primary human prostate cancer cells.

Thiosulfinates, a substance of Allium tuberosum L., is a known folk medicine that has been extensively used in diet to treat diseases. In the present study, we have evaluated the effect of thiosulfinates from Allium tumberosum L. on proliferation of metastasis (DU145) and primary malignant tumor (RC-58T/h/SA#4)-derived human prostate cancer cells. Thiosulfinates decrease viable cell numbers in a dose- and time-dependent manner and induce apoptosis. The apoptosis induced by thiosulfinates is associated with the activation of initiator caspase-8, and -9, and the effector caspase-3. Thiosulfinates stimulated Bid cleavage, indicating that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. Thiosulfinates decreased the expression of the anti-apoptotic protein Bcl-2, and increased the expression of the pro-apoptotic protein Bax. Thiosulfinates also increased the expression of AIF, a caspase-independent mitochondrial apoptosis factor, in RC-58T/h/#4 cells and induced DNA fragmentation and chromatin condensation. These results indicate that thiosulfinates from Allium tuberosum L. inhibit cell proliferation by inducing apoptosis in RC-58T/h/#4 cells which may be mediated via both caspase-dependent and caspase-independent pathways.

Inhibitory effects of Orostachys japonicus extracts on the formation of N-nitrosodimethylamine.

In Korea, Orostachys japonicus has been used traditionally as a drug and health food. The aim of this study was to investigate possible inhibitory effects of O. japonicus extracts on the formation of N-nitrosodimethylamines (NDMA). Chloroform extraction was the most effective method for recovering the highest number of phenolic compounds and flavonoids; in these extracts the greatest nitrite-scavenging activity and inhibition of NDMA formation occurred at pH 2.5. The chloroform extract was separated into 10 fractions (J1-J10); fraction J4 inhibited NDMA formation by 90.1 +/- 0.4%. This fraction was then separated into five subfractions (J4-1-J4-5) using a silica gel column. Subfractions J4-2 [(+)-catechin] and J4-4 (3,4-dihdroxybenzoic acid) inhibited NDMA formation by 89.5 +/- 0.9 and 77.6 +/- 0.8%, respectively.

Antimutagenic, antioxidant and free radical scavenging activity of ethyl acetate extracts from white, yellow and red onions.

The beneficial effects of red, yellow and white onion extracts have been assessed by antioxidant activity and antimutagenic activity. And the effects compared to BHT and ascorbic acid. Total phenolic compounds and flavonoids in onion extracts were determined. Yellow onion extract had more organic acid and free sugar than those detected in the white and red onion extract. The scavenging activity of DPPH radical and H(2)O(2) were increased depending on the concentration. The antioxidant activities using beta-carotene-linoleate system and reducing power were increased but the effect was small to that of BHT and ascorbic acid. After digested, extracts showed antimutagenic activities, and it seems that they inhibit the mutagenicity for digesting. This study demonstrated that the antimutagenicities and antioxidant properties of ethyl acetate extract against mutagens were related to their phenols and flavonoids, which are heat stable and losses digestive juices are relatively low.