• 한국버섯학회지
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• 제13권1호
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• pp.1-10
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• 2015

Russula rosacea, a mycorrhizal fungus, has been used for edible and medicinal purposes. This study was conducted to evaluate the in vitro antioxidant, anti-hyperglycemic, anti-cholinesterase, and nitric oxide inhibitory effects of the fruiting bodies from R. rosacea extracted with methanol, and hot water. The 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activities of the methanol and hot water extracts (2.0 mg/ml) of R. rosacea were comparable with BHT, the positive control. The chelating effects of the mushroom and hot water extracts were significantly higher than that of BHT. The reducing power of methanol and hot water extract (6 mg/ml) were significantly lower than that of BHT. Seven phenolic compounds were detected from acetonitrile and hydrochloric acid solvent extract of the mushroom. alpha-amylase and alpha-glucosidase inhibitory activities of methanol and hot water extracts were lower than that of acarbose, the positive control. The acetylcholinesterase and butyrylcholinesterase inhibitory effects were moderate compared with galanthamine, the standard drug. Nitric oxide (NO) production in lipopolysaccharide (LPS) induced RAW 264.7 cells were inhibited significantly by the mushroom extracts in a concentration dependent manner. Therefore, we demonstrated that fruiting bodies of R. rosacea possess in vitro antioxidant, anti-hyperglycemic, anti-cholinesterase, and NO production inhibitory activities. The experimental results suggest that the fruiting bodies of R. rosacea are good natural antioxidant, anti-hyperglycemic, anti-cholinesterase, and anti-inflammatory sources.

• Mycobiology
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• 제45권3호
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• pp.199-203
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• 2017

This study was done to produce ${\gamma}$-aminobutyric acid (GABA) from wild yeast as well as investigate its anti-hyperglycemic effects. Among ten GABA-producing yeast strains, Pichia silvicola UL6-1 and Sporobolomyces carnicolor 402-JB-1 produced high GABA concentration of $134.4{\mu}g/mL$ and $179.2{\mu}g/mL$, respectively. P. silvicola UL6-1 showed a maximum GABA yield of $136.5{\mu}g/mL$ and $200.8{\mu}g/mL$ from S. carnicolor 402-JB-1 when they were cultured for 30 hr at $30^{\circ}C$ in yeast extract-peptone-dextrose medium. The cell-free extract from P. silvicola UL6-1 and S. carnicolor 402-JB-1 showed very high anti-hyperglycemic ${\alpha}$-glucosidase inhibitory activity of 72.3% and 69.9%, respectively. Additionally, their cell-free extract-containing GABA showed the anti-hyperglycemic effect in streptozotocin-induced diabetic Sprague-Dawley rats.

• 한국식품영양학회지
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• 제23권2호
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• pp.233-239
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• 2010

Phenolic acid concentrates of rice bran(RB-ex) and hydroxycinnamic acids were investigated for their anti-hyperglycemic activities through glucose uptake and glucokinase activity using HepG2 cells and stimulatory effects on insulin secretion using HIT-T15 cells. RB-ex was prepared as an ethylacetate extract after alkaline hydrolysis and hydroxycinnamic acids, found as major compositions of RB-ex, such as ferulic acid(FA), sinapic acid(SA) and p-coumaric acid(p-CA) were investigated to compare with the properties of RB-ex. The properties of glucose uptake in HepG2 cells were examined in the absence of insulin and two different glucose concentrations(5.5 mM and 25 mM). RB-ex and FA showed anti-hyperglycemic activities through the increase of glucose uptake and the stimulation of glucokinase activity in HepG2 cells. RB-ex exhibited higher glucose uptakes with higher glucose concentrations, whereas FA exhibited the same increasing effects on both concentrations of glucose. RB-ex and FA exhibited doubled glucokinase activities relative to control. In the presence of insulin in the 25 mM glucose-containing medium, the levels of glucose uptake were increased in all treatments compared with control. As stimulatory effects of samples on insulin secretion were estimated, RB-ex and FA stimulated insulin secretion at a concentration of 25 ${\mu}g/m{\ell}$ and in particular, FA showed the highest amount of insulin-release in HIT-T15 cells. Antioxidative effects on HIT-T15 cells, RB-ex and hydroxycinnamic acids, excluding p-CA, showed inhibitory activities of 78% to 80% at a concentration of 100 ${\mu}g/m{\ell}$. On the basis of these results, we conclude that RB-ex and FA could help decrease blood glucose levels and prevent the cell damages via antioxidant activity.

• BMB Reports
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• 제40권5호
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• pp.670-677
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• 2007

Although polysaccharide is believed to play an important role in the medicinal effect of Dendrobium chrysotoxum Lindl (DCL), its role as an antioxidant and in anti-hyperglycemic induction was not reported. In this study, polysaccharide with molecular weight of approximately 150 kDa, herein named DCLP, was isolated from the stem of DCL, and its antioxidative, hypoglycemic and immune stimulating effects were evaluated using various in vitro and in vivo assay systems. DCLP inhibited hydroxyl radicals ($^{\cdot}$OH)-mediated deoxyribose degradation by scavenging hydroxyl radicals directly as well as by chelating iron ions. DCLP also showed dose-dependent scavenging activity on superoxide anions ($O_2^{{\cdot}-}$) and offered significant protection (p < 0.001) against glucose oxidase-mediated cytotoxicity in Jurkat cells. DCLP had immune stimulating effects, as evidenced by the DCLP-mediated increases in the level of DNA synthesis, viability, and cytokine secretion in mouse lymphocytes. Moreover, oral administration of DCLP produced a significant reduction in blood glucose level in alloxan-induced diabetic mice. These findings suggest that DCLP has a potential utility in treating patients who require enhanced antioxidation, immune function and/or hypoglycemic activity.

• Advances in Traditional Medicine
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• 제5권1호
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• pp.1-15
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• 2005

Ginseng is a popular medicinal plant highly valued throughout the world. Asian ginseng is one of the most common species of ginseng. It has long occupied a significant position in oriental medicine and has been justified its name as the 'king herb'. As a nutritional supplement, ginseng is an extremely common and popular herbal medicine in the United States and Canada in recent decades. The multiple constituents of ginseng possess equally multifaceted pharmacological actions as demonstrated by numerous studies. Ginseng root and its constituents influenced the central nervous system, endocrine, cardiovascular, gastrointestinal system, sexual, renal organ and immune system, etc. One important action is its anti-hyperglycemic effect. Previous studies on ginseng demonstrate that only the root of ginseng has been used in the treatment of diabetes, while the other parts of ginseng plant were always neglected. Recently, we analyzed the constituents of ginseng berry, leaf and discovered that ginseng berry, leaf extracts and its total ginsenosides have the ability to reduce hyperglycemia and body weight and increase the peripheral glucose utilization in obese or diabetic ob/ob or db/db mice. Our data suggest that all parts of ginseng plant, including root, berry, leaf and stem exhibit potent anti-hyperglycemic and anti-obese effects and may provide an opportunity to develop a novel class of anti-diabetic agents.

• Natural Product Sciences
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• 제14권4호
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• pp.260-264
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• 2008

To find the antidiabetic activity of the tripterpenoid-rich fractions of Rubus coreanus (TRF-cor) and R. crataegifolius (TRF-cra) leaves or its main component niga-ichigoside $F_1$ (Niga-$F_1$), anti-hyperglycemic and antihyperlipidemic effects were investigated in the diabetic rat model induced by streptozotocin (STZ). Treatments of rats with 200 mg/kg of the TRF-cor, TRF-cra (each, p.o.) or 20 mg/kg of Niga-$F_1$ significantly inhibited the increase of blood glucose concentration about 44.8%, 28.7% or 20.6%, respectively, in the diabetic rats. In addition, treatments with those fractions inhibited the increase of serum concentrations of triglyceride, total cholesterol or LDL-cholesterol caused by STZ. The inhibitory rate on atherogenic index (AI) values of the TRFcor (200 mg/kg), TRF-cra (200 mg/kg) or Niga-$F_1$ (20 mg/kg)-treated groups were decreased about 55.7%, 36.3% or 22.6%, respectively, comparable to STZ-treated group. In the oral glucose tolerance test, treatment of TRF-cor or TRF-cra inhibited the increase of blood glucose concentration in the STZ-induced rats. Administration of 20 mg/kg of Niga-$F_1$ (p.o.) also exhibited similar effects with the effects of both TRFs at 200 mg/kg dose (p.o.). These results support that the triterpenoids, in particular Niga-$F_1$, are contributed to the antidiabetic effects of R. coreanus or R. crataegifolius.

• Natural Product Sciences
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• 제8권4호
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• pp.111-126
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• 2002

The chemistry of secondary products from Acanthopanax species and their pharmacological activities were reviewed. A nitrogenous compound, a furan compound, a quinoid, benzoids, coumarins, phenylpropanoids, lignans, flavonoids, terpenoids, phytosterols, polyacetylenes, a pyrimidine, cyclitols, monosaccharides and an aliphatic alcohol have been isolated from Acanthopanax species and have been shown to have various levels of activities such as anti-bacterial, anti-cancer, anti-gout, anti-hepatitis, anti-hyperglycemic, anti-inflammatory, anti-leishmanicidic, anti-oxidant, anti-pyretic, anti-xanthine oxidase, choleretic, hemostatic, hypocholesterolemic, immunostimulatory and radioprotectant effects, etc.

• Nutrition Research and Practice
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• 제7권1호
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• pp.15-21
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• 2013

Leaf of Sasa borealis, a species of bamboo, has been reported to exhibit anti-hyperglycemic effect. However, its antidiabetic mechanism is not fully understood. In this study, we examined whether an extract of S. borealis activates AMP-activated protein kinase (AMPK) and exerts anti-hyperglycemic effects. Treatment with the S. borealis extract increased insulin signaling and phosphorylation of AMPK and stimulated the expression of its downstream targets, including $PPAR{\alpha}$, ACO, and CPT-1 in C2C12 cells and $PPAR{\alpha}$ in HepG2 cells. However, inhibition of AMPK activation attenuated insulin signaling and prevented the stimulation of AMPK target genes. The S. borealis extract increased glucose uptake in C2C12 cells and suppressed expression of the gluconeogenic gene, PEPCK in HepG2 cells. The extract significantly reduced blood glucose and triglyceride levels in STZ-induced diabetic mice. The extract enhanced AMPK phosphorylation and increased Glut-4 expression in the skeletal muscle of the mice. These findings demonstrated that the S. borealis extract exerts its anti-hyperglycemic effect through activation of AMPK and enhancement of insulin signaling.

• 생약학회지
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• 제25권1호
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• pp.51-58
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• 1994

The studies were conducted to investigate the anti-diabetic activities on the hyperglycemia induced by streptozotocin in rats, anti-hypertensive activities in SHR, anti-fatigue and decrease of body weight activities in mice by Kyung Ok-Ko water extract and drink, which is a traditional preparation in Korea. 1. The blood glucose levels of streptozotocin-induced hyperglycemic rats were dose-dependently decreased by administrations of various doses(300, 600, 1200 mg/kg) of Kyung Ok-Ko water extract. Particularly, administration of 600, 1200 mg/kg were significantly shown to decrease glucose levels comparing with control group. 2. The serum total cholesterol levels of streptozotocin-induced hyperglycemic rats were dose-dependently decreased by administrations of various doses(300, 600, 1200 mg/kg) of Kyung Ok-Ko water extract. Particularly, administration of 600, 1200 mg/kg were significantly shown to decrease total cholesterol levels comparing with control group. 3. The serum triglyceride levels of streptozotocin-induced hyperglycemic rats were dose-dependently decreased by administrations of various doses(300, 600, 1200 mg/kg) of Kyung Ok-Ko water extract. Particularly, administration of 600, 1200 mg/kg were significantly shown to decrease triglyceride levels comparing with control group. 4. The blood pressure in SHRs were dose-dependently lower descended by administration of Kyung Ok-Ko water extract 300, 600, and 1200 mg/kg, respectively. 5. The swimming time of Kyung Ok-Ko water extract(100, 200, 400 mg/kg) and drink(0.7, 1.4, 2.1 ml/kg) were significantly extended to all experimental group dose-dependantly. 6. The decrease of body weight of Kyung Ok-Ko water extract(100, 200, 400 mg/kg) and drink(0.7, 1.4, 2.1 ml/kg) were significantly evaluated dose-dependently in all experimental group.

• 생약학회지
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• 제36권4호통권143호
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• pp.291-298
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• 2005

Anti-hyperglycemic effects of 17 medicinal plants that have been used for ameliorating diabetes in oriental medicine were evaluated using glucose transport assay in 3T3-L1 adipocytes. Higher activities were obtained by treating water or alcohol extract of Phellodendri Cortex (PC), which showed enhancing effects both on basal and insulin-stimulated glucose uptake. The latter effect of PC was completely inhibited by wortmannin, a specific inhibitor for phosphatidyl inositol 3-kinase (PI 3-kinase), but not affected by SB203580, A specific inhibitor for p38 mitogen-activatedprotein kinase(MAPK). Genistein, an inhibitor for tyrosine kinases, abolished the PC effects completely. Treatment of vanadate, an inhibitor for tyrosine phosphatases, together with PC showed no significant synergic enhancement in glucose uptake. The results of inhibitors associated with insulin signaling pathway indicated that extracts of PC enhance glucose uptake by PI-3 kinase activation which is an upstream event for GLUT4 translocation. Antidiabetic effects of PC extract might be also due to enhanced tyrosine phosphorylation and reduced tyrosine dephosphorylation. In addition, PC accelerated insulin-stimulated glucose uptake in insulin-resistant cells, recovering the uptake level close to that of normal cells. These findings may offer a new way to utilize extracts of PC as novel anti-hyperglycemic agents.