• Food Science and Preservation
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• v.23 no.1
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• pp.97-103
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• 2016

The antioxidant and digestive enzyme inhibitory effects of Eisenia bicyclis extracted by various extraction methods (RE, reflux extraction; SE, ultrasonification extraction; AE, autoclave extraction; LE, low-temperature high-pressure extraction) were investigated. The extraction yield (55.21%) and the laminarin (39.03%), fucoidan (24.75%), total polyphenol (115.68 mg GAE/g) and flavonoid (36.67 mg RHE/g) contents of AE were higher than those in other methods. The DPPH radical (86.60%, 500 mg%), ABTS radical (58.56%, 25 mg%), nitrite (86.38%, 100 mg%) scavenging activities of the Eisenia bicyclis extracted by AE were higher than those of Eisenia bicyclis extracted by other methods. The ABTS radical and nitrite scavenging activities were above 98% in all tested Eisenia bicyclis extracts and these activities were dependent on its concentration. The inhibitory effects of AE against amylase (50 mg%) and ${\alpha}$-glucosidase (5 mg%) were 64.76% and 86.71%, respectively. The AE showed the best inhibitory effect of Eisenia bicyclis extracts (50 mg%) against trypsin (24.37%) and ${\alpha}$-chymotrypsin (49.05%), respectively. These results suggest that Eisenia bicyclis extracted by AE can be used as a bioactive and functional material in the food industry.

• Journal of Life Science
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• v.23 no.3
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• pp.399-405
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• 2013

This study was carried out to analyze the effects on antioxidative, antidiabetic, and anti-inflammatory activities of Parthenocissus tricuspidata (PT) stem extracts. The total phenolic contents of hot water and ethanol extracts from PT stems were 61.5 mg TAE/g and 122.1 mg TAE/g, respectively. The antioxidative activities of hot water and ethanol extracts from PT stem were measured by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and superoxide dismutase (SOD) assay. The DPPH radical scavenging activities of ethanol extract and butanol fraction were approximately 95% and 92% at 1 mg/ml, respectively, and the SOD activities of ethanol extract and butanol fraction were about 91% and 97% at 1 mg/ml, respectively. The DPPH radical scavenging and SOD activities of ethanol extract and butanol fraction from PT stem increased remarkably increased in a dose-dependent manner and were higher than in the hot water extracts. Compared to the acarbose, a known anti-diabetic drug, which was used as a positive control, the ${\alpha}$-glucosidase inhibitory capacity of PT stem showed a strong inhibitory rate in ethanol extract and in butanol and hexane fractions. We investigated the effect of hot water extract from PT stem on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells. Hot water extract from PT stem inhibited LPS-induced NO production up to 40% at a treatment of 1 mg/ml. These results suggest that PT stem extracts have an effect on antioxidative, antidiabetic, and anti-inflammatory activities and thus have great potential as antidiabetic materials and a source for natural health products.

• Journal of Nutrition and Health
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• v.46 no.5
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• pp.401-409
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• 2013

Smilax china L., a native plant found in Asian countries, has several medicinal properties including antioxidant, anti-inflammatory, and anti-cancer effects. Although the root of the plant is commonly used as traditional herbal medicine in Korea and China, the medicinal properties of the leaves have not gained the same attention. In this study, we analyzed the antioxidant activity, ${\alpha}$-glucosidase inhibitory effect and lipid accumulation inhibition effect of Smilax china L. leaf water extract (SCLE) and its solvent fractions. SCLE was fractionated by using a series of organic solvents, including ethylacetate (EA) and n-butanol (BuOH). The EA fraction had the highest total polyphenol content ($440.20{\pm}12.67$ mg GAE/g) and total flavonoid content ($215.14{\pm}24.83$ mg QE/g). The radical scavenging activity $IC_{50}$ values of the EA fraction for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) were 0.022 mg/mL and 0.13 mg/mL, respectively. Further, SOD-like activity and reducing power values of the EA fraction were higher than those of the other fractions. However, both the ${\alpha}$-glucosidase and lipid accumulation inhibition assays showed that the BuOH fraction ($83.35{\pm}4.18%$ at 1 mg/mL) and water extract ($11.27{\pm}2.67%$) were more effective than the EA fraction ($64.13{\pm}6.35%$, and $45.66{\pm}7.20%$). These results provide new insights into the potential anti-diabetic and anti-obesity effects of Smilax china L. leaf.

• The Korea Journal of Herbology
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• v.32 no.5
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• pp.39-46
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• 2017

Objective : This study was designed to evaluate the hypoglycemic effects of Helianthus tuberosi Rhizoma extracts and its optimum Heat processing conditions Methods : We investigated the Salivary ${\alpha}$-amylase, pancreas ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibitory activities of extracts from Steam Heated Helianthus tuberosi Rhizoma Ext. The inhibitory activities of a 50% EtOH extract of Steam Heated Helianthus tuberosi Rhizoma Ext against ${\alpha}$-glucosidases were evaluated in this study. Inhibiting these enzymes involved in the absorption of disaccharides significantly decreases the postprandial increase in blood glucose level after a mixed carbohydrate diet. Furthermore, the postprandial blood glucose lowering effect of Steam Heated Helianthus tuberosi Rhizoma Ext. was compared to a known type 2 diabetes drug(Acarbose(R)) in a mice model. Steam Heated Helianthus tuberosus L. Ext significantly reduced the blood glucose increase after glucose loading. Results : The results were confirmed by real-time PCR that after treated with Streptozotocin in L6 cells, induced expression of GLUT4, after the steamed Helianthus tuberosus L. Ext. treated, observed its expression was increased. Steam Heated Helianthus tuberosus L Ext treated 4 hours in L6 cells, cytotoxicity was measured in MTT assay. Its toxicity were 5.7%, 9% and 11.3% at the treatment concentration $12.5{\mu}g/m{\ell}$, $25{\mu}g/m{\ell}$, the $50{\mu}g/m{\ell}$ respectively. Conclusions : Overall, the results of this study indicate that Hypoglycemic effect of Helianthus tuberosi Rhizoma caused by the Steam heat treatment, the optimum Heat processing condition is steamming at $121^{\circ}C$ for 30 min, and it will provide the basis for developing a useful dietary supplement for controlling postprandial hyperglycemia.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.12
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• pp.1761-1768
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• 2010

Hypoglycemic effect through activity inhibition of $\alpha$-glucosidase and $\alpha$-amylase was evaluated using leaves of Eleutherococcus senticosu, Eleutherococcus gracilistylus, Eleutherococcus sieboldianus and Eleutherococcus sessiliflorus which belong to Acanthopanax sessiliflorus genus. As a result of measuring $\alpha$-glucosidase activity inhibition, extract of Eleutherococcus gracilistylus showed around 43.38% of activity inhibition compared with acarbose and extract of Eleutherococcus senticosu showed 41.24% inhibitory effect. As a result of measuring $\alpha$-amylase activity inhibition, acarbose showed 73.25% of activity inhibition in 10 mg/mL concentration, and the extract of Eleutherococcus senticosu leaves showed 91.90% higher activity inhibition compared with acarbose. Also, after subjects in a model were induced diabetes with streptozotocin (STZ) intake plant extract from Acanthopanax sessiliflorus for 2 weeks, effect of improving blood glucose level and fat was examined. In all groups with specimen, Eleutherococcus senticosu (T1), Eleutherococcus gracilistylus (T2), Eleutherococcus sieboldianus (T3) and Eleutherococcus sessiliflorus (T4), blood glucose level was significantly decreased compared with that in control group (C). In an experiment of examining changes in fat concentration in blood, total cholesterol content increased in a control group compared with a normal, while in T1, T3 and T4, it decreased significantly compared with the control group. As for HDL-cholesterol, it significantly increased in all diabetes induced groups compared with the normal group, and in T3, it increased the most significantly by 55.61% compared with the control group. In case of LDL-cholesterol, specific difference between the normal group and the control group was not found; however, significant increase was detected in T2 and T3, whereas in T1 and T4, it decreased significantly compared with the control group. As for triglyceride, its concentration increased in the control group like total cholesterol. It decreased 60.16% in T3, 60.80% in T4 and 50.16% in T1 compared with the control group. As a result of measuring the concentration of triglyceride in extracted liver, the control group showed significant increase compared with the normal group, whereas T1 and T2 showed significant decrease compared with the normal group. The above results show that extracts from Acanthopanax sessiliflorus genus are effective for hypoglycemic and improving fat metabolism due to diabetes.

• Food Science and Preservation
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• v.22 no.2
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• pp.182-189
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• 2015

Four different kinds of coffee beans (CS, Colombia supremo; EY, Ethiopia yirgacheffee; IM, Indonesia mandheling; and IMM, India monsooned malabar) were roasted at 200 and $250^{\circ}C$ for 10, 15, and 20 min. To determine the optimum roasting conditions, various components of the coffee beans such as pyrazines produced during the roasting, and their antioxidant and antidiabetic effects were analyzed. The different roasting condition did not affect on the concentration of caffeine. However, the amount of 5-caffeoylquinic acid and the total phenolics decreased significantly, at a greater temperature and a longer roasting time. The greatest amount of pyrazines was produced from the IMM however, the amount of pyrazines decreased rapidly at $250^{\circ}C$ according to increasing in roasting time. The DPPH free radical scavenging activity was mostly 80% more effective than that of BHT and ${\alpha}$-tocopherol activities at the same concentration. In the case of the FRAP assay, the reducing power of the coffee slightly decreased at a greater temperature pand longer time. While the inhibitory effect on ${\alpha}$-glucosidase was negligible, the activity decreased by more than 80% when the coffee beans were roasted at $250^{\circ}C$ for 20 min. The inhibitory effect on ${\alpha}$-amylase showed similar results. Taken together, the optimum roasting conditions were determined to be $200^{\circ}C$ and 15 min, which provided the best physiological activity and nutty and chocolatey aromas from the pyrazine of coffee.

• The Korean Journal of Food And Nutrition
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• v.30 no.6
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• pp.1222-1228
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• 2017

In the current study, we investigated the inhibitory activity of water soluble ${\beta}-glucan$ from oat (Avena sativa) against various digestive enzymes such as ${\alpha}-glucosidase$, sucrase, maltase and glucoamylase. Inhibition of these enzymes involved in the absorption of disaccharide can significantly decrease the post-prandial increase of blood glucose level after a mixed carbohydrate diet. The ${\beta}-glucan$ had the highest documented rate of small intestinal sucrase inhibitory activity (2.83 mg/mL, $IC_{50}$) relevant for potentially managing post-prandial hyperglycemia. Furthermore, we evaluated the effects of ${\beta}-glucan$ on the level of post-prandial blood glucose in animal model. The post-prandial blood glucose levels were tested two hours after sucrose/starch administration, with and without ${\beta}-glucan$ (100, and 500 mg/kg-body weight). The maximum blood glucose levels (Cmax) of ${\beta}-glucan$ administration group were decreased by about 23% (from $219.06{\pm}27.82$ to $190.44{\pm}13.18$, p<0.05) and 10% (from $182.44{\pm}13.77$ to $165.64{\pm}10.59$, p<0.01) in starch and sucrose loading test, respectively, when compared to control in pharmacodynamics study. The ${\beta}-Glucan$ administration significantly lowered the mean, maximum, and minimum level of post-prandial blood glucose at 30 min after meal. In view of the foregoing, it is felt that our findings suggest that ${\beta}-glucan$ from oat serves to reduce post-prandial blood glucose rise secondary to slower absorption of glucose in the small intestine, via carbohydrate hydrolyzing enzymes inhibition.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.2
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• pp.89-102
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• 2009

Objectives : The purpose of this study was evaluated hypoglycemic effect of culture broth of germanium-fortified Tricholoma matsutake mycelium and yeast. Methods : We examined $\alpha$-glucosidase inhibitory activity, blood glucose level, concentration of serum lipid, and serum metabolic variables of Tricholoma matsutake mycelium and yeast fortified Germanium. in streptozotocin induced diabetic rat. Results : In the $\alpha$-glucosidase inhibitory activity, germanium-fortified yeast was significantly higher than germanium-fortified Tricholoma matsutake mycelium. The hypoglycemic effects of germaniumfortified Tricholoma matsutake mycelium was higher than germanium-fortified yeast. The activity of alkaline phosphatase(ALP), aspartate aminotransferase(AST) and alanine aminotransferase(ALT) was significantly lower in the germanium-fortified Tricholoma matsutake mycelium and yeast than in diabetic control(DC) group and diabetic positive control(PC) group. The concentration of total cholesterol and triglyceride of germanium-fortified yeast was significantly lower than germanium-fortified Tricholoma matsutake mycelium, DC group and PC group. Conclusions : The results suggest that germanium-fortified Tricholoma matsutake mycelium and yeast have improvement effects in blood glucose, serum lipid and liver function.

• Journal of Life Science
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• v.26 no.8
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• pp.921-927
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• 2016

Postprandial hyperglycemia is an early defect of type 2 diabetes and one of primary anti-diabetic targets. The alpha-glucosidase inhibitors regulate postprandial hyperglycemia by impeding the rate of carbohydrate (such as starch) digestion in the small intestine. This study was designed to investigate the inhibitory actions of mulberry fruit extract (MFE) on α-glucosidase and α-amylase activities, and its alleviating effect on postprandial hyperglycemia activities in vitro and in vivo. Male four-week old ICR mice and streptozotocin (STZ)-induced diabetic mice were treated with mulberry fruit extract. MFE showed strong inhibitory effects against α-glucosidase and α-amylase activities, with half-maximal inhibitory concentration (IC₅₀) values of 0.16 and 0.14 mg/ml, respectively, and was more effective than acarbose, which was used as a positive control. The increase in postprandial blood glucose levels was more significantly attenuated in the MFE-administered group mice than in the control group mice of both STZ-induced diabetic and normal mice. Moreover, the area under the glucose response curve significantly decreased following MFE administration in diabetic mice. These results indicate that MFE may be a potent inhibitor of α-glucosidase and α-amylase, and helpful in suppressing postprandial hyperglycemia in diabetic mice. The mulberry fruit extracts may be considered as a potential candidate for the management of diabetes.

• Journal of Life Science
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• v.24 no.9
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• pp.1006-1011
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• 2014

Ginseng has been known to be highly effective for health as a traditional medicinal herb. Ginseng berry, or fruit of ginseng, contains ginsenoside, saponin, polyphenol, polyacetylene, alkaloid, etc. as the main compounds as does ginseng. The aim of this study is to evaluate any effect of ginseng berry water extract (GBE) on diabetic-associated molecules, such as enzymes, which are responsible for the glucose entry of the cells and the insulin receptor signaling molecules using HepG2 cells. Therefore, two enzymes, ${\alpha}$-amylase and ${\alpha}$-glucosidase, were selected and assayed for their activities in the presence of GBE in vitro. These two enzymes are responsible for producing glucose from dietary starch. Protein-tyrosine phosphatase 1B (PTP1B) and Akt1 are key proteins in the insulin receptor signaling pathway. These two intracellular signaling molecules were investigated for their expression levels in HepG2 cells after insulin and GBE treatment. GBE, at concentrations up to $1,000{\mu}g/ml$, did not exert any inhibitory effect on ${\alpha}$-amylase and ${\alpha}$-glucosidase. It was observed that the expression level of PTP1B was increased by insulin and the $25{\mu}g/ml$ GBE treatment enhanced the PTP1B level. However, GBE at a concentration of $200{\mu}g/ml$ reduced the expression level of PTP1B. In the case of Akt1, the Akt1 level by insulin was decreased by GBE treatment. These data suggest that the water extracts of ginseng berry have an influence on intracellular signaling by insulin.