• Journal of Life Science
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• v.30 no.11
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• pp.965-972
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• 2020

Sambucus sieboldiana var. miquelii (Nakai) Hara is distributed in Korea, China, and Japan, and has been used as an anti-rheumatic in folk medicine in oriental countries. The present study aims to investigate the potential use of this species in health functional foods, cosmetics, and food preservatives. Methanol extracts of leaves and branches from this plant were prepared to quantitatively analyze the total phenol and flavonoid contents, and to investigate the antioxidative and enzyme inhibitory activities, and the inhibition of nitric oxide (NO) production activity. The results showed that the total polyphenol and flavonoid contents of the crude extract were 1.52±0.1 mg/g and 1.73±0.1 mg/g, respectively. S. sieboldiana polyphenols exhibited potent scavenging activity shown by 2, 2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and 2, 2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation assay. The crude extract also exhibited significant α-glucosidase and tyrosinase inhibitory activity with IC₅₀ values of 183.5 ㎍/ml and 323.9 ㎍/ ml, respectively. Additionally, the crude extract exhibited strong anti-inflammatory activity determined through the nitric oxide inhibition assay in a dose-dependent manner with an IC₅₀ value of 36.7 ㎍/ml and no cytotoxic effect on the macrophages. Therefore, we demonstrated that the leaves and branches of S. sieboldiana extract possess antioxidant, anti-diabetic, depigmentation potential, and NO production inhibitory activities. According to recent research, S. sieboldiana has great potential as a source of the bioactive compound which could be used as food, cosmetics, and pharmaceutical agents.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.551-558
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• 1992

The extracellular endoinulase from Streptomyces sp. 556 was purified and characterized, The culture broth was fractionated by ammonium sulfate saturation followed by DEAE-cellulose column chromatography and 5ephadex G-200 gel filtration, The ultimately purified fraction revealed a single band in 7.5% polyacrylamide gel electropherogram. The purified enzyme showed the maximal activity at pH 5.5-6.0 and $50^{\circ}C$, but lost 93% of inulase activity after 30 min incubation at $55^{\circ}C$ . The essen.tial amino acid residue for catalytic activity appeared to be tryptophan. This endo inulase was activated by $Mn^{2+}$, whereas inactivated by $Ag^{+}$, $Hg^{+}$, $Cu^{2+}$, $Zn^{2+}$, $Fe^{3+}$ and $Mo^{6+}$ EDTA and 8-hydroxyquinoline inhibited the enzyme so that the enzyme was considered to be a metalloenzyme. The Km value for inulin was 0.287 mM, and no invertase or $\alpha$-glucosidase activity was found in the enzyme.

• Journal of Life Science
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• v.30 no.1
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• pp.18-25
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• 2020

This study was designed to investigate whether Loranthus parasiticus extract (LPE) could inhibit the activities of carbohydrate digestive enzymes and alleviate postprandial hyperglycemia in diabetic mice. Lyophilized L. parasiticus was extracted with 80% ethanol and concentrated. The inhibitory effects of LPE on carbohydrate digestive enzymes were evaluated by examining α-glucosidase and αamylase, and it was seen to inhibit the activities of both enzymes in a dose-dependent manner. More specifically, the IC50 values of LPE against α-glucosidase and α-amylase were 0.121±0.007 and 0.157±0.004 mg/ml, respectively, significantly lower than those of acarbose, showing that LPE has stronger inhibitory effects than the positive control. These results suggest that LPE strongly inhibits the activities of these digestive enzymes. Blood glucose levels in the control group of diabetic mice increased to 490.00±28.52 mg/dl and 474.60±25.30 mg/dl at 60 and 120 min after a meal, respectively. However, when LPE was added to starch, postprandial blood glucose levels were significantly reduced (463.0±23.73 and 418.5±24.50 mg/dl at 60 and 120 min, respectively; p<0.05). The area under the curve also significantly decreased following administration of LPE, with no cytotoxicity. These results therefore indicate that LPE could be used as an α-glucosidase and α-amylase inhibitor and delay carbohydrate digestion and, thus, glucose absorption after a meal.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.402-406
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• 2014

Six kinds of newly recorded yeasts such as Rhodosporidium diobovatum SY4-2, Cryptococcus bestiolae SY7-1, Kazachstania unispora SY14-1, Kazachstania servazzii SY14-3, Pichia holstii SY20-2 and Cryptococcus tephrensis SY26-1 were screened from sixty one yeasts derived from wild flowers found in Seonyudo, Gogunsanyeoldo, Jeollabuk-do, Korea. All of them grew in 50% glucose-containing yeast extract-peptone-dextrose (YPD) broth and Pichia holstii SY20-2 was also halophile, growing in 20% NaCl-containing YPD broth. All of them, except Cryptococcus tephrensis SY26-1, were assimilated to glucose. Cell-free extract from Kazachstania servazzii SY14-3 showed the highest 98.6% of ${\alpha}$-glucosidase inhibitory activity and maximal production of the ${\alpha}$-glucosidase inhibitor was obtained with 24h incubation at $30^{\circ}C$. The antihypertensive angiotensin I-converting enzyme inhibitory activity of the unrecorded yeasts were showed 58.6-80.4% in their supernatants.

• The Korean Journal of Food And Nutrition
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• v.28 no.2
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• pp.295-301
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• 2015

Biological compounds such as crude saponin and total polyphenol were determined in Allium hookeri roots and leaves. In addition, activities of DPPH radical scavenging activity, hydroxyl radical scavenging activity, ${\alpha}$-amylase inhibition activity and nitrite scavenging were detected in concentrates of 70% ethanol extracts of Allium hookeri roots and leaves. The crude saponin content of the roots and leaves were 4.28 mg/g, and 4.17 mg/g, respectively. Total polyphenol and total flavonoid content was higher in leaves than roots. Furthermore the DPPH radical scavenging activity and hydroxyl radical scavenging activities of leaves was higher than roots. For ${\alpha}$-glucosidase inhibitory activity, 70% ethanol extracts of Allium hookeri roots and leaves showed 60% activity inhibition at a 10 mg/mL concentration. Nitrite scavenging abilities under acidic conditions were most effective for Allium hookeri leaves extracts. These results suggested that Allium hookeri leaves might be used as the components of health functional food.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.763-771
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• 2015

Components and physiological activity of crops are strongly affected by the natural environments of the growth regions. In this study, we carried out soil analysis and determined the allicin, alliin, total pyruvate, total phenol and flavonoid, and reducing sugar contents of garlic from garlic-cultivating regions in the eastern and western portions of Jeju Province. Significantly higher contents of macronutrients were found in the soil and garlic from the eastern region of Jeju compared to western region, but micronutrients were higher in the western region than eastern region. In addition, the alliin and total phenolic contents were higher in the western region than in the eastern region. Also, allicin, total pyruvate, total flavonoid content, and ${\alpha}$-glucosidase inhibitory activity of the eastern region samples were higher than those of the western region in Jeju. This study promotes our understanding of the different components of garlic according to the cultivation regions of Jeju.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1637-1644
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• 2015

To develop health-functional food ingredients for improvement of diabetes, we examined biological activities, including total contents of polyphenols and flavonoids, antioxidant activity, and inhibition of ${\alpha}$-glucosidase and pancreatic lipase activities of ethanol extracts from unripe fruit of Momordica charantia L. cultivated in Hamyang, Korea. Ethanol extracts were tested using different ethanol concentrations (0%, 30%, 50%, and 70%) and temperatures ($50^{\circ}C$ and $70^{\circ}C$). Experimental results showed that total polyphenol and flavonoid contents were achieved concentrations of 7.77 mg/g (tannic acid), 7.66 mg/g (gallic acid), and 10.66 mg/g (rutin). The hydroxyl radical scavenging, ABTS cation radical scavenging, and FRAP activities were 82.19%, 42.82%, and 0.19 under the same conditions, respectively. The highest inhibitory activities of ${\alpha}$-glucosidase and pancreatic lipase were achieved in the 70% ethanol extract at $70^{\circ}C$. These results will be useful for development of health functional foods for anti-diabetes using 70% ethanol extract from unripe fruit of bitter melon.

• Food Science and Preservation
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• v.24 no.2
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• pp.282-288
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• 2017

This study provided the evidence activity for biological of phenolic compounds from Trachelospermum asiaticum var. intermedium nakaier as a beauty food. The contents of phenolic compounds in water and 70% ethanol extracts were 16.8 mg/g and 38.1 mg/g, respectively. DPPH free radical scavenging activities of water and ethanol extracts at $100{\mu}g/mL$ of phenolic concentration were 80.9% and 83.1%, respectively. ABTS radical decolorization activity was 95.0% in water extracts and 95.8% in ethanol extracts at $200{\mu}g/mL$ phenolic concentration. Antioxidant protection factor (PF) was determined to 2.43 and 2.45 PF in water extracts and ethanol extracts at $100{\mu}g/mL$ phenolic concentration. TBARs of water and ethanol extracts were 89.9% and 89.3% each at $200{\mu}g/mL$ phenolic concentration. The inhibitory effect of ethanol extracts at $200{\mu}g/mL$ phenolic concentration on xanthine oxidase was 50.5%. The inhibitory activity of a-glucosidase was 92.6% in ethanol extracts at $200{\mu}g/mL$ phenolic concentration. As a result, this study will provide valuable information as a functional material with antioxidant activity, inhibitory activities of xanthin oxidase and ${\alpha}-glucosidase$.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.3
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• pp.451-459
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• 2015

Raw-red bean (RR) should be boiled in hot water, and only boiled-red bean (BR) has been used in the food industry. In the course of development of functional food using red- bean (Phaseolus radiatus L), hot- water extracts (HWEs) of RR and BR were prepared, respectively and their components and various biological activities were compared. The extraction yield at $100^{\circ}C$ of RR (16.2%) was higher than that of BR (14.8%), and contents of total polyphenols, total flavonoids and reducing sugars of HWE of RR were 2.5-fold, 2.1-fold and 1.5-fold higher than those of HWE of BR. In anti-oxidation activity assay, scavenging activities against DPPH anion and ABTS cation as well as reducing power of RR was higher than those of BR. The results suggest that the anti-oxidant compounds in red bean might be heat-liable or discarded during boiling in hot-water as a cooking drip. Unexpectedly, nitrite scavenging activity was stronger in HWE of BR than RR. In anti-microbial activity assay, HWE of RR ($500{\mu}g/disc$) showed growth inhibition activity against gram-positive bacteria, whereas HWE of BR did not show any activity against any tested bacteria and fungi. Assay of in-vitro anti-diabetes and anti-thrombosis activities, which were previously reported in ethanol extract of red-bean, revealed that HWEs of RR and BR did not show significant activities against ${\alpha}$-amylase, ${\alpha}$-glucosidase, thrombin, prothrombin, or blood coagulation factors. Our results suggest that the anti-oxidation, anti-diabetes and anti-thrombosis activities of HWEs of RR and BR were lower than those of ethanol extracts of red bean, and bioactive substances in RR were destroyed during boiling or discarded after boiling. Further research on suitable boiling and re-use of cooking drip of red bean is necessary.

• Journal of Life Science
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• v.32 no.1
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• pp.1-10
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• 2022

Natural products have gained increasing attention due to their advantage of long-term safety and low toxicity for a very long time. Torreya nucifera is widespread in southern Korea and Jeju Island and its seeds are commonly used as edible food. Oriental ingredients have often been reported for their insecticidal, antioxidant and antibacterial properties, but there have not yet been any studies on their antidiabetic effect. In this study, we investigated several biological activities of T. nucifera pericarp (TNP) and seeds (TNS) extracts and proceeded to characterize the antidiabetic compounds of TNS. The initial results suggested that TNS extract at 15 and 10 ㎍/ml concentration has inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, that is 14.5 and 4.35 times higher than TNP, respectively. Thus, the stronger antidiabetic TNS was selected for the subsequent experiments to characterize its active compounds. Ultrafiltration was used to determine the apparent molecular weight of the active compounds, showing 300 kDa or more. Finally the mixture was then partially purified using Diaion HP-20 column chromatography by eluting with 50~100% methanol. Therefore we concluded that the active compounds of TNS have potential as therapeutic agents in functional food or supplemental treatment to improve diabetic diseases.