This study was conducted to analyze the antioxidant and antidiabetic activities of acorns according to the types of Quercus serrata Thunb (QST) and Q. acutissima Carruther (QAC). The total polyphenol contents of the extracts from QST and QAC were 220.59 and 320.96 mg GAE/g, respectively. The content of total polyphenol of QAC was higher than that of QAC (p<0.001). DPPH (2,2 Diphenyl 1 picrylhydrazyl) radical scavenging activity, reducing power and superoxide dismutase (SOD)-like activity were increased in a concentration-dependent manner by both acorn extracts, and QAC showed high activity in all antioxidant experiments (p<0.05). The inhibitory activities of α-glucosidase and α-amylase were also increased in a concentration-dependent manner, and QAC showed higher inhibitory activity than QST (p<0.05). Our study indicates that QST and QAC are functional food materials with high antioxidant and antidiabetic activities. In addition, QAC has a higher physiological activity than QST.

This study was performed to investigate the antioxidant and antidiabetic activities of soybean fermented with Monascus. Also, the changes in the content of isoflavones and Monacolin K were analyzed. It was observed that the glycoside forms of daidzin and genistin were converted to aglycones of daidzein and genistein within 6 days of fermentation. The product can be used as a health functional material that can increase bioavailability. Monacolin K production was found to increase significantly with the progression of fermentation with an increase to 0.04 mg/g and 0.44 mg/g on 6 and 12 days of fermentation, respectively. The DPPH radical scavenging activity of soybean fermented with Monascus was significantly increased compared to that of soybean. The protein expression of inflammation-related genes (TNF-α, IL-6, and COX-2) in the MIN cell was significantly increased in the presence of alloxan compared to the normal group, but a decrease was observed in the presence of soybean fermented with Monascus. In conclusion, soybean fermented with Monascus showed the highest antidiabetic and antioxidant effects. These results suggest that soybean fermented with Monascus has the potential to be used as a beneficial ingredient with antidiabetic and antioxidant effects.

In this study, we assessed antioxidant, anti-diabetic, and anti-Alzheimer activities of Opuntia ficus-indica var. saboten (OFI) at harvest time. OFIs were cultivated December 2015~November 2016 in Jeju island. The 70% ethanol extracts of OFI were used to investigate total polyphenol and flavonoid contents, antioxidant(DPPH and ABTS radical scavenging assay), anti-diabetic(yeast α-glucosidase and rat α-glucosidase inhibition assay), and anti-Alzheimer(Acetylcholinesterase and butyrylcholinesterase inhibition assay) activities. Total polyphenol and flavonoid contents of OFIs were 17.40~23.11 μg garlic acid/mg Ex and 2.17~6.22 ug (+)-catechine/mg Ex, respectively. DPPH and ABTS radical scavenging activity of OFIs were 131.98~184.90 mg ascorbic acid(AA) eq/100 g and 63.60~101.83 mg AA eq/100 g, respectively. In the anti-diabetic and anti-Alzheimer activities, 70% ethanol extracts of OFI exhibited moderate inhibition activity, compared to control (acarbose and beberine). Total polyphenol and flavonoid contents, antioxidant, anti-diabetic, and anti-Alzheimer activities were no significant differences by season, respectively. Therefore, information on comparative biological evaluations of OFI may be a beneficial in exploring functional food and drug development.

This study aimed to evaluate the efficacy of the antioxidative and antidiabetic activities of the flowers, leaves, and roots of the Jerusalem artichoke (Helianthus tuberosus L.). The total polyphenol and flavonoid contents of the leaves were higher than those of the flowers and roots. However, the DPPH radical-scavenging and hydroxyl radical-scavenging activities of the flowers were higher than those of the leaves and roots. The nitrite-scavenging ability under acidic conditions was high in Jerusalem artichoke flower extracts. The α-glucosidase inhibitory activity and α-amylase inhibitory activity of a methanol extract of Jerusalem artichoke roots were about 60% (5 mg/mL concentration). Based on these experiments, it can be concluded that the flowers leaves, and roots of the Jerusalem artichoke can be used as natural preservatives. Therefore, they can be developed as functional foods, to take advantage of their antioxidant activity and abundant polyphenols. This study suggests that the whole Jerusalem artichoke, including roots, leaves, and flowers, is useful as a functional, nutritious food product.

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-TI5 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㎕/㎖ and in particular, FA showed the highest amount of insulin-release in HIT-TI5 cells. Antioxidative effects on BIT-TI5 cells, RB-ex and hydroxycinnamic acids, excluding p-CA, showed inhibitory activities of 78% to 80% at a concentration of 100㎕㎖. 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.

Background : Cudrania tricuspidata Bureau belonging to the mulberry family has attracted much attention as a nutrition ingredient many times as many as the mulberry tree. In this study, we examined the inhibitory effect of hot water extract of Cudrania tricuspidata Bureau fruits (CT-F) on inflammation and inflammatory diseases such as diabetes and gastiritis in cell-level experiments and animal models using mice. Methods and Results : The inhibitory effect of CT-F was investigated in LPS_stimulated RAW264.7 macrophages. Treatment with CT-F significantly inhibited the production of inflammatory mediators such as NO, IL-6 and TNF-a. The inhibitory effect of CT-F was shown to be related to inhibition of NF-kB activation in LPS-stimulated macrophages. In in vivo diabetic models using mice, treatment of CT-F lowered the level of blood glucose in alloxan-induce type-1 diabetic model as well as db/db type-2 mice model. CT-F also dramatically inhibited gastiritis induced by EtOH/HCl in mice. Conclusion : Hot water extract of Cudrania tricuspidata Bureau fruits was effective for inhibition of inflammation, diabetes and gastirits. Therefore, CT-F is thought to be a beneficial candidate for development of functional foods to prevent inflammation-associated diseases.

This study investigated the antioxidant and antidiabetic activities of Stachys sieboldii Miq. extracts by solvents (water, ethanol, butanol, chloroform, and hexane). The contents of total polyphenols (7.18-37.25 mg/g) and flavonoids (0.21-5.21 mg/g) in extracts from Stachys sieboldii Miq. showed a significant difference dependent on the extraction solvents, butanol > ethanol > water > chloroform > hexane. Antioxidant activities by DPPH and ABTS radical scavenging were increased in a dose-dependent manner. These activity trends associated with the extraction solvent were different at each concentration, but resembled phenolic compound contents trend, generally. FRAP value increased in a dose-dependent manner, but there was a difference in radical scavenging activities when comparing between extraction solvents by butanol > ethanol > hexane > chloroform > water on all concentrations. The trend of α-amylase inhibition of extracts from 1,000 μg/mL to 2,000 μg/mL was not affected as enzyme activity is promoted and not inhibited. The inhibition of α-glucosidase was increased in a dose-dependent manner without water extracts, the activity on hexane extracts was higher than others per the extraction solvent. α-Glucosidase inhibition of hexane extracts showed 57.76% at 250 μg/mL, which is 2.8 times higher than the second highest chloroform extract (20.65%). From these results, we presume that the active ingredients of Stachys sieboldii Miq. is different according to the extraction solvent and also the activity is different by these major functional groups.

C3GHi 쌀 품종은 흑진주벼와 수원425호를 교배조합으로 하여 색소 성분인 cyanidine-3-glucoside(C3G)의 함량을 비약적으로 증대시킨 품종이다. C3GHi 벼품종을 활용하여 기능성 제품 및 소재로의 개발 가능성을 타진하기 위하여 본 연구에서는 C3GHi 벼품종의 항산화 활성 및 항당뇨 기능의 검증을 수행하였다. 1. C3GHi 벼품종의 항산화 활성을 비교 분석한 결과에서 C3GHi는 일반 벼 및 흑진주벼보다 매우 우수한 항산화 활성을 가진 것으로 나타났으며, 대표적 항산화 소재인 glutathione과 유사한 활성을 나타내었다. 2. C3GHi 벼품종의 혈당지수를 인체 시험을 통해서 산출한 결과에서도 일반 현미나 백미에 비해서 15%정도 낮은 혈당지수를 나타내 당뇨 환자들의 식사 대용식의 소재로서 활용 가능성이 높을 것으로 사료된다. 3. db/db mice 모델 및 STZ를 통해 당뇨병을 유발한 동물 모델에서 C3GHi 쌀추출물 및 C3GHi쌀 현미의 동결건조 분말이 혈당 상승을 막고, 산화적 손상을 억제하는 것으로 나타났다. 4. 이상의 결과에서 C3GHi쌀은 낮은 혈당지수 및 항산화 활성, 항당뇨 활성 등을 보유하고 있어 이후 당뇨 환자용 기능성 식사 대용식 및 기능성 식품 원료로서의 개발 가능성이 높다고 판단된다.

Machilus thunbergii was an important medicinal resource and distributed widely in China. In this study, the bioactivities of dichloromethane fraction (DF) and water fraction (AF) from Machilus thunbergii methanol extract were investigated. Total phenolic contents of DF and AF were 57.90 mg Gal/g and 189.92 mg Gal/g, and total flavonoid contents were 17.34 mg Que/g and 58.38 mg Que/g respectively. The EC50 for DPPH radical scavenging activity of DF and AF were 24.37 μg/ml and 2.10 μg/ml. Reducing power and hydroxyl radical scavenging activities of AF were higher than those of DF. The α-glucosidase inhibitory activity of AF (IC50 = 1.13 μg/ml) was higher than that of DF (IC50 = 5.34 μg/ml). The cell viability was showed that only the DF had anti-proliferation effect on human cancer cell HT-29. These results suggested that both the DF and AF extract of Machilus thunbergii were potential materials for anti-diabetes and functional food for their radical scavenging activity.