• Journal of Dairy Science and Biotechnology
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• v.37 no.4
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• pp.223-236
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• 2019

This study aimed to investigate the physiological characteristics and anti-diabetic effects of Lactobacillus plantarum KI69. The α-amylase and α-glucosidase inhibitory activity of L. plantarum KI69 was 91.17±2.23% and 98.71±4.23%, respectively. The propionic, acetic, and butyric acid contents of the MRS broth inoculated with L. plantarum KI69 were 8.78±1.12 ppm, 1.34±0.07% (w/v), and 0.876±0.003 g/kg, respectively. L. plantarum KI69 showed higher sensitivity to penicillin-G, oxacillin, and chloramphenicol among 16 different antibiotics and showed the highest resistance to ampicillin and vancomycin. The strain showed higher β-galactosidase, β-glucosidase, and N-acetyl-β-glucosaminidase activities than other enzymes. Additionally, it did not produce carcinogenic enzymes, such as β-glucuronidase. The survival rate of L. plantarum KI69 in 0.3% bile was 96.42%. Moreover, the strain showed a 91.45% survival rate at pH 2.0. It was resistant to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus with the rates of 15.44%, 50.79%, 58.62%, and 37.85%, respectively. L. plantarum (25.85%) showed higher adhesion ability than the positive control L. rhamnosus GG (20.87%). These results demonstrate that L. plantarum KI69 has a probiotic potential with anti-diabetic effects.

• Food Science and Preservation
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• v.24 no.3
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• pp.483-489
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• 2017

Phloridzin is a predominant member of the chemical class of dihydrochalcones and mainly found in apple. The biological activity of phloridzin treated with dielectric barrier discharge (DBD) plasma was evaluated to investigate whether exposure to plasma can be used as a tools to enhance the biological activity of natural resources. DBD plasma treatment of phloridzin was carried out for three different exposure times. The antioxidant effects of degraded phloridzin for different reaction time were evaluated via radical scavenging assay using DPPH radical. In addition, the anti-diabetic and anti-obesity properties of the degraded phloridzin were measured based on ${\alpha}$-glucosidase and pancreatic lipase inhibitory activities. Phloridzin treated for 60 min showed significantly higher radical scavenging, ${\alpha}$-glucosidase and pancreatic lipase inhibitory activities compared to the tested positive controls. Degradation of phloridizin induced by DBD plasma might be responsible for enhancing the biological activity of phloridizin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.8
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• pp.989-994
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• 2007

This study was designed to investigate whether Sasa borealis leaves extracts (SLE) may inhibit yeast ${\alpha}-glucosidase$ and ${\alpha}-amylase$ activities and postprandial hyperglycemia in STZ-induced diabetic mice. Freeze-dried SLE was extracted with 70% methanol and followed by a sequential fractionation with dicholoromethan, ethylacetate, butanol, and water. Both ethylacetate and butanol fractions showed high inhibitory activities against the ${\alpha}-glucosidase$ and ${\alpha}-amylase$ enzymes. The $IC_{50}$ of ethylacetate and butanol fractions against ${\alpha}-glucosidase$ were 0.54 and 0.63 mg/mL, respectively, indicating a greater inhibition effect than acarbose (0.68 mg/mL) (p<0.05). Likewise, the two fractions exhibited a smaller $IC_{50}$ against ${\alpha}-amylase$, compared with acarbose (p<0.05). However, the yield of ethylacetate fraction of SLE was relatively small. Postprandial blood glucose testing of normal mice and STZ-induced diabetic mice by starch soln. loading (2 g/kg B.W.) showed that postprandial blood glucose level at 30, 60, and 120 min were markedly decreased by single oral administration of SLE butanol fraction (200 mg/kg B.W.) in both normal (p<0.0l) and diabetic mice (p<0.0l). Furthermore, the incremental area under the curve (AUC) was significantly lowered via SLE administration (5,745 versus 12,435 $mg{\cdot}mim/dL$) in the diabetic mice (p<0.0l). The incremental AUC in normal mice corroborated the hypoglycemic effect of SLE (p<0.0l) found in the diabetic mice. These results suggest that SLE may delay carbohydrate digestion and thus glucose absorption. In addition, SLE may have the potential to prevent and treat diabetes via its ability on lowering postprandial hyperglycemia.

• Journal of Life Science
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• v.23 no.5
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• pp.616-621
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• 2013

Aconitum pesudo-laeve var erectum has been known to possess anti-inflammatory activity and modulate the intestinal immune system. In addition, it has traditionally been used for the treatment of water retention in the body. In this study, the anti-aging and anti-diabetes effects of water and ethanol extracts from Aconitum pesudo-laeve var. erectum were investigated. The activities of each extract were measured by antioxidant tests such as DPPH and ABTS radical scavenging activity, antioxidant protection factor (PF), TBARs content, and ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibition activity assay. DPPH radical scavenging activity was found in over 50% of water and ethanol extracts at $100{\mu}g/ml$, $50{\mu}g/ml$, respectively. The ABTS radical scavenging activity of ethanol extract was $99.8{\pm}0.1$% at $1,000{\mu}g/ml$ in water, which was highest among the ethanol extract concentrations. PFs measured with ${\beta}$-carotene-linoleate model systems were in the order of ethanol (1.49 PF at $1,000{\mu}g/ml$) > ethanol (1.40 PF at $500{\mu}g/ml$) > water (1.33 PF at $1,000{\mu}g/ml$) > water (1.27 PF at $500{\mu}g/ml$). TBARs content in ethanol extracts ($1,000{\mu}g/ml$) was $0.16{\pm}0.03{\mu}M$, which was lower than that of water extracts and other ethanol extract concentrations. The extracts also showed over 90% of ${\alpha}$-amylase inhibition and over 60% of ${\alpha}$-glucosidase inhibition ratio in water ($1,000{\mu}g/ml$) and ethanol extracts (100~$1,000{\mu}g/ml$). These results suggest that Aconitum pesudo-laeve var. erectum extracts could be used as a cosmetic source and preventive agent for aging and diabetes.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.194-202
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• 2015

Agaricus brasiliensis, belonging to the family Agaricaceae of Agaricales, Basidiomycota, has been used for edible and medicinal purposes. This study was initiated to evaluate the antioxidant, anti-diabetic, and nitric oxide inhibitory activities of fruiting bodies of A. brasiliensis extracted with methanol. The HPLC analysis of phenolic compounds from the mushroom extracts identified 10 phenolic compounds including gallic acid, procatechuic acid, chlorogenic acid, (-)-epicatechin, vanillin, rutin hydrate, naringin, quercetin, formononetin, and biochanin-A. The free radical scavenging activities of methanol extract were lower than that of positive control, BHT. The chelating effects of methanol extract were significantly higher than those of the positive control, BHT at the all concentrations tested. The methanol extract exhibited the lower reducing power activities compared with the positive control at the 0.5~6.0 mg/mL concentration. The mushroom extract inhibited the ${\alpha}$-glucosidase activity by 54.48% and 78.43% at the 1.0 and 2.0 mg/mL while acarbose, the positive control, inhibited the ${\alpha}$-glucosidase activity by 51.77% and 81.81% at the same concentrations, respectively. Nitric oxide (NO) production in lipopolysaccahride (LPS) induced RAW 264.7 cells were inhibited by the methanol extracts in a concentration dependent manner. Therefore, it is concluded that fruiting bodies of A. brasiliensis contained natural antioxidant, anti-diabetic, and anti-inflammatory substances which can be useful for human health.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.325-334
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• 2013

The objective of this study was to compare the content and metabolic activities between fresh pine needle juice (PNJ) and fermented pine needle juice (FPNJ). A variety of factors were measured, including total phenolic content (TPC), antioxidant activity [DPPH radical scavenging activity (RSA), total radical-trapping antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), cellular antioxidant capacity (CAC)], anti-genotoxic activity, ${\alpha}$-glucosidase inhibitory activity, and angiotensin converting enzyme (ACE) inhibitory activity. The TPC was $17.3{\pm}0.2$ and $4.6{\pm}0.0$ mg GAE/g in PNJ and FPNJ, respectively. The DPPH RSA, TRAP, and ORAC values increased in a dose-dependent manner for both PNJ and FPNJ, with significantly higher activities in PNJ than FPNJ. The CAC against AAPH-induced oxidative stress in HepG2 cells was protected by both PNJ and FPNJ. Pretreatment with PNJ and FPNJ in human leukocytes produced significant reductions in $H_2O_2$-induced DNA damage at a concentration of $50{\mu}g/mL$. ${\alpha}$-Glucosidase inhibitory activity was significantly higher in FPNJ than PNJ. The ACE inhibitory activity was about 87.1% and 60.0% in 1:1 diluted PNJ and FPNJ, respectively. This study suggests that the fermentation of PNJ could enhance the regulation of blood glucose metabolism and both PNJ and FPNJ might be a new potential source of natural antioxidant, anti-diabetic, and anti-hypertensive agents applicable to food.

• Natural Product Sciences
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• v.18 no.2
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• pp.130-136
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• 2012

In the present work, we have collected 19 species of macroalgae (9 Phaeophta and 10 Rhodophyta) f rom all around of Korea: Dictyopteris divaricata, D. prolifera, Myelophycus cavus, Papenfussiella kuromo, Petalonia zosterifolia, Petrospongium rugosum, Rugulopteryx okamurae, Sargassum fulvellum, S. muticum, Callophyllis japonica, Gloiopeltis tenax, Gracilaria longissima, Gracilaria vermiculophylla, Grateloupia asiatica, Grateloupia lanceolata, Grateloupia sparsa, Grateloupia turuturu, Grateloupia sp, and Polyopes affinis. The macroalgal species were extracted by 70% ethanol (EtOH) for 24 h and evaluated its inhibitory effects on ${\alpha}$-glucosidase. Among ethanol extracts, Myelophycus cavus showed the most effectively inhibitory activity ($IC_{50}$, 2.17 ${\mu}g/ml$) against ${\alpha}$-glucosidase, followed by Sargassum fulvellum (<$IC_{50}$, 8.13 ${\mu}g/ml$), Dictyopteris prolifera ($IC_{50}$, 16.66 ${\mu}g/ml$), Rugulopteryx okamurae ($IC_{50}$, 50.63 ${\mu}g/ml$), and Petrospongium rugosum ($IC_{50}$, 101.62 ${\mu}g/ml$). Furthermore, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay showed no cytotoxicity on mouse pre-adipocytes cell line (3T3-L1). These results suggest that some edible macroalgae merit further evaluation for clinical usefulness as anti-diabetic functional foods.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.808-812
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• 2009

The ${\alpha}-glucosidase$ inhibitory and antioxidant effects of water chestnut (Trapa japonica Flerov.) were assessed to explore its possible use as an anti-diabetic agent. Methanol extracts of the fruit shell and meat of water chestnut were assayed for inhibitory activity against yeast ${\alpha}-glucosidase$ and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Effect of fruit shell extract on postprandial glucose response was assessed. Compared with fruit meat, shell extract showed stronger inhibition against ${\alpha}-glucosidase$ with an $IC_{50}$ of 273 ${\mu}g/mL$. Oral administration of fruit shell extract (500 mg/kg) significantly lowered the postprandial area under the glucose response curve to starch (1 g/kg) in streptozotocin (STZ)-induced diabetic rats (p<0.01). Compared with fruit meat, shell extract showed stronger scavenging activity against DPPH, with an $IC_{50}$ of 27.1 ${\mu}g/mL$. The results indicate that the fruit shell of water chestnut was effective in controlling postprandial hyperglycemia and exerted an antioxidant effect. Therefore, water chestnut may be useful in treating diabetes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1385-1390
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• 2016

Gallic acid is a representative hydroxybenzoic acid and is found in free form in several plants and in various esterified forms as a part of hydolyzable tannins. Convenient enzymatic transformation of trihydroxylated gallic acid with polyphenol oxidase originating from pear was evaluated to investigate whether polyphenol oxidase can be used as a valuable compound to improve the biological activity of gallic acid. Enzymatic oxidation processing of gallic acid using polyphenol oxidase was carried out for five different reaction times. The antioxidant effects of transformed gallic acid for different reaction times were evaluated via radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals. In addition, the anti-diabetic property of the transformed gallic acid was measured based on ${\alpha}$-glucosidase. Gallic acid reacted for 5 h showed significantly higher antioxidant and ${\alpha}$-glucosidase inhibitory activities compared to the tested positive control substances. Biotransformation of simple gallic acid induced by polyphenol oxidase might be responsible for enhancing the biological activity of gallic acid.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.542-547
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• 2008

The anti-diabetic effects of water extracts (WE) from medicinal herbs on hepatic glucose-regulating enzymes, such as glucokinase (GCK), pyruvate dehydrogenase (PDH), acetyl-CoA carboxylase (ACC) and ${\alpha}$-glucosidase, were studied using the cytosol fraction in liver and mitochondia fraction in heart of a type II diabetic animal (GK rat, Goto-Kakizaki). The free radical scavenging activity of water extracts by DPPH method was also tested. We found that free radical scavenging activity was strong in Corni fructu (CF), Mokdan Bark (MDB), Chenhwabon (CHB) and Sanyack (SY), while that of Backbocreng (BBR), Shuckgihwang (SGH) and Taecsa (TS) was lower. For GCK activity in cytosol of liver, CF and CHB had a more effective activity than other extracts. PDH activity in mitochondria fraction of heart was higher in all of the extracts, expect for the TS extract, than in the control. ACC activity in cytosol fraction of liver was significantly higher in the CF, CHB, SGH, TS and SY extracts than in the control. CF, BBR and MDB led to a decrease in the ${\alpha}$-glucosidase activity. Therefore, these results suggest that all of the extracts may be used as functional material in the development as anti-diabetic functional food and medicine.