• Journal of Life Science
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• v.28 no.4
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• pp.421-428
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• 2018

Postprandial hyperglycemia plays an important role in the development of Type 2 Diabetes and diabetic complications. Controlling postprandial hyperglycemia is the most important factor for reducing the risks of diabetic complications in Type 2 diabetic patients. This study was designed to determine whether Portulaca oleracea L. extract suppresses the activation of carbohydrate-digesting enzymes, and lowers postprandial hyperglycemia in diabetic mice through streptozotocin. P. oleracea was extracted with either 80% ethanol (PEE) or water (PWE), and the extract solutions were concentrated. The ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibition assays were performed using the chromogenic method. Normal mice and STZ-induced diabetic mice were orally treated with PEE, PWE (300 mg/kg of body weight) or acarbose (100 mg/kg of body weight), with soluble starch (2 g/kg of body weight). The ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory effectiveness by PEE were markedly more effective than PWE, and both extracts indicated a higher effectiveness than the acarbose (positive control). The rise in postprandial blood glucose due to starch loading was markedly inhibited in the PEE group when compared to the control group in diabetic and normal mice. Furthermore, the area under the concentration-time curve values were markedly declined by the PEE injection in the diabetic group when compared to that exerted for the control group. These results demonstrate that P. oleracea extracts lower postprandial hyperglycemia by inhibiting carbohydrate-digesting enzymes, and that the ethanol extract is more efficacious than the water extract.

• Applied Biological Chemistry
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• v.38 no.4
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• pp.302-307
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• 1995

Four strains of lactic acid bacteria which produced bacteriocins inhibitory to Listeria species were isolated from Kimchi, and were identified as Leuconostoc mesenteroides subsp. mesenteroides (2 strains), Leuconostoc paramesenteroides and Pediococcus pentosaceus. The bacteriocins produced by the isolates inhibited all of the Listeria monocytogenes strains tested, but L. denigrificans 28 and L. welchimeri 89 were not inhibited by the bacteriocin produced by the Leu. paramesenteroides isolate. The bacteriocin produced by the P. pentosaceus isolate was more inhibitory against sensitive strains and showed broader spectrum of antimicrobial activity than those produced by other isolates. The bacteriocins produced by Leuconostoc isolates were sensitive to pronase E treatment, but that produced by the P. pentosaceus isolate was not completely inactivated. The bacteriocins produced by all of the isolates were not sensitive to catalase, ${\alpha}$-amylase and lysozyme and heat (30 min at $100^{\circ}C$) treatments.

• Journal of Life Science
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• v.22 no.7
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• pp.920-927
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• 2012

The objective of this research was to develop the functional material of water and 60% ethanol extracts from nine kinds of mulberry fruits (Morus alba L.) that influence the inhibitory activity on angiotensin-converting enzyme, xanthine oxidase, ${\alpha}$-amylase, and ${\alpha}$-glucosidase. The total phenolic contents in the water extracts were over 2 mg/g in two species (Cheongilppong and Kangwon III) and five species (Daeyoupchosaeng, Cheongilppong, Kangwon III, Hihak, and Cataneo) of 60% ethanol extracts. The inhibitory activity against the angiotensin-converting enzyme was determined with them. Baekwoon III was $90.9{\pm}4.5%$ in the water extracts, and Hihak was $81.8{\pm}4.5%$ in the 60% ethanol extracts. The inhibitory activity of Kuksang 20 against xanthin oxidase was about 10% in the water extracts, and Cataneo was $21.4{\pm}2.3%$ in the 60% ethanol extracts. Six of the species (Daeyoupchosaeng, Suwonppong, Cheongilppong, Kangwon III, Hihak, and Kuksang 20) in the water extracts showed inhibitory activities against ${\alpha}$-amylase, as 100%, respectively. The inhibitory activity of ${\alpha}$-glucosidase was determined for these nine species. Four species (Baekwoon III, Daeyoupchosaeng, Cheongilppong, Kangwon III, Hihak, and Kuksang 20) in the water extracts and three species (Daechoukmyeun, Kangwon III, and Kuksang 20) in the 60% ethanol extracts showed inhibition of over 20%. The results revealed strong biological activity in spite of little total phenolic contents. These water and 60% ethanol extracts with high-quality biological activity from various mulberry fruits (Morus alba L.) are expected to represent good candidates for the development of antihypertentive and antidiabetes sources.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.571-577
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• 2010

Korean traditional medicinal herbs have been reported to possess antioxidant and anti-hyperglycemic activities. We tested the antioxidant and anti-hyperglycemic activities of 6 kinds of medicinal herbs: Angelica gigas N., Poria cocos, Mori radicis Cortex, Mori folium, Aralia elata Cortex, and Panax ginseng, prepared as hot water, ethanol, and sonication extracts. The antioxidant activities of the extracts were examined by performing total polyphenol, total flavonoid, and ${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) assays. For M. folium, the ethanol extract showed the strongest effects in DPPH radical scavenging activity among the three extraction methods. In addition, sonication extracts of M. radicis Cortex and M. folium showed the highest inhibitory activities for ${\alpha}$-glucosidase among the different extracts. The ethanol extracts of M. folium had the highest inhibition effects against ${\alpha}$-amylase. A direct correlation between antioxidant and anti-hyperglycemic inhibition activity was found in the ethanol and sonication extracts. From the results, it is considered that these six medicinal herbal extracts have antioxidative, anti-hyperglycemic, and correlation effects based on different extraction methods.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.101-108
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• 2014

This study was conducted in order to compare the biological activities of water extracts and sugar immersion extracts of green pepper (Capsicum annuum L.), purslane (Portulaca oleracea L.) and shiitake (Lentinula edodes (Berk.) Pegler) by measuring total polyphenol and flavonoid contents, antioxidant activities and inhibitory effects on ${\alpha}$-amylase and ${\alpha}$-glucosidase. The contents of total polyphenols and flavonoids were higher in water extracts than in sugar immersion extracts. The anti-oxidative activities of water and sugar immersion extracts were measured using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity assay and reducing power assay. All extracts scavenged radicals in a concentration-dependent manner, and water extracts showed stronger radical scavenging activity and reducing power than sugar immersion extract. However, they all exhibited lower activities than ascorbic acid. Compared to the anti-diabetic drug acarbose, which was used as a positive control, the two types of extracts exhibited low ${\alpha}$-glucosidase inhibitory activities, although the activity of sugar immersion extracts were 2-fold higher than that of water extracts. ${\alpha}$-Amylase inhibitory action was not observed for any of the extracts. Finally, by cytotoxicity test, we confirmed that sugar immersion extracts were safer than water extracts. These results indicate that water extracts and sugar immersion extracts of green pepper, purslane and shiitake have different advantages in terms of their antioxidant and anti-diabetic effects, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1308-1315
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• 2017

This study was conducted to develop Momordica charantia L. juice fermented by four Lactobacillus species such as Lactobacillus paracasei (LPA), Lactobacillus plantarum (LPL), Lactobacillus rhamnosus (LRH), and Lactobacillus reuteri (LRE) as well as to investigate their inhibitory effects against digestive enzymes and antioxidant activities. Fermentation was performed at $37^{\circ}C$ without nutrient supplementation for 72 h. The pH and total lactic acid contents were within the ranges of 3.75~3.96 and 5.21~10.04% in fermented juices, respectively. The type of starter culture and fermentation time induced changes in flavonoid contents more than total phenolic contents. All juices fermented for 48 h strongly inhibited ${\alpha}$-glucosidase activity with the percentage of inhibition ranging of 91.24~95.05%. Antioxidant activities of all juices mostly increased after 48 h of fermentation. Our results suggest that fermented juice possesses inhibitory activity against digestive enzymes and antioxidant activity, and they can be used as health functional beverages.

• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.317-323
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• 1994

Nine plant foods (persimmon leaf, perilla seed, Chinese quince, ginger root, walnut, mugwort leaf, arrowroot, buckwheat and sorghum) rich in phenolic substances were examined for their effects on the digestive enzymes, food-poisoning bacteria and mutagenicity/antimutagenicity by Ames test. Among tested samples, Chinese quince significantly inhibited the $\alpha-amylase$ activity (97%), exhibiting an uncompetitive inhibition type. Protease activity was inhibited by Chinese quince (86%), persimmon leaf (51%) and mugwort leaf (20%), in which mugwort extract exhibited a noncompetitive type. Lipase was activated >50% by all samples. The inhibition of $\alpha-amylase$ was highly correlated with the content of condensed tannin (r=0.89) and the inhibition of protease, with total phenolic content (r=0.84). Total phenolies fraction of tested samples showed the growth inhibition toward E. coli. Streptococcus faecalis and Salmonella enteritidis, in which the effect of perilla, sorghum and arrowroot was the highest for E. coli. Standard phenolics and food samples did not show any mutagenicity toward Salmonella typhimurium TA98 and TA100. Tannic acid inhibited the mutation of the two strains by benzo[a]pyrene whereas total phenolics fractions of Chinese quince and walnut exhibited antimutagenicity to a lesser extent.

• Food Science and Preservation
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• v.30 no.3
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• pp.538-545
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• 2023

This study aimed to assess the in vitro safety of a probiotics mixture (Lactobacillus acidophilus PBS066, Lactiplantibacillus plantarum PBS067, and Limosilactobacillus reuteri PBS072), along with its inhibitory effect on carbohydrate digestion. All three strains met the antibiotic resistance profile of the European Food Safety Authority (EFSA) guidelines. None of the strains exhibited hemolytic activity or cytotoxicity against Caco-2 cells. Strains PBS067 and PBS072 inhibited α-amylase activity, whereas all three strains suppressed α-glucosidase activity, indicating that the mixture might limit carbohydrate digestion in the gastrointestinal tract. These findings support the safety of this probiotics mixture and its potential to modulate carbohydrate metabolism in the gut.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.9
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• pp.1384-1390
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• 2010

In this study, we investigated the quality of glasswort (Salicornia herbacea L.) mixture fermented by Aspergillus oryzae at $30^{\circ}C$ for 7 days. Changes of pH, titratable acidity, amino-nitrogen content, reducing sugar content, activities of $\alpha$-amylase and protease and number of mold were determined in the course of the fermentation. Angiotensin converting enzyme (ACE) inhibition activities and electron donating ability (EDA) were measured after 7 days fermentation. The pH lowered from 6.19~6.22 into the level of 5.41~6.08 after fermentation for 7 days. Titratable acidity increased from 0.59~0.68 into the highest level of 0.95~1.13% after 6 days fermentation. Furthermore, the amino-nitrogen content increased from 128.0~167.2 mg% to 159.4~209.0 mg% after fermentation for 7 days. For the reducing sugar content, it decreased from 2.0~5.9% into the level of 0.4~1.1% during 7 days fermentation. The number of molds decreased from $10^7\;CFU/g$ to approximately $10^6\;CFU/g$ after 5 days fermentation. $\alpha$-Amylase activity showed from the beginning of the fermentation in all samplings, but protease activity reached the value of food code standards after 5 days of fermentation. ACE inhibition activities were slightly increased from 9.5~16.6% to 19.3~22.7% and electron donating ability were slightly increased from 55.6~57.8% to 60.9~62.7% after 7 days of fermentation.

• Food Science and Preservation
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• v.25 no.1
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• pp.124-135
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• 2018

This study investigated the nutritional properties and biological activities of Ganoderma lucidum (GL). The round type of GL contained higher carbohydrate content, while the Nokgak type of GL contained higher crude ash, crude fat, and crude protein content. The most abundant amino acid, fatty acid, mineral, and soluble vitamin observed were valine (round type: 11.90 mg/g and Nokgak type: 17.18 mg/g), linoleic acid (round type: 47.56% and Nokgak type: 75.68%), potassium (round type: 116.50 mg/100 g and Nokgak type: 184.36 mg/100 g), and vitamin B3 (round type: 1.78 mg/100 g and Nokgak type: 1.81 mg/100 g), respectively. In addition, the ${\beta}$-glucan content were 34.15 g/100 g (round type) and 30.07 g/100 g (Nokgak type). The GL 70% ethanol extract at $40^{\circ}C$ showed higher radical scavenging as well as carbohydrate and lipid enzyme inhibition than other conditions. At 1 mg/mL of treatment with the 70% ethanol extract at $40^{\circ}C$ of round type GL, the DPPH, ABTS, hydroxyl radical scavenging, and ${\alpha}$-glucosidase, ${\alpha}$-amylase, and pancreatic lipase inhibition activities obtained were approximately 92.85, 99.74, 58.09, 89.68, 44.68, and 67.56%, respectively.