• Food Science and Preservation
• /
• v.21 no.3
• /
• pp.396-403
• /
• 2014

In this study, the antioxidant effect of water and ethanol extracts from Juniperus rigida Sieb were investigated. The activities of each of the extracts were measured based on their total phenolic and flavonoid contents and using antioxidant test such as of 2,2-azinobis (3-ethyl benzothiazoline-6-sulfonic acid (ABTs) radical scavenging activities, ferric reducing antioxidant power (FRAP), angiotensin I converting enzyme (ACE) inhibition activity, antioxidant protection fator (PF), thiobarbituric acid reactive substances (TBARs) content, and ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibition activity assay. The result of the examination to measure the polyphenol content by investigating the antioxidativity of the J. rigida Sieb. extract showed 71.3 mg/g polyphenol content in the water extract, and 116.0 mg/g in the ethanol extract and a 17.7 mg/g flavonoid content in the water extract and in 76.4 mg/g in the ethanol extract. The ABTS radical cation decolorization showed 76.4% and 79.3% scavenging activities of the $500{\mu}g/mL$ water extract and ethanol extract, respectively. The FRAP showed 1.83 mM efficacy in the water extract and a lower 1.77 mM in ethanol extract. Both the water extract and the ethanol extract showed reduced ACE activities of 75.39% and 71.25% at $500{\mu}g/mL$, respectively. The antioxidant protection factor of the water and 70% ethanol extracts of J. rigida Sieb were 1.5 PF and 2.1 PF, respectively. In the TBARS inhibitory activity, the extracts showed 55.78% and 71.48% antioxidant activities at the $500{\mu}g/mL$ concentration. The results of the measurrement of the ${\alpha}$-amylase inhibitory activity indicated more than 90% of activity inhibition in the $500{\mu}g/mL$ concentration of the ethanol extract. For the ${\alpha}$-glucosidase inhibitory activity, the ethanol extract showed 70% activity inhibition at the $500{\mu}g/mL$ concentration.

• Korean Journal of Plant Resources
• /
• v.26 no.5
• /
• pp.526-532
• /
• 2013

In this study, we investigated the effect of 88 marine algae extracts on melanin synthesis to develop new whitening agents. Among varieties of marine algae tested, the ethyl acetate extracts from Endarachne binghamiae (EB), Scytosiphon lomentaria, Sargassum yezoense, Ecklonia cava and Sargassum fusiforme inhibited melanin synthesis in melan-a cells. EB treatment showed the strongest inhibitory activity in melanin synthesis, compared with that of other extracts. EB-mediated inhibition of melanin synthesis appeared to be associated with inhibition of ${\alpha}$-glucosidase-dependent glycosylation of tyrosinase in melan-a cells. In addition, EB treatment did not affect mushroom tyrosinase or cell-extracted tyrosinase activity in vitro. Taken together, our findings suggest that anti-browning effect of EB on skin is mediated through regulation of ${\alpha}$-glucosidase activity and subsequent inhibition of tyrosinase activity and melanin synthesis, and further development of EB as a potential agent for skin whitening.

• Korean Journal of Plant Resources
• /
• v.30 no.4
• /
• pp.352-363
• /
• 2017

To investigate skin-whitening effect of Adenophora triphylla var. japonica sprout extract, antioxidant activity, inhibitory effect on tyrosinase and melanin synthesis in B16/F10 melanoma cell were examined. Total phenolic content (246.25 mg GAE/g) and total flavonoid content (303.94 mg RE/g) of ethyl acetate fraction from Adenophora triphylla sprout (EFAT) showed the highest contents than other fractions (n-hexane, chloroform and distilled water). Antioxidant activities of EFAT has been evaluated using ABTS, DPPH radical scavenging activities, FRAP and inhibitory effect of lipid peroxidation. EFAT showed excellent radical scavenging activity and inhibitory effect on MDA production. Inhibitory effect of tyrosinase as a major enzyme of melanin synthesis was also measured. In these results, EFAT showed higher inhibitory effect against L-DOPA (51.27%) than L-tyrosine. $IC_{50}$ value on ${\alpha}-glucosidase$ was $41.93{\mu}g/ml$. In B16/F10 melanoma cells, EFAT inhibited melanin synthesis at $200{\mu}g/ml$ concentration (about 42% decrease). Finally, main physiological compounds of EFAT were identified as a rutin and a chlorogenic acid using high performance liquid chromatography.

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

• Food Science and Biotechnology
• /
• v.18 no.2
• /
• pp.541-545
• /
• 2009

Water and ethanol extracts were prepared from the haesongi mushroom (Hypsizigus marmoreus) to measure functional components. The ability of the extracts to inhibit angiotensin-converting enzyme (ACE) and their hypoglycemic effects were also determined; the latter was measured by $\alpha$-amylase and glucosidase inhibition. Extraction yield, protein content, total phenol, and $\beta$-glucan in the water extracts were 55.86, 17.71, 1.89, and 21.93%, respectively. The respective values for the ethanol extracts were lower than those for water extracts. Both water and ethanol extracts showed dosedependent ACE inhibition, the effect of the former being greater. The water extract inhibited ACE activity by 95.34% at 40 mg/mL. The $IC_{50}$ values of the water extracts were 63.32 and 0.41 mg/mL for $\alpha$-amylase and glucosidase, respectively. Thus, the water extracts had a greater hypoglycemic effect than the ethanol extracts. From these results, water is a better solvent than ethanol to extract from the haesongi mushroom functional components that show ACE inhibition and have hypoglycemic effects.

• Korean Journal of Plant Resources
• /
• v.26 no.5
• /
• pp.519-525
• /
• 2013

The Opuntia extract has been traditionally used to treat diabetes, inflammation, and rheumatoid arthritis in oriental medicine. The purpose of this study is to investigate characteristics of biological activity between Opuntia humifusa and Opuntia ficus-indica which is cultivating in korea using cell-free system or cell-based assay. O. humifusa extract effectively inhibited ${\alpha}$-glucosidase activity or improved the immune function, and its biological activity was more effective than O. ficus-indica extract. The scavenging activity of DPPH radical and the inhibitory effect of tyrosinase similarly showed by O. humifusa and O. ficus-indica extract, however neuroprotective effect only showed a tendency to increase compared with control in PC12 cells. Therefore the results suggest that O. humifusa can be a useful agent for treatment of diabetes and immunodeficiency.

• Nutrition Research and Practice
• /
• v.7 no.3
• /
• pp.166-171
• /
• 2013

The purpose of this study was to investigate the effects of lotus leaf on hyperglycemia and dyslipidemia in animal model of diabetes. Inhibitory activity of ethanol extract of lotus leaf against yeast ${\alpha}$-glucosidase was measured in vitro. The effect of lotus leaf on the postprandial increase in blood glucose levels was assessed in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without lotus leaf extract (500 mg/kg) was administered to the rats after an overnight fast, and postprandial plasma glucose levels were monitored. Four-week-old db/db mice were fed a basal diet or a diet containing 1% lotus leaf extract for 7 weeks after 1 week of acclimation to study the chronic effect of lotus leaf. After sacrifice, plasma glucose, insulin, triglycerides (TG), total cholesterol (CHOL), high-density lipoprotein (HDL)-CHOL, and blood glycated hemoglobin levels were measured. Lotus leaf extract inhibited ${\alpha}$-glucosidase activity by 37.9%, which was 1.3 times stronger than inhibition by acarbose at a concentration of 0.5 mg/mL in vitro. Oral administration of lotus leaf extract significantly decreased the area under the glucose response curve by 35.1% compared with that in the control group (P < 0.01). Chronic feeding of lotus leaf extract significantly lowered plasma glucose and blood glycated hemoglobin compared with those in the control group. Lotus leaf extract significantly reduced plasma TG and total CHOL and elevated HDL-CHOL levels compared with those in the control group. Therefore, we conclude that lotus leaf is effective for controlling hyperglycemia and dyslipidemia in an animal model of diabetes mellitus.

• 한국약용작물학회:학술대회논문집
• /
• 2010.10a
• /
• pp.363-364
• /
• 2010

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.7
• /
• pp.975-979
• /
• 2010

Biological activities of different parts (stems, leaves, roots, fruits) and solvents (water, ethanol) of seabuckthorn (Hippophae rhamnoides L.) grown in Korea were tested as follows. In the experiment of inhibiting $\alpha$-glucosidase activity, ethanol extract of Hippophae rhamnoides L. stem showed the highest inhibitory activity by 93% and the next highest was the ethanol extract of its leaf by 88.7%. In the case of these two extracts, the effect of inhibiting $\alpha$-glucosidase activity was extraordinarily great when comparing with control group, acarbose. In the experiment of inhibiting $\alpha$-amylase activity, water extract of leaf showed the highest result by 54.7%, among all extracts. Regarding anticancer effect for HT-29 cell and DU-145 cell, water extract of root showed 47.1% and 32.3% activities, respectively. The experiment on antibacterial activity showed that the ethanol extract from the leaf inhibitory activity of Clostridium butyricum, Proteus mirabilis, and Shigella flexneri which are the several food borne pathogenic strains. In future research, materials for biological activity appear isolated and purified and research should continue.

• The Korean Journal of Food And Nutrition
• /
• v.26 no.4
• /
• pp.806-813
• /
• 2013

Agrimonia pilosa Ledeb. is a medicinal plant with anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic activities. However, few studies of the anti-diabetic effect of A. pilosa on insulin resistance status have been performed. In the present study, the anti-diabetic effect of A. pilosa water extract (AP) was determined by investigating its ${\alpha}$-glucosidase inhibitory property, glucose utilization, and uptake, as well as insulin resistance mechanism of action in C2C12 skeletal muscle cells. Compared to positive control (acarbose), AP ($10mg/m{\ell}$) showed a similar ${\alpha}$-glucosidase inhibitory capacity. Glucose uptake was significantly increased by $1{\mu}m$ insulin treatment (p<0.05). However, palmitic acid (FFA, 1 mM) induced muscle insulin resistance and glucose uptake dysfunction. On the other hand, AP ($10{\mu}g/m{\ell}$) was capable of reversing the FFA-induced insulin resistance in C2C12 myotubes. Compared to control, AP ($100{\mu}g/m{\ell}$ without insulin) significantly increased the utilization of glucose (p<0.05) in C2Cl2 myotubes cultured in normal glucose (7 mM). AP treatment significantly increased the relative mRNA and protein expression levels of Akt. In particular, the effect of A. pilosa on the insulin signaling system is associated with the up-regulation of Akt genes and glucose uptake in C2Cl2 myotubes. These results suggest that A. pilosa is useful in the prevention of diabetes and the treatment of hyperglycemic disorders.