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

• Journal of Life Science
• /
• v.28 no.8
• /
• pp.931-937
• /
• 2018

Triptolide is a compound found in Tripterygium wilfordii and reported to have an anti-inflammatory and anti-oxidant activities. A previous study shows that the dietary supplementation with triptolide increases resistance to environmental stressors, including oxidative stress, heat shock, and ultraviolet irradiation, and extends lifespan in C. elegans. Here, we investigated the underlying mechanisms involved in the lifespan-extending effect of triptolide. The effect of triptolide on age-related diseases, such as diabetes mellitus and Alzheimer's disease, was also examined using animal disease models. The longevity phenotype conferred by triptolide was not observed in the eat-2 mutant, a well-known genetic model of dietary restriction, while there was an additional lifespan extension with triptolide in age-1 and clk-1 mutants. The long lifespan of age-1 mutant is resulted from a reduced insulin/IGF-1-like signaling and the clk-1 mutant lives longer than wild-type due to dysfunction of mitochondrial electron transport chain reaction. The effect of dietary restriction using bacterial dilution on lifespan also overlapped with that of triptolide. The toxicity of high glucose diet or transgenic human amyloid beta gene was significantly suppressed by the supplementation with triptolide. These findings suggest that triptolide can mimic the effect of dietary restriction on lifespan and onset of age-related diseases. We conclude that triptolide can be a strong candidate for the development of dietary restriction mimetics.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.7
• /
• pp.951-957
• /
• 2009

In this study, antibacterial activity of extruded ginseng extract by 60 and 80% Et-OH were investigated by agar diffusion assay against two bacteria causing dental caries (Streptococcus mutans and Lactobacillus casei). Extrusion conditions were 20% moisture content $100^{\circ}C$ and $140^{\circ}C$ barrel temperature. The inhibition effect of 60% Et-OH ginseng extract was higher than 80% Et-OH ginseng extract. The minimum inhibitory concentration (MIC) of 80% Et-OH extruded ginseng extract at 140 and $100^{\circ}C$ barrel temperature against L.casei were 100 and 150 mg/mL respectively using broth assay method. The amount of glucosyltransferase (GTase) inhibitory content was the highest in extruded ginseng at $140^{\circ}C$ barrel temperature with 60% Et-OH. Moreover, n-hexane and n-butanol fraction ginseng extract had potential against tested bacteria. Our results demonstrated that antibacterial activities of extruded ginseng extract at $140^{\circ}C$ barrel temperature were more effective than Ex-$100^{\circ}C$, RG and WG.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.12
• /
• pp.1972-1980
• /
• 2013

The purpose of this study is to evaluate the storage quality characteristics of bread with added dried mulberry pomace (DMP, 0, 1, 3 or 5%) during storage at $4^{\circ}C$ for 7 days. During the entire storage period, the moisture content was higher in breads containing DMP compared with the control bread. Textural properties by TPA showed that the hardness of DMP bread maintained a lower hardness than that of the control during the entire storage period. Moreover, DSC (Differential Scanning Calorimetry) result showed that ${\Delta}H$ (crystal melting enthalpy) of the bread containing DMP was lower than that of the control bread, which indicate the retarding of retrogradation. The sensory preference test results demonstrated that the bread with 3% DMP had higher scores in over-all preference than the others. These results suggest that DMP delays the retrogradation of bread during storage.

• Horticultural Science & Technology
• /
• v.29 no.4
• /
• pp.374-381
• /
• 2011

Stilbenes are polyphenolic natural products, which have antioxidative and antifungal activities. In some plants, including grapevine, the stilbene compounds, as resveratrol derivatives, exist in very diverse forms. Experiments to identify the individual stilbene compounds were carried out first to quantify them in UV-irradiated grapevine leaves. For this, stilbene glycosides were extracted from grapevine leaves which irradiated intensively with UV light. The glycoside samples were hydrolyzed by ${\beta}$-glucosidase, before analyzed by HPLC-mass spectrometer at each m/z corresponding to the mass of specific stilbenes. As results, in chromatograms, the enzymatic hydrolysis resulted in decrease and increase of the peaks expected for glycosides and aglycones, respectively. The samples were also exposed to sunlight in order to photo-isomerize the stilbene compounds. The light exposure resulted in disappearance and appearance of peaks expected for trans- and cis-isomers of stilbenes, respectively. Such a change of the peaks in chromatograms provided information needed for the inference to peak components. In this way, it was possible to identify 16 kinds of stilbene compounds from grapevine leaves. The identified stilbenes were quantified from grapevine leaves irradiated mildly by UV light. The UV-irradiation increased markedly in the content of stilbene compounds, especially trans-resveratrol by several hundredfold. In addition, piceatannol, which is a mere minor component of stilbenes in control leaves and a more active radical scavenger than resveratrol, was also increased by several tenfold by the treatment. The increase in stilbene contents as influenced by UV irradiation seems to be one of the stress coping responses of grapevine as a hormesis phenomenon.

• Journal of Life Science
• /
• v.25 no.9
• /
• pp.984-992
• /
• 2015

Sanguinarine is a benzophenanthridine alkaloid originally isolated from the roots of Sanguinaria canadensis. It has multiple biological activities (e.g., antioxidant and antiproliferative) and immune-enhancing potential. In this study, we explored the proapoptotic properties and modes of action of sanguinarine in human hepatocellular carcinoma HepG2 cells. Our results revealed that sanguinarine inhibited HepG2 cell growth and induced apoptosis in a dose-dependent manner. The induction of apoptosis by sanguinarine was associated with the up-regulation of Fas and Bax, the release of cytochrome c from the mitochondria to the cytosol, and the loss of the mitochondrial membrane potential. In addition, sanguinarine activated caspase-9 and -8, initiator caspases of the intrinsic and death extrinsic pathways, respectively, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Sanguinarine also triggered the generation of reactive oxygen species (ROS). The elimination of ROS by N-acetylcysteine reversed sanguinarine-induced apoptosis. Furthermore, sanguinarine induced the dephosphorylation of Akt and the phosphorylation of mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38. The growth inhibition was enhanced by the combined treatment of sanguinarine with a phosphatidylinositol 3'-kinase (PI3K) inhibitor and an ERK inhibitor but not JNK and p38 inhibitors. Overall, our data indicate that the proapoptotic effects of sanguinarine in HepG2 cells depend on ROS production and the activation of both intrinsic and extrinsic signaling pathways, which is mediated by blocking PI3K/Akt and activating the ERK pathway. Thus, our data suggest that sanguinarine may be a natural compound with potential for use as an antitumor agent in liver cancer.

• Journal of Life Science
• /
• v.27 no.8
• /
• pp.888-895
• /
• 2017

Salsola collina (S. collina) is an annual plant widely distributed in drought and semi-drought areas, which has been used for a long time as a kind of folk remedy in traditional Chinese medicine for the treatment of hypertension. Previously, the anti-oxidative and anti-cancer activities of S. collina were elucidated in our research group. In this study, the anti-obesity activities of S. collina ethanol extract (SCEE) were evaluated using a pancreatic lipase enzyme inhibition assay and cell culture model. The results showed that SCEE effectively suppressed pancreatic lipase enzyme activity in a dose-dependent manner. Furthermore, SCEE significantly suppressed adipocyte differentiation, lipid accumulation, and triglyceride (TG) content, and triggered lipolysis on insulin, dexamethasone, and 3-isobutyl-l-methylxanthine-treated 3T3-L1 preadipocytes in a dose-dependent manner without cytotoxicity. Its anti-obesity effect was modulated by cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding proteins ${\alpha}$ ($C/EBP{\alpha}$), $C/EBP{\beta}$, and the peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) gene, as well as protein expressions. Taken together, these results offer the important new insight that S. collina possesses anti-obesity properties, such as pancreatic lipase inhibition and anti-adipogenic and lipolysis effects through the modulation of their upstream signaling pathway. It could become a promising source in the field of nutraceuticals, and the identification of active compounds that confer the biological activities of SCEE may be needed.

• Journal of Applied Biological Chemistry
• /
• v.60 no.2
• /
• pp.155-159
• /
• 2017

This study was to evaluate the effect of the moisturizing cream containing five kinds of plants extracts for human facial improvements such as hydrating ability, transepidermal water loss and erythema reaction. The antioxidant activities of yellowish natural colorants, extracted from five kinds of plants (Ceramium kondoi, Phellodendron amurense, Carthamus tinctorius, Gardenia jasminoides for. grandiflora and Aphis chinensis) were tested. Twenty-one volunteers were subjected to analyze the effects, and each result was determined by treating the complex cream containing plants extracts on their skin in three times. The moisture content on skin was significantly increased more than 50% by treating the cream containing five kinds of plants extracts. The transepidermal water loss was reduced and the level of the skin erythema reaction was improved after treatment of the complex cream. Survey analysis showed that the volunteers had highly satisfaction on the tested creams. The results suggest that the complex cream containing five plants extracts had an improved effect on facial skin, and therefore can be used as moisturizing ingredients in the related industry.

• Reproductive and Developmental Biology
• /
• v.29 no.3
• /
• pp.155-162
• /
• 2005

The present study evaluated whether an exogenous antioxidants, taurine and $\alpha$-tocopherol, could, when added to the freezing extender, improve the post-thaw sperm characteristics, function, the level of reactive oxygen species (ROS) generation, and the level of lipid peroxidation (LPO) in frozen-thawed porcine semen. CASA (computer-aided sperm analysis), HOST (hypoos-motic swelling test), chemiluminescence using luminol and lucigenin and the detection of malondialdehyde for LPO was performed in frozen-thawed porcine sper-matozoa. The results obtained in these studies are as follows. While no beneficial effects of taurine and $\alpha$-tocopherol supplementation were visible in motility, viability, acrosome reaction, tail swelling patterns, and the generation of $O^{2-}$ of frozen-thawed porcine sper-matozoa, $H_{2}O_{2}$ was decreased by all treatments except taurine 50mM treatment. In conclusion the taurine and $\alpha$-tocopherol treatments during freezing reduced generation of reactive oxygen species and production of malondialdehyde in frozen-thawed porcine semen, and the ROS savangers may minimize various damages of spermatozoa during freezing.

• Applied Biological Chemistry
• /
• v.40 no.4
• /
• pp.283-288
• /
• 1997

The antioxidant activities of Korean Red Ginseng Extract(RGE) and ${\alpha}-tocopherol$, as reference compound, were tested with HPLC and fluorometry which measure the MDA after reacting an aqueous 1% linoleic acid buffer solution, and LDL(1 mg protein/ml) buffer solution with $H_2O_2{\;}and{\;}FeCl_2$. The generation of conjugated-diene in LDL(0.25 mg protein/ml) was also measured by spectrometry. MDA determination showed the antioxidant effect on linoleic acid oxidation with oxidation inhibition ratio of 71.8% and 76.1%, respectively, by addition of 1000 ppm RGE and 100 ppm ${\alpha}-tocopherol$. LDL(1 mg protein/ml) oxidation was inhibited by 25.2% and 21.2%, respectively, by addition of 200 ppm REG and 100 ppm ${\alpha}-tocopherol$. The generation of conjugated diene in LDL(0.25 mg protein/ml) was also inhibited by 44.2%, by addition of 50 ppm RGE.