• Preventive Nutrition and Food Science
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• v.10 no.2
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• pp.172-178
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• 2005

Dandelions have been reported to have medicinal properties and bioactive components that impact human health. However, the precise biological properties of dandelions and the parts of the plants possessing bioactive components remain uncertain. In this study, we evaluated 3 different types of dandelions based on their cultivation origin (Songpa, Uiryung, and native Uiryung types) as well as their 4 different plant parts (leaf, flower, root, skin). Each sample was extracted with $80\%$ methanol and then compared for the biological activities (anti-oxidative, immune cell proliferative and tumor cell growth inhibitory activities). All 3 types of dandelions possessed a degree of biological functions including the hydroxyl radical scavenger activity, immune cell proliferative activity and tumor cell growth inhibitory activity. However, there was no significant difference in these activities between the 3 dandelion types. Leaves of all three dandelion types showed the highest levels of all biological activities. To a lesser degree, the flower and root parts displayed biological activities. In the skin parts, anti-oxidative activity was also detected only at higher doses of dandelion extracts. Heating the dandelion leaf extract did not affect the biological activity, suggesting a heat-stable nature of the biological compounds. Taken together, these collective data suggest that dandelions, in particular their leaves, possess a high concentration of heat-resistant biological compounds, which are responsible for anti-oxidative, immune cell proliferative and tumor cell growth-inhibitory activities.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.437-440
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• 2006

To explore the possible usefulness of ${\beta}$-glucans as natural antioxidants, the antioxidant profiles of ${\beta}$-glucan, extracted from Saccharomyces cerevisiae KCTC 7911, and water soluble and insoluble mutant ${\beta}$-glucan, isolated from yeast mutant S. cerevisiae IS2, were examined by five different in vitro evaluation methods: lipid peroxidation value (POV), nitric oxide (NO), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, reducing power, and ${\beta}$-carotene diffusion assay. The antioxidant activities of all ${\beta}$-glucans evaluated in POV test were comparable to or better than that of the known antioxidant, vitamin C. Remarkably, the ${\beta}$-glucan and water insoluble mutant ${\beta}$-glucan possessed 2.5-fold more potent activity than vitamin C at a dosage of 2 mg. Although vitamin C showed 100-fold greater activity than all ${\beta}$-glucans in NO and DPPH tests for measuring the radical scavenging capacity, all ${\beta}$-glucans revealed higher radical scavenging activity than the known radical scavenger, N-acetyl-L-cysteine (NAC), in DPPH test. The water insoluble mutant ${\beta}$-glucan had 2.6- and 5-fold greater antioxidative activity than water soluble ${\beta}$-glucan in NO and DPPH tests, respectively, showing that all ${\beta}$-glucans were able to scavenge radicals such as NO or DPPH. While all ${\beta}$-glucans revealed lower antioxidant profiles than vitamin C in both reducing power activity and ${\beta}$-carotene agar diffusion assay, the ${\beta}$-glucan and water insoluble mutant ${\beta}$-glucan did show a marginal reducing power activity as well as a considerable ${\beta}$-carotene agar diffusion activity. These results confirmed the potential usefulness of these ${\beta}$-glucans as natural antioxidants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.979-984
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• 2006

Although iron is essential for many physiological processes, excess iron can lead to tissue damage by promoting the generation of reactive oxygen species (ROS). There is increasing evidence that ROS might play an important role in the pathogenesis of cardiovascular disease. However, the effects of iron excess on platelet function and the thrombotic response to vascular injury are not well understood. We examined the effects of iron excess-induced oxidative stress and the antioxidants on platelet aggregation. Oxidative stress was accessed by either free iron $(Fe^{+2})$ or hydrogen peroxide $(H_2O_2)$, as well as their combination on washed rabbit platelets (WPs) in vitro. When WPs were stimulated with either $Fe^{+2}$ alone or a subthreshold concentration of collagen, which gave an aggregatory curve with a little effect, and a dose dependent increase in platelet aggregation was observed by increasing concentrations of $Fe^{+2}$ with $H_2O_2$. This aggregation was associated with the iron-catalyzed formation of hydroxyl radicals from $H_2O_2$, and were inhibited by NAD/NADP (proton acceptor), catalase $(H_2O_2\;scavenger)$, tiron (iron chelator), mannitol (hydroxyl radical scavenger), and indomethacin (cyclooxygenase inhibitor), but not by NADH/NADPH (proton donor), superoxide mutase, and aspirin. However, NADH/NADPH, an essential cofactor for the antioxidant capacity by the supply of reducing potentials, showed the effect of an enhanced radical formation, suggesting a role for NADH/NADPH-dependent oxidase. These results suggest that iron $(Fe^{+2})$ can directly interact with washed rabbit platelets and this aggregation be mediated by OH formation as in the Fenton reaction, inhibited by radical scavengers.

• The Korean Journal of Nuclear Medicine
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• v.37 no.5
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• pp.308-316
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• 2003

Purpose: The green tea polyphenol (GTPP) has been known to exert antioxidant activity as a radical scavenger as well as cancer preventive and cancer growth inhibition effect. The aim of this study was to identify whether GTPP not only potentiate the growth inhibition effect in ${\gamma}-irradiated$ human cancer cell but also exert protection action for irradiated human normal cell. Materials and Methods: GTPP (80% catechin including >45% EGCG) added in the HL60, human leukemia, and NC37, human lymphoblast, before irradiation. After establishing the amount of GTPP and the dose of radiation, the cells were treated with the GTPP for 6 hours and irradiated with the determined doses. Results: Viability when $10{\mu}g/ml$ GTPP added before ${\gamma}-irradiation$ with 1 Gy to NC37 cells was not different in comparison with control but it when was irradiated with 3 Gy significantly different (1 Gy;P=0.126, 3 Gy;P=0.010). $20{\mu}g/ml$ GTPP did not show significant difference in both NC37 cells irradiated with 1 Gy and 3 Gy (1 Gy;P=0.946, 3 Gy;P=0.096). Viabilities were significantly decreased with concentration of additional GTPP in HL60 with 1 or 3 Gy (1 Gy $69.0{\pm}1.7%\;vs\;42.4{\pm}1.3%,\;3\;Gy;\;66.9{\pm}3.9%\;vs\;44.2{\pm}1.6%$). Conclusion: In vitro study, we certified that when the cells were irradiated with dose below 3 Gy, GTPP provide not only anticancerous effect against cancer cells but also radioprotective effect in normal cells simultaneously. Theses results suggest the possibility that consumption of green tea could give the radioprotective effect and maximize the effect on internal radiation such as radioiodine therapy concomitantly.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.121-128
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• 1998

Ochratoxin A (OA) is a mycotoxin produced by Aspergillus ochraceus as well as other molds. It is a natural contaminant of mouldy food and feed. OA has a number of toxic effects, the most prominant being nephrotoxicity. Futhermore, OA is immunosuppressive, genotoxic, teratogenic and carcinogenic. OA inhibits protein synthesis by competition with phenylalanine in the phenylalanine-tRNA aminoacylation reaction. Recently, lipid peroxidation induced by OA has been reported, indicating that the lesion induced by this mycotoxin could be also related to oxidative pathway. Since it seems impossible to avoid contamination of foodstuffs by toxigenic fungi, detoxification and detoxication of OA are needed. In this study we investigated the protective effects of aspartame (Asp), phenylalanine (Phe), polyphenol 70S (PP) and aloe extract (AE) on the nephrotoxicity induced by subacute exposure to the OA. Asp and Phe are structural analogues of OA. PP, an ingredient of Green Tea and AE have been known as antioxidant and radical scavenger. Phe (40 mg/kg, i.p.) and Asp (25 mg/kg, p.o.) were administered to Sprague-Dawley rats simultaneously with OA (2.0 mg/kg, p.o.) for 2 weeks. PP (200 mg/kg, p.o.) and AE (50 mg/kg, i.v.) were pretreated before administration of OA, for 2 weeks and 3 days, respectively. Using enzymuria, BUN level, creatinemia and histophathologic examination as indices of renal damage, we observed that all of four compounds prevented the nephrotoxic effects induced by OA. It seems that structural analogues of OA such as Asp and Phe have better protective effect on the nephrotoxicity of OA than antioxidants. These results indicate that 1) formation of free radical and lipid peroxidation are likely to be involved in the nephrotoxicity of OA in vivo, 2) Asp, PP and AE might be used for prevention of renal lesions in cases of ochratoxicosis.

• Journal of Pharmacopuncture
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• v.19 no.1
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• pp.51-58
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• 2016

Objectives: Oldenlandia diffusa is traditionally used to relieve the symptoms of and to treat various diseases, but its anti-cancer activity has not been well studied. In the present study, the authors investigated the anti-cancer effects of an ethanol extract of Oldenlandia diffusa (EOD) on HT-29 human adenocarcinoma cells. Methods: Cells were treated with different concentrations of an EOD, and cell death was assessed by using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Analyses of the sub G1 peak, the caspase-3 and -9 activities, and the mitochondrial membrane depolarizations were conducted to confirm cell death by apoptosis. Also, intracellular reactive oxygen species (ROS) generation was determined using carboxy-H2DCFDA (5-(and-6)-carboxy-20,70-dichlorodihydrofluorescein diacetate). Results: EOD inhibited the proliferation of HT-29 cells for 24 hours by $78.6%{\pm}8.1%$ at $50{\mu}g/mL$, $74.4%{\pm}4.6%$ at $100{\mu}g/mL$, $65.9%{\pm}5.2%$ at $200{\mu}g/mL$, $51.4%{\pm}6.2%$ at $300{\mu}g/mL$, and by $41.7%{\pm}8.9%$ at $400{\mu}g/mL$, and treatment for 72 hours reduced the proliferation at the corresponding concentrations by $43.3%{\pm}8.8%$, $24.3{\pm}5.1mV$, $13.5{\pm}3.2mV$, $6.5{\pm}2.3mV$, and by $2.6{\pm}2.3mV$. EOD increased the number of cells in the sub-G1 peak in a dose-dependent manner. The mitochondrial membrane depolarization was elevated by EOD. Also, caspase activities were dose-dependently elevated in the presence of EOD, and these activities were repressed by a pan-caspase inhibitor (zVAD-fmk). The ROS generation was significantly increased by EOD and N-acetyl-L-cysteine (NAC; a ROS scavenger) remarkably abolished EOD-induced cell death. In addition, a combination of sub-optimal doses of EOD and chemotherapeutic agents noticeably suppressed the growth of HT-29 cancer cells. Conclusion: These results indicate that EOD might be an effective chemotherapeutic for the treatment of human colorectal cancer.

• International Journal of Oral Biology
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• v.35 no.2
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• pp.61-67
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• 2010

Selenoprotein S (SelS) is widely expressed in diverse tissues where it localizes in the plasma membrane and endoplasmic reticulum. We studied the potential function of SelS in erythrocyte differentiation using K562 cells stably over-expressing SelS wild-type (WT) or one of two SelS point mutants, $U_{188}S$ or $U_{188}C$. We found that in the K562 cells treated with $1\;{\mu}M$ Ara-C, SelS gradually declined over five days of treatment. On day 4, intracellular ROS levels were higher in cells expressing SelS-WT than in those expressing a SelS mutant. Moreover, the cell cycle patterns in cells expressing SelS-WT or $U_{188}C$ were similar to the controls. The expression and activation of SIRT1 were also reduced during K562 differentiation. Cells expressing SelS-WT showed elevated SIRT1 expression and activation (phosphorylation), as well as higher levels of FoxO3a expression. SIRT1 activation was diminished slightly in cells expressing SelS-WT after treatment with the ROS scavenger NAC (12 mM), but not in those expressing a SelS mutant. After four days of Ara-C treatment, SelS-WT-expressing cells showed elevated transcription of $\beta$-globin, $\gamma$-globin, $\varepsilon$-globin, GATA-1 and zfpm-1, whereas cells expressing a SelS mutant did not. These results suggest that the suppression of SelS acts as a trigger for proerythrocyte differentiation via the ROS-mediated downregulation of SIRT1.

• Journal of Life Science
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• v.25 no.12
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• pp.1370-1376
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• 2015

The 1, 1- diphenyl 2-picrylhyorazyl (DPPH) is a well-known radical and a trap (scavenger) for other radicals. Hyaluronidase (HAase) is an enzyme that depolymerizes the polysaccharide hyaluronic acid (HA) in the extracellular matrix of connective tissue. Lipoxygenase (LOX) enzyme was reported to convert the arachidonic, linoleic and other polyunsaturated fatty acid into biologically active metabolites involved in the inflammatory and immune responses. The purpose of the present study is to evaluate plant extracts as sources of natural antioxidants and to examine whether Achyranthes japonica having significant DPPH, HAase and LOX inhibitory activity. The inhibitory effect of HAase by A. japonica was assayed using a Morgan microplate assay. The antioxidant activity of the A. japonica extracts was measured on the basis of the scavenging activity of the stable 1, 1- diphenyl 2-picrylhyorazyl (DPPH) free radical. DPPH scavenging activity of matured roots of A. japonica was evaluated at 4.0 mg/ml was 87.8% and that of young roots was 86.2% at same concentration. The roots of A. japonica showed maximum inhibition of HAase activity (IC₅₀ = 27.7 μg/ml). The highest LOX inhibition was recorded in the root extract among three vegetative parts. Inhibition of HAase activity of roots may contribute towards the development of herbal medicines. Although percent inhibition of lipoxygenase by Achyranthes japonica for all young and matured groups for leaves, stems, and roots at different concentrations, there were not show a statistically significant difference (p<0.05).

• Journal of Life Science
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• v.21 no.11
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• pp.1573-1578
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• 2011

Milk thistle (silybum marianum) is a famous dietary supplement widely used in the United States and Europe. Silbinin is a major biologically active compound of milk thistle and has strong antioxidant and radical scavenger activities. Anticancer activities, as well as chemopreventive effects on various cancer cell lines, including prostate, lung, colon, skin, and bladder, have also been reported in silbinin. In the present study, we investigated the anticancer effects of silibinin and apoptosis through cell cycle arrest on prostate cancer cell PC-3. We performed cell viability by MTT assay and western blotting to confirm cell cycle check point proteins such as cyclin A/D1/E and cyclin-dependent kinase (CDK) 2/4/6. To quantify silibinin-induced apoptotic cell death of PC-3, Annexin V and PI double staining was performed by flow cytometry, by which its cell distribution was determined. As a result, silibinin inhibited the cell growth of PC-3 cells in a time- and dose-dependent manner, and its treatment resulted in cell cycle arrest at the G1 phase. Also the level of cell cycle check point proteins (cyclin, CDK) was decreased by silibinin in a dose-dependent manner. Taken together, we suggest that apoptosis of prostate cancer cell line PC-3 induced by silibinin is associated with cell cycle arrest through decrease of cell cycle check point proteins, caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage.

• Journal of Life Science
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• v.26 no.9
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• pp.1022-1026
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• 2016

In this study the hot water extract was prepared from Hydrocotyle sibthorpioides (Araliaceae) leaves and stems to study antioxidant activities and lipoxygenase inhibition. The extract showed the protective hydroxyl radical (-OH) which can damage virtually all types of macromolecules: carbohydrates, nucleic acids (mutations), lipids (lipid peroxidation), and amino acids. Hydroxyl radical scavenging activity of H. sibthorpioides was 78.6%. The extract showed strong activity against 1, 1- diphenyl 2-picrylhyorazyl (DPPH) which is a well-known radical and a trap (scavenger) for other radicals. DPPH scavenging activity of leaves of H. sibthorpioides was evaluated at 8.0 mg/ml was 86.0%. Lipoxygenases (LOXs) constitute a heterogeneous family of lipid peroxidizing enzymes capable of oxygenating polyunsaturated fatty acids to their corresponding hydroperoxy derivatives. The inhibitory effect of 15-LOX by H. sibthorpioides was assayed using a Morgan microplate assay. The extract of H. sibthorpioides was 55.5% inhibitory effects on the inhibition of LOX at 8.0 mg/ml. The IC₅₀ values for OH activity, DPPH activity, and LOX inhibition from leaves 5.23 mg/ml, 6.44 mg/ml, and 3.71 mg/ml, respectively. Antioxidative activity assay showed that the water extracts from leaf and stem had a strong reducing power. These results show that H. sibthorpioides has some phytochemical constituents which may be active against the free radicals (OH and DPPH) and lipoxygenase enzyme.