• Toxicological Research
• /
• 제23권2호
• /
• pp.143-150
• /
• 2007

Although animal and epidemiological studies have suggested oxidative stress as an etiological factor in pathogenesis including cancer, inflammation, sepsis, fibrosis, cardiovascularlneurodegenerative diseases and aging-related disorders, conflicting results have been obtained in clinical trial with antioxidants. The reason for this discrepancy remains unknown but may be due, in part, to the lack of a validated assay system for evaluating antioxidant capacity. The antioxidant activity of a series of sugar alcohols against peroxyl radicals, hydroxyl radicals and peroxynitrites was determined by the total oxy-radical scavenging capacity (TOSC) assay and cell-based assay using H4IIE cells. Specific TOSC values calculated from the slope of the linear regression for erythritol, xylitol, sorbitol or mannitol against peroxyl radicals was $2.1{\pm}0.2,\;3.7{\pm}0.3,\;9.1{\pm}0.3$ or $8.7{\pm}1.1$ TOSC/mM, respectively. Specific TOSC values for erythritol, xylitol, sorbitol or mannitol against peroxynitrite was $1.9{\pm}0.3,\;3.9{\pm}0.4,\;7.8{\pm}0.7$ or $7.7{\pm}0.5$ TOSC/mM, respectively. These results suggest that oxy-radical scavenging capacity is dependent on the number of aliphatic hydroxyl group in sugar alcohols of monosaccharide. Tert-butylhydroperoxide (t-BHP)-induced cell toxicity determined by MTT assay was marginally attenuated by 10 mM erythritol, but completely inhibited by 10 mM xylitol, 2 mM sorbitol or 0.75 mM maltitol, a disaccharide alcohol. Oxidative stress markers, such as glutathione (GSH) and malondial-dehyde (MDA) levels, were measured in t-BHP-treated cells using HPLC equipped with a fluorescence detector and a reverse phase column. Erythritol did not change the levels of GSH and MDA in H411E cells treated with t-BHP. The t-BHP-induced changes in cellular GSH and MDA levels were ameliorated by 10 mM xylitol and completely blocked by 10 mM sorbitol and maltitol. These results indicate that sugar alcohols protect cells against oxidative stress via scavenging oxy-radical and suggest that TOSC assay in conjunction with cell-based assay is a valid method for evaluating antioxidant capacity of natural and synthetic chemicals.

• 한국자원식물학회지
• /
• 제23권5호
• /
• pp.445-450
• /
• 2010

본 연구에서는 개머루덩굴 95% 에탄올추출물의 항산화 효과를 조사하였다. Pyrogallol의 억제율을 100%로 기준하였을 때, DPPH 라디칼을 50% 억제시키는데 필요한 개머루덩굴 추출물의 농도는 0.42 mg/mL이었다. 총항산화 활성은 ABTS 라디칼에 대한 항산화능으로 측정하였다. 개머루덩굴 추출물 0.1 및 1 mg/mL의 총항산화능은 각각 0.65 및 3.71 mM Trolox와 동등한 수준이었다. 개머루덩굴 추출물 5 및 $100\;{\mu}g/mL$의 peroxyl radical 소거능은 각각 22.75 및 $131.25\;{\mu}M$ gallic acid와 동등한 수준이었다. 개머루덩굴 추출물 0.1 및 1 mg/mL의 superoxide 소거능은 각각 27.7 및 56.0%이었다. 개머루덩굴 추출물 0.5 및 2 mg/mL의 총페놀 함량은 각각 0.55 및 2.06 mM gallic acid와 동등한 수준이었다. 또한, HepG2 세포주를 이용한 세포배양에서 개머루덩굴 추출물 0.1 mg/mL 농도의 첨가는 0.2 및 0.5 mM tert-butyl hydroperoxide로 유도된 세포독성을 각각 36.2 및 23.3% 감소시켰다. 따라서, 본 연구 결과들은 개머루덩굴 추출물의 강력한 항산화 효과와 세포독성 억제 효과를 나타내며, 이러한 효능은 적어도 자유라디칼의 산화 억제와 높은 총페놀 함량에 기인하는 것으로 사료된다.

• Natural Product Sciences
• /
• 제20권3호
• /
• pp.176-181
• /
• 2014

The antioxidant activities of 29 components isolated from the aerial parts of Artemisia iwayomogi were evaluated in vitro and in cell culture. Among the tested compounds, 2, 6, 8, 10, 13, and 14 exhibited the greatest peroxyl radical-scavenging activities in the oxygen radical absorbance capacity (ORAC) assay, and 2, 10, and 14 also showed significant reducing capacities. However, all compounds showed weak metal chelating activities. Their cellular antioxidant activities were evaluated in HepG2 cells. At $10{\mu}M$, compounds 6, 8, and 14 exhibited stronger protection against 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative stress than compounds 2, 10, and 13. Moreover, Compounds 2 and 8 were more effective in protecting against $Cu^{2+}$-induced oxidative stress than compounds 6, 10, 13, and 14 at $10{\mu}M$. These results suggest that the phenolic compounds in A. iwayomogi have the potential to be developed as natural antioxidants for the treatment of oxidative stress-related diseases.

• Food Science and Biotechnology
• /
• 제14권1호
• /
• pp.123-130
• /
• 2005

Hydrogen-donating capacity, scavenging activity of reactive oxygen including superoxide anion radical and hydrogen peroxide, metal-chelating activity, and reducing power of garlic extracts were investigated. All tested garlic extracts exhibited in vitro antioxidant activities, with Uiseong extract showing highest hydrogen-donating and hydrogen peroxide-scavenging activities, and reducing power, followed by Seosan and Samchek extracts, in proportion to total thiosulfinate contents. Higher scavenging activity of superoxide anion radical was observed in Uiseong than Seosan and Samchek extracts. Metal-chelating activity increased in order of Uiseong < Seosan < Samchek, showing inverse relations to total thiosulfinate content. Garlic extracts of Uiseong and Seosan showed weak prooxidant activities and that of Samchek showed strong antioxidant activity against $Cu^{+2}$-induced human LDL oxidation. Protective effects on peroxyl and hydroxyl radical-induced DNA strand damages were observed in all tested garlic cloves. These results indicate growing conditions of garlic cloves affect total thiosulfinate content and antioxidant activities.

• Preventive Nutrition and Food Science
• /
• 제12권4호
• /
• pp.191-196
• /
• 2007

We investigated radical scavenging effects and protective activities of fucoidan and alginic acid, active polysaccharide components from brown seaweeds, against peroxyl radical-induced oxidative stress under in vitro and cellular system. Fucoidan exerted strong radical scavenging effects against nitric oxide (NO) and superoxide anion $(O_2)$. On the other hand, alginic acid did not show inhibitory activity against NO and relatively weak $O_2{^-}$ scavenging effect. Additionally, alginic acid exhibited higher hydroxyl scavenging activity than fucoidan. Both fucoidan and alginic acid significantly enhanced cell viability against oxidative stress induced by 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH). At $1000{\mu}g/mL$ concentration of fucoidan and alginic acid, the viability was increased from 16.4% to 85.9% and 67.7%, respectively. In addition, fucoidan and alginic acid ameliorated the lipid peroxidation in LLC-PK1 cell induced by AAPH in a dose-dependent manner. In particular, fucoidan showed stronger inhibitory effect than alginic acid in the cellular system. The present study suggests that fucoidan and alginic acid may be promising antioxidants against oxidative stress induced by free radicals.

• 농업과학연구
• /
• 제38권4호
• /
• pp.717-722
• /
• 2011

In this study, we investigated the antioxidant activity of hesperidin and hesperetin, which are the active compounds from Citrus junos, in the cellular system. Under cellular model of oxidative damage using LLC-$PK_1$ renal epithelial cell, the oxidative damage induced by 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) led to the loss of cell viability, while treatment of hesperidin and hesperetin increased significantly the cell viability as dose-dependent manner. In addition, NO-induced cellular oxidative damage by sodium nitroprusside were significantly recovered by the treatment of hesperidin and hesperetin, showing the increase of cell viability. But hesperidin and hesperetin showed no significant protective effect on $O_2{^-}$-induced cellular oxidative damage. The present study indicates that hesperidin and hesperetin protect against free radical, especially AAPH-induced peroxyl radical. In particular, hesperetin has stronger protective effect against oxidative stress than hesperidin.

• 한국식품영양학회지
• /
• 제26권1호
• /
• pp.150-153
• /
• 2013

본 연구에서는 한국, 중국, 일본 등의 대표적 면요리 육수의 항산화 활성을 검토하였다. 이를 위하여, 한국식, 중국식, 일본식 육수를 각각 제조하여, ESR과 비색법을 이용하여 DPPH, hydroxyl, peroxyl, superoxide, ABTS 등의 radical 소거 활성을 측정함으로써 항산화력을 비교하였다. 한국식 육수, 중국식 육수 및 일본식 육수의 DPPH radical 소거 활성은 2 $mg/m{\ell}$의 농도의 실험에서 2.78%, 25.37% 및 40.74%의 소거 활성을 보였다. 한국식 및 중국식 육수는 hydroxyl radical 소거 활성은 매우 낮았으나, 일본식 육수는 0.5 $mg/m{\ell}$에서 59.06%로 소거 활성이 높았다. 한국식, 중국식 및 일본식 육수의 peroxy radical 소거 활성($IC_{50}$)은 각각 0.121 $mg/m{\ell}$, 0.222 $mg/m{\ell}$ 및 0.013 $mg/m{\ell}$으로 일본식 육수가 peroxy radical 소거 활성이 높았다. 한국식, 중국식 및 일본식 육수의 ABTS radical 소거 활성의 $IC_{50}$ 값은 1.2 $mg/m{\ell}$, 1.8 $mg/m{\ell}$ 및 1.249 $mg/m{\ell}$였다.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제5권5호
• /
• pp.366-371
• /
• 2000

The aim of this study was to investigate the efficiency of the pentagalloic acid compound in inhibiting the metal ions and cell lines that mediate in low density lipoprotein (LDL) oxidation. Pentagalloic acid prolonged the lag time preceeding the onset of conjugated diene formation. In chemically induced LDL oxidation by Cu$^2$(sup)+ plus hydrogen peroxide or peroxyl radical generated by 2, 2-azo-vis (2-amidino propane) hydrochloride (AAPH), pentagalloic acid inhibited LDL oxidation as monitored by measuring the thiobarbituric acid reactive substances(TBARS), malondialdehyde(MDA), and gel electrophoretic mobility. The physiological relevance of the antioxidative activity was validated at the cellular level where pentagalloic acid inhibited mouse macrophage J774 and endothelial cell-mediated LDL oxidation. When compared with several other antioxidants, pentagalloic acid showed a much higher ability than naturally occuring antioxidants, ${\alpha}$-tocopherol and ascorbic acid, and the synthetic antioxidant, probucol.

• Biomolecules & Therapeutics
• /
• 제21권2호
• /
• pp.146-152
• /
• 2013

This study examined the total polyphenol content of eight wild edible plants from Ethiopia and their effect on NO production in Raw264.7 cells. Owing to its relatively high polyphenol concentration and inhibition of NO production, the methanol extract of Adansonia digitata L. leaf (MEAD) was subjected to detailed evaluation of its antioxidant and anti-inflammatory effects. Antioxidant effects were assessed by measuring free-radical-scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and oxygen-radical-absorbance capacity (ORAC) assays, while anti-inflammatory effects were assessed by measuring inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In the ORAC assay, MEAD was 10.2 times more potent than vitamin C at eliminating peroxyl radicals. In DPPH assay, MEAD also showed a strong ROS scavenging effect. MEAD significantly inhibited iNOS activity ($IC_{50}=28.6{\mu}g/ml$) of LPS-stimulated Raw264.7 cells. We also investigated the relationship between iNOS expression and nuclear factor kappa B (NF-${\kappa}B$) activation. MEAD inhibited $I{\kappa}B{\alpha}$ degradation and NF-${\kappa}B$ translocation from the cytosol to the nucleus in LPS-induced RAW264.7 cells without significant cytotoxic effects, as confirmed by MTT assay. These results suggest that MEAD inhibits anti-inflammatory iNOS expression, which might be related to the elimination of peroxyl radicals and thus the inhibition of $I{\kappa}B{\alpha}$-mediated NF-${\kappa}B$ signal transduction.

• Environmental Analysis Health and Toxicology
• /
• 제25권1호
• /
• pp.85-94
• /
• 2010

Platycodon grandiflorum, Doraji as Korean name, is one of the most widely used traditional oriental medicine for bronchial diseases and also used as a folk remedy for geriatric diseases and inflammatory diseases. In recent studies, it has been reported that some effect of P. grandiflorum is derived from its antioxidant activity, although there is still a lack of evidence to establish its oxy-radical scavenging activity. In this study, total oxy-radical scavenging capacity (TOSC) assay was used to evaluate antioxidant activity of total extracts (T-PG), polysaccharide fraction (Po-PG), and saponin fraction (Sa-PG) isolated from P. grandiflorum against peroxyl radicals and peroxynitrites. And MTT assay was taken to assess cyto-protective effects of T-PG, Po-PG and Sa-PG in H4IIE cells treated with hydrogen peroxide and tert-butylhydroperoxide. In the TOSC assay, Sa-PG showed strong oxy-radical scavenging capacity compared with T-PG and Po-PG. In cell-based assay, T-PG and Po-PG protected cells from oxidative stress, but Sa-PG did not protect cells because of cytotoxicity of Sa-PG. These results suggest that the saponin components of P. grandiflorum have relatively strong antioxidant capacity and cytotoxicity in rat hepatoma cells.