• ALGAE
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• v.28 no.4
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• pp.371-378
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• 2013

Water and methanolic extracts of Ecklonia cava, a marine brown alga, were prepared by ultrasonic extraction (UE) and conventional extraction (CE) methods. The radical-scavenging activity and the inhibitory effects against hydrogen peroxide ($H_2O_2$)-induced DNA damage of the extracts were investigated. All extracts prepared by CE exhibited higher total polyphenolic content than that in the extracts prepared by UE. Extraction yield and total phenolic content increased as the UE time increased. The radical-scavenging activities increased as the UE time increased. All extracts prepared by CE exhibited higher 1,1-diphenyl-2-pricrylhydrazyl (DPPH) and hydroxyl radical-scavenging activities than did those prepared by UE. Extracts prepared by UE showed stronger scavenging activities on alkyl radical and $H_2O_2$ than those prepared by CE did. Methanolic extract with UE 12 h (100MEU-12h) and methanolic extract with CE 24 h (100MEC-24h) were selected and evaluated by comet assay for their inhibitory effect against $H_2O_2$-induced DNA damage. 100MEU-12h showed slightly greater protective effect against $H_2O_2$-induced DNA damage than 100MEC-24h. Thus, UE can be effectively used as a seaweed extraction technique, and there is potential for scale-up of the extraction process.

• Archives of Pharmacal Research
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• v.21 no.5
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• pp.508-513
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• 1998

The hepatoprotective effect of DA-9601, a quality-controlled extract of artemisisa asiatica, on liver damage induced by acetaminophen (APAP) and carbon tetrachloride ($CCI_{4}$) was investigated by means of serum-biochemical, hepatic-biochemical, and histopathological examinations. Doses of Da-9601 (10, 30, or 100 mg/kg) were administered intragastrically to each rat on three consecutive days i.e. 48 h, 24 h and 2 h before a single administration of APAP (640 mg/kg, i.p.) or $CCI_{4}$ (2 ml/kg, p.o.). Four h and 24 h after hepatotoxin treatment, the animals were sacrificed for evaluation of liver damage. Pretreatment of Da-9601 reduced the elevation of serum ALT, AST. LDH and histopathological changes such as centrilobular necrosis, vacuolar degeneration and inflammatory cell infiltration dose-dependently. Da-9601 also prevented APAP- and $CCI_{4}$-induced hepatic glutathione (GSH) depletion and $CCI_{4}$-induced increase of hepatic malondialdehyde (MDA), a parameter of lipid peroxidation, in a chemically induced liver injury by complex mechanisms which involve prevention of lipid peroxidation and preservation of hepatic GSH.

• Journal of Nutrition and Health
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• v.36 no.1
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• pp.24-31
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• 2003

The present study was attempted to investigate the antioxidant capacity of popular yellow-green vegetable juices (kale, Angelica keishei, carrot, small water dropwort) and to investigate the effect of vegetable juices on protecting oxidative damage to DNA in cultured Chinese hamster lung (CHL) cells. Antioxidant capacity was analyzed by TRAP assay (Total radical-trapping antioxidant potential). Cellular DNA dmamage was measured by SCGE (single-cell gel electrophoresis, also known as comet assay. Cells incubated in medium with PBS (negative control) or with various concentration of the freeze dried green juices (25, 50, 100, 250 $\mu\textrm{g}$/$m\ell$) resuspended in PBS were treated with $H_2O_2$ (200 ${\mu}{\textrm}{m}$) as an oxidative stimulus for 5 min at 4$^{\circ}C$. The physiological function of each vegetable juice on oxidative DNA damage was analyzed and expressed as tail moment (tail length X percentage migrated DNA in tail) . Kale juice had the highest TRAP value suggesting that kale has the highest antioxidant capacity followed by Angelica keishei, small water dropwort and carrot. Cells treated with $H_2O_2$ had extensive DNA damage compared with cells treated with PBS or pre-treated with vegetable juice extracts. All green juices inhibited $H_2O_2$-induced DNA damage with kale being the most effective juice among the tested juices. These results indicate that green juice supplementation to CHL cells followed by oxidative stimulus inhibited damage to cellular DNA, supporting a protective effect against oxidative damage induced by reactive oxygen species. (Korean J Nutrition 36(1) : 24-31, 2003)

• Biomedical Science Letters
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• v.24 no.2
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• pp.130-133
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• 2018

The aim of this study was to evaluate the protective function of fisetin, a natural flavonoid in zebrafish heart for the treatment of myocardial infarction in coronary and ischemic heart disease. For this purpose, we induced oxidative stress zebrafish (Danio rerio)-Tg (cmlc2: egfp) by $H_2O_2$ and then administered fisetin, the protective effect of fisetin was determined by measuring the heart rate following fisetin administration. After testing the toxicity of fisetin, we found that the heartt increased in a concentration-dependent manner, however there was no difference between the heart rates of embryos and adults. The improved heart rate demonstrated the cardioprotective effect of fisetin. The result showed that fisetin, at concentration of 3and $5{\mu}M$, significantly increased heart rate compared with the heart with $H_2O_2$ alone. This indicates that fisetin plays an important role in the prevention of heart damage and treatment of cardiovascular diseases caused by oxidative stress due to ischemia / reperfusion.

• Journal of Microbiology and Biotechnology
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• v.24 no.1
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• pp.36-43
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• 2014

Magnesium-protoporphyrin IX (Mg-PPn), which is formed through chelation of protoporphyrin IX (PPn) with Mg ion by Mg chelatase, is the first intermediate for the (bacterio)chlorophyll biosynthetic pathway. Interestingly, Mg-PPn provides peroxidase activity (approximately $4{\times}10^{-2}units/{\mu}M$) detoxifying $H_2O_2$ in the presence of electron donor(s). The peroxidase activity was not detected unless PPn was chelated with Mg ion. Mg-PPn was found freely diffusible through the membrane of Escherichia coli and Vibrio vulnificus, protecting the cells from $H_2O_2$. Furthermore, unlike photosensitizers such as tetracycline and PPn, Mg-PPn did not show any phototoxicity, but rather it protected cell from ultraviolet (UV)-A-induced stress. Thus, the exogenous Mg-PPn could be used as an antioxidant and a UV block to protect cells from $H_2O_2$ stress and UV-induced damage.

• Journal of Oriental Neuropsychiatry
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• v.20 no.2
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• pp.19-29
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• 2009

Objectives : Antioxidant effects of Gagam-jangwonhwan(LMK01 and 02) water extract against $H_2O_2$-induced oxidative damage and cell death were investigated in rat pheochromocytoma line PC 12. Methods : The cells were treated with LMK01 and 02 water extract and $H_2O_2$, oxidative damage-inducing materials for 24 h. The cellular viability was assessed by WST-1 assay, oxidative damages of the cells by 8-OHdG quantitation, apoptosis by Hoechst 33342 staining assay and activity of antioxidant enzymes by catalase and glutathione peroxidase assay. Results : 1. LMK01 and LMK02 water extracts improved significantly cell viability in $H_2O_2$-treated groups than $H_2O_2$-alone treated cells 2, LMK02 suppressed significantly oxidative damage in $H_2O_2$-treated groups than $H_2O_2$-alone treated cells but LMK01 didn't. Meanwhile, difference of oxidative damages in conditions treated with LMK01 or LMK02 was not significant, 3. The $H_2O_2$ induced-apoptosis in PC 12 cell lines was inhibited effectively by LMK01 and LMK02, and especially the features of apoptosis were obviously reduced in LMK02-treated cells. 4. LMK01 and LMK02 increased significantly activities of both catalase and glutathione peroxidase than those of $H_2O_2$-alone treated group and moreover, LMK02 showed significantly higher activities than those of LMK01. Conclusions : As shown, LMK01 and LMK02 suppressed $H_2O_2$-induced oxidative damage and cell death in PC 12 cell effectively. And they increased activity of major antioxidant enzymes in PC 12 cell line. Therefore, this study suggests the possibility of clinical usage over oxidative stress-induced neurodegenerative disease such as Alzheimer's disease.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.24-31
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• 2010

Taurine, 2-aminoethanesulfonic acid, is an abundant free amino acid present in brain cells and exerts many important biological functions such as anti-convulsant, modulation of neuronal excitability, regulation of learning and memory, anti-aggressiveness and anti-alcoholic effects. In the present study, we investigated to explore whether taurine has any protective actions against oxidative stress-induced damages in neuronal cells. ERK I/II regulates signaling pathways involved in nitric oxide (NO) and reactive oxygen species (ROS) production and plays a role in the regulation of cell growth, and apoptosis. We have found that taurine significantly inhibited AMPA induced cortical depolarization in the Grease Gap assays using rat cortical slices. Taurine also inhibited AMPA-induced neuronal cell damage in MTT assays in the differentiated SH-SY5Y cells. When the neuronal cells were treated with $H_2O_2$, levels of NO were increased; however, taurine pretreatment decreased the NO production induced by $H_2O_2$ to approximately normal levels. Interestingly, taurine treatment stimulated ERK I/II activity in the presence of AMPA or $H_2O_2$, suggesting the potential role of ERK I/II in the neuroprotection of taurine. Taken together, taurine has significant neuroprotective actions against AMPA or $H_2O_2$ induced damages in neuronal cells, possibly via activation of ERK I/II.

• Natural Product Sciences
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• v.24 no.3
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• pp.148-154
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• 2018

Chronic oxidative stress due to the accumulation of reactive oxygen species (ROS) in neuronal cells ultimately leads to neurodegenerative diseases. The use of natural therapies for the prevention of ROS-induced cell damage and for the treatment of neurodegenerative disorders has shown promising results. In this study, we evaluated the neuroprotective effects of the ethyl acetate (EtOAc) fraction of A. okamotoanum against the hydrogen peroxide ($H_2O_2$)-induced oxidative stress in C6 glial cells. Results show that cell viability was decreased in cells incubated with $H_2O_2$, whereas the addition of EtOAc fraction treatments in such cells significantly increased viability. The EtOAc fraction showed the highest inhibitory activity against ROS production and it also decreased the expressions of inflammatory proteins including cyclooxygenase-2, inducible nitric oxide synthase and interleukin-$1{\beta}$. Furthermore, the EtOAc fraction inhibited apoptosis by regulating the protein expressions cleaved caspase -9, -3, poly ADP ribose polymerase, Bax and Bcl-2. Therefore, these results show that the EtOAc fraction of A. Okamotoanum exhibits neuroprotective effects against $H_2O_2$ induced oxidative damage by regulating the inflammatory reaction and apoptotic pathway.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.805-812
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• 2010

DNA damage including base modifications, loss of base and breaks in DNA strands can occur by exposure to irradiation, smoking and several components of food. Unrepaired DNA damage is known to lead to cellular dysfunction, cell death, cancer, and other diseases such as arteriosclerosis and diabetes. The protective effect of garlic on oxidative stress induced DNA damage has been reported recently. In this study, we investigated the protective effect of garlic extracts prepared by different processing methods (raw garlic extracts, RGE; grilled garlic extracts, GGE; pickled garlic extracts, PGE) on leukocytic DNA damage using comet assay. Human leukocytes were incubated with ethanol and methanol extract of garlic at various concentrations (1, 5, 10, 50 ${\mu}g$/mL), followed by oxidative stimuli (200 ${\mu}M$ $H_2O_2$ or 200 ${\mu}M$ 4-hydroxynonenal (HNE)). The methanol and ethanol extracts of RGE, GGE, and PGE showed inhibitory activities of DNA damage induced by $H_2O_2$ or HNE. Especially methanol extract of RGE ($ED_{50}$; 13.3 ${\mu}g$/mL) had a higher antigenotoxic effect on $H_2O_2$ induced DNA damage than those of GGE (23.5 ${\mu}g$/mL) or PGE (24.5 ${\mu}g$/mL). HNE induced DNA damage tended to be effectively inhibited by the lower concentration of all garlic extracts. Therefore, garlic might have protective effects against oxidative DNA damage regardless of processing methods (raw, grilled, pickled) which are the general consumed forms of garlic in Korea.

• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.402-407
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• 1996

Effects of oxidative stress on the induction of apoptosis and the activity of antioxidant enzymes were investigated in HL-60 cells using $H_2O$$_2$and cisplatin which generate oxygen species in the cell. Various concentrations of oxidants were treated to cells and at different incubation time, cells were harvested for assays. Cell viability, morphology by propidium iodide staining and DNA fragmentation by agarose gel electrophoresis were observed to determine whether they induce apoptosis. The activity of antioxidant enzymes such as superoxide dismutase and catalase was also measured to evaluate the cellular response to the oxidative damage. The results are as follows: $H_2O$$_2$ induced apoptosis at 10 $\mu$M after 6h incubation, while it took 12h for cisplatin. Both oxidants induced the superoxide dismutase activity at a tolerable low concentration. However, at a concentration which causes apoptotic cell death, the enzyme level was dropped markedly at first and then recovered to the normal level after which it declined again, probably due to cell death. On the other hand, changes in the activity of catalase were not significant at most concentrations except the statistically significant decrease at 24h after 10 $\mu$M-$H_2O$$_2$treatment. In this study, $H_2O$$_2$- and cisplatintreated cells showed similar results in apoptotic response and enzyme activities, suggesting that anticancer activity of cisplatin may be related, at least in part, to the production of oxygen free radicals.