Estrategias para la evaluación de extractos de polifenoles en modelos in vitro de cáncer de vías digestivas / Strategies for Evaluation of Polyphenol Extracts on in vitro Models of Digestive Tract Cancer / Estratégias para a avaliação de extratos de polifenóis em modelos in vitro de câncer do sistema digestivo

Introducción: Los polifenoles son compuestos que se encuentran naturalmente en alimentos como frutas, verduras, té, vino y chocolates, a los que se les atribuyen beneficios a la salud humana por su capacidad antioxidante. El cáncer de las vías digestivas se encuentra entre la tercera y quinta causas de muerte para la población, por lo que se ha incrementado el interés por realizar los estudios dirigidos a encontrar compuestos polifenólicos que ayuden en su prevención o tratamiento. Objetivo: Identificar las estrategias disponibles para la evaluación de polifenoles en células de cáncer de vías digestivas. Metodología: Búsqueda de literatura en bases de datos como Ovid, Pubmed, Science Direct y Elsevier Journal. Se seleccionaron artículos en los cuales se reporta el efecto biológico de los polifenoles sobre líneas celulares de cáncer de vías digestivas publicados entre 2012 y 2022. Resultados: Varios estudios han reportado el uso de un buen número de líneas celulares como modelos in vitropara estudios de polifenoles en cáncer y han resaltado las líneas AGS y HT-29, además de técnicas para la caracterización de los polifenoles, como el ensayo 2,2-Difenil-I-Picril Hidrazilo (DPPH). Sin embargo, para evaluar el efecto biológico se identifican diversas pruebas que deben analizarse antes de su implementación. Conclusiones: En la literatura se identifica que existen varias alternativas y estrategias para la evaluación de extrac-tos vegetales en cultivos in vitro de cáncer de vías digestivas; no obstante, antes de pasar al diseño experimental, deben tenerse en cuenta una serie de consideraciones para garantizar la utilidad de los resultados.

Introduction: Polyphenols are compounds naturally found in foods such as fruits, vegetables, tea, wine and chocolates, and it was attributed with benefits to human health due to their antioxidant capacity. Cancer of the digestive tract is between the third and fifth cause of death for the population, increasing the interest in carrying out studies aimed at finding polyphenolic compounds that help in their prevention or treatment. Objective: Identify the available strategies for the evaluation of polyphenols in digestive tract cancer cells. Method: A literature search was performed in databases such Ovid, Pubmed, Science Direct and Elsevier Journal and selected articles reporting the biological effect of polyphenols on digestive tract cancer cell lines, published between 2012 and 2022. Results: Currently studies report the use of a good number of cell lines as in vitro models for poly-phenol studies in cancer highlighting the AGS and HT-29 lines, in addition to techniques for the characterization of polyphenols such as the α, α-diphenyl-ß-picrylhydrazyl DPPH assay, however, to evaluate the biological effect various tests are identified that should be analyzed before implemen-tation. Conclusions: The literature identifies that there are many alternatives and strategies for the evaluation of plant extracts in in vitro cultures of digestive tract cancer, however, before moving on to the experimental design, a number of considerations should be taken into account to ensure the usability of the results

Introdução: Os polifenóis são compostos encontrados naturalmente em alimentos como frutas, legumes, chá, vinho e chocolates, aos quais são atribuídos benefícios para a saúde humana devido à sua capacidade antioxidante. O câncer do sistema digestivo está entre a terceira e a quinta principais causas de morte na população, o que levou a um interesse crescente em estudos destinados a encon-trar compostos polifenólicos que ajudem a prevenir ou tratar esse tipo de câncer. Objetivo: Identificar as estratégias disponíveis para a avaliação dos polifenóis nas células cancerosas do sistema digestivo. Metodologia: Pesquisa bibliográfica em bases de dados como Ovid, Pubmed, Science Direct e Elsevier Journal. Foram selecionados artigos que relatam o efeito biológico dos polifenóis em linhas celulares de câncer do sistema digestivo, publicados entre 2012 e 2022. Resultados: Vários estudos relataram a utilização de várias linhas celulares como modelos in vitro para estudos de polifenóis no câncer destacando as linhas AGS e HT-29, bem como técnicas para a ca-racterização de polifenóis, como o ensaio 2,2-Difenil-I-Picril Hidrazil (DPPH). No entanto, para avaliar o efeito biológico, são identificados vários testes que devem ser analisados antes da sua aplicação. Conclusões: A literatura identifica que existem várias alternativas e estratégias para a avaliação de extratos de plantas em culturas in vitro de câncer do sistema digestivo; no entanto, antes de passar à concepção experimental, é necessário ter em conta uma série de considerações para garantir a uti-lidade dos resultados

Antioxidant potential, tannin and polyphenol contents of seed and pericarp of three Coffea species

OBJECTIVE@#To investigate the antioxidant activity, total phenolic and total tannin content of the pericarp and the seed of Coffea benghalensis (C. benghalensis) and Coffea liberica compared to Coffea arabica (C. arabica).@*METHODS@#The antioxidant potential, total tannin and polyphenol contents of the immature and mature seed and pericarp of C. benghalensis and Coffea liberica were quantified and compared to C. arabica. Enhanced chemiluminescence (ECL), 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity, Folin-Ciocalteau method and total tannin content assays were used.@*RESULTS@#Trolox equivalent (TE/g plant material) values obtained by ECL and DPPH methods showed loose correlation (r(2) = 0.587) while those measured by oxygen radical absorbance capacity assay were higher without correlation in each plant. A closer correlation was detected between the ECL method and the percentage antioxidant activity of the DPPH technique (r(2) = 0.610 7) in each species, however the immature pericarp of C. benghalensis showed much higher DPPH scavenging potential than was seen in the ECL assay. The immature pericarp of C. benghalensis expressed the highest tannin and polyphenol content, and a high polyphenol level was also detected in the immature seed of C. arabica. The immature pericarp of Bengal and Liberian coffees showed the largest amount of phenolic contents.@*CONCLUSIONS@#The obtained data highlight the potential role of C. benghalensis as a new source of natural antioxidants and polyphenols compared to C. arabica.

Antioxidant potential, tannin and polyphenol contents of seed and pericarp of three Coffea species

Objective: To investigate the antioxidant activity, total phenolic and total tannin content of the pericarp and the seed of Coffea benghalensis (C. benghalensis) and Coffea liberica compared to Coffea arabica (C. arabica). Methods: The antioxidant potential, total tannin and polyphenol contents of the immature and mature seed and pericarp of C. benghalensis and Coffea liberica were quantified and compared to C. arabica. Enhanced chemiluminescence (ECL), 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity, Folin-Ciocalteau method and total tannin content assays were used. Results: Trolox equivalent (TE/g plant material) values obtained by ECL and DPPH methods showed loose correlation (r

Capacidade antioxidante e triagem farmacológica de extratos brutos de folhas de Byrsonima crassifolia e de Inga edulis / Antioxidant capacity and pharmacologic screening of crude extracts of Byrsonima crassifolia and Inga edulis leaves

Com o objetivo de avaliar o efeito de duas espécies amazônicas em doenças relacionadas aos processos de oxidação, determinou-se a capacidade antioxidante (método Oxygen Radical Absorbance Capacity), o teor de polifenóis totais (método Folin-Ciocalteu - PT), bem como os efeitos farmacológicos in vitro (efeito antiproliferativo) e in vivo (antinociceptivo, antiinflamatório, antiulcerogênico) dos extratos hidroalcoólicos (65:35; v/v; etanol:água) das folhas de Byrsonima crassifolia (BC) e Inga edulis (IE). Os extratos de BC e IE apresentaram elevada capacidade antioxidante (1.422 e 694 µmol de Trolox Equivalente g-1 de folha seca - FS, respectivamente) e um valor relativamente alto de PT (35,93 e 24,50 mg Equivalente ácido gálico g-1 FS, respectivamente). Essa atividade antioxidante não teve relação direta com o teor de compostos fenólicos dos extratos, sugerindo a contribuição de outros grupos químicos nessa atividade. Em cultura de células tumorais humanas (nove linhagens), os extratos não apresentaram atividade antiproliferativa significante, com efeito citotóxico somente na concentração mais elevada. Em modelo de nocicepção induzida pelo calor (placa quente), o extrato de IE apresentou efeito antinociceptivo (P < 0,05) após 30 (250 e 500 mg kg-1) e 60 min (125 e 500 mg kg-1) de sua administração oral. Nos modelos de inflamação houve somente redução do edema para IE na concentração de 500 mg kg-1. Os extratos das duas espécies reduziram as lesões ulcerativas produzidas por etanol em até 84% (P < 0,05), sugerindo uma possível ligação com a atividade antioxidante observada e indicando a necessidade de estudos para a elucidação do mecanismo de ação envolvido.

In order to evaluate the effect of two Amazonian species on chronic diseases linked with the oxidative processes, we performed antioxidant capacity analyses (Oxygen Radical Absorbance Capacity - ORAC and Folin-Ciocalteu - PT assays) and pharmacological effects in vitro (antiproliferative effect) and in vivo (antinociceptive, antiinflammatory, antiulcerogenic effects) for ethanolic extracts (65:35; v/v; ethanol:water) from Byrsonima crassifolia (BC) and Inga edulis (IE) leaves. Both BC and IE extracts showed high ORAC values (1,422 and 694 mmol of Trolox equivalent/g of dry leaf, respectively) and high PT contents (35.93 and 24.50 mg gallic acid equivalent g-1 dry leaf, respectively). The ORAC values had no correlation with PT, suggesting the presence of other chemical groups in the antioxidant activity value. The two extracts did not present significant antiproliferative activity on nine lines of human tumor cells, and cytotoxic effect was detected only at the highest concentration. The antinociceptive effect was investigated using the hot plate test, and IE extract presented a longer latency (P < 0.05) 30 and 60 min after oral administration. The antiinflammatory activity was only observed at the highest concentration, suggesting that the antinociceptive effect observed was not due to the antiinflammatory effect. The extracts of both species reduced the ulcerative lesions produced by ethanol up to 84% (P < 0.05), suggesting a relation with the antioxidant capacity. More studies are necessary to elucidate the mechanisms of action involved on antiulcerative effects.

Assessment of Lifestyle Effects on the Levels of Free Oxygen Radicals in the Korean Population / 가정의학회지

BACKGROUND: As many studies revealed that oxidative stress due to the imbalance of reactive oxygen species (ROS) and antioxidant capacity is related with pathologic processes such as cardiovascular diseases, diabetes, as well as aging and obesity, the relationship between lifestyle and oxidative stress has recently gained much medical attention. However, little information exists on the effects of lifestyle on ROS in Korea. In this study, we investigated the effects of lifestyle on free oxygen radical levels in men and women in Korea. METHODS: A total of 138 adults participated in this study from September 2007 to June 2010 at a health promotion center and department of family medicine. Information on the lifestyle of each participant was obtained by questionnaire. Biochemical markers and a free oxygen radical test (FORT) were also measured. RESULTS: The average age was 47.28 +/- 10.85 years and 79.7% were male. High sensitivity C-reactive protein (hs-CRP; r = 0.418, P = 0.012), triglycerides (r = -0.243, P = 0.008), hemoglobin (r = -0.445, P < 0.001), total protein (r = 0.210, P = 0.036), creatinine (r = -0.294, P = 0.001), fruit intake per day (P = 0.047), and smoking (P = 0.003) were related to the FORT levels in univariate analysis. Multiple linear regression analysis showed that hs-CRP (P = 0.039) was an independent predictor of serum FORT values. This statistical model can explain 78% of the variance in FORT values. CONCLUSION: This result suggests that hs-CRP showed a statistically significant positive association with FORT values. Further studies on the relationship between lifestyle and antioxidant capacity as well as ROS seem to be warranted to evaluate the overall effect of oxidative stress.

Oxidative stress and Alzheimer's disease / 中国药理学通报

Alzheimer's disease(AD)is a progressive neurodegenerative disease characterized by cognition impairment and behavioral abnormalities.While the mechanisms involved in AD remain unclear,various hypotheses have been proposed regarding pathogenesis of AD,among which the oxidative stress hypothesis has attracted more and more attention.In the present article,the relationship between oxidative stress and AD is reviewed,including sources of neuronal oxygen radical generation,the link of oxidative stress to pathogenesis of AD,preclinical and clinical studies of AD,therapeutic effects of antioxidants and phosphodiesterase inhibitors on AD.

Effects of Atomic Oxygen Radical Anion on Escherichia coli Cells / 生物化学与生物物理进展

The effects of atomic oxygen radical anion (O-) on the inactivation and morphological changes ofEscherichia coli (E. coli)on the surface of bio-indicator carrier were investigated. The O- flux was generated from a novel developed O- generator where the Oinactivation ofE. coli was sensitive to the O- intensity and the cell mortality was enhanced to more than 3-logarithm reduction with the exposure to 1.5 mA/cm2 O- flux for 120 min. Field emission scanning electron microscopy (FESEM) observations showed that O- flux destroyed cellular structures. Lipid peroxidation reaction induced by atomic oxygen radical anion for E. coli cells was also observed using product of malondialdehyde (MDA) as an index. The concentration of MDA increased to 1.2 μmol/g(dry weight) of cells when E. coli suspension (5.6×107 cfu/ml) was treated by the O- flux (1.5 μA/cm2) for 15 min. The findings revealed that the atomic oxygen radical anions, with strong oxidation power, was effective in inactivating E. coli and caused lipid peroxidation reaction at the first time,which would be potential useful to develop a novel approach for the microbial decontamination and for the study on the interactions between microorganisms and O-.

Correlation of serum total hydroperoxide levels and diseases of prematurity / 소아과

PURPOSE: Total hydroperoxide (TH), free radical-mediated oxidation product can be used as a measure of free radical injury. The aim of the present study was to see if preterm newborns are at increased risk for oxidative stress compared with term newborns, and to determine whether oxidative stress during postnatal first 1 week is associated with clinical outcomes in preterm infants. METHODS: Serum TH levels of preterm infants (n=39) were compared with those of term infants (n=24) on the postnatal day 1. Among the preterm infants, serum TH levels of uncomplicated group (n=23) were also compared with those of complicated group (n=16) who developed oxygen radical related diseases on the postnatal day 1 and 7. Retrospective analysis was performed to find out risk factors for oxygen radical injuries based on birth history, laboratory data, neuroimaging findings and clinical progress in two preterm groups. RESULTS: Serum TH levels on postnatal day 1 were higher in the preterm infant group than the term infant group. Serum TH levels on postnatal day 1 in the complicated preterm infant group were significantly higher compared with uncomplicated group, but there was no significant difference in serum TH levels on postnatal day 7. Also, there was no significant difference in serum TH levels between uncomplicated preterm infants and term infants. Serum TH level on postnatal day 1 was independently associated with higher morbidity after adjusting for gestational age, Apgar score (5 min), arterial blood gas analysis. CONCLUSION: Complicated preterm newborns are at increased risk for oxidative stress compared with uncomplicated newborns and term newborns. Oxidative injury during the prenatal or postnatal day 1 is associated with adverse outcomes in preterm infants. Elevated TH levels on postnatal day 1 may have a value to predict clinical outcomes in preterm infants.

Immunohistochemical Study on the SVCT Expression in the Spinal Cord of Experimental Allergic Encephalomyelitis (EAE) Model / 대한해부학회지

Experimental allergic encephalomyelitis (EAE) lesions by autoimmune inflammatory mechanism are characterized by the activation of microglia and astrocytes during the peak symptomatic stage of the disease. Besides it is well known that ROS and nitric oxide (NO), which is come out from activated inflammatory cells, play important role in the pathogenesis of EAE lesions. And vitamin C (L-ascorbic acid), which may protect from the deleterious effect by reducing iron (Fe2+) or copper (Cu2+) ions and maintain tissue homeostasis by removing of oxygen free radical, is inevitable to help many enzymatic reactions of cells. Previous report already investigated expression and functional analysis on various vitamin C transporters of vitamin C in many cell types. However, the researches for the vitamin C transporters are mostly performed in the normal state but not disease model yet. Therefore, for the first time, we investigated to know whether the SVCT1, 2 immunoreactivity may be observed in the astrocyte of EAE rat spinal cord. In the comparison of control and peak time group, the number of SVCT1, 2 immunoreactive cell was inclined to increase (P<0.05) as respectively 100+/-29.93, 135+/-34.62 in the control group, and 179+/-54.29, 349+/-73.56 in the peak time group. SVCT2 immunoreactivity was not doubly colocalized with GFAP antibody in the control group. In contrast, the astrocytes of the peak time group showed SVCT2 immunoreactivity in the perivascualr region and the cell number of doubly (SVCT2, GFAP) colocalized was 15+/-5.67 (P<0.05). We are firstly demonstrated that, in the evolving processes of EAE, astrocytes are able to use the vitamin C via the SVCT2. Taken all findings into consideration, the present data on the typical anti-oxidant vitamin C and its transporters, which may play a role in removing ROS, could be considered as a target to the therapeutic strategy of EAE and is also very useful to identify the characterization of vitamin C in the biological organism.

Effects of Different Reperfusion Sequence on Hepatic Ischemia-Reperfusion Injury / 中国普外基础与临床杂志

Objective To investigate the effects of different reperfusion sequence on hepatic warm ischemia-reperfusion injury and its related mechanisms.Methods Ninety-six healthy male Sprague Dawley rats were randomly divided into 6 groups by using random digits method(n=16,each): Sham operation group,only shammed operation for negative control;the other 5 groups were all experimental groups,which were divided according to different reperfusion sequences of portal vein and hepatic artery: reperfusion first through the portal vein for 1 min with subsequent full reperfusion group,reperfusion first through the portal vein for 2 min with subsequent full reperfusion group,reperfusion first through the hepatic artery for 1 min with subsequent full reperfusion group,reperfusion first through the hepatic artery for 2 min with subsequent full reperfusion group,simultaneous reperfusion through the portal vein and hepatic artery group.Each group was further randomly divided into two subgroups(n=8,each) for sample collection at 2,4 hours after reperfusion respectively.Serum alanine aminotransferase(ALT),aspartate aminotransferase(AST) and malondialdehyde(MDA),superoxide dismutase(SOD) and glutathion(GSH) in hepatic tissue were detected respectively.HE staining of histopathologic slides was used to observe the morphological changes of hepatic tissue.TUNEL method was used to assess the apoptosis index(AI) of hepatocytes.Results The liver of rat was approximately normal in the sham operation group with lower levels of ALT,AST,MDA and AI,and higher levels of SOD and GSH as compared with all the experimental groups(P

Effect of Antioxidants on the Toxicity of Oxygen Radicals to the Cultured Mouse Schwann Cells in vitro / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Oxygen radical scavengers and inhibitors are known to have protective functions (or roles) against hypoxia and noise exposure in the cochlea and brain. The purpose of this study was to examine the toxic effect of oxygen radicals (xanthine oxidase and hypoxanthine) on cultured mouse facial nerve Schwann cells, and determine if antioxidants (TPEN and DFO) might ptotect Schwann cells from oxidant-induced neurotoxicity. MATERIALS AND METHODS: Dissociated cell cultures were prepared from the facial nerve of a mouse. After dissociation of Schwann cells, isolated cells were washed, resuspended in feeding medium, and plated onto poly-L-lysine-coated Aclar plastic cover slips (12 mm diameter) in petri dishes or in 96 well multichambers at cell density of 2X105 ceIls/coverslip or lX10(5) ceIls/we11. The feeding medium consisted of Eagle's minimum essential medium (MEM) containing 5% horse serum, 5 mg/ml D-glucose, and 25 ng/ml gentamicin. Cultures were grown in 5% CO2/95% atmosphere at 37degreesC, and the medium was renewed twice a week. Cultures grown for 4-5 days were utilized for experiments. Oxygen radical exposure was done using XO and HX, and antioxidant pretreatment was carried out using tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) and desferrioxamine (DFO). Cytotoxicity assay was performed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxic assay and inverted microscopy. RESULTS: Cell viability of cultured mouse Schwann cells treated with markedly decreased in a dose-dependent manner. Cultured mouse Schwann cells exposed to XO/HX for 4 hours showed degenerative changes such as the decrease of cell number and process. Pretreatment of 80 uM TPEN for 2 hours increased remarkably the cell viability of cultured Schwann cells exposed to 20 mU/ml XO/0.1 mM HX, while DFO did not show any protective effects on oxidant-induced neurotoxicity in these cultures. CONCLUSION: It is suggested that oxygen radicals induce neurotoxic effect on cultured mouse Schwann cells, and that selective antioxidants such as TPEN is very effective in blocking oxidant-induced neurotoxicity.

Effect of NMDA Receptor Antagonist (APV)on the Toxicity Induced by Oxygen Radicals in Cultured Myocardial Cells / 체질인류학회지

Toxic effect of oxygen radicals and cardioprotective effect of N -methyl -D -aspartate (NMDA) receptor antagonists against xanthine oxidase (XO) and hypoxanthine (HX)-induced cardiotoxicity were measured in order to elucidate the mechanism of cardiotoxicity on cultured mouse myocardial cells. MTT assay was performed after myocardial cells were cultured for 12 hours at various concentrations of XO/HX alone or with D -2 -amino -5 -phosphonovaleric acid (APV) or 6 - cyano -7 -nitroquinoxaline -2,3 -dione (CNQX). In this study, XO/HX was toxic in a time -and dose -dependent manners on cultured myocardial cells, and midcytotoxicity value 50 (MTT50) was at 30 mU/ml XO and 0.1 mM HX after myocardial cells were grown for 12 hours in media containing 1 ~50 mU/ml XO and 0.1 mM HX. When cultures were treated with 30 mU/ml XO and 0.1 mM HX flus 20 80 microM APV for 12 hours, cell viability was increased remarkably, while treatment with 30 mU/ml XO and 0.1 mM HX flus 10 ~50 microM CNQX did not show any protective effect against XO/HX -induced neurotoxicity. From the above results, it is suggested that oxygen radicals are toxic on cultured mouse myocardial cells by the decrease of cell viability, and NMDA receptor antagonists such as APV are very effective in the prevention of myocardial toxicity induced by oxygen radicals.

In vivo Assessment for the Antioxidant Activity of the Calcium Channel Blocker Nicardipine in 3% Sodium-Taurocholate-induced Acute Pancreatitis

BACKGROUND: Although several pathophysiological sequences, such as protease activation, free radical generation, and inflammatory mediator release, have been described in acute pancreatitis, the precise mechanism by which acute pancreatitis is initiated is unkown. Cellular calcium, a key function and also a crucial pathological intracellular messenger in cell injury, appears to be involved in the initiation and development of acute pancreatitis. The aim of this study is to evaluate the role of cellular calcium and therapeutic effect of administering the Ca++ channel blocker nicadipine as an antioxidant. METHOD:Nicardipine, known to be a calcium channel blocker and a most potent antioxidant, was wed as a pretreatment 1 hour before induction of pancreatitis by intraductal infusion of 3% sodium taurocholate or as a post-treatment 1 hour after induction of aucte pancreatitis by retrograde infusion of sodium taurocholate. The net weight of the pancrease, the amounts of s-amylse, GSH and MDA in the pancreatic tissue, and the histologic damage were examined 12 hours after the induction of pancreatitis. RESULTS: Nicardipine administration ameliorated pancreatic edema and reduced the amount of s-amylase compare to untreated necrotizing pancreatitis group. Also, pre- or post-treatment with nicardipine had beneficial protective effect with respect to free radical-induced injury; in particular, pre-treatment with nicardipine was much better. With respect to the histologic findings, pancreatic necrosis, hemorrhage, and neutrophil infiltration were prominent in the necrotizing group, however, in the group treated with nicardipine, the necrosis and hemorrhage were ameliorated remarkably. CONCLUSION:The free oxygen radicals and the intracellular calcium influx were major elements in the pathogenesis of acute pancreatitis, and nicardipine ameliorated pancreatic necrosis and hemorrage and exerted an antioxidant effect. The administration of nicardipine should be considered in the early stage of pancreatitis or in case of risk of pancreatitis.

Expression of Superoxide Dismutase in Alkali-burned Rat Corneal Epithelium

During the acute stage of inflammation such as alkali burn, an intense local oxidation process takes place at the inflammatory foci through production of oxygen-derived free radicals. The extent of tissue damage would be the result of the balance between free radical generated and the local antioxidation defense system. Superoxide dismutase (SOD) is a major oxygen radical scavenging enzyme. Major active molecule in rat, rabbit and human is known as Cu-Zn SOD. We have been studied the difference of the distribution of SOD between normal and alkali burned rat cornea by immunohistochemical staining method. In normal rat corneal epithelium, the basal and intermediate layer cells exhibited intense intacellular staining, average 4.13 cell layers. In alkali burned rat corneal epithelium, average cell layers of intracelluar staining were 0.73, 2.2, 2.93 at postburn 1 day, 3 dyas, 7 days, respectively. We think these results are mainly due to the increase of oxygen free radical and decreased production of SOD at early postburn period. Therefore, free radical scavenging agent such as SOD may be helpful in would healing of corneal alkali burn.

Effect of Allopurinol on Methylmercuric Chloride in Cultured O1igodendrocytes / 체질인류학회지

In order to examine the neurotoxic mechanism of oxygen radicals on cultured bovine oligodendrocytes, cytoxic effect of oxygen radicals was examined when cultures were treated with various concentrations of xanthine oxidase (XO) and hypoxanthine (HX) in culture medium. In addition, the neuroprotective effect of iron-chelators against the neurotoxicity induced by oxygen radicals was evaluated by MTT assay. Cell viability was remarkably decreased in a time-dependent manner after exposure of cultured bovine oligodendrocytes to 20mU/ml XO and 0.1mM HX for 4 hours. In the neuroprotective effect of iron-chelators on oxidant-induced neurotoxicity, tetrakis (2-pyridylmethyl)ethylenediamine (TPEN) blocked the neurotoxicity induced by oxygen radicals, while DFX was not effective in blocking oxidant-induced neurotoxicity in these cultures. These results suggest that oxygen radicals are toxic in cultured bovine oligodendrocytes, and also selective iron-chelators such as TPEN are effective in blocking the neurotoxicity induced by oxygen radicals.

Effect of Iron-chelator on the Neurotoxicity Induced by Oxygen Radicals / 체질인류학회지

In order to elucidate the neurotoxicity of oxygen radicals, neurotoxic effect was investigated after cultured mouse spinal sensory ganglionic cells were exposed to oxygen radicals which were generated enzymatically by reaction of xanthine oxidase (XO) and hypoxanthine (HX) in culture medium. And also the neuroprotective effect of iron-chelators against oxidant-induced neurotoxicity was assessed by MTT assay and neurofilament enzymeimmuno assay (EIA). Cell viability was significantly decreased in a time-dependent planner after exposure of cultured neurons to 25mU/ml XO and 0.3mM HX for 3 hours. In the examination of neuroprotective effect of iron-chelators on oxidant-mediated neurotoxicity. TPEN was effective in blocking the neurotoxicity induced by oxygen radicals, while DFX did not showed any neuroprotective effect in these cultures. These results suggest that oxygen radicals are toxic in cultured mouse spinal sensory ganglionic cells, and also iron involves in oxidant-induced neurotoxicity. While, selective iron-chelators such as TPEN are effective in blocking the neurotoxicty induced by oxygen radicals.

STUDIES ON POLYSACCHARIDE FROM SARGASSUM THUN-BERGII FOR ITS ABILITY TO SCAVENGE ACTIVE OXYGEN SPECIES Ⅱ On Effect of Far Ultraviolet Radiation on Antioxidation of Polysaccharides / 中国海洋药物

The effect of far ultraviolet radiation on scavenging active oxygen radiacal of polysaccharides from Sargassum thvnbergii and Sargassum kvrneri was studied. The results showed that the scavenging superoxide an ion radiacal levels of two polysaccharides were obviously decreased after 24h by UVc radiation,but the inhibition of the peroxidization of PU-FA was very prominent.The changes of IR spectra before and after far ultraviolet radiation on the two polysac-charide were also studied by differential scanning calorimetry(DSC)and infrared absorption spectroscopy(IR)

Improvement of Guangdong Liangcha Granules on Restraint-stress-induced Perox idation in Genital Organs of Mice / 中药新药与临床药理

Objective To observe the improvement of Guangdong Liangcha Granules (GLG) on restraint-stress-induced peroxidation in genital organs of mice. Meth ods Mice models of peroxidation injury in genital organs were induced by 18-hou r restraint stress. Testicular and ovarian malondialdehyde (MDA) level was detec ted by thiobarbituric acid method,glutathione (GSH) content by HPLC,xanthine o xidase (XOD) and GSH-PX activities by colorimetric method,nitric oxide (NO) co ntent by Griess chemical method and oxygen radical absorbance capacity (ORAC) by enzyme-linked fluorescent immunoassay. Results Compared with model group,GLG can markedly reduce MDA level,XOD acitivity and NO contents,in addition,GLG c an effectively increase the ORAC value,GSH content,GSH-PX activity in testis and ovaries. Conclusion Oral treatment of Guangdong Liangcha Granules was found to reduce the status of peroxidation in testis and ovaries,and the improvement may be related to the increase of its free radical scavenging activity and lipid peroxidation.

Effect of active oxygen on hepatocarcinoma tissues of rabbits / 中国普通外科杂志

80) via portal vein.After reperfusion 1 h,1 d,3d and 7 d respectively,the concentration of superoxide dismutase(SOD) and catalase(CAT) were tested,and the apoptosis of hepatocarcinoma also was observed using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling(TUNEL) method.Results The results indicated that the SOD concentration in both hepatocarcinoma tissue and normal hepatic tissues decreased following I/R and perfusion with hyperoxic fluid liquid.The concentration of CAT increased following I/R in normal hepatic tissues.In hepatocarcinoma tissue,concentration of CAT decreased after reperfusion for 1 d and reached its lowest point.After perfusion with hyperoxic fluid,the concentration of SOD in both hepatocarcinoma tissue and normal hepatic tissues decreased more quickly following I/R and the low level was still found on 7 d after reperfusion.The concentration of CAT in tissues of both groups decreased and reached the lowest level at 1 h after reperfusion,but it was restored at 3 d reperfusion in normal hepatic tissues,and in hepatocarcinoma tissue was still at lower level until 7 d after reperfusion. After I/R,the apoptotic cells increased in normal hepatic and hepatic cancer tissues,and were most marked in tissues of hepatic carcinoma at 1 d and 3 d after perfusion with hyperoxic fluid.After I/R and perfusing with hyperoxic fluid,the changes of SOD and CAT and apoptosis in hepatocarcinoma tissue were more obvious than that in normal hepatic tissues(P

The effect of free oxgen radical scavengers and interleukin-2 on the UVB-induced suppression of human natural killer activity in vitro / 대한피부과학회지

BACKGROUND: Previous studies have shown that in vitro exposure to ultraviolet B(UVB) radiation resulted in a dose-dependent inhibition of natural killer activity(NK activity) of normal human peripheral blood mononuclear cella(PBMC), and that in vivo exposure to snlight also induced NK activity suppression. The precise meehanism of the UV-regulation on the riat iral killer system(NK system) is not established. Objective & METHOD: The purpose of this study is to examine whether the addition of interleukin-2(IL-2) and/or free oxygen radical scavengers, superoxide dismutas(SOD) or sodium azide(SA), is effective in reducing the UVJ3-induced suppression of NK activity of FBMC. RESULTS: The results are as follows 1. The suppressive effect of UVB radiat,ion on NK activity could successfully be prevented in the presence of SOD(100 and 1,000U/ml) during the radiation. 2. SA( LO and 10 M/ml) did not prevent the suppression of NK activity. 3. IL-2(100U/ml) markedly enhanced the NK activity of nonirradiated PBMC, but had no effect on irradiated PBMC. 4. Combination treatment with both IL-2 and free radical scavengers on UVB-irradiated PBMC resulted in no additive or synergistic effect on the prevention of the suppression of NK activity compared with a single treatment with either IL-2 or free radical scavengers. CONCLUSION: In the presserit study, we found that SOD providec a protective effect on NK activity during the UVB radiation and we suggest that superoxide anion(O ) might play a major role in the UV-regulatory mechanisms of the NK system.