The effect of Allium sativum in experimental peritoneal adhesion model in rats

Abstract Purpose: To evaluate the effect of garlic on formation of postoperative adhesions in rats. Methods: Twenty-four Sprague dawley rats were divided into three groups. In Group 1 (sham), laparotomy was performed and stitched up. In Group 2 (control), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and 2 cc of saline was intraperitoneally administered to each rat. In Group 3 (experimental), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and each rat was intraperitoneally administered a sterile Allium sativum derivative. The rats in all groups were re-laparotomized on postoperative day 7; samples were obtained from the peritoneal tissue surrounding the cecum Results: In Group 3, there was a statistically significant difference in terms of inflammation, lymph node size, and free oxygen radicals; these parameters tended to increase. In terms of fibrosis evaluated using H&E and MT, there was no significant difference between groups 2 and 3. Conclusions: No positive outcomes indicating that Allium sativum reduces intra-abdominal adhesions were obtained. However, it caused severe inflammation in the tissue. Additionally, in immunohistochemical analyses conducted to detect oxidative stress, allium sativum increased the production of free oxygen radicals in the tissue.

The effect of pycnogenol on lymphatic nodes and adhesion during in a peritoneal adhesion model in rats

Abstract Purpose: To investigate the effects of pycnogenol on peritoneal adhesions and additionally to investigate the immunohistochemical effects of free oxygen radicals and reactive lymph nodes detected in the adhesive tissue that was sampled surrounding the cecum on intra-abdominal adhesions. Methods: Twenty-seven Wistar Albino rats were divided into three groups. In group 1 (sham), laparotomy was performed and stitched up. In group 2 (control), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and each rat was intraperitoneally administered 2 cc of saline. In group 3 (experimental), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and each rat was intraperitoneally administered a sterile Pycnogenol derivative. The rats in all groups were re-laparotomized on postoperative day 7; samples were obtained from the peritoneal tissue surrounding the cecum, and the rats were sacrificed. Results: In group 3, there was a statistically significant difference in terms of inflammation, lymph node size, and free oxygen radicals; these parameters tended to increase. In terms of fibrosis evaluated using H&E and MT, there was no significant difference between groups 2 and 3. Conclusions: No positive outcomes indicating that pycnogenol reduces intra-abdominal adhesions were obtained. However, it caused severe inflammation in the tissue. Moreover, a significant increase in lymph node size was detected secondary to inflammation. Additionally, in immunohistochemical analyses conducted to detect oxidative stress, pycnogenol increased the production of free oxygen radicals in the tissue.

Activities of different types of Thai honey on pathogenic bacteria causing skin diseases, tyrosinase enzyme and generating free radicals

BACKGROUND: Honey is a natural product obtained from the nectar that is collected from flowers by bees. It has several properties, including those of being food and supplementary diet, and it can be used in cosmetic products. Honey imparts pharmaceutical properties since it has antibacterial and antioxidant activities. The antibacterial and antioxidant activities of Thai honey were investigated in this study. RESULTS: The honey from longan flower (source No. 1) gave the highest activity on MRSA when compared to the other types of honey, with a minimum inhibitory concentration of 12.5% (v/v) and minimum bactericidal concentration of 25% (v/v). Moreover, it was found that MRSA isolate 49 and S. aureus were completely inhibited by the 50% (v/v) longan honey (source No. 1) at 8 and 20 hours of treatment, respectively. Furthermore, it was observed that the honey from coffee pollen (source No. 4) showed the highest phenolic and flavonoid compounds by 734.76 mg gallic/kg of honey and 178.31 mg quercetin/kg of honey, respectively. The antioxidant activity of the honey obtained from coffee pollen was also found to be the highest, when investigated using FRAP and DPPH assay, with 1781.77 mg FeSO4•7H2O/kg of honey and 86.20 mg gallic/kg of honey, respectively. Additionally, inhibition of tyrosinase enzyme was found that honey from coffee flower showed highest inhibition by 63.46%. CONCLUSIONS: Honey demonstrates tremendous potential as a useful source that provides anti-free radicals, anti-tyrosinase and anti-bacterial activity against pathogenic bacteria causing skin diseases.

Investigations of anticholinestrase and antioxidant potentials of methanolic extract, subsequent fractions, crude saponins and flavonoids isolated from Isodon rugosus

BACKGROUND: Based on the ethnomedicinal uses and the effective outcomes of natural products in various diseases, this study was designed to evaluate Isodon rugosus as possible remedy in oxidative stress, alzheimer's and other neurodegenerative diseases. Acetylecholinestrase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of crude methanolic extract (Ir.Cr), resultant fractions (n-hexane (Ir.Hex), chloroform (Ir.Cf), ethyl acetate (Ir.EtAc), aqueous (Ir.Aq)), flavonoids (Ir.Flv) and crude saponins (Ir.Sp) of I. rugosus were investigated using Ellman's spectrophotometric method. Antioxidant potential of I. rugosus was determined using DPPH, H2O2 and ABTS free radicals scavenging assays. Total phenolic and flavonoids contents of plant extracts were determined and expressed in mg GAE/g dry weight and mg RTE/g of dry sample respectively. RESULTS: Among different fractions Ir.Flv and Ir.Cf exhibited highest inhibitory activity against AChE (87.44 ± 0.51, 83.73 ± 0.64%) and BChE (82.53 ± 0.71, 88.55 ± 0.77%) enzymes at 1 mg/ml with IC50 values of 45, 50 for AChE and 40, 70 µg/ml for BChE respectively. Activity of these fractions were comparable to galanthamine causing 96.00 ± 0.30 and 88.61 ± 0.43% inhibition of AChE and BChE at 1 mg/ml concentration with IC50 values of 20 and 47 µg/ml respectively. In antioxidant assays, Ir.Flv, Ir.Cf, and Ir.EtAc demonstrated highest radicals scavenging activities in DPPH and H2O2 assays which were comparable to ascorbic acid. Ir.Flv was found most potent with IC50 of 19 and 24 µg/ml against DPPH and H2O2 radicals respectively. Whereas antioxidant activates of plant samples against ABTS free radicals was moderate. Ir.Cf, Ir.EtAc and Ir.Cr showed high phenolic and flavonoid contents and concentrations of these compounds in different fractions correlated well to their antioxidant and anticholinestrase activities. CONCLUSION: It may be inferred from the current investigations that the Ir.Sp, Ir.Flv and various fractions of I. rugosus are good sources of anticholinesterase and antioxidant compounds. Different fractions can be subjected to activity guided isolation of bioactive compounds effective in neurological disorders.

Antioxidant effect of 4-nerolidylcatechol and -tocopherol in erythrocyte ghost membranes and phospholipid bilayers

4-Nerolidylcatechol (4-NC) is found in Pothomorphe umbellata root extracts and is reported to have a topical protective effect against UVB radiation-induced skin damage, toxicity in melanoma cell lines, and antimalarial activity. We report a comparative study of the antioxidant activity of 4-NC and α-tocopherol against lipid peroxidation initiated by two free radical-generating systems: 2,2′-azobis(2-aminopropane) hydrochloride (AAPH) and FeSO4/H2O2, in red blood cell ghost membranes and in egg phosphatidylcholine (PC) vesicles. Lipid peroxidation was monitored by membrane fluidity changes assessed by electron paramagnetic resonance spectroscopy of a spin-labeled lipid and by the formation of thiobarbituric acid-reactive substances. When lipoperoxidation was initiated by the hydroxyl radical in erythrocyte ghost membranes, both 4-NC and α-tocopherol acted in a very efficient manner. However, lower activities were observed when lipoperoxidation was initiated by the peroxyl radical; and, in this case, the protective effect of α-tocopherol was lower than that of 4-NC. In egg PC vesicles, malondialdehyde formation indicated that 4-NC was effective against lipoperoxidation initiated by both AAPH and FeSO4/H2O2, whereas α-tocopherol was less efficient in protecting against lipoperoxidation by AAPH, and behaved as a pro-oxidant for FeSO4/H2O2. The DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical assay indicated that two free radicals were scavenged per 4-NC molecule, and one free radical was scavenged per α-tocopherol molecule. These data provide new insights into the antioxidant capacity of 4-NC, which may have therapeutic applications for formulations designed to protect the skin from sunlight irradiation.

Peroxidação lipídica em ratos tratados com sulfato de vincristina e decanoato de nandrolona / Lipid peroxidation in rats treated with vincristine sulphate and nandrolone decanoate

Brain and serum lipid peroxidation was studied in rats treated with vincristine sulphate and different doses of nandrolone decanoate. Thirty rats were distributed into six groups (n=5). The treatments were applied once a week for two weeks. Sample collection was performed in the third week. Treatments during the first week were: G1 (control) - physiologic solution, G2 - vincristine sulphate (4mg/m²), G3 - physiologic solution, G4 - physiologic solution, G5- vincristine sulphate (4mg/m²), and G6 - vincristine sulphate (4mg/m²). In the second week, they were: G1 (control) - physiologic solution, G2- physiologic solution, G3 - nandrolone decanoate (1.8mg/kg-1), G4 - nandrolone decanoate (10mg/kg-1), G5 - nandrolone decanoate (1.8mg/kg-1), and G6 - nandrolone decanoate (10mg/kg-1). Lipid peroxidation increased with the isolated use of vincristine and nandrolone decanoate, and with vincristine associated to the highest dose of the ester as well. These results suggest that vincristine sulphate and nandrolone decanoate increase free radical production. Therapeutic dose of nandrolone decanoate when associated with vincristine sulphate proved to be beneficial, as it was able to protect the organism from damaging processes involved in free radical production.

Este estudo teve por objetivo detectar a peroxidação lipídica presente no cérebro e no soro de ratos tratados com sulfato de vincristina e diferentes doses de decanoato de nandrolona. Trinta ratos foram distribuídos em seis grupos (n=5). Os tratamentos foram aplicados uma vez por semana, durante duas semanas, e a coleta de amostras foi realizada na terceira semana. Na primeira semana, os tratamentos consistiram de: G1(controle) - solução fisiológica; G2 - sulfato de vincristina (4mg/m 2 ); G3 - solução fisiológica; G4 - solução fisiológica; G5 - sulfato de vincristina (4mg/m 2 ) e G6 - sulfato de vincristina (4mg/m 2 ). Na segunda semana: G1(controle) - solução fisiológica; G2 - solução fisiológica; G3 - decanoato de nandrolona (1.8mg/kg-1 ); G4 - decanoato de nandrolona (10mg/kg-1 ); G5 - decanoato de nandrolona (1.8mg/kg-1 ) e G6 - decanoato de nandrolona (10mg/kg-1 ). A peroxidação lipídica aumentou com o uso isolado tanto da vincristina quanto do decanoato de nandrolona e com a associação da vincristina à dose mais alta do éster. Estes resultados sugerem que o sulfato de vincristina e o decanoato de nandrolona aumentam a produção de radicais livres. A dose terapêutica do decanoato de nandrolona, quando associada ao sulfato de vincristina, provou ser benéfica, já que foi capaz de proteger o organismo dos processos prejudiciais induzidos pela produção de radicais livres.

Capacidade antioxidante total de óleos vegetais comestíveis: determinantes químicos e sua relação com a qualidade dos óleos / Total antioxidant capacity of edible vegetable oils: chemical determinants and associations with oil quality

A capacidade antioxidante total de óleos vegetais comestíveis é determinada por sua composição físico-química e pode estar associada a atributos de qualidade dos óleos, especialmente a sua bioatividade e possivelmente a sua estabilidade oxidativa. Este artigo apresenta os fundamentos dos ensaios de capacidade antioxidante total e avalia criticamente os ensaios aplicáveis na análise de óleos e os pontos críticos nas aplicações dos ensaios para a análise dessas amostras. Discute-se o potencial papel dos componentes químicos dos óleos comestíveis como determinantes da capacidade antioxidante total, assim como a possível relação da capacidade antioxidante com a bioatividade e a estabilidade oxidativa dos óleos. Finalmente, discutem-se evidências de que, caso seja sistematicamente investigado em trabalhos experimentais futuros, o uso de ensaios de capacidade antioxidante total na análise de óleos vegetais pode contribuir para integrar o conhecimento da composição química com a bioatividade e possivelmente com a estabilidade de óleos vegetais específicos. Dessa forma, os ensaios de capacidade antioxidante apresentam potencial para aplicação no controle da qualidade integral de óleos comestíveis.

The total antioxidant capacity of edible vegetable oils is determined by their physical-chemical composition and might be associated with their quality attributes, especially with bioactivity and possibly with oxidative stability. The current review presents the fundamentals of total antioxidant capacity assays and critically evaluates the assays applicable to the analysis of oils. The role of the chemical components of edible oils as determinants of total antioxidant capacity is discussed, as well as the potential associations between antioxidant capacity and bioactivity or oxidative stability of the selected oils. Finally, we discuss evidences that, if systematically addressed in future experimental work, the application of total antioxidant capacity assays to vegetable oils might contribute to link the knowledge about their chemical composition with their bioactivity, and possibly with the stability of specific vegetable oils. Thus, antioxidant capacity assays can potentially be used for the quality control of edible oils.

Associação entre atividade antioxidante in vitro e características químicas, sensoriais, cromáticas e comerciais de vinhos tintos Sul-Americanos / Association between in vitro antioxidant activity and chemical, sensory, chromatic and commercial characteristics of South-American red wines

O vinho tinto é rico em compostos fenólicos com atividade antioxidante, capazes de inativar espécies reativas de oxigênio, minimizando danos celulares oriundos do estresse oxidativo, proporcionando uma redução de risco para doenças crônicas não transmissíveis. Assim, os objetivos desta pesquisa foram identificar associações entre a atividade antioxidante in vitro e fatores relacionados ao tipo de uva, região de produção, perfil sensorial, safra, valor comercial e concentração de compostos fenólicos de vinhos tintos produzidos no Brasil, Chile e Argentina. Inicialmente, os vinhos brasileiros (n=29) foram avaliados em relação à atividade antioxidante (ORAC e DPPH), cor instrumental e compostos fenólicos majoritários, no intuito de verificar qual classe de fenólicos estaria associada com a atividade antioxidante. Verificou-se que tanto os compostos fenólicos totais como os flavonóides totais, com destaque aos flavonóides não-antociânicos, se associaram significativamente (p<0,05) com a atividade antioxidante. Em um segundo passo, as características sensoriais, a cor, o valor comercial e a atividade antioxidante das 80 amostras de vinhos Sul-Americanos, distribuídas em Merlot (n=9), Pinot Noir (n=17), Malbec (n=11), Syrah (n=12), Cabernet Sauvignon (n=24), e vinhos de uvas americanas (Vitis labrusca) (n=7) foram avaliados usando estatística multivariada, objetivando-se verificar se a qualidade sensorial das amostras estaria associada com o valor comercial, cor, e à atividade antioxidante. De uma forma geral, os vinhos chilenos e argentinos apresentaram maior atividade antioxidante, valor comercial, intensidade de odor, qualidade sensorial, índice de acidez e taninos, ao passo que os vinhos brasileiros obtiveram os menores valores para os atributos sensoriais. Os vinhos de uvas americanas apresentaram menores valores para todas as variáveis. As varietais Syrah, Malbec e Cabernet Sauvignon apresentaram maior capacidade antioxidante e melhores características ...

Red wine is rich in phenolic compounds with antioxidant activity, being able to buffer reactive oxygen species, thus decreasing the risk of non-transmissible chronic diseases. In this regard, the objectives of this research aimed at identifying associations between the in vitro antioxidant activity and factors related to grape varietal, region of production, sensory profile, vintage, color, commercial value, and concentration of phenolic compounds of red wines produced in Brazil, Chile, and Argentina. Initially, the Brazilian red wines (n = 29) were assessed in relation to antioxidant activity, instrumental color, and major phenolic compounds with the objective to verify which phenolic class was associated with the antioxidant activity. Both the total phenolic compounds and total flavonoids, with special attention to non-anthocyanin flavonoids, were significantly associated with the antioxidant activity. In a second step, the sensory characteristics, color, commercial value, and antioxidant activity of the 80 red wine samples, which were distributed in Merlot (n=9), Pinot Noir (n=17), Malbec (n=11), Syrah (n=12), Cabernet Sauvignon (n=24), and table wines (Vitis labrusca) (n=7) were evaluated using multivariate statistical techniques, with the aim to verify how the overall perception of quality of wines was related to commercial value, color and antioxidant activity. In a general way, te Chilean and Argentinean red wines displayed a higher antioxidant activity, commercial value, intensity of odors, sensory perception of quality, acidity level, and tannin level, whereas the Brazilian samples obtained the lowest values for the sensory attributes. The table wines presented the lowest values for all response variables. Syrah, Malbec and Cabernet Sauvignon varietals presented the highest antioxidant activity and most favorable sensory features, and this result was independent of wine's vintage and origin. As a last step, the wines produced with V. vinifera grapes …

The importance of oxygen free radicals in the etiopathogenesis of diversion colitis in rats / A importância dos radicais livres de oxigênio na etiopatogenia da colite de exclusão em ratos

PURPOSE: Quantify the levels of oxidative DNA damage of epithelial colon cells comparing segments with and without fecal stream. METHODS: Sixty Wistar rats were subjected to deviation of fecal stream by proximal colostomy and a distal mucosal fistula. Animals were divided into three experimental groups that were sacrificed 6, 12 and 24 weeks after surgery. In each experimental group, five animals underwent laparotomy without intestinal deviation (sham subgroup). The diagnosis of colitis was made by histopathological analysis and the inflammatory activity index by graduated scale. The neutrophil infiltration was determined by myeloperoxidase tissue levels and the intensity of oxidative DNA damage by comet assay. The Mann-Withney and Student t test were used to compare the results among experimental subgroups and the Kruskal-Wallis test for variance analysis, adopting a significance level of 5 percent (p<0.05). RESULTS: Colon segments without fecal stream was shown higher histological inflammatory score of the colon wall after 12 and 24 weeks (p=0.001) that increased with the time of diversion (p=0.01). The activity of myeloperoxidase in segments without fecal stream decreased with the time (p=0.001). Oxidative DNA damage levels were significantly higher in the segments without fecal stream, (p=0.0001), independent of time of colon diversion, and increase with the time (p=0.0007). CONCLUSIONS: Colon segments without fecal stream showed high levels of oxidative DNA damage related to histological alterations observed in diversion colitis. The levels of oxidative DNA damage in segments devoid of the fecal stream increase with the time of intestinal exclusion.

OBJETIVO: Quantificar os níveis de dano oxidativo ao DNA em células epiteliais da mucosa cólica comparando segmentos com e sem trânsito fecal. MÉTODOS: Sessenta ratos Wistar foram submetidos à derivação do trânsito intestinal por colostomia proximal e fístula mucosa distal. Os animais foram divididos em três grupos experimentais segundo terem sido sacrificados 6, 12 e 24 semanas após a cirurgia. Em cada grupo experimental, cinco animais foram submetidos à laparotomia isolada sem derivação fecal (grupo sham). O diagnóstico de colite foi estabelecido por análise histopatológica e o índice de atividade inflamatória por escala graduada. A infiltração neutrofílica foi determinada pelos níveis teciduais da mieloperoxidase e a intensidade do dano oxidativo ao DNA pelo ensaio em cometa. Utilizaram-se os testes de Mann-Withney e o teste t de Student para comparar os resultados encontrados entre os subgrupos experimentais e o teste de Kruskal-Wallis para análise de variância, adotando-se nível de significância de 5 por cento (p<0,05). RESULTADOS: Os segmentos cólicos, sem trânsito fecal apresentaram maior escore histológico de inflamação após 12 e 24 semanas (p=0,001), que aumentou com o tempo de derivação (p=0,01). A atividade da mieloperoxidase nos segmentos sem trânsito fecal diminuiu com o progredir do tempo (p=0,001). Os níveis de dano oxidativo ao DNA foram significativamente maiores nos segmentos sem trânsito fecal (p=0,0001), independente do tempo de exclusão considerado, aumentando com o progredir do tempo de exclusão (p = 0,0007). CONCLUSÕES: Segmentos cólicos desprovidos de trânsito fecal apresentam níveis elevados de dano oxidativo ao DNA relacionados às alterações histológicas observadas na colite de exclusão. Os níveis de dano oxidativo ao DNA nos segmentos desprovidos de trânsito fecal aumentam com o decorrer do tempo de exclusão.

Free radical scavenging and antimicrobial properties of extracts of wild mushrooms / Atividade sequestradora de radicais livres e propriedades antimicrobianas de extratos de cogumelos selvagens

Antioxidant and antimicrobial potentials of extracts obtained from four wild mushrooms, Termitomyces clypeatus (TCE), Termitomyces robustus (TRE), Lentinus subnudus (LSE) and Lenzites species (LZE) collected in Nigeria were investigated. LSE and LZE displayed good scavenging activity against 2, 2-Diphenyl-1-Picrylhydrazyl (DPPH) and ferrous ion radicals at concentration of 2 mg/mL. However, TRE and TCE exhibited better superoxide anion scavenging effect at 2 mg/mL. All extracts (TCE, TRE, LSE and LZE) had comparable scavenging effect on hydroxyl radicals as butylated Hydroxytoluene (BHT) used as control. Moreover, extracts from the wild mushrooms were able to inhibit the growth of all indicator organisms at concentrations between 12.5 mg/mL to 100 mg/mL. LSE and LZE, however, showed better antimicrobial effect on the indicator organisms. The results suggest that extracts obtained from the four wild mushrooms may serve as sources of new bioactive compounds with effective antioxidant and antimicrobial activity.

Foram investigadas as propriedades antioxidantes e antimicrobianas de extratos obtidos de quatro cogumelos selvagens da Nigéria: Termitomyces clypeatus (TCE), Termitomyces robustus (TRE), Lentinus subnudus (LSE) and Lenzites species (LZE). LSE e LZE, na concentração de 2 mg/ml, apresentaram boa atividade sequestrante contra 2,2'-difenil-b-picrilhidrazil (DPPHò) e radicais ferrosos. Entretanto, TER e TCE a 2 mg/ml apresentaram melhor efeito sequestrador de anions superóxido .Todos os extratos apresentaram feito semelhante de seqüestro de radicais hidroxila como BHT usado como controle. Além disso, todos os extratos dos cogumelos selvagens, na concentração de 12,5 mg/ml até 100 mg/ml, foram capazes de inibir a multiplicação de todos os microrganismos indicadores testados, mas LSE e LZE apresentaram efeito antimicrobiano mais intenso. Os resultados sugerem que os extratos obtidos dos quatro cogumelos selvagens podem ser fontes de novos compostos bioativos com atividade antimicrobiana e antioxidante.

Papel de los metabolitos reactivos del oxígeno en las periodontopatías / Role of the oxygen reactive metabolites in periodontal diseases

La enfermedad periodontal es una de las enfermedades que más afectan al ser humano en cualquier parte del mundo, en su patogenia y desarrollo participan varios factores de riesgo, algunos de difícil control. Los radicales libres o metabolitos reactivos del oxígeno están presentes y desempeñan un papel muy importante en el agravamiento de esta entidad. Es necesario conocer los aspectos conceptuales vinculados con los mecanismos de generación de las formas de los metabolitos reactivos del oxígeno y su consecuencia a nivel celular y molecular por su acción sobre los lípidos, proteínas y ácidos nucleicos, así como sobre el sistema de defensa antioxidante de que dispone el organismo para su protección. Poder medir el estrés o el nivel de daño oxidativo presente en pacientes con afecciones periodontales para establecer un diagnóstico predictivo y actuar precozmente para evitar el avance de la enfermedad, sería un paso a implementar en un futuro inmediato. Con este trabajo exponemos estas reflexiones basadas en estudios realizados en Cuba y en otras partes del mundo con buenos resultados

The periodontal disease is one of the diseases that most affect the human being anywhere in the world. In its pathogenesis and development take part several risk facts, some of them difficult to control. The oxygen free radicals or reactive metabolites are present and play a very important role in the worsening of this entity. It is necessary to know the conceptual aspects related with the generating mechanisms of the forms of the oxygen reactive metabolites and its consequences at the molecular and cellular levels by its action on the lipids, proteins and nucleic acids, and also on the antioxidant defence system the organism has for its protection. To be able of measuring the stress or the level of oxidative damage in patients with periodontal affections to establish a predictive diagnostic and to act early to avoid the advance of the disease, would be a step to implement in the immediate future. In this work we expose these reflections based on the studies carried out in Cuba and in other pats of the world with good results.

Inhibition of selenium dependent glutathione peroxidase and superoxide dismutase in rats by diethyldithiocarbamate: effect of pre-administration of alpha-tocopherol.

Rats pre-administered with alpha-tocopherol (10 mgs/day) for 7 days afforded a significant protection at the tissue level against the lowering of superoxide dismutase and glutathione peroxidase, especially the selenium-dependent glutathione peroxidase. The protective action of alpha-tocopherol in the diethyldithiocarbamate treated rats may be attributed to its antioxidant/free radical scavenging action. It is concluded that selenium-dependent glutathione peroxidase and alpha-tocopherol act in a complementary fashion to block free radical formation.

Influencia del hábito de fumar sobre las concentraciones séricas de zinc, cobre y selenio en adultos jóvenes / Influence of smoking on serum concentrations of zinc, copper and selenium in young adults

Zinc, cobre y selenio son cofactores de enzimas antioxidantes, por lo que una disminución de sus niveles séricos, compromete su papel preventivo de enfermedades degenerativas. En este estudio se planteó evaluar la influencia del hábito de fumar cigarrillo sobre las concentraciones séricas de estos cofactores en adultos jóvenes. La muestra estuvo conformada por 40 individuos sanos del sexo masculino, con edades entre 18 y 25 años, índice de masa corporal normal y consumo de nutrientes acorde con sus requerimientos nutricionales, divididos en grupo control (n=20) y grupo de fumadores crónicos (n=20), a los cuales se les cuantificó los niveles séricos de zinc, cobre, selenio y se les estimó la ingesta de nutrientes a través del recordatorio de 24 horas y la frecuencia de consumo de alimentos. En los fumadores los niveles séricos de zinc se mostraron severamente disminuidos (0,36 + 0,10 mg/L) y significativamente inferiores a los encontrados en los controles (0,71 + 0,09 mg/L), mientras que los niveles sérico de cobre y selenio no mostraron diferencia significativa. Los resultados indican que aún cuando el consumo de minerales en los fumadores fue adecuado, la dieta habitual no logró mantener la concentración sérica de zinc en los rangos normales, haciéndolos más susceptibles al estrés oxidativo.

Presence of free radicals in spinal cord injury: experimental evidence in rats / Presença de radicais livres em lesão medular: evidência experimental em ratos

Um total de 24 ratos da raça Wistar pesando 230 a 350g foram submetidos a uma compressão medular experimental e a liberação de radicais livres resultante foi detectada por um reagente óptico (nitro azul de tetrazolio). Os animais foram separados em 3 grupos de oito. No primeiro grupo foi realizada uma laminectomia e a medula examinada. Nos grupos II e III um clipe de aneurisma foi introduzido para comprimir a medula por 1 minuto e depois foi administrado o reagente óptico no espaço subpial. O material foi investigado pelo microscópio de luz e de transmissão. O grupo III revelou a ação dos radicais livres sobre a biomembrana em virtude da presença de restos membranosos eletrontranslucentes e cristas mitocondriais rompidas dentre outros achados.O íon superóxido foi considerado o radical livre mais freqüente na compressão medular murina pela maioria dos autores na revisão da literatura. O nitro azul de tetrazolio não é específico para este radical livre mas a maioria dos que chegaram a essa conclusão usaram-no. O conceito de síndrome de reperfusão é impreciso e segundo os diversos autores deve ser substituído por síndrome de anóxia-reoxigenação

Estresse oxidativo e atuacao do sistema antioxidante como removedor de radicais livres no sangue periferico de pacientes hansenianos / Oxidativo Estresse and performance of the antirust system as remover of free radicals in the peripheral blood of hansenianos patients

A hanseniase e uma doença infecciosa cronica causada pelo mycobacterium leprae com um amplo espectro clinico e imunopatologico. Entre os mecanismos de defesa devenvolvidos pelo hospedeiro esta a geração de radicais livres, os quais promovem a destruição do bacilo. Os radicais livres são produzidos dentro das celulas por reaçoes endogeneas, geralmente oxidativas, que ocorrem em processos metabolicos normais, e temabem em condições anormais, como na inflamação causada por doença infecciosas. Este trabalho visa estudar a atividade de substâncias antioxidantes e sua relação com o estresse oxidativo gerado na resposta à hanseniase. Foram realizados experimentos com as enzimas superoxido dismutase(SOD) e catalase(CAT), além do antioxidantes glutationa(GSH) e a participação de óxido nitrico(NO) como indicador da presença de radicais livres. Os resultados foram comparados com um grupo controle e aqueles de pacientes sem tratamento e em tratamento com PQT. Os resultados obtidos indicam um aumento de até 280 por cento dos niveis dos antioxidantes, bem como dos metabolitos do oxido nitrico (596 por cento) em relação ao controle, sugerindo estresse oxidativo severo nos pacientes hansenianos. Os pacientes em tratamento mostram um aumento de até 87 por cento nos niveis de antioxidantes comparados ao controle, reduzindo a geração de radicais livres em relação aos individuos sem tratamento. Portanto, a medida do balanço entre defesas antioxidantes e a presença de radicais livres pode ser uma excelente ferramenta de estudo dos niveis de estresse oxidativo e sua contribuição na evolução da hanseniase.

Isquemia e reperfusão em músculo esquelético: mecanismos de lesão e perspectiva de tratamento / Ischemia and reperfusion in skeletal muscle: injury mechanisms and treatment perspectives

Apesar dos avanços da medicina, persiste alta a incidência da oclusão arterial aguda dos membros, decorrente do aumento da longevidade e, conseqüentemente, da aterosclerose. É uma doença grave que apresenta, inclusive, freqüência elevada de amputações dos membros e de óbito. A isquemia leva à falência energética da célula muscular, à reação inflamatória e a alterações bioquímicas. Essas lesões são agravadas pela reperfusão, que desencadeia grande produção de radicais livresdo oxigênio e ativação de neutrófilos, que acentuam as lesões locais e sistêmicas. Muitas pesquisas têm sido feitas no sentido de se esclarecerem os pormenores das alterações decorrentes da isquemia-reperfusãoe também de se buscarem alternativas terapêuticas mais eficientes para essa doença. O objetivo do presente artigo é rever o conhecimento atual da fisiopatologia e as perspectivas terapêuticas de atenuação das lesões decorrentes da isquemia e reperfusão da musculatura esquelética,na oclusão arterial aguda dos membros, bem como rever os modelos experimental experimentais usados para estudar essas alterações.

Identification of hydroxyl radicals after UV irradiation of aqueous extracts of cigarette smoke and evaluation of urinary 8-OHdG in smokers.

The role of oxidative stress in tobacco smoke damage was examined using a combination of in vitro and in vivo approaches. Aqueous extracts of cigarette smoke were irradiated with UV and hydroxyl radical generation was evaluated by electron spin resonance (ESR). The spectra obtained revealed spin adducts of the hydroxyl radical (*OH) to increase with the volume of the aqueous extract of cigarette smoke, cigarette smoke collection flow, and UV irradiation time. Hydroxyl radical generation persisted for long hours, showing no change over time. Ascorbic acid protected against radical generation in a marked concentration-dependent fashion. In specimens of urine from volunteers, 8-OHdG levels and the 8-OHdG-production rate per hour were found to be higher in smokers than non-smokers. Our results suggest that more marked oxidative stress occurs with the smoking habit.

Application of electron spin resonance for evaluation of the level of free radicals in the myometrium in full-term pregnancy with normal labour and uterine inertia.

In order to identify and quantify free radicals in the tissues of patients with normal physiological and pathological states of births, we developed a method to evaluate the amount of free radicals in myometrium of subplacental area and from body of uterus, using electron spin resonance spectroscopy. Analysis of the concentration of free radicals in the myometrium in full-term pregnancy with normal labour and during uterine inertia was studied. The activities of Ca2+-ATPase, cytochrome c oxidase and succinate dehydrogenase in samples of these tissues were tested too. Low free radical concentrations in these tissues were associated with disturbances in contractile activity of myometrium along with reduction of Ca2+-ATPase, cytochrome c oxidase and succinate dehydrogenase activity. There proved to be an association between the level of free radicals in the tissues and alteration in the physiological processes.

Efecto de la N-acetilcisteina sobre los niveles séricos de vitaminas antioxiodantes en conejos que reciben cocimiento de poleo / Effect of the N-acetilcisteinwith free radical of vitamin antioxidant in rabbiis treated with poleo dicoction

La N-acetilcisteina es un aminoácido con capacidad de barrer radicales libres e incrementar la síntesis del glutatión, potenciando así, los mecanismos naturales de defensa de la célula contra el daño oxidativo (Harrison y col, 1991). El poleo es un arbusto comúnmente usado en la medicina popular en forma de cocimiento, en procesos gripales, cuadros febriles de niños y adultos sin embargo, no están claras las evidencias de sus efectos beneficiosos y además uno de de sus metabolitos, la pulegona ha demostrado reducción del glutation, facilitando los procesos oxidativos. Este estudio evaluó el provable efecto protector de la N-acetilcisteina sobre los niveles de las vitaminas antioxidantes (A y E) en conejos Nueva Zelanda tratados con Poleo. El diseño experimental fue: grupo A: conejos que recibieron solamente cocimiento de Poleo (250ml); grupo B: poleo+ N-acetilcisteina (140mg/kg.IM) y el Grupo C: control. Los resultados mostraron una persistente y significativa disminución del alfa-tocoferol y retinol (p<0,001), en el Grupo A mientras que en el Grupo B fue transitorio. Estos efectos de poleo podrían estar relacionados con su acción depletora de glutatión, mediando la disminución de retinol y alfa-tocoferol. Se requieren de nuevos estudios que profundicen ésta hipótesis