The importance of oxygen free radicals in the etiopathogenesis of diversion colitis in rats

Martinez, Carlos Augusto Real; Ribeiro, Marcelo Lima; Gambero, Alessandra; Miranda, Daniel Duarte da Conceição; Pereira, José Aires; Nadal, Sidney Roberto

doi:10.1590/s0102-86502010000500002

Cited by 40 publications

(112 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As expected, the colon without fecal stream showed further reduction of the crypt length, mucosal neutrophil infiltration and epithelial erosions regardless of treatment, compared with the colon segments with preserved fecal streams. This observation is in agreement with previous studies by our own group proving that the colon without fecal stream, in the absence of SCFA, is more exposed to the action of ROS, which can lead epithelial damage 13 .…”

Section: Discussionsupporting

confidence: 94%

“…In recent years, the importance of the role of reactive oxygen species (ROS) in the etiopathogenesis of ulcerative colitis and other inflammatory diseases that affect the colon mucosa, such as DC, has increased 13,16,17,18,19 . Likewise, experimental studies have confirmed the role of ROS in the development of chemically induced colitis by acetic acid, TNBS and DSS 20,21,22,23 .…”

Section: Discussionmentioning

confidence: 99%

“…ROS is the adopted name because most free radicals are generated from the cellular metabolism of oxygen. The ROS are constantly formed during respiration of all living cells 13,24 .…”

Section: Discussionmentioning

confidence: 99%

“…Studies have shown that the antioxidant systems in the colonic mucosa are deficient compared to other organs and tissues, making it more susceptible to oxidative stress 30 . Colonic mucosa oxidative stress occurs more frequently and intensely than in other organs because of its the constant exposure to antigens and oxidizing substances formed within the intestinal lumen 13,23 .…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Reduction in oxidative stress levels in the colonic mucosa without fecal stream after the application of enemas containing aqueous Ilex paraguariensis extract

Cunha¹,

Silva

Almeida

et al. 2011

Acta Cir. Bras.

Self Cite

View full text Add to dashboard Cite

PURPOSE: To evaluate the antioxidant effects of enemas containing aqueous extract of Ilex paraguariensis, comparing segments with and without fecal stream and correlating the segments with the duration of intervention. METHODS: Twenty-six Wistar rats were subjected to a diversion of the fecal stream in the left colon by a proximal colostomy and distal mucosal fistula. The rats were distributed randomly into two experimental groups of 13 animals each based on the time of sacrifice after surgical procedure (two or four weeks). Each group was then divided into two experimental subgroups that received either second daily enemas containing 0.9% saline solution or aqueous extract of Ilex paraguariensis at 0.2g/100g. Colitis was diagnosed by histopathological analysis and the detection of oxidative tissue damage by measuring the levels of malondialdehyde. The Mann-Whitney test was used to compare the tissue levels of malondialdehyde between colon segments with and without fecal stream in each experimental group, and the Kruskal-Wallis test was used to verify the variance between the levels of oxidative stress according the duration of the irrigation; both tests determined significance at 5% (p<0.05). RESULTS: The levels of malondialdehyde in the animals subjected to intervention in the colon with saline with and without fecal stream after two and four weeks of irrigation were 0.05±0.006 and 0.06±0.006, and 0.05± 0.03 and 0.08 ±0.02, respectively. The malondialdehyde levels in the animals irrigated with Ilex paraguariensis with and without fecal stream after two and four weeks of irrigation were 0.010±0.002 and 0.02±0.004, and 0.03±0.007 and 0.04±0.01, respectively. After two and four weeks of intervention, the levels of malondialdehyde were lower in the animals irrigated with Ilex paraguariensis regardless of the time of irrigation (p=0.0001 and p=0.002, respectively). CONCLUSION: The daily rectal application of enemas containing aqueous extract of Ilex paraguariensis decreases oxidative tissue damage in the colon without fecal stream regardless of the time of irrigation.

show abstract

Section: Discussionsupporting

confidence: 94%

Section: Discussionmentioning

confidence: 99%

“…ROS is the adopted name because most free radicals are generated from the cellular metabolism of oxygen. The ROS are constantly formed during respiration of all living cells 13,24 .…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Reduction in oxidative stress levels in the colonic mucosa without fecal stream after the application of enemas containing aqueous Ilex paraguariensis extract

Cunha¹,

Silva

Almeida

et al. 2011

Acta Cir. Bras.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The deficient supply of SCFAs as a factor that triggers DC was confirmed with the results of clinical and experimental studies showing that the restoration of fecal stream or the application of butyrate-rich solutions, the main subtype of SCFAs metabolized by colonocytes, reverted the clinical symptoms and the characteristic endoscopic and histological alterations of the disease [11][12][13][14][15][16][17][18][19] . However, despite these evidences, the molecular mechanisms through which the deficient supply of SCFAs determines the tissue inflammation, have not been fully explained 20 . With the purpose of evaluating the molecular mechanisms involved in the DC etiopathogenesis, the epithelial cells of colonic mucosa without fecal stream were recently demonstrated to produce high amounts of oxygen free radicals (OFRs).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of topical n-acetylcysteine in diversion colitis

Almeida¹,

Pereira²,

Silva³

et al. 2012

J. Coloproctol. (Rio J.)

Self Cite

View full text Add to dashboard Cite

Introduction: Diversion colitis (DC) is a benign condition characterized by the appearance of inflammation in the mucosa of the colon or rectum devoid of fecal stream. Oxidative stress has been associated with the etiopathogenesis of the disease. N-acetylcysteine (NAC) is a substance with antioxidant properties, used in different treatments of inflammatory diseases. The purpose of this study was to evaluate the effects of topical applications of NAC in an experimental model of DC. Methods: Thirty-six Wistar rats were submitted to deviation of fecal stream by proximal colostomy and a distal mucosal fistula. They were distributed into 3 experimental groups of 12 animals according to the daily application of enemas containing 0.9% saline or 2 doses of NAC, 25 mg/kg and 100 mg/kg, respectively. In each group, half of the animals were sacrificed after two weeks of irrigation and half after four weeks of irrigation. The diagnosis of colitis was assessed by histopathological analysis and the grade of inflammation by inflammatory grading scale. The results were evaluated with the Mann-Whitney test, adopting significance level of 5% (p<0.05). Results: Daily enema of NAC improved the inflammatory alterations in colon without fecal stream. In colonic segments without fecal stream, the inflammatory score was significantly lower in the animals treated with 100mg/kg, compared with those treated with saline solution or 25 mg/kg of NAC, regardless of the duration of intervention (p<0.05). The inflammatory score in colon segments without fecal stream was significantly lower in the animals treated with both concentration of NAC, compared with those treated with saline, regardless of the concentration and duration of irrigation (p<0.01). Conclusions: Enemas containing NAC improve the inflammatory process and constitute a beneficial tool in the treatment of DC.Keywords: acetylcysteine; colon; colitis; fatty acids, volatile; histology; rats. RESUMO: Introdução:Colite de exclusão (CE) é uma condição benigna caracterizada pelo desenvolvimento de inflamação na mucosa do cólon desprovida de trânsito fecal. O estresse oxidativo tem sido implicado na patogênese da doença. A n-acetilcisteína (NAC) é uma substân-cia com efeitos antioxidantes, sendo utilizada no tratamento de várias doenças inflamatórias. Objetivo: Avaliar os efeitos da aplicação tópica de NAC em modelo de CE. Método: Trinta e seis ratos Wistar foram submetidos ao desvio do trânsito por meio de colostomia proximal e fístula mucosa distal. Os animais foram distribuídos em três grupos experimentais de igual tamanho segundo a aplicação de enemas diários contendo soro fisiológico 0,9% ou NAC nas concentrações de 25 mg/kg ou 100 mg/kg. Em cada grupo, metade dos animais foi sacrificada após duas ou quatro semanas de irrigação. O diagnóstico de CE foi feito por estudo histopatológico e a graduação por escala inflamatória. Na avaliação dos resultados, utilizou-se o teste de Mann-Withney, adotando-se nível de significância de 5% (p<0,05). Resultados: A aplicação intrarretal...

show abstract

Enemas with n-Acetylcysteine Can Reduce the Level of Oxidative Damage in Cells of the Colonic Mucosa Diverted from the Faecal Stream

et al. 2013

View full text Add to dashboard Cite

show abstract

The importance of oxygen free radicals in the etiopathogenesis of diversion colitis in rats

Cited by 40 publications

References 42 publications

Reduction in oxidative stress levels in the colonic mucosa without fecal stream after the application of enemas containing aqueous Ilex paraguariensis extract

Reduction in oxidative stress levels in the colonic mucosa without fecal stream after the application of enemas containing aqueous Ilex paraguariensis extract

Evaluation of topical n-acetylcysteine in diversion colitis

Enemas with n-Acetylcysteine Can Reduce the Level of Oxidative Damage in Cells of the Colonic Mucosa Diverted from the Faecal Stream

Contact Info

Product

Resources

About