Resumo
Purpose:To evaluate red propolis, gum arabic and L-lysine activity on colorectal preneoplastic lesions induced by azoxymethane (AOM).Methods:The study featured 4 control groups (I-IV) and 4 experimental groups (V-VIII), totaling 48 rats. Once a week for 2 weeks, animals on control groups received saline, while animals in experimental groups received azoxymethane (15 mg/kg i.p.). The follow up along 16 weeks included daily oral gavage to administer water (I and V), L-lysine (150 mg/kg)(II and VI), própolis (100mg/5ml/kg)(III and VII), or gum arabic (5ml/kg)(IV and VIII). Was performed surgery on the animals in the end of this time in order to collect blood for biological assays (TBARS, GSH), followed by their sacrifice to tissue extract.Results:Oxidative stress (TBARS) and the number of aberrant crypt foci (ACF) in distal colon were lower using própolis (p<0.01 for both parameters). Gum arabic reduced preneoplastic lesions (ACF ≤ 4 crypts) on distal colon and on the entire colon (p<0.05).Conclusions:Red propolis reduced AOM-induced oxidative stress (TBARS) and total number of ACF in the distal colon. L-lysine neither protected against nor enhanced AOM-induced ACF. Gum arabic reduced the number of ACF.(AU)
Assuntos
Animais , Ratos , Goma Arábica , Própole/uso terapêutico , Colo/lesões , Azoximetano , Lisina , Neoplasias ColorretaisResumo
PURPOSE: To assess weight changes in rats fed diets with different ratios of omegas 3, 6 and 9 submitted to colonic carcinogenesis induced by Azoxymethane (AOM). METHODS: Sixty rats with three weeks of life were distributed into five groups of specific diets containing 12 animals each: GI- Standard diet without adminstration of AOM, GII- Standard diet with adminstration of AOM; GIII- Hyperlipidic diet with adminstration of AOM; GIV-Normolipidic diet with adminstration of AOM; GV- Hypolipidic diet with adminstration of AOM. The weight and food intake of each group were assessed four times in each week throughout the experiment until euthanasia at 36th week. RESULTS: GI and GII had no significant difference in weight. GI showed a significant increase when compared to GIII, GIV and GV. GII also showed a significant increase when compared to GIII, GIV and GV. When comparing intake of GI as compared to GII no significant difference was found, however such groups had higher intake than groups III, IV and V. There were found no difference in weight when comparing amoung rats with and without cancer within each groups: GII, GIII, GIV and GV. CONCLUSIONS: Diets rich in omega 3, 6 and 9 reduced food intake and weight. Rats with colorectal cancer had no decrease in weight as compared to those without this condition in the same group.(AU)
Assuntos
Animais , Ratos , Dieta , Neoplasias/patologia , Azoximetano/análise , Ratos/classificação , Gorduras/análiseResumo
PURPOSE: To determine whether a hypercaloric and hyperlipidic diet enriched with polyunsaturated fatty acids influences the formation of aberrant crypt foci (ACF) in colonic mucosa of Wistar rats treated with azoxymethane (AOM). METHODS: At eight weeks of life, the rats were assigned to four groups: Group I―standard diet (STD) not treated with AOM; Group II―hypercaloric and hyperlipidic diet (FED), not treated with AOM; Group III―STD, treated with AOM; Group IV―FED, treated with AOM. At 16 weeks, the animals were injected intraperitoneal with 0.9 percent saline solution (Group I and II) or AOM at 15mg/Kg (Groups III and IV) once a week for two weeks. Fifteen weeks later, the animals were euthanized. RESULTS: FED promoted weight gain in Groups II and IV compared to Groups I and III, respectively. The groups did not differ with regard to the total number of ACF. The Chi-square test revealed no predominance of the presence of foci with <4 crypts. However, foci with ≥5 crypts were proportionally more prevalent in Group III than in Group IV (p=0.043). CONCLUSION: The administration of polyunsaturated fatty acids did not interfere with the formation of aberrant crypt foci, but reduced ACF multiplicity, exercising an attenuating effect on carcinogenesis.(AU)
OBJETIVO: Determinar se uma dieta hipercalórica, hiperlipídica, rica em ácidos graxos poliinsaturados (FED) tem influência na formação de focos de cripta aberrante (FCA) em mucosa cólica de ratos Wistar expostos ao azoximetano (AOM). MÉTODOS: Com oito semanas de vida, os ratos foram distribuídos em quatro grupos: Grupo I: Dieta padrão (SD) sem AOM; Grupo II: FED, sem AOM; Grupo III: SD, com AOM; Grupo IV: FED com AOM. Com 16 semanas, os animais dos grupos I e II receberam injeções intraperitoneais de solução salina 0,9 por cento, enquanto os dos grupos III e IV receberam AOM na dose de 15mg/Kg de peso, 1 vez por semana por duas semanas. Quinze semanas após, os animais foram mortos. RESULTADOS: FED promoveu aumento de peso nos grupos II e IV em relação aos grupos I e III. Não houve aumento significante no número total de FCA entre os grupos. Em relação à multiplicidade das criptas por FCA, o teste do qui-quadrado mostrou que não houve predominância da presença <4 criptas por foco. Contudo, focos ≥5 criptas foram proporcionalmente mais prevalentes no grupo III que no grupo IV (p=0,043). CONCLUSÃO: Os ácidos graxos poliinsaturados não interferem na formação de focos de cripta aberrante, contudo reduz sua multiplicidade, exercendo efeito atenuador na carcinogênese.(AU)
Assuntos
Ratos , Dieta , Gorduras na Dieta , Neoplasias/patologia , Ácidos Graxos Ômega-3 , Ácidos Graxos Ômega-6Resumo
PURPOSE: To study the antitumor action of Tabebuia avellanedae in experimentally induced colon carcinogenesis by azoxymethane in mice. METHODS: Fifty (n=50) mice were divided into five groups: in group I azoxymethane (AOM) was administered, in Group II - β-lapachone, in group III - vehicle (diluent) and in group IV - vehicle + AOM and finally in group V - β-lapachone + AOM. RESULTS: It was observed the presence of aberrant crypt foci in all animals of groups I and IV, 50 percent in group II and 90 percent in group V. CONCLUSION: The β-lapachone extracted from the Tabebuia avellanedae showed no protective effect of lesions induced by azoxymethane in colon of mice.(AU)
OBJETIVO: Estudar a ação antitumoral da Tabebuia avellanedae (Ipê-Roxo) na carcinogênese colônica induzida experimentalmente pelo azoximetano em camundongos. MÉTODOS: Foram utilizados 50 camundongos divididos em 5 grupos: grupo I administrado Azoximetano (AOM); grupo II - β-lapachona; grupo III - veículo (diluente); grupo IV - veículo + AOM; e grupo V - β-lapachona + AOM. RESULTADOS: Observou-se presença de focos de criptas aberrantes em todos os animais dos grupos I e IV, 50 por cento no grupo II e 90 por cento no grupo V. CONCLUSÃO: A β-lapachona extraída da Tabebuia avellanedae não apresentou efeito protetor das lesões induzidas pelo azoximetano em cólon de camundongos.(AU)
Assuntos
Animais , Camundongos/classificação , Antineoplásicos/análise , Tabebuia/classificação , Azoximetano/químicaResumo
PURPOSE: To study the protein Fas ligand (FasL) on the expression of apoptosis, using a model of oxidative stress induced by azoxymethane (AOM), in the crypt of colon in rats. METHODS: Wistar rats (n=14) were assigned into two groups: control (n=7) and AOM (n=7). A single subcutaneous administration of AOM (5mg/kg) or saline solution was performed at the beginning of third week and after three hours samples of proximal colon were collected. The expression of FasL was quantified (Software ImageLab) in percentage of areas in the top, base and all crypt. Results were expressed as mean ± sd (Shapiro-Wilks test and t Student test) (p < 0.05). RESULTS: In the animals of CG there was no significant difference between the FasL expression of the top (10.75±3.33) and basal (11.14±3.53) colon crypt (p=0.34293740). In the animals of AOM there was no significant difference between the FasL expression of the top (8.86±4.19) and basal (8.99±4.08) colon crypt (p=0.78486003). In the animals of CG (10.95±3.43) and AOM (8.92±4.13) there was a significant difference of the FasL expression (p=0.026466821). A significantly decrease on the FasL expression was observed in the animals of CG (10.75±3.33) and AOM (8.86±4.19) in the top crypt (p=0.00003755*). A significant decrease was also observed in the animals of CG (11.14±3.53) and AOM (8.99±4.08) in the basal colon crypt (p=0.00000381**). CONCLUSION: Azoxymethane induce the oxidative stress and the significantly decrease of FasL expression, although there is no significant difference between basal and top of colon crypt linked to consumption-activation of Fas ligand.(AU)
OBJETIVO: Avaliar o marcador de apoptose Fas ligante (FasL) em um modelo de estresse oxidativo induzido pelo azoximetano (AOM) na cripta de cólon em ratos. MÉTODOS: 14 ratos Wistar foram distribuídos em dois grupos: controle (n=7) e AOM (n=7). A AOM (5mg/kg) ou solução salina foi aplicada via subcutânea e a coleta de amostras de colo proximal ocorreu 3 horas após. A FasL foi quantificada pelo percentual de áreas no topo, base e toda a cripta. Os resultados foram submetidos aos testes de Shapiro-Wilks e t de Student (p < 0,05). RESULTADOS: No grupo GC, não houve diferença significativa entre a expressão da FasL no topo (10,75 ± 3,33) e base (11,14 ± 3,53) da cripta (p=0,34293740). No grupo AOM não houve diferença significativa entre a expressão da FasL no topo (8,86 ± 4,19) e base (8,99 ± 4,08) e cripta (p=0,78486003). No grupo GC (10,95 ± 3,43) e AOM (8,92 ± 4,13), houve uma diferença significativa da expressão da FasL (p=0,026466821). Redução significativa na expressão da FasL ocorreu nos em GC (10,75 ± 3,33) e AOM (8,86 ± 4,19) no topo da cripta (p = 0,00003755*). Foi observada diminuição significativa em GC (11,14 ± 3,53) e AOM (8,99 ± 4,08) na base da cripta (p=0,00000381**). CONCLUSÃO: Azoximetano induziu o estresse oxidativo identificado pela diminuição significativa da expressão da FasL, embora não haja diferença significativa entre a base e parte superior da cripta associada à ativação de consumo do FasL.(AU)
Assuntos
Animais , Ratos , Proteína Ligante Fas/uso terapêutico , Estresse Oxidativo , Azoximetano/administração & dosagem , Apoptose , Transformação Celular Neoplásica , Proteína Ligante Fas/efeitos adversos , Azoximetano/farmacologia , Colo/imunologiaResumo
Purpose: Test immersion of microscopy samples in water as an aid to visualizing and quantifying aberrant crypt foci (ACF) in rat colon mucosa. Methods: Carcinogenesis was induced with azoxymethane in Wistar rats kept on a conventional diet or a hypercaloric diet containing unsaturated fat. Fifteen weeks after induction, colon samples were retrieved and fixated in a 10 percent formaldehyde solution. The samples were divided into segments (distal, middle, proximal) and stained with 1 percent toluidine blue. The technique tested in the study consisted of immersing microscopy samples in distilled water in order to eliminate the problem of light reflection known from conventional microscopy. Results: When samples were immersed in water during microscopy, significantly more ACF could be visualized in all colon segments than with the conventional method proposed by Bird. Conclusion: Immersing microscopy samples in water aids the visualization and quantification of aberrant crypt foci in rat colon mucosa fixed in formaldehyde.(AU)
Objetivo: Otimizar a visibilização de focos de criptas aberrantes (FCA) em mucosa cólica de ratos Wistar. Métodos: Colo de rato Wistar, sob diferentes dietas e submetidos a iniciação de carcinogênese pelo azoximetano há 4 meses, foram previamente lavados, abertos e fixados em solução de formalina a 10 por cento por 24 horas. Após serem corados em azul de toluidina a 1 por cento, foram divididos em segmentos distal, médio e proximal e imersos em água destilada para quantificação de FCA. Resultados: No método de imersão foi visibilizado maior quantidade de focos de criptas aberrantes em todos os segmentos cólicos, com diferença significante, quando comparado com o método de Bird. Conclusão: O método de imersão otimiza a visibilização e quantificação de focos de criptas aberrantes em mucosa cólica (ratos Wistar) fixada em solução de formalina a 10 por cento.(AU)
Assuntos
Ratos , Microscopia/métodos , Mucosa Intestinal/anatomia & histologia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/induzido quimicamente , Azoximetano , RatosResumo
PURPOSE: To investigate the expression of superoxide dismutase (SOD), with use of antioxidant inositol hexaphosfate, in the presence of the carcinogen azoxymethane, in FCA of colon rats. METHODS: Wistar rats (n=48) were distributed in four groups of 12 mice. Divided in control (n=12); with azoxymethane administration AOM (n=12); administration of IP6 (n=12) and with administration of IP6/AOM (n=12). The subcutaneous administration of azoxymethane happened in the week 3 and 4 of the experiment, in dose 20mg/Kg, weekly; and administration of IP6 to 1 percent in water of drinking for 6 weeks in the group 3 and 4. The identification of the expression SOD-1 was accomplished through the quantification imunohistochemistry by the image processing attended by computer in crypts and focus of aberrant crypts in right colon. RESULTS: The group control presented expression of SOD1, on average 16,0 percent; group AOM, 26,7 percent; group IP6, 16,9 percent; group IP6/AOM, 20,9 percent. Variance analysis among the groups, was calculated 0,0078. CONCLUSION: The azoxymethane increase expression SOD1, while inositol hexaphosphate decreases in a significant way the expression of SOD1 promoted by the administration of the carcinogen azoxymethane.(AU)
OBJETIVO: Investigar a expressão de superóxido dismutase, com uso de antioxidante inositol hexafosfato, na presença do carcinógeno azoximetano em FCA de cólon de ratos. MÉTODOS: Quarenta e oito ratos Wistar, distribuídos em 4 grupos, divididos em controle (n=12); com administração de azoximetano AOM (n=12); administração de IP6 (n=12) e com administração de IP6/AOM (n=12). A administração subcutânea de azoximetano aconteceu na semana 3 e 4 do experimento, em dose 20mg/Kg, semanal; e administração de IP6 a 1 por cento em água de beber durante 6 semanas no grupo 3 e 4. A identificação da expressão SOD1 foi realizada através da quantificação imunohistoquimíca pelo processamento de imagem assistida por computador em criptas e focos de cripta aberrante em cólon direito. RESULTADOS: O grupo controle apresentou expressão de SOD1, em média 16,0 por cento; grupo AOM, 26,7 por cento; grupo IP6, 16,9 por cento; grupo IP6/AOM, 20,9 por cento. Análise de variância entre os grupos calculou-se 0,0078. CONCLUSÃO: A expressão de SOD-1 mostrou aumento significativo na presença de azoximetano e quando administrou-se IP6 concomitante houve diminuição na expressão de SOD1 promovido pela administração do carcinógeno azoximetano.(AU)