Effect of probiotics on the development of dimethylhydrazine-induced preneoplastic lesions in the mice colon

PURPOSE: To determine the effect of probiotics on the development of chemically induced (1, 2-dimethylhydrazine) colonic preneoplastic lesions, in mice. METHODS: The animals were divided into five groups. The control group was injected with carcinogen alone and the other groups also received probiotics (1- Lactobacillus delbrueckii UFV-H2b20; 2- Bifidobacterium animalis var. lactis Bb12; 3- L. delbrueckii UFV-H2b20 plus B. animalis var. lactis Bb12; and 4- Saccharomyces boulardii) administered orally in drinking water throughout fourteen weeks. RESULTS: Consumption of lactobacilli and bifidobacteria alone resulted in a significant reduction of the total number of aberrant crypt foci (55.7% and 45.1%, respectively). Significant reduction in the number of these small foci (<3 aberrant crypts) was only observed in the group treated with lactobacilli (52.2%) in comparison to control group. The number of larger foci (>3 aberrant crypts) crypts had no significant reduction. CONCLUSION: L. delbrueckii UFV-H2b20 and B. animalis var. lactis Bb12 administered alone protect colonic preneoplastic lesions in mice, while the combined treatment of these bacteria and the administration of S.boulardii were not effective in reducing such colonic lesions.

Effect of a hyperlipidic diet rich in omegas 3, 6 and 9 on aberrant crypt formation in rat colonic mucosa / Efeito de uma dieta hiperlipídica rica em ômegas 3, 6 e 9 na formação de criptas aberrantes em mucosa cólica de ratos

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.

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.