[Effects of the diet ratio of polyunsaturated fatty acids ω-3/ω-6 on experimental colitis in mice].
摘要
OBJECTIVE: To investigate the effect of changed ratio of polyunsaturated fatty acids (PUFA) on dextran sulfate sodium (DSS)-induced colitis in mice. METHODS: Thirty-two male BALB/c mice were randomly divided into two groups: control group and PUFA group, PUFA group was continuously divided into 3 sub-groups: PUFA ω-3/ω-6 1:3 group, PUFA ω-3/ω-6 1:15 group and PUFA ω-3/ω-6 1:30 group. According to the difference in the sub-groups, PUFA group mice were fed with the corresponding modified diet. The control group was fed with the common diet, whose ratio of PUFA ω-3/ω-6 was 1:15. After eight weeks of different diets, experimental colitis in the three sub-groups of PUFA group was induced by DSS exposure. The mice were placed on three five-day cycles of 30 g/L DSS with ten days of recovery after each cycle, then were sacrificed after the final ten-day period. Overall symptomatic score and histopathological score were evaluated. And levels of mucosal prostaglandin E2 (PGE2) in the proximal and distal colon were measured respectively by enzyme immunoassay. RESULTS: The changed ratio of PUFA ω-3/ω-6 had no effect on the weight gain of the growing mice. Although there were no significant differences among the PUFA groups from the three separate aspects: weight gain, stool character and blood in the stool, there were significant differences among the three groups in overall symptomatic scores. A further comparison showed the overall symptomatic score of 1:3 group was significantly lower than that of the 1:30 group (P<0.05). There were significant differences among the PUFA groups in the histopathological score. The following comparison between the sub-groups showed the histopathological score of the 1:3 group was significantly lower than that of the 1:30 group (P<0.05). One mouse in the 1:30 group died of severe hemorrhage and one mouse also in this group had a huge dysplastic adenomatous polyp. The mucosal PGE2 which could reflect the level of intestinal inflammation showed t