Consumption of whole aronia berry powder inhibits adoptive transfer‐induced colitis in mice

Abstract

BackgroundAronia berries are rich in polyphenols which may inhibit inflammation by modulating gut immunocyte function. However, the mechanisms responsible for this effect is unclear.ObjectiveTo identify the effects of aronia consumption on intestinal inflammation and T cell populations in the mouse adoptive transfer model of colitis.DesignRecombinase activating gene (RAG)−/− mice were obtained at 4 wk age and were acclimatized for 2 weeks prior to experiments. Live CD4+CD45RBhigh cells were obtained by magnetic activated cell sorting (MACS) from gender and age‐matched syngeneic C57BL6 mice and transferred to RAG1−/− mice by intraperitoneal (IP) injection. Injected RAG1−/− mice were randomly assigned to receive a control or 4.5% w/w lyophilized ‘Viking’ aronia berry supplemented diet (n = 21/group). A negative control group of RAG−/− mice were injected with sterile phosphate‐buffered saline (PBS) as the sham group (n = 21). Body weight (BW) and food intake were recorded twice a week. Groups of mice were sacrificed at 7–8 wk post injection. Colons were collected for weight and length measurement. Lamina propria lymphocytes (LPL) and mesenteric lymph nodes (MLN) were isolated from colon and analyzed by flow cytometry to determine Th17 and Treg populations.ResultsBW declined at 4 weeks after CD4+CD45RBhigh transfer, and was accompanied by reduced food intakes. The aronia diet prevented colitic weight loss. Control BW decreased to 82.5% at wk 7, whereas the aronia‐fed mice decreased to 93.2% BW at wk 7. Intestinal inflammation was evident by noticeable increases in colon weight/length ratios compared to sham. Aronia consumption inhibited increases in colon weight/length ratios relative to the control (0.042 ± 0.008 vs. 0.058 ± 0.006 g/cm). MLN and LPL Treg populations in both groups of colitic mice did not differ from that in the sham. The total Th17 in LPL but not MLN was higher in aronia group than the control (P = 0.0216, n = 5–7/group).ConclusionWhole aronia berry consumption reduced wasting in T‐cell transfer‐induced colitis, and increased Th17 but not Treg populations in LPL.Support or Funding Information USDA NIFA AFRI WIS01909