trans-Resveratrol Ameliorates Stress-Induced Irritable Bowel Syndrome-Like Behaviors by Regulation of Brain-Gut Axis

Abstract

Background: Irritable bowel syndrome (IBS) is a functional disorder characterized by abdominal pain and abnormalities in defecation associated with psychiatric disorders such as depression and anxiety due to the dysfunction of brain-gut axis. This study aims to determine whether trans-Resveratrol affects chronic-acute combined stress (CACS)-induced IBS-like symptoms including depression, anxiety and intestinal dysfunction. Methods: ICR male mice were exposed to the CACS for 3 weeks. trans-Resveratrol were administrated daily (2.5, 5, and 10 mg/kg, i.g.) 30 min before CACS. Behavioral tests were performed to evaluate the treatment effects of trans-Resveratrol on IBS. Hippocampus tissues were collected and processed Golgi staining and immuno-blot analysis. Ileum and colon tissues were collected and processed Hematoxylin and Eosin staining and immuno-blot analysis. Results: Administration with trans-Resveratrol before CACS for 3 weeks significantly reversed CACS-induced depression- and anxiety-like behaviors and intestinal dysfunction in mice, which implied a crucial role of trans-Resveratrol in treatment of IBS-like disorder. Furthermore, trans-Resveratrol improved hippocampal neuronal remodeling, protected ileal and colonic epithelial barrier structure against CACS insults. The further study suggested that trans-Resveratrol normalized phosphodiesterases 4A (PDE4A) expression and CREB-BDNF signaling that were disturbed by CACS. The increased pCREB and BDNF expression in the hippocampus were found, while decreased pCREB and BDNF levels were observed after treatment with trans-Resveratrol. Conclusions: The dual effects of trans-Resveratrol on stress-induced psychiatric and intestinal dysfunction may be related to normalization of PDE4A expression and subsequent pCREB-BDNF signaling in the hippocampus, ileum and colon.

Keywords: anxiety; depression; irritable bowel syndrome; phosphodiesterases 4A; trans-Resveratrol.

Figure 1

The antidepressant- and anxiolytic-like effects of trans-Resveratrol on mice exposed to chronic-acute combined stress (CACS). Mice were exposed to stress (subjected to CACS) and daily treated with vehicle (Veh), trans-Resveratrol (Resv, 2.5, 5.0 and 10.0 mg/kg, i.g.), rolipram (Rol, 1.25 mg/kg, i.p.) or desipramine (Des, 0.5 mg/kg, i.p.) in SPT and FST, or diazepam (Dia, 10 mg/kg, i.p.) in OFT and EPM 30 min before stress for 3 weeks. The sucrose preference ratio was measured in sucrose preference test (SPT) on day 0 and day 20 (A,B, respectively). Immobility time was measured in forced swimming test (FST) on day 21 (C). The distance in the center area, time spent in the center area and velocities were measured in the open field test (OFT) on day 21 (D–F). The percentage of open arm entries and the percentage of time spent in open arms were measured in the elevated plus-maze (EPM) test on day 22 (G,H). Results are expressed as mean ± SEM (n = 12). ^***P < 0.001 vs. control group (Ctrl), ^#P < 0.05, ^##P < 0.01, and ^###P < 0.001 vs. CACS + Veh group.

Figure 2

The peripheral effects of trans-Resveratrol on mice exposed to CACS. Mice were exposed to stress (subjected to CACS) and daily treated with vehicle (Veh), trans-Resveratrol (Resv, 2.5, 5.0, and 10.0 mg/kg, i.g.), rolipram (Rol, 1.25 mg/kg, i.p.), desipramine (Des, 0.5 mg/kg, i.p.) or diazepam (Dia, 10 mg/kg, i.p.) 30 min before stress for 3 weeks. (A) The ratio of the dye migration distance to the total intestinal length was measured in intestinal motility assay (IMA) test on day 23. (B–E) The abdominal withdrawal reflex (AWR) scores at 0.25, 0.35, 0.50, and 0.65 ml distension volumes were measured in AWR test on day 22. Results are expressed as mean ± SEM (n = 12). ^**P < 0.01 and ^***P < 0.001 vs. Ctrl group, ^#P < 0.05, ^##P < 0.01, and ^###P < 0.001 vs. CACS + Veh group.

Figure 3

The potential protective effects of trans-Resveratrol on hippocampal neuronal remodeling against CACS. Mice were exposed to stress (subjected to CACS) and daily treated with vehicle (Veh), trans-Resveratrol (Resv, 2.5, 5.0, and 10.0 mg/kg, i.g.), rolipram (Rol, 1.25 mg/kg, i.p.), desipramine (Des, 0.5 mg/kg, i.p.), or diazepam (Dia, 10 mg/kg, i.p.) 30 min before stress for 3 weeks. (A) Photomicrographs of representative Golgi stained hippocampal CA1 pyramidal neuron (scale bar = 50 μm). (B,C) Number of dendrites and total dendritic length were quantified. (D) Photomicrographs of representative Golgi stained hippocampal CA1 pyramidal neuron's spine (scale bar = 5 μm). (E) Spine density (10 μm distances) was quantified. Results are expressed as mean ± SEM (n = 4). ^**P < 0.01 vs. Ctrl group, ^#P < 0.05, ^##P < 0.01, and ^###P < 0.001 vs. CACS + Veh group.

Figure 4

The intestinal structural changes after treatment with trans-Resveratrol in CACS mice. Mice were exposed to stress (subjected to CACS) and daily treated with vehicle (Veh), trans-Resveratrol (Resv, 2.5, 5.0 and 10.0 mg/kg, i.g.), rolipram (Rol, 1.25 mg/kg, i.p.), desipramine (Des, 0.5 mg/kg, i.p.) or diazepam (Dia, 10 mg/kg, i.p.) 30 min before stress for 3 weeks. (A–F) Photomicrographs of representative HE staining in the ileum. (G–L) Photomicrographs of representative HE staining in the colon. Immune cellular infiltrate is indicated by arrow. Scale bar = 100 μm (A–C, G–I) and 10 μm (D–F, J–L). (M,N) Histopathological scores representing the severity of inflammation were quantified in the ileum and colon. Results are expressed as mean ± SEM (n = 4). ^***P < 0.001 vs. Ctrl group, ^#P < 0.05, ^##P < 0.01, and ^###P < 0.001 vs. CACS + Veh group.

Figure 5

Immuno-blot analyses for pCREB and BDNF expression in the hippocampus. Mice were exposed to stress (subjected to CACS) and daily treated with vehicle (Veh), trans-Resveratrol (Resv, 2.5, 5.0, and 10.0 mg/kg, i.g.), rolipram (Rol, 1.25 mg/kg, i.p.), desipramine (Des, 0.5 mg/kg, i.p.) or diazepam (Dia, 10 mg/kg, i.p.) 30 min before stress for 3 weeks. (A) Photomicrographs of representative immune-blotting bands; (B–D) PDE4A expression, the ratio of pCREB to total CREB and BDNF protein levels in the hippocampus were measured. Results are expressed as mean ± SEM (n = 8). ^***P < 0.001 vs. Ctrl group, ^#P < 0.05, ^##P < 0.01 and ^###P < 0.001 vs. CACS + Veh group.

Figure 6

Immuno-blot analyses for pCREB and BDNF expression in the ileum and colon. Mice were exposed to the stress (subjected to CACS) and daily treated with vehicle (Veh), trans-Resveratrol (Resv, 2.5, 5.0, and 10.0 mg/kg, i.g.), rolipram (Rol, 1.25 mg/kg, i.p.), desipramine (Des, 0.5 mg/kg, i.p.) or diazepam (Dia, 10 mg/kg, i.p.) 30 min before stress for 3 weeks. (A) Photomicrographs of representative immune-blotting bands; (B–D) PDE4A expression, the ratio of pCREB to total CREB and BDNF protein level in the ileum were measured. (E) Photomicrographs of representative immune-blotting bands. (F–H) PDE4A, the ratio of pCREB to total CREB and BDNF levels were measured in the colon. Results are expressed as mean ± SEM (n = 8). ^*P < 0.05, ^**P < 0.01, and ^***P < 0.001 vs. Ctrl group, ^#P < 0.05, ^##P < 0.01, and ^###P < 0.001 vs. CACS + Veh group.