Background: The number of patients with food allergy has increased dramatically over the last several decades. However, there is no effective drug for food allergies. In the present study, we evaluated the effects of kakkonto, a traditional Japanese herbal medicine, in a mouse model of food allergy with gastrointestinal symptoms. Methods: BALB/c mice were systemically sensitized twice with ovalbumin (OVA) and then were repeatedly given OVA by oral intubation (OVA mice). Kakkonto was administered orally before the OVA challenges. Results: The OVA mice developed allergic diarrhea (91.8 ± 3.8% after 6 OVA challenges), and myeloperoxidase (MPO) activity was dramatically elevated in the colons of the OVA mice. Kakkonto significantly suppressed the occurrence of allergic diarrhea and MPO activity in the OVA mice. Furthermore, the number of mucosal mast cells was greatly increased in the proximal colons of the OVA mice, and this was also suppressed by kakkonto. Interestingly, mRNA expression of helper T cell type 1 (Th1) cytokines (IFN-γ) and Th2 cytokines (IL-4, IL-5 and IL-10) were significantly upregulated in the proximal colons of the OVA mice, an effect which was also reduced by kakkonto. Transcriptome analysis detected increased mRNA expression of suppressor of cytokine signaling-3 in the proximal colons of OVA mice, which was decreased by kakkonto administration. Conclusion: Kakkonto has immunosuppressive effects and interferes with the infiltration of mucosal mast cells in the colons of mice with induced food allergy, leading to improvement of allergic symptoms. Kakkonto has potential as a therapeutic drug for treatment of allergic symptoms induced by the disruption of intestinal mucosal immunity.

Background: The number of patients with food allergy (FA) has dramatically increased. Although satisfactory drug therapies for FA are not available, we have found that kakkonto, a traditional Japanese herbal medicine, suppressed the occurrence of allergic symptoms in an FA mouse model. Thus, we investigated whether kakkonto could regulate the activation and differentiation of T cells in the colon. Methods: BALB/c mice were systemically sensitized and then orally challenged with ovalbumin. FA mice were orally treated with kakkonto. Lamina propria (LP) cells from their colons were isolated and analyzed. Results: Kakkonto significantly reduced the proportion of CD69⁺ cells and the elevated helper T cell type 2-specific transcription factor GATA-3 mRNA expression in the LP CD4⁺ T cells, showing that kakkonto has a suppressive effect on the activation and Th2 differentiation of LP effector CD4⁺ T cells of the FA mouse colon. Furthermore, kakkonto significantly increased the proportion of Foxp3⁺CD4⁺ regulatory T cells in the LP CD4⁺ T cells of the FA mouse colon. Similarly, the number of Foxp3-positive cells was dramatically increased in the colonic mucosa of kakkonto-administered FA mice. However, the pharmacological effect and Foxp3⁺CD4⁺ regulatory T cell-inducing ability of kakkonto were not attenuated by the administration of an anti-CD25 monoclonal antibody in the FA model. Conclusions: The induction of Foxp3⁺CD4⁺CD25^- regulatory T cells in the colon as a novel mechanism underlying the therapeutic action of kakkonto could be utilized for the development of a novel anti-FA drug.

Background: Ulcerative colitis is an intractable inflammatory colonic disease, and its etiology remains unclear. Saireito, a traditional herbal medicine, is widely used for treating ulcerative colitis in Japan. We analyzed the immunological characteristics of an oxazolone (OXZ)-induced colitis (OC) model and examined the effects of sareito on this model. Methods: OXZ was injected into the colon of BALB/c mice. Saireito was orally administered once a day for 3 consecutive days. Colitis was assessed by scoring the symptoms and macroscopic findings. The transcription patterns in the middle colon and spleen were analyzed with global transcriptome analysis and real-time polymerase chain reaction (PCR). Results: The above-mentioned scores were increased in the OC mice. The transcription levels of Th2 cytokines were significantly upregulated in the spleen and middle colon of the OC mice, whereas those of the Th1 cytokine interferon (IFN)-γ decreased in the spleen and increased in the middle colon. Saireito significantly ameliorated OC. In the middle colon of the saireito-treated mice, enhanced expression of Th2 cytokine mRNAs was markedly downregulated, while that of IFN-γ mRNA was further upregulated. In contrast, in the spleen, saireito had no effect on the transcription of either type of cytokine. After global transcriptome analysis, real-time PCR analysis revealed that saireito greatly downregulated the enhanced expression of the suppressor of cytokine signaling (SOCS)-3 mRNA in the middle colon of OC mice. Conclusions: Saireito exhibits inhibitory effects on OC by the induction of Th1-polarized immune responses in the mucosal immune system of the colon.

No abstract

No abstract