Tannic acid acts as an agonist of the dopamine D2L receptor, regulates immune responses, and ameliorates experimentally induced colitis in mice

• Published in: Brain, behavior, & immunity. Health behavior, & immunity. Health, 2020-05, Vol.5, p.100071-100071, Article 100071
• Main Authors: Kawano, Masaaki, Saika, Kikue, Takagi, Rie, Matsui, Masanori, Matsushita, Sho
• Format: Article
• Language: English
• Subjects: Cytokine; Dopamine receptor; Full Length; Galloyl group; Herbal polyphenol; Inflammation; Inflammatory bowel disease; Lipopolysaccharide; T cell receptor; T-helper; Tannic acid
• ISSN: 2666-3546; 2666-3546
• DOI: 10.1016/j.bbih.2020.100071

Tannic acid (TA) is an herbal polyphenol containing a galloyl group that has been prescribed to treat gastroenteritis, diarrhea, and irritable bowel syndrome. TA has anti-inflammatory, anti-cancer, and anti-viral properties; however, the molecular mechanisms of these potential therapeutic effects are still largely unknown. Here, we examined the ability of TA to induce anti-inflammatory responses. TA was found to be an agonist of the dopamine D2L receptor. TA reduced interferon (IFN)-γ and interleukin (IL)-1β secretion but upregulated tumor necrosis factor α and IL-10 secretion from lipopolysaccharide (LPS)-stimulated mouse splenocytes. TA also reduced IFN-γ secretion but enhanced IL-10 secretion from anti-cluster of differentiation (CD) 3/CD28 antibody-stimulated splenocytes. An immune subset study confirmed that TA regulated cytokine secretion by various types of immune cells in the context of stimulation with LPS or anti-CD3/CD28 antibodies. Administration of TA to mice with experimentally induced colitis strikingly suppressed weight loss, colon shrinkage, and IL-17 secretion from mesenteric lymph node lymphocytes in response to CD3/CD28 stimulation. These data suggest that TA suppresses inflammatory responses in colitis by regulating cytokine secretion by immune cells in the colon. •Tannic acid is an agonist of the dopamine D2L receptor.•Tannic acid suppresses IFN-γ secretion by LPS-stimulated splenocytes.•Tannic acid modulates anti-CD3/CD28 antibody-stimulated cytokine levels in CD4+ T cells.•Tannic acid ameliorates dextran sodium salt (DSS)-induced colitis in C57BL/6 mice.•Tannic acid reduces production of IL-17 in DSS-induced colitis.