3, 3'-Diindolylmethane attenuates Riemerella anatipestifer infection by suppressing inflammatory responses

Authors: FERNANDEZ-COLORADO, CP - Gyeongsang National University; CAMMAYO, PLT - Gyeongsang National University; FLORES, RA - Gyeongsang National University; BINH,, NT - Gyeongsang National University; KIM, WH - US Department Of Agriculture (USDA); KIM, S - Gyeongsang National University; Lillehoj, Hyun; MIN, W - Gyeongsang National University

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2020
Publication Date: 11/11/2020
Citation: Fernandez-Colorado, C., Cammayo, P., Flores, R., Binh,, N., Kim, W., Kim, S., Lillehoj, H.S., Min, W. 2020. 3, 3'-Diindolylmethane attenuates Riemerella anatipestifer infection by suppressing inflammatory responses. Frontiers in Microbiology. https://doi.org/10.1371/journal.pone.0242198.
DOI: https://doi.org/10.1371/journal.pone.0242198

Interpretive Summary: Comprehensive understanding of mechanisms by which the host immune system mediates protective immunity against various pathogens will lead to a logical treatment strategy. Increasing evidence suggests that dietary intervention strategy using 3,3'-diindolylmethane (DIM), a natural bioactive compound found in cruciferous vegetables such as cabbage, cauliflower, brussels sprouts, kale, turnips, and broccoli, regulates immune responses and exhibits a broad range of biological activities in several disease models, including infections with enteric pathogens in humans and animals. The immunomodulatory properties of DIM are associated with its ability to regulate signaling pathways involved in inflammatory responses. Therefore, this study was conducted in collaboration with scientists at a South Korean university to investigate the potential use of DIM in alleviating the adverse effects of inflammatory response using a duck disease model. Study showed that dietary DIM treatment decreased inflammatory response, increased survival rate and significantly decreased bacterial burden compared to the control in a duck bacterial disease model infected with R. anatipestifer. Furthermore, the expression levels of inflammatory proteins were significantly reduced both in DIM-treated spleen and liver. Thus, dietary DIM can potentially be used to treat inflammatory diseases via inhibition of inflammatory cytokine expression and will be a good antibiotic alternative in inflammatory diseases affecting poultry.

Technical Abstract: 3,3'-Diindolylmethane (DIM) is found in cruciferous vegetables and is used to treat various inflammatory diseases because of its potential anti-inflammatory effects. To investigate effects of DIM in Riemerella anatipestifer-infected ducks which induce upregulation of inflammatory cytokines, ducks were treated with DIM and infected the following day with R. anatipestifer. Infected ducks treated with DIM exhibited increased survival rate and significantly decreased bacterial burden compared to infected untreated ducks. Generally, the expression levels of inflammatory cytokines (interleukin [IL]-17A, IL-17F, IL-6, IL-1ß) were significantly reduced both in DIM-treated splenic lymphocytes stimulated with killed R. anatipestifer and in the spleens and livers of DIM-treated R. anatipestifer -infected ducks compared to stimulated untreated splenic lymphocytes and infected untreated ducks. This study demonstrated the ameliorative effects of DIM in ducks infected with R. anatipestifer. Thus, DIM can potentially be used to prevent and/or treat R. anatipestifer infection via inhibition of inflammatory cytokine expression.