Effect of Succulents (Dudleya brittonii and Sedeveria pink ruby) Extracts on Poly(I:C)-Induced Inflammation in DF-1 Chicken Fibroblasts

Excessive inflammation in broilers is associated with a decrease in meat productivity, feed intake, and survivability, and consequently has a major impact on the poultry industry. Nowadays, the use of plant-derived substances is increasingly focused on because of their safety and benign properties to prevent and treat inflammation. Therefore, we aimed to evaluate the anti-inflammatory activity of succulents [<i>Dudleya brittonii</i> (DB) and <i>Sedeveria pink ruby</i> (SP)] against polyinosinic:polycytidylic acid [poly(I:C)] induced DF-1 chicken fibroblasts <i>in vitro</i>. To do that, the DF-1 cells were treated with different concentrations of succulent plant extracts and poly(I:C) to investigate dose-dependent effects on cell viability. In addition, the investigation of the cytotoxicity and gene expression of several pro-inflammatory marker genes and mitogen-activated protein kinase (MAPK) genes was also conducted. The results show that when treated with 7 μg/mL and 70 pg/mL, respectively, DB and SP extracts significantly (<i>P</i>&lt;0.05) reduced pro-inflammatory gene expressions such as <i>interleukin 8-like 2</i> (<i>IL8L2</i>) and <i>interferon regulatory factor 7</i> (<i>IRF7</i>) that were induced by poly(I:C). Moreover, the DB and SP extracts also strongly reduced the mRNA expression of MAPK genes in the DF-1 cells treated compared with the non-treated group. As a conclusion, the DB and SP extracts showed anti-inflammatory properties against poly(I:C)-induced DF-1 cells, potentially influencing inflammation by altering pro-inflammatory and MAPK gene expression and suggesting succulent plant extracts could be a valuable alternative natural source of inflammation reduction in chickens.