Background: In this study, we investigated the anti-inflammatory effect of Piper sarmentosum extract (PSE) in the IPEC-J2 cells induced by lipopolysaccharide (LPS). Meanwhile, we also tested the metabolomics profile of cells treated by LPS and PSE.Method: IPEC-J2 cells (6×10 5 cell/well) were seeded on 6-well plates, and cells were divided into three treatments (control, LPS treatment and LPS + PSE-NB treatment). Each treatment was conducted in five replicates. After incubation for 24 h, cells in LPS + PSE-NB treatment were treated by media containing PSE-NB at 10 ug/ml (cells in control and LPS treatments were treated by complete medium). Cells were culture for 24 h, and cells in LPS treatment and LPS + PSE-NB treatment then were treated by media contain 1 μg/ml of LPS (cells in control was treated by complete medium) for another 24 h. After treatment, cells were used for gene expression assays, protein expression assays and metabolomics analysis. Results:We demonstrated that LPS stimulation significantly up-regulated the mRNA expression of IL-1, IL-6 and TNF-α (P < 0.05) compared with the control in the IPEC-J2 cells. Piper sarmentosum extract with n-butanol (PSE-NB) pre-treatment with 10 ug/mL before LPS stimulation significantly decreased the expression of IL-1, IL-6 and TNF-α compared with LPS treatment (P < 0.05). We found that PSE-NB improved the expression of intestinal tight junction proteins (ZO1 and Occludin) and NHE3 that were reduced by LPS stimulation (P < 0.05). Moreover, PSE-NB alleviated LPS-induced protein expression of p65 and p-p65 (P < 0.05) and inhibited the NF-κB signaling pathway. Metabolic pathway analysis indicated that PSE-NB exert anti-inflammatory activity mainly through affecting tryptophan metabolism. Its metabolic product, melatonin, has anti-inflammatory properties by inhibition of NF-κB activation, which consistent with our results regarding to anti-inflammatory activity of PSE-NB on inflammatory signaling pathway. Conclusion: These results suggested that PSE-NB might attenuate LPS-induced inflammatory responses in the IPEC-J2 cells by regulating inflammatory NF-κB signaling pathway and intracellular metabolic pattern. Background 3 Intestinal epithelial cells (IECs) play important roles in the animal's physical defense, which is the first line of defense against the invasion of various pathogens and antigens in the external environment of gut lumen [1]. Impaired intestinal epithelium tends to be associated with a series of both intestinal and systemic diseases, including intestinal inflammation and diarrhea [2]. Although gut inflammation may not cause the full-blown clinical symptoms in weaned piglets, it could lead to increased mucosal permeability and reduced growth performance [3]. So, it is necessary to prevent gut inflammation and maintain normal barrier function of IECs in animals. Piper sarmentosum, is a terrestrial herb. This plant is distributed mainly in tropical and subtropical region of Asia. It is used as a folk medicine in certain countries of Southeast Asia for the...