Objective To evaluate the effects and mechanisms of bovine lactoferrin (bLF) on cell viability, proliferation, and the protective roles in intestinal epithelial cell-6 (IEC-6) treated by lipopolysaccharide(LPS). Methods The rat jejunum epithelial cell lines IEC-6 were cultured in vitro.The effects of bLF on cell viability and proliferation in IEC-6 cells were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay and 5-Bromo-deoxyuridine (Brdu) assay, respectively.Inflammatory cytokines and their mRNA of interleukin-1β(IL-1β), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α)and interleukin-8(IL-8)were analyzed by real-time PCR and enzyme-linked immunosorbent assay(ELISA). Western blot was used to measure the levels of mitogen-activated protein kinase(MAPK)activation and nuclear factor kappa β (NF-κB) nuclear translocation. Results Dose dependent effects of bLF on cell viability and proliferation were observed in IEC-6 cells in vitro(F=3.825, 5.861, all P<0.05), especially in a dose of 100 mg/L, and bLF significantly stimulated cell viability and proliferation compared with non-treatment group(q=5.240, 3.765, all P<0.05). The mRNA levels of IL-1β, IL-6 and TNF-α were decreased by co-stimulation of bLF and LPS compared with the LPS treatments alone in IEC-6 cells in vitro(q=14.28, 10.12, 16.45, all P<0.001). The secretion of IL-6 and TNF-α was also decreased by co-stimulation of bLF and LPS (q=15.06, 6.74, all P<0.01). In vitro, bLF treatment at dose of 100 mg/L could inhibit the activation of MAPK/NF-κB signal pathway induced by LPS (q=12.96, 18.54, all P<0.001). Conclusion In vitro, bLF can promote IEC-6 viability and proliferation, and have anti-inflammatory effects via inhibited activation of MAPK/NF-κB nuclear translocation. Key words: Bovine lactoferrin; Intestinal epithelial cell; Proliferation; Inflammation