Effects of bovine lactoferrin on cell viability, proliferation and inflammation in intestinal epithelial cells treated by lipopolysaccharide

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