To study the effects of sanguinarine,chelerythrine,protopine and allocryptopine from Macleaya cordata on intestinal porcine epithelial cells(IPEC-1)proliferation at different concentrations and different pe-riods. IPEC-1 cells were pre-incubated for 24 hours,and then exposed to different concentrations(4,2,1, 0.5,0.25,0.1,0.05,0.025,0.012 5 and 0.006 25 μg / mL of sanguinarine or chelerythrine,and 100,50, 25,12.5,6.25,3.125 and 1.562 5 μg / mL of protopine or allocryptopine;each treatment had 8 replicates) for additional 12 or 24 hours,respec...