Figure 3

Inhibition of larval invasion of a Caco-2 cell monolayer with different concentrations of PMSF, E-64, 1,10-Phe or pepstatin. Various concentrations of diverse enzyme inhibitors were replenished in semisolid MEM, which was used to co-culture IIL with a Caco-2 cell monolayer for 2 h, and worm intrusion into the Caco-2 cell monolayer was examined under a microscope. The inhibitory effects of the various inhibitors on larval invasion are expressed as the inhibition (%) normalized to the PBS control group, and the results are expressed as the mean ± SD of three independent tests. A Various concentrations of PMSF. B Various concentrations of E-64. C Various concentrations of 1,10-phenanthroline (1,10-Phe). D Various concentrations of pepstatin. E Comparison of the suppressive effects of the 4 kinds of inhibitors on IIL invasion of Caco-2 cell monolayers when the optimal inhibitor concentrations (1.25 mM PMSF, 24 μM E-64, 2.4 mM 1,10-Phe and 10 μM pepstatin) were used. F: Comparison of the suppressive effects of mixtures of the various inhibitors on IIL invasion of Caco-2 cell monolayers. *P < 0.0001 compared with the DMSO control group.