The in vivo LBP-pre and LBP-aft study was mimicked in N9 cells. N9 cells were treated with different medicines for 2 days. Relative numbers to the first group were shown. N9 cells were incubated with LBP for first one day and LBP plus LPS + IFNγ + IL-4 for next day, and presented a higher M1 and suppressed M2 polarization compared to its LBP-free control. If the cells were treated with LPS + IFNγ + IL-4 for first day, and the LBP plus LPS + IFNγ + IL-4 for the second, LBP group displayed reduction in iNOS and elevation in Arg1 expression in comparison to its control that stimulated with LPS + IFNγ + IL-4 for corresponding 2 days. *p < 0.05, **p < 0.01, compared to the corresponding controls treated with same medicine but lack of LBP. L,Iγ,IL4, abbreviation for LPS + IFNγ + IL-4.