Effect of 4-
-methylhonokiol in LPS-induced memory impairment. To investigate effect of 4-O-methylhonokiol in LPS-induced memory impairment, we performed water maze test (A, B), probe test (C) and step-through type passive avoidance test (D). Memory function was determined by the escape latencies (A, sec) and distance (B, cm) for 5 days, and time spent in target quadrant (C,%) in probe test after administration of LPS. Each value is mean ± S.E. from 10 mice. #, Significantly different from control group (p < 0.05). *, Significantly different from LPS-treated group (p < 0.05). Control, saline-treated group. LPS, lipopolysaccharide. MH, 4-O-methylhonokiol.