Objective:To study pharmacodynamic action of Ji-Ming-San(JMS) in animal model and acute toxicity in mice.The circadian variations of the dosing action and toxicity were approached as well

to certify the rationality about the experience of predecessors

i.e.medication of timing in administering JMS.Methods:Bliss method was used to evaluate medial lethal dose(LD50) and circadian variation on the acute mortality rate of JMS was observed with identical dosage in mice.The analgesic effects were observed by hot-plate test and body torsion test in mice.Nitrate reductase method was used to measure nitric oxide(NO) levels in blood serum and brain tissue in acetic acid caused-pain mice.The anti-inflammatory action was observed by auricle swelling test in mice and voixpedis swelling test in rats.Ultraviolet spectrophotometer method was employed to measure Prostaglandin E2(PGE2) level in voixpedis swelling rat model.Results:JMS produced marked time-dependent acute toxicity in mice with dosage of LD50) and remarkably analgesic effect on mice model with a diurnal rhythmicity.Furthermore

the results coincided with the circadian changes of decreased NO levels in blood serum and brain tissue.JMS obviously inhibited the ear edema in mice induced by dimethylbenzene and pedes intumesce in rats induced by egg white.The anti-inflammatory action of JMS showed circadian dependent change with dosing time. Furthermore

the rhythm was in line with the circadian change of PGE2 level reduced by JMS.Conclusion:JMS has obvious analgesia

anti-inflammatory effects

showing dosing time-dependent.Analgesic effect may be correlated with decreased NO levels and anti-inflammatory effect probably relates to reduced PGE2 level.