Objective: To study on anti-inflammatory

analgesic and acute toxicity effects of the aqueous extract and alcohol extract of Onychium japonicum. Method: Anti-inflammatory and analgesic effects of O. japonicum were observed by means of dimethylbenzene induced ear edema model

acetic acid writhing test. LD50 of the aqueous extract of O. japonicum (1.62 g ·mL-1)

and that of the alcohol extract of the herb (2.34 g ·mL-1) and with its maximal dose (40 mL ·kg-1) resp ectively by intragastric administration were observed. Result: The aqueous extract and alcohol extract of O. japonicum could significantly inhibit the inflammation caused by xylene (P<0.05)

the inhibition rate were 35.9%

32.5%

29.5% and 31.0%

30.0%

24.6%

respectively

and inhibit writhing caused by 0.7% acetic acid in mice. The maximal tolerance dose for acute toxicity of the aqueous extract and alcohol extract of O.japonicum was 56.5 g ·kg-1 and 85.7 g ·kg-1 (raw medicine amount). Conclusion: O.japonicum has anti-inflammatory and analgesic effects. The aqueous extract and alcohol extract of Onychium japonicum did not show any acute toxicity.