Abstract: The acute toxicity of water and alcohol extracts of Diplazium lanceum was preliminarily studied and the polar sites with anti-inflammatory and analgesic effects were screened. The maximum tolerable dose （MTD） of the water and alcohol extracts of Diplazium lanceum was obtained by gavage administration to mice using the maximum dosage measurement method, and the safety of Diplazium lanceum was investigated; the analgesic effect of different polar parts of Diplazium lanceum was investigated using mouse acetic acid twisting and hot plate method; the anti-inflammatory effects of different polar parts were investigated using the mouse ear swelling method; the effect of ethyl acetate extract （high, medium, low） on the levels of inflammatory factors in the serum of mice with xylene- induced ear inflammation was measured using ELISA method. The results showed that LD₅₀ was not obtained in the acute toxicity experiment of water extract and alcohol extract of Diplazium lanceum. The MTD of water extract and alcohol extract were 238.0 g/kg and 165.2 g/kg, respectively; the extracts of different polar parts of Diplazium lanceum prolonged the mice's licking time of feet; the different polar parts of Diplazium lanceum had inhibitory effects on mouse torsion, with analgesic rates ranging from 11.14% to 40.36% in each group. Among them, the ethyl acetate part had the best analgesic effect, followed by the petroleum ether part; different parts of Diplazium lanceum had inhibitory effects on mouse ear swelling, with inhibition rates ranging from 24.71% to 48.47% in each group, and ethyl acetate and petroleum ether parts had the best anti-inflammatory effects; the levels of tumor necrosis factor （TNF-α）, interleukin-1β （IL-1β）, and prostaglandin E₂（PGE₂） inflammatory factors in the serum of mice in the high, medium, and low dose groups of ethyl acetate decreased compared to the model control group. The levels of IL-1β and PGE₂ in the low and medium dose groups of ethyl acetate, as well as the level of TNF-α in the low dose group of ethyl acetate, showed significant differences compared to the model control group.

Key words: Diplazium lanceum, maximum tolerance, acute toxicity test, anti-inflammatory and analgesic, effective parts