目的 观察马钱子粗粉和超微粉对佐剂性关节炎模型大鼠的干预作用，探讨其有效性、安全性的量效关系差异。方法 采用佐剂性关节炎大鼠模型，马钱子超微粉与粗粉ig给药剂量分别为50.0、35.0、24.5、17.2、12.0 mg/kg，每天给药1次，连续给药21 d，测定试药对模型大鼠的足跖容积、超氧化物歧化酶（SOD）、丙二醛（MDA）、一氧化氮（NO）、肿瘤坏死因子-α（TNF-α）有效性评价指标的影响，以及对血液学指标、血液生化学指标、脏器指数等安全性评价指标的影响，并比较马钱子粗粉和超微粉最小起效剂量、有效剂量范围、最小中毒剂量。结果 马钱子超微粉与粗粉均能明显降低模型大鼠的足跖容积，最低起效剂量分别为17.2、24.5 mg/kg；有效剂量分别为17.2～35.0、24.5～50 mg/kg；马钱子超微粉安全剂量为17.2～24.5 mg/kg，而马钱子粗粉的有效剂量同时也是中毒剂量。结论 马钱子超微粉的最小起效剂量低于其粗粉，临床应用宜采用超微粉。

Objective To observe the intervention effects of Strychni Semen Pulveratum (SSP) with different grain sizes and its ultramicro powder on the rats suffered from rheumatoid arthritis, and to discuss the difference of dose-effect relationship between efficacy and safety. Methods The rats with adjuvant-induced arthritis were taken as model animals. Ultramicro powder and crude powder of Strychni Semen were ig adminstrated at the concentration of 50.0, 35.0, 24.5, 17.2, and 12.0 mg/kg, respectively for four weeks continuously. The influence of ultramicro powder and crude powder of Strychni Semen on the effectiveness evaluation indexes, including the volume of hindpaw, superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), and tumor necrosis factor-α (TNF-α), and safety evaluation indexes, including the minimum initial efficient dose, the range of effective dose, and the lowest toxic dose of model rats were determined. Results Ultramicro powder and crude powder of Strychni Semen could reduce the volume of hindpaw of model rats significantly. The minimum initial efficient doses of ultramicro powder and crude powder of Strychni Semen are 17.2 and 24.5 mg/kg, respectively, the range of effective dose was 17.2－35.0 and 24.5－50 mg/kg, respectively, the range of safety dose of ultramicro powder of Strychni Semen was 17.2－24.5 mg/kg, and the range of effective dose of crude powder of Strychni Semen was its range of the toxic dose. Conclusion The minimum initial efficient dose of ultramicro powder of Strychni Semen is lower than that of crude powder, ultramicro powder will be used to clinical application and its dose is reduced to 1/3－1/2.

湖南省自然科学基金重点项目（09JJ3055）；湖南省科技厅资助项目（20107D2004）