目的 研究栀子苷的镇痛作用及其机制, 为其临床应用提供理论依据。方法 通过小鼠热板实验和醋酸诱发小鼠扭体反应实验研究栀子苷的镇痛作用。通过纳洛酮拮抗实验和预先给予一氧化氮供体左旋精氨酸 (L-Arg)和一氧化氮合酶抑制剂N-硝基-L-精氨酸甲酯 ( L-NAME )及测定一氧化氮（NO）含量初步探讨栀子苷镇痛作用与阿片受体和NO的关系。结果 栀子苷（12.5、25、50 mg/kg）可以剂量依赖性地减少醋酸所致的小鼠扭体数（P<0.05）, 并可显著提高热板所致疼痛小鼠痛阈值（P<0.05）。纳洛酮与L-Arg均可部分地抑制栀子苷的镇痛作用（P<0.05）, 而L-NAME可以增强栀子苷的镇痛作用。栀子苷可显著降低小鼠血清和脑组织中NO的含量（P<0.05）。结论 栀子苷具有较强的镇痛作用, 其镇痛机制与激动阿片受体及抑制NO的合成和释放有关。

Objective To investigate the analgesic effect of geniposide and its underlying mechanisms. Methods The analgesic effect of geniposide was studied by the hot-plate test and the acetic acid-induced writhing test. Through the naloxone antagonistic experiment and pretreated with nitric oxide donor L-arginine (L-Arg) and nitric oxide synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME) and then the contents of nitric oxide (NO) were measured to discuss the relationship of opioid receptors and NO to the analgesic effect of geniposide. Results Geniposide (12.5, 25, 50 mg/kg) showed a dose-dependent reduction of acetic acid-induced writhing counts and a significant improvement of pain threshold in hot plate test in mice(P<0.05). The analgesic effect of geniposide was partly antagonized by naloxone and L-Arg, but enhanced by L-NAME. Geniposide significantly reduced the contents of NO in serum and brain tissue of model animals (P<0.05). Conclusions Geniposide has strong analgesic effect, and the analgesic effect is related to activating opium receptor and suppressing the synthesis or releases of excessive NO.