皖南地区眼镜蛇毒活性组分镇痛效应的初步研究

 目的：从皖南地区眼镜蛇毒粗毒中分离纯化出活性组分眼镜蛇毒镇痛因子（cobra venom analgesic factor, CVAF)，并研究其镇痛效应。方法：采用阳离子交换色谱（cation-exchange chromatography, CEC）和分子排阻层析（size-exclusion chromatography, SEC）从眼镜蛇粗毒中分离纯化出镇痛活性组分CVAF，SDS-聚丙烯酰胺凝胶电泳法和毛细管区带电泳法进行纯度及相对分子量的鉴定；将小鼠随机分为生理盐水正常对照组和盐酸吗啡阳性对照组、CVAF实验组，采用小鼠热板法和醋酸扭体法评估活性组分CVAF的镇痛效应。结果：纯化后得到活性产物为单一组分，相对分子量为6 500 D；热板法显示吗啡组在给药0.5 h后达高峰，6 h镇痛作用消失；活性组分CVAF的镇痛作用自用药后0.5 h开始，且持续8 h仍存在。扭体法中0.03 mg/kg、0.1 mg/kg和0.3 mg/kg的活性组分在给药后小鼠扭体抑制率分别为27%、50%和70%；0.3 mg/kg实验组与吗啡组相比无明显差异（P> 0.05）。结论：从皖南地区眼镜蛇粗毒中分离纯化出的活性组分CVAF具有剂量依赖性镇痛效应。

Analgesic effect of active component from crude cobra venom in Wannan area

AIM：To explore the analgesic effect of active component from cobra venom in Wannan area. METHODS：The active component was purified from crude venom of cobra by cation-exchange chromatography and size-exclusion chromatography. The purity and molecular weight of the active component were determined by SDS-polyacrylamide gel electrophoresis and capillary zone electrophoresis. The analgesic activity was analyzed by hot-plate test and acetic acid writhing test. Normal saline and morphine were used as controls. RESULTS：A single active component was obtained from crude cobra venom. The molecular weight was about 6 500 D. The analgesic effect of the active component persisted from 0.5 h to 8 h after hot-plate test. With intraperitoneal injection of the active component at doses of 0.03 mg/kg, 0.1 mg/kg and 0.3 mg/kg in mice, the writhing inhibition rates were 27%, 50% and 70%, respectively. No statistical difference between 0.3 mg/kg group and morphine group was observed. CONCLUSION：The active component from crude cobra venom has a dose-dependent analgesic effect.