柴胡皂苷体外干预大鼠胸腔炎性白细胞5-LO活性的实验研究

Effect of saikosaponins on the activity of 5-1ipoxygenase in thoracic cavity leukocytes from acute pleurisy rat model in vitro

目的:观察柴胡皂苷体外对大鼠胸腔炎性白细胞脂氧酶(5-LO)活性的影响,探讨其干预花生四烯酸代谢的抗炎机制。方法:以角叉菜胶所致急性胸膜炎模型大鼠的胸腔炎性白细胞为基本反应体系,分别加入CaCl2,MgCl2,花生四烯酸(AA),A23187以及柴胡皂苷(0.04,0.08,0.16,0.24mg.mL-1)或齐留通(0.625μg.mL-1),提取完整白细胞的5-LO代谢产物白三烯B4(LTB4)和5-羟基二十碳四烯酸(5-HETE),运用反相高效液相色谱(RP-HPLC)紫外检测分离测定LTB4和5-HETE的合成水平,来反映5-LO的活性。结果:柴胡皂苷在0.08～0.24mg.mL-1浓度范围内(经MTT法测定为安全剂量范围),对大鼠胸腔炎性白细胞LTB4与5-HETE的生物合成呈现抑制作用,其中0.16、0.24mg.mL-1剂量作用明显(p<0.01)。结论:柴胡皂苷(0.04～0.24mg.mL-1浓度)体外可抑制大鼠胸腔白细胞花生四烯酸代谢酶5-LO的活性,降低LTB与5-HETE合成水平,提示其抗炎作用可能与抑制5-LO活性,减少致炎代谢产物的生成有关。

Objective:To observe the effect of saikosaponins on the activity of 5-1ipoxygenase(5-LO)in inflammatory leukocytes from acute pleurisy rat model in vitro,so as to elucidate the mechanisms of anti-inflammatory action which related to the arachidonic acid(AA)metabolism.Method:Acute pleurisy model was induced by injecting carrageenan into the pleural cavity in rat,and intact leukocytes of thoracic cavity were collected to extract LTB4 and 5-HETE.Based on the reaction system of intact leukocytes,CaCl2,MgCl2,AA,A23187 were added into to stimulate the production of metabolite of 5-LO,and detected their synthesis level by RP-HPLC.Saikosaponins(final concentrations were 0.04,0.08,0.16,0.24mg·mL-1)or zileuton(final concentration was 0.625μg·mL-1)were added into this reaction system in the same time as drug group.Result:Compared with control group,saikosaponins significantly inhibited the production of LTB4 and 5-HETE at final concentration between 0.16mg·mL-1and 0.24 mg·mL-1.Conclusion:Saikosaponins could inhibit the activity of 5-LO which is the enzyme of AA metabolism in the reaction system of intact leukocytes from acute pleurisy model rat in vitro.It suggestes that the mechanism of anti-inflammatory action of saikosaponins may be related to the inhibition of the activity of 5-LO,that decrease the level of major inflammatory mediators.