九头狮子草有效部位解热作用及其作用机制研究

目的:比较九头狮子草水提液,石油醚部位及水部位解热作用的差异,初步探讨石油醚部位的解热作用机制。方法:雄性SD大鼠,经筛选后随机分为正常对照组、模型对照组、石油醚组、水部位组和水提组(不同极性部分的剂量设定以水提物的大鼠剂量为基础,结合各个部位得膏率,按相同生药量8 g.kg-1换算成各极性部位剂量),采用干酵母皮下注射方法制备发热模型,于模型制备后5 h,分别ip石油醚部位(0.4 g.kg-1)、水部位(1.4 g.kg-1)、水提液(8 g.kg-1)后分别于各个时间点监测直肠温度,比较三者作用的差异性;采用放射免疫法测定大鼠血清白介素-1(IL-1)、白介素-6(IL-6)及下丘脑内环磷酸腺苷(cAMP)、前列腺素E2(PGE2)含量。结果:九头狮子草水提液,石油醚部位及水部位均能降低发热模型大鼠体温,三者对体温指数(TRI9)的影响分别为:(10.24±0.83),(10.08±0.47),(8.23±0.64)cm2,与模型组比较,差异具有显著性(P<0.05);放射免疫结果显示,石油醚组血清IL-6含量,下丘脑cAMP,PGE2含量低于模型组,其差异具有显著性(P<0.05)。结论:九头狮子草水提液,石油醚部位及水部位均具有解热作用,石油醚部位及水部位解热作用强于九头狮子草水提液;石油醚部位的解热作用可能是通过抑制IL-6的生成进而阻断PGE2,cAMP等中枢发热介质,或直接对抗IL-6的作用而发挥解热作用。

Study on Antipyretic Effect and its Mechanism of Peristrophe japonica

Objective: To study the antipyretic effect and the mechanism of Peristrophe japonica by comparing with variances of the antipyretic effect among water extract of P. japonica,ligarine fraction and water fraction. Method: The rat febrile model was induced by injecting fresh yeast subcutaneously and treated with water extract of P. japonica,ligarine fraction and water fraction,then the rectal temperature was monitored to show the differences of effect from those groups.The contents of interleukin-1 (IL-1),interleukin-6 (IL-6) in blood serum and cyclic adenosine monophosphate(cAMP),prostaglandin E₂(PGE₂) in the hypothalamus were measured by radioimmunoassav (RIA),respectively. Result: Three drug administration groups(including water extract of P. japonica,ligarine fraction and water fraction) showed marked antipyretic effect on the yeast-induced fever(P<0.05) and the effects were stronger on the ligarine fraction and water fraction groups than water extract of P. japonica group. The ligarine fraction group showed remarkable decreased the contents of IL-6 in blood serum and PGE₂,cAMP in the hypothalamus of febrile rats. Conclusion: The water extract ofP. japonica,ligarine fraction and water fraction all have obvious antipyretic effect,but the effect of ligarine fraction and water fraction are stronger than that of water extract of P. japonica,which might be related to decreasing the levels of IL-6 in serum and the interferencing the content of PGE₂,cAMP in the hypothalamus.