黄芪总甙的镇痛作用及其作用机制(英文)

目的:研究黄芪总甙(astragalosides,AST)的镇痛作用及其作用机制。方法:采用小鼠福尔马林致痛模型,对痛反应进行评分。通过福尔马林试验前30min皮下注射吗啡和纳络酮或福尔马林试验前20min腹腔内注射L-精氨酸和L-NAME以研究阿片肽和一氧化氮在此疼痛模型中的作用并对AST的作用与吗啡和L-NAME进行比较。结果:AST20,40和80mg/kg可显著降低小鼠福尔马林致痛后第二时相的疼痛反应(P<0.01)。AST 40mg/kg最大镇痛作用见于给药后4h(第二时相疼痛反应的抑制率为34.4％)。吗啡5mg/kg对两个时相的疼痛反应均有明显抑制作用(P<0.01),此抑制作用能被纳络酮2mg/kg拮抗(P<0.01),而AST的镇痛作用不受纳络酮影响。L-精氨酸(400或800mg/kg)可部分抑制AST的作用(P<0.01)。结论:AST所具有的镇痛作用不是通过内源性阿片肽系统介导,而可能与抑制NO等参与疼痛反应的炎症介质的生成有关。

Antinociceptive effect of astragalosides and its mechanism of action

AIM: To study the effect and mechanism of astragalo-sides (AST) related to the antinociceptive activity. METHODS: The standardized formalin test was performed to induce the direct stimulation of nociceptors followed by inflammatory process in the Kunming strain mice. The involvement of opioid and nitric oxide was studied by subcutaneous injection of morphine with/ without naloxone 30 min before formalin test, or peritoneal injection of L-arginine with/without L-NAME 20 min before formalin. RESULTS: AST 20, 40, and 80 mg/kg significantly lowered pain score of the second phase of formalin response as compared with control group (P < 0.01). The maximum analgesic effect of AST 40 mg/kg was found at 4 h after the administration of AST (34.4 % inhibition at the second phase). Injection of morphine 5 mg/kg significantly inhibited pain response of both phases (P < 0.01) and this was reversed by naloxone 2 mg/kg (P <0.01). However, naloxone did not alter the effect of AST on the second phase. Antinociceptive effect of AST 40 mg/kg was partially blocked by L-arginine 400 or 800 mg/kg ( P < 0.01). CONCLUSION: AST has an antinociceptive effect on formalin test in mice that is not mediated by the endogenous opioid system but related to its inhibitory effect on the production of NO.