Gadotti Vinícius M, Schmeling Leonardo O, Machado Cláudia, Liz Fernanda H, Filho Valdir Cechinel, Meyre-Silva Christiane, Santos Adair R S
Departamento de Ciências Fisiológicas, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário, Trindade, Florianópolis 88040-900, SC, Brazil.
J Pharm Pharmacol. 2005 Oct;57(10):1345-51. doi: 10.1211/jpp.57.10.0014.
This study examined the antinociceptive effect of Bauhinia microstachya (Leguminosae), a native plant widely distributed in the South of Brazil, in several chemical and mechanical models of pain. The methanolic extract (ME) from B. microstachya (3--30 mg kg(-1), i.p.) and the isolated compound quercitrin (1--10 mg kg(-1), i.p.), given 30 min earlier, produced a dose-dependent inhibition of acetic-acid-induced visceral pain in mice, with a mean ID50 value (dose necessary to reduce the nociceptive response by 50% relative to the control value) of 7.9 and 2.4 mg kg(-1), respectively. The ME of B. microstachya (3--100 mg kg(-1), i.p., 30 min earlier) also caused a dose-dependent inhibition of capsaicin-induced pain, with a mean ID50 value of 18.8 mg kg(-1). Moreover, the ME (3--100 mg kg(-1), i.p., 30 min earlier) produced marked inhibition of both phases of formalin-induced pain, with mean ID50 values for the neurogenic and the inflammatory phases of 30.3 and 17.2 mg kg(-1), respectively. In addition, the ME of B. microstachya (3--300 mg kg(-1), i.p., 30 min earlier) inhibited, in a graded manner, the hyperalgesia induced by bradykinin (3.2 microg/paw), substance P (13.5 microg/paw), carrageenan (300 microg/paw), capsaicin (100 microg/paw) and adrenaline (100 ng/paw) in the rat paw, with mean ID50 values of 20.5, 17.9, 101.8, 54.2 and 99.7 mg kg(-1), respectively. Taken together, these data demonstrate that ME of B. microstachya elicited a pronounced antinociceptive action against several chemical and mechanical models of pain in mice and rats. The precise mechanism responsible for the antinociceptive effect of the extract still remains unclear, but seems to be partly related to modulation of the release or action of pro-inflammatory mediators involved in the models of pain used. Finally, the flavonoid quercitrin isolated from this plant appears to contribute for the antinociceptive property of the methanolic extract.
本研究考察了巴西南部广泛分布的本土植物微穗羊蹄甲（豆科）在多种化学和机械性疼痛模型中的镇痛作用。微穗羊蹄甲的甲醇提取物（ME，3 - 30毫克/千克，腹腔注射）和分离得到的化合物槲皮苷（1 - 10毫克/千克，腹腔注射），提前30分钟给药，对小鼠乙酸诱导的内脏疼痛产生剂量依赖性抑制，平均ID50值（相对于对照值将伤害性反应降低50%所需的剂量）分别为7.9和2.4毫克/千克。微穗羊蹄甲的ME（3 - 100毫克/千克，腹腔注射，提前30分钟）也对辣椒素诱导的疼痛产生剂量依赖性抑制，平均ID50值为18.8毫克/千克。此外，ME（3 - 100毫克/千克，腹腔注射，提前30分钟）对福尔马林诱导的疼痛的两个阶段均产生显著抑制，神经源性和炎症性阶段的平均ID50值分别为30.3和17.2毫克/千克。另外，微穗羊蹄甲的ME（3 - 300毫克/千克，腹腔注射，提前30分钟）以分级方式抑制大鼠足爪中缓激肽（3.2微克/爪）、P物质（13.5微克/爪）、角叉菜胶（300微克/爪）、辣椒素（100微克/爪）和肾上腺素（100纳克/爪）诱导的痛觉过敏，平均ID50值分别为20.5、17.9、101.8、54.2和99.7毫克/千克。综上所述，这些数据表明微穗羊蹄甲的ME对小鼠和大鼠的多种化学和机械性疼痛模型均产生显著的镇痛作用。提取物镇痛作用的确切机制仍不清楚，但似乎部分与所使用的疼痛模型中促炎介质的释放或作用的调节有关。最后，从该植物中分离得到的黄酮类化合物槲皮苷似乎对甲醇提取物的镇痛特性有贡献。
