Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Av. Paranjana 1700, 60.740-000, Fortaleza, Ceará, Brazil.
Fundam Clin Pharmacol. 2013 Apr;27(2):201-9. doi: 10.1111/j.1472-8206.2011.00987.x. Epub 2011 Sep 5.
The objective of this study was to evaluate the antinociceptive effects of a lectin from Canavalia brasiliensis (ConBr) when administered orally to murine models of chemical and thermal nociception. ConBr up to 100 mg/kg produced significant and dose-dependent antinociceptive effects: 81% reduction in abdominal writhing induced by 0.6% acetic acid; 26 and 52% reduction in early- and late-stage paw licking, respectively, induced by 2.5% formalin; and 155% increase in reaction latency (heightened thermal pain threshold). In all models, the antinociceptive effect was reversed by the lectin-binding carbohydrate α-d-methyl-mannoside and by the nonselective opioid antagonist naloxone. The antinociceptive effect observed in the formalin test was inhibited by the δ-selective antagonist naltrindole and the κ-selective antagonist nor-binaltorphimine but not by the μ-selective antagonist cyprodime. In conclusion, when administered orally to Swiss mice, the ConBr lectin displayed antinociceptive activity, both peripheral and central, mediated by the opioid system and involving δ-and κ-receptors and the lectin domain.
本研究旨在评估巴西栗凝集素（ConBr）经口给予时对化学和热痛觉模型的镇痛作用。ConBr 高达 100mg/kg 时产生显著且剂量依赖性的镇痛作用：对 0.6%乙酸引起的腹部扭曲减少 81%；对 2.5%甲醛引起的早期和晚期爪舔舐分别减少 26%和 52%；反应潜伏期（热痛觉阈值升高）增加 155%。在所有模型中，镇痛作用均被凝集素结合碳水化合物α-d-甲基甘露糖苷和非选择性阿片受体拮抗剂纳洛酮逆转。在福尔马林试验中观察到的镇痛作用被 δ-选择性拮抗剂naltrindole 和 κ-选择性拮抗剂 nor-binaltorphimine 抑制，但不受 μ-选择性拮抗剂 cyprodime 抑制。综上所述，当经口给予瑞士小鼠时，ConBr 凝集素表现出外周和中枢镇痛活性，通过阿片系统介导，涉及 δ-和 κ-受体以及凝集素结构域。
