Department of Veterinary Biomedicine, Faculty of Veterinary Medicine, University of Montreal, Saint-Hyacinthe, QC, Canada.
Phytother Res. 2010 Apr;24(4):525-30. doi: 10.1002/ptr.2975.
The analgesic effects of vanillin on neuropathic pain was evaluated using thermal sensitivity and mechanical allodynia using the sciatic nerve constriction model (n = 30 rats). To determine the pharmacokinetics of vanillin, rats (n = 6/administration route) received either 20 or 100 mg/kg of vanillin i.v. and p.o., respectively. For the pharmacodynamic study, baseline levels for hyperalgesia and allodynia were taken for 5 days prior to surgery. Following surgery each group (n = 6 rats/group) received either vanillin (50 mg/kg or 100 mg/kg), morphine (2 mg/kg or 6 mg/kg) or the vehicle only. Pharmacokinetic results following p.o. administrations are C(max) 290.24 ng/mL, T(max) 4 h, relative clearance 62.17 L/h/kg and T(1/2) 10.3 h. The bioavailability is 7.6%. Mechanical allodynia was decreased on treatment days 1, 2, 3, 5 (p < 0.003) and not on day 4 (p > 0.02) with 50 mg/kg vanillin, whereas at 100 mg/kg p.o. a decrease was noted only on days 7 and 8 (p < 0.003). No effect on hyperalgesia was seen following vanillin administration. In conclusion, vanillin is bioavailable and seems to have an alleviating effect on mechanical allodynia, and not on hyperalgesia, when evaluated with a chronic constriction nerve injury rat model of neuropathic pain.
采用坐骨神经结扎模型（n = 30 只大鼠），评估香草醛对神经病理性疼痛的镇痛作用，采用热敏感性和机械性痛觉过敏来评估。为了确定香草醛的药代动力学，分别给大鼠（n = 6/给药途径）静脉内和口服给予 20 或 100 mg/kg 的香草醛。在药效学研究中，在手术前 5 天测量痛觉过敏和痛觉过敏的基线水平。手术后，每组（n = 6 只大鼠/组）分别给予香草醛（50 mg/kg 或 100 mg/kg）、吗啡（2 mg/kg 或 6 mg/kg）或仅给予载体。口服给药后的药代动力学结果为 C(max)290.24 ng/mL、T(max)4 h、相对清除率 62.17 L/h/kg 和 T(1/2)10.3 h。生物利用度为 7.6%。在治疗第 1、2、3、5 天（p < 0.003），但在第 4 天（p > 0.02），50 mg/kg 香草醛降低了机械性痛觉过敏，而在口服 100 mg/kg 时，仅在第 7 和第 8 天（p < 0.003）观察到降低。香草醛给药后对痛觉过敏没有影响。结论，用慢性缩窄性神经损伤大鼠神经病理性疼痛模型评估时，香草醛是可生物利用的，似乎对机械性痛觉过敏有缓解作用，而对痛觉过敏没有作用。
