姜黄素对大鼠糖尿病神经病理性痛的效应

目的 评价姜黄素对大鼠糖尿病神经病理性痛(DNP)的效应.方法 雄性SD大鼠48只,随机分为6组(n=8):正常对照组(C组)、DNP组(D组)、DNP+二甲基亚砜组(DD组)和DNP+姜黄素50、100、200 mg/kg组(DC50组、DC100组和DC200组).D组、DD组、DC50组、DC100组和DC200组采用腹腔注射链唑霉素75 mg/kg的方法 制备糖尿病神经病理性痛模型,注射链唑霉素后14 d开始腹腔注射二甲基亚砜(姜黄素的溶媒)或相应剂量姜黄素,1次/d,连续2周.分别造模前2 d、注射链唑霉素后14 d、姜黄素给药1、3、7、14 d时测定机械缩足痛阚(MWT)和热缩足潜伏期(TWL),最后一次测定痛阈后处死大鼠,测定脊髓背角和背根神经节细胞核磷酸化JNK(p-JNK)和NF-кB p65的表达水平.结果 与C组相比,D组各时点MWT降低,TWL缩短,脊髓背角和背根神经节细胞核p-JNK和NF-кB p65表达上调(P<0.05).与D组相比,DC50组、DC100组和DC200组姜黄素给药期间MWT升高,TWL延长,且与剂量有关,脊髓背角和背根神经节细胞核p-JNK和NF-кB p65表达下调(P<0.05).结论 姜黄素可减轻大鼠糖尿病神经病理性痛,其机制可能与抑制脊髓背角和背根神经节JNK和NF-кB的激活有关.

Effect of curcumin on diabetic neuropathic pain in rats

Objective To evaluate the effect of curcumin on diabetic neuropathic pain (DNP) in rats. Methods Forty-eight male SD rats weighing 200-230 g were randomly divided into 6 groups ( n = 8 each) : group Ⅰ normal control (group C); group Ⅱ DNP (group D) ; group Ⅲ DNP+ DMSO (solvent of curcumin) (group DD) and group Ⅳ , Ⅴ , Ⅵ DNP + curcumin 50, 100 or 200 mg/kg ( group DC50, 100, 200 ). Diabetes was induced with intraperitoneal (IP) streptozocin 75 mg/kg in group Ⅱ -Ⅵ. Curcumin 50, 100 and 200 mg/kg were given IP once a day for 14 consecutive days starting from 14 d after streptozocin in group Ⅳ , Ⅴ and Ⅵ respectively. Venous blood samples were taken before and 72 h after IP streptosocin for determination of blood glucose level. Successful induction of diabetes was defined as blood glucose > 14.6 mmol/L. Mechanical paw withdrawal threshold to yon Frey stimuli (MWT) and paw withdrawal latency to thermal nociceptive stimulus (TWL) were measured 2 d before and 14 d after IP streptesocin and on the 1, 3, 7, 14 d of curcumin administration. Animals with pain threshold measured at 14 d after IP streptozocin decreasing by less than 15% of the baseline were excluded from the study. The animals were sacrificed after the last pain threshold measurement and the lumbar segment of the spinal cord and p65 was significantly higher in group D than in group C ( P < 0.05). Curcumin administration significantly reduced thermal and mechanical hyperalgesia induced by diabetes and down-regulated the expression of p-JNK and horn and DRG.