Kolahdouz Mahnoush, Jafari Faranak, Falanji Farahnaz, Nazemi Samad, Mohammadzadeh Mohammad, Molavi Mehdi, Amin Bahareh
Student Research Committee, Sabzevar University of Medical Sciences, Sabzevar, Iran.
Cellular and Molecular Research Center, Department of Physiology and Pharmacology, Faculty of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran.
Neurochem Res. 2021 Jul;46(7):1759-1770. doi: 10.1007/s11064-021-03308-y. Epub 2021 Apr 12.
Diabetic neuropathy is one of the most common complications of diabetes mellitus. Excess glutamate release and oxidative stress are hypothesized to be involved in the pathophysiology of diabetes-induced neuropathy. This study was designed to investigate the effect of clavulanic acid (CLAV), a competitive beta-lactamase inhibitor, on the streptozocin (STZ)-induced neuropathic pain and possible mechanisms in the spinal cord of rats. Male Wistar rats were divided into naive group; control group which got a single dose of STZ (50 mg/kg, i.p.), as a model of diabetic neuropathic pain; prophylactic groups: animals received CLAV (10, 20 and 40 mg/kg, i.p.) 1 week after STZ for 10 days; and therapeutic group: animals received 20 mg/kg CLAV, 21 days after STZ for 10 days. Study of pain behaviors was started on days 0, 7, 14, 21, 28, 35 and 42 after STZ. The expression of the glutamate transport 1 (GLT1), genes of oxidative stress including inducible nitric oxide synthase (iNOS), proinflammatory cytokine, tumor necrosis factor alpha (TNF-α), as well as genes involved in the apoptosis including bcl2, bcl2-associated x (bax) were measured in the spinal cord tissue by Real Time PCR, on day 42. On day 21 post injection of STZ, diabetic animals showed significant mechanical allodynia, cold allodynia and thermal hyperalgesia. CLAV in all doses of 10, 20 and 40 mg/kg reduced symptoms of allodynia and hyperalgesia, in both prophylactic and therapeutic regimens. While iNOS, TNF-α, bax/bcl2 were found significantly overexpressed in spinal cord of diabetic animals, their expression in animals received CLAV had been reduced. In contrast, GLT1 that had decreased in the spinal cord of diabetic animals, significantly increased in those received CLAV. CLAV was found a promising candidate for reliving neuropathic pain in diabetes mellitus. Such beneficial effect of CLAV could be, in part, attributed to the increased expression of GLT 1, inhibition of nitrosative stress, anti-inflammation, and inhibition of some apoptotic mediators followed by administration into diabetic animals.
糖尿病性神经病变是糖尿病最常见的并发症之一。过量的谷氨酸释放和氧化应激被认为与糖尿病性神经病变的病理生理学有关。本研究旨在探讨竞争性β-内酰胺酶抑制剂克拉维酸（CLAV）对链脲佐菌素（STZ）诱导的大鼠脊髓神经性疼痛的影响及其可能机制。雄性Wistar大鼠分为正常组；对照组单次注射STZ（50mg/kg，腹腔注射），作为糖尿病性神经病变疼痛模型；预防组：动物在STZ注射1周后接受CLAV（10、20和40mg/kg，腹腔注射），持续10天；治疗组：动物在STZ注射21天后接受20mg/kg CLAV，持续10天。在STZ注射后的第0、7、14、21、28、35和42天开始研究疼痛行为。在第42天通过实时PCR检测脊髓组织中谷氨酸转运体1（GLT1）、氧化应激相关基因（包括诱导型一氧化氮合酶（iNOS））、促炎细胞因子肿瘤坏死因子α（TNF-α）以及凋亡相关基因（包括bcl2、bcl2相关X蛋白（bax））的表达。在注射STZ后第21天，糖尿病动物出现明显的机械性异常性疼痛、冷异常性疼痛和热痛觉过敏。在预防和治疗方案中，10、20和40mg/kg剂量的CLAV均减轻了异常性疼痛和痛觉过敏症状。虽然在糖尿病动物的脊髓中发现iNOS、TNF-α、bax/bcl2明显过表达，但在接受CLAV的动物中其表达降低。相反，在糖尿病动物脊髓中减少的GLT1在接受CLAV的动物中显著增加。发现CLAV是缓解糖尿病性神经病变疼痛的有前景的候选药物。CLAV的这种有益作用部分可归因于其给药后糖尿病动物中GLT1表达增加、抑制亚硝化应激、抗炎以及抑制一些凋亡介质。
