目的:高患病率的面部疼痛是人类重大的健康问题之一。当发现口面疼痛时,这件事的重要性变得更加明显,直接和间接,影响认知表现。目前,研究人员专注于研究药物以减轻疼痛并改善其随后的认知障碍。
方法:在本研究中,首先用茉莉酸甲酯(MeJA)对大鼠进行集中治疗,这是一种抗氧化剂和抗炎的生物化合物。20分钟后,通过在大鼠牙髓中注射辣椒素可引起大鼠口面疼痛。随后,对动物的疼痛行为进行了分析,使用Morris水迷宫(MWM)测试评估/比较疼痛和MeJA治疗对大鼠学习和记忆的影响。此外,肿瘤坏死因子-α(TNF-α)的表达,IL-1β,BDNF,使用实时聚合酶链反应评估大鼠海马中的COX-2基因。
结果:经历口面部疼痛导致大鼠学习和记忆能力显著下降。然而,中央给药20μg/大鼠的MeJA有效地减轻了这些损伤。在MWM中,与未治疗的大鼠相比,MeJA治疗的大鼠的表现表现出2至3倍的改善。此外,在疼痛诱发大鼠的海马中,促炎因子TNF-α的表达,IL-1β,COX-2显著增加,而BDNF表达降低。相比之下,MeJA下调促炎因子并上调BDNF超过50%。
结论:这些发现强调了MeJA的显著的抗伤害潜能,以及通过其抗炎作用抑制疼痛引起的学习和记忆功能障碍的能力。
OBJECTIVE: Orofacial pain with high prevalence is one of the substantial human health issues. The importance of this matter became more apparent when it was revealed that orofacial pain, directly and indirectly, affects cognition performances. Currently, researchers have focused on investigating pharmaceutics to alleviate pain and ameliorate its subsequent cognitive impairments.
METHODS: In this study, the rats were first treated with the central administration of methyl jasmonate (MeJA), which is an antioxidant and anti-inflammatory bio-compound. After 20 min, orofacial pain was induced in the rats by the injection of capsaicin in their dental pulp. Subsequently, the animals\' pain behaviors were analyzed, and the effects of pain and MeJA treatments on rats learning and memory were evaluated/compared using the Morris water maze (MWM) test. In addition, the expression of tumor necrosis factor-α (TNF-α), IL-1β, BDNF, and COX-2 genes in the rats\' hippocampus was evaluated using real-time polymerase chain reaction.
RESULTS: Experiencing orofacial pain resulted in a significant decline in the rats learning and memory. However, the central administration of 20 μg/rat of MeJA effectively mitigated these impairments. In the MWM, the performance of the MeJA-treated rats showed a two- to threefold improvement compared to the nontreated ones. Moreover, in the hippocampus of pain-induced rats, the expression of pro-inflammatory factors TNF-α, IL-1β, and COX-2 significantly increased, whereas the BDNF expression decreased. In contrast, MeJA downregulated the pro-inflammatory factors and upregulated the BDNF by more than 50%.
CONCLUSIONS: These findings highlight the notable antinociceptive potential of MeJA and its ability to inhibit pain-induced learning and memory dysfunction through its anti-inflammatory effect.