Microglia-mediated neuroinflammation is one of the key mechanisms involved in acute brain injury and chronic neurodegeneration. This study investigated the inhibitory effects of 2-hydroxy-4-methylbenzoic anhydride (HMA), a novel synthetic derivative of HTB (3-hydroxy-4-trifluoromethylbenzoic acid) on neuroinflammation and underlying mechanisms in activated microglia in vitro and an in vivo mouse model of Parkinson’s disease (PD). In vitro studies revealed that HMA significantly inhibited lipopolysaccharide (LPS)-stimulated excessive release of nitric oxide (NO) in a concentration dependent manner. In addition, HMA significantly suppressed both inducible NO synthase and cyclooxygenase-2 (COX-2) at the mRNA and protein levels in LPS-stimulated BV-2 microglia cells. Moreover, HMA significantly inhibited the proinflammatory cytokines such as interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha in LPS-stimulated BV-2 microglial cells. Furthermore, mechanistic studies ensured that the potent anti-neuroinflammatory effects of HMA (0.1, 1.0, and 10 μM) were mediated by phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) in LPS-stimulated BV-2 cells. In vivo evaluations revealed that intraperitoneal administration of potent neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 20 mg/kg, four times a 1 day) in mice resulted in activation of microglia in the brain in association with severe behavioral deficits as assessed using a pole test. However, prevention of microglial activation and attenuation of Parkinson’s disease (PD)-like behavioral changes was obtained by oral administration of HMA (30 mg/kg) for 14 days. Considering the overall results, our study showed that HMA exhibited strong anti-neuroinflammatory effects at lower concentrations than its parent compound. Further work is warranted in other animal and genetic models of PD for evaluating the efficacy of HMA to develop a potential therapeutic agent in the treatment of microglia-mediated neuroinflammatory disorders, including PD.

中文翻译：

---

2-羟基-4-甲基苯甲酸酐抑制帕金森氏病细胞模型和实验动物模型的神经炎症

小胶质细胞介导的神经炎症是急性脑损伤和慢性神经变性所涉及的关键机制之一。这项研究调查了2-羟基-4-甲基苯甲酸酐（HMA），HTB的一种新型合成衍生物（3-羟基-4-三氟甲基苯甲酸）对激活的小胶质细胞和体外小鼠体内神经炎症和潜在机制的抑制作用。帕金森氏病（PD）的模型。体外研究表明，HMA以浓度依赖性方式显着抑制脂多糖（LPS）刺激的一氧化氮（NO）过度释放。此外，HMA在LPS刺激的BV-2小胶质细胞的mRNA和蛋白水平上均显着抑制了诱导型NO合酶和环氧合酶2（COX-2）。而且，HMA在LPS刺激的BV-2小胶质细胞中显着抑制促炎细胞因子，例如白介素（IL）-1beta，IL-6和肿瘤坏死因子-α。此外，机制研究确保HMA（0.1、1.0和10μM）的有效抗神经炎症作用是通过LPS刺激的B细胞抑制剂Kappa轻型多肽基因增强子的核因子，α（IκBα）的磷酸化介导的。 BV-2细胞。体内评估显示，腹膜内给予小鼠强效神经毒素1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP，20 mg / kg，一日四次）导致小鼠小胶质细胞活化。使用极点测试评估的大脑与严重的行为缺陷有关。然而，通过口服HMA（30 mg / kg）14天获得了预防小胶质细胞活化和减轻帕金森氏病（PD）行为改变的效果。考虑到总体结果，我们的研究表明，HMA在比其母体化合物更低的浓度下显示出强大的抗神经炎作用。在PD的其他动物和遗传模型中，还需要进行进一步的工作，以评估HMA在开发小胶质细胞介导的神经炎性疾病（包括PD）中开发潜在治疗剂的功效。