姜黄素纳米粒子调控ABC转运体抑制癫痫耐药性的作用和机制研究

Drug-resistant is a major problem in epilepsy. The ABC transporter in BBB is one of the factors causing drug-resistant epilepsy. Curcumin can inhibit multi-drug resistant in cancer cells, which has the potential to treat drug resistant epilepsy in clinic. However, the mechanism and effectiveness of curcumin in blocking ABC transporter in blood-brain barrier (BBB) and its effect on drug-resistant epilepsy is unclear. Based on our own work, we hypothesize that: Curcumin can inhibit the upregulation of ABC transporters in BBB of epileptic brain through blocking Glu/NMDAR/COX-2 signaling pathway, block the efflux of AEDs, increase AED brain uptake, and improve the treatment of AEDs for patients with drug resistant epilepsy. The objectives in this application are to identify the influence and mechanism of curcumin on the expression and activity of ABC transporters in BBB, and to evaluate the efficacy of curcumin as an add-on drug to treat patients with drug resistant epilepsy. To accomplish the objectives, we will: I. Develop curcumin nanoparticle formulation; II. Determine the influence of curcumin nanoparticles on the expression and activity of ABC transporters in BBB of rat and mouse epilepsy models, brain capillaries, and hBMEC cells; III. Determine the regulation of key molecules in Glu/NMDAR/COX-2 signaling pathway by curcumin nanoparticles; 4) Develop an add-on therapeutic strategy, which combining curcumin nanoparticles and AEDs, to reduce seizures in mice with drug resistant epilepsy. The proposed research is significant because the expected outcomes will potentially provide a new strategy to improve pharmacotherapy in patients with drug resistant epilepsy and Alzheimer’s disease. And it will also illustrate the mechanism underlying the regulation of ABC transporters by curcumin and epileptogenesis.

血脑屏障中药物转运体高表达是引起癫痫耐药性的重要原因。我们及前人研究显示姜黄素具有抑制多药耐药性和抗癫痫发作的双重潜能，有可能开发成新型多功能抑制剂，与抗癫痫药物（AED）联合治疗耐药性癫痫。但姜黄素抑制癫痫耐药性、调控血脑屏障中药物转运体的疗效和机理尚不清楚，尚无其调控AED脑内转运的研究。我们发现姜黄素能够调控脑血管中ABC转运体的表达，抑制AED转运。据此，我们假设姜黄素通过调控脑内ABC转运体，增加AED脑内浓度，抑制癫痫耐药性。该课题拟在癫痫大/小鼠、离体脑毛细血管、细胞中研究姜黄素纳米粒子对脑内药物转运体的调控及机理，评估其抑制癫痫耐药性的效果，具体包括：制备姜黄素纳米粒子；在癫痫动物中检测其调控AED脑内浓度、抑制癫痫耐药性的作用；研究姜黄素对血脑屏障中ABC转运体的调控及其分子通路。本研究对解析耐药性癫痫中ABC转运体的调控，开发新型抑制剂，推动姜黄素临床应用具有重要意义。

癫痫是一种严重的慢性神经系统疾病，其发病率约为总人口1%，中国癫痫患者约900万，其中30%以上的患者为耐药性癫痫。血脑屏障中药物转运体高表达是引起癫痫耐药性的重要原因之一。我们及前人研究显示姜黄素具有抑制多药耐药性和抗癫痫发作的双重潜能，有可能开发成新型多功能抑制剂，与抗癫痫药物（AED）联用治疗耐药性癫痫。但姜黄素抑制癫痫耐药性、调控血脑屏障中药物转运体的疗效和机理尚不清楚，尚无其调控AED脑内转运的研究。通过本项目研究，我们完成了姜黄素制剂的制备及其药效和药代动力学研究、姜黄素对抗癫痫药物疗效的影响、姜黄素对药物转运体和抗癫痫药物脑内转运的影响、姜黄素对不同中枢神经系统药物与P-gp、BCRP等ABC转运体结合的影响，以及姜黄素对P-gp表达和转运功能的影响。结果显示，姜黄素包合物显著提高了其生物利用度，提高了姜黄素在急性癫痫和自发性癫痫中的治疗作用。并且，姜黄素增加了奥卡西平和苯妥英钠的口服吸收，增加了苯妥英钠的脑内分布。进一步的机制研究表明，姜黄素是P-gp抑制剂，可影响P-gp功能和表达。此外，我们发现胡椒碱等天然产物也能调控抗癫痫药物疗效和药物转运，改善癫痫发作中的炎症和氧化应激损伤。这些结果表明姜黄素等天然产物有作为耐药性癫痫联合用药的潜力，对耐药性癫痫的治疗具有重要意义。