School of Pharmaceutical Sciences, Lovely Professional University, Phagwara 144411 Punjab, India.
Department of Pharmacognosy, Faculty of Pharmacy, Tishk International University, Erbil, 44001, KRG, Iraq.
Curr Neuropharmacol. 2023;21(7):1558-1574. doi: 10.2174/1570159X20666220810105421.
Quercetin (Qu), a dietary flavonoid, is obtained from many fruits and vegetables such as coriander, broccoli, capers, asparagus, onion, figs, radish leaves, cranberry, walnuts, and citrus fruits. It has proven its role as a nutraceutical owing to numerous pharmacological effects against various diseases in preclinical studies. Despite these facts, Qu and its nanoparticles are less explored in clinical research as a nutraceutical. The present review covers various neuroprotective actions of Qu against various neurodegenerative diseases (NDs) such as Alzheimer's, Parkinson's, Huntington's, and Amyotrophic lateral sclerosis. A literature search was conducted to systematically review the various mechanistic pathways through which Qu elicits its neuroprotective actions and the challenges associated with raw Qu that compromise therapeutic efficacy. The nanoformulations developed to enhance Qu's therapeutic efficacy are also covered. Various ongoing/completed clinical trials related to Qu in treating various diseases, including NDs, are also tabulated. Despite these many successes, the exploration of research on Qu-loaded nanoformulations is limited mostly to preclinical studies, probably due to poor drug loading and stability of the formulation, time-consuming steps involved in the formulation, and their poor scale-up capacity. Hence, future efforts are required in this area to reach Qu nanoformulations to the clinical level.
槲皮素（Qu）是一种膳食类黄酮，可从许多水果和蔬菜中获得，如香菜、西兰花、刺山柑、芦笋、洋葱、无花果、萝卜叶、蔓越莓、核桃和柑橘类水果。由于其在临床前研究中对各种疾病具有多种药理学作用，因此已被证明具有作为营养保健品的作用。尽管如此，Qu 及其纳米颗粒在营养保健品的临床研究中仍较少被探索。本综述涵盖了 Qu 对各种神经退行性疾病（NDs）如阿尔茨海默氏病、帕金森氏病、亨廷顿氏病和肌萎缩性侧索硬化症的多种神经保护作用。进行了文献检索，以系统地综述 Qu 发挥其神经保护作用的各种机制途径，以及与 Qu 相关的原始制剂的挑战，这些挑战会影响治疗效果。还涵盖了为提高 Qu 的治疗效果而开发的纳米制剂。还列出了与 Qu 治疗各种疾病（包括 NDs）相关的各种正在进行/已完成的临床试验。尽管取得了许多成功，但对负载 Qu 的纳米制剂的研究探索主要局限于临床前研究，这可能是由于制剂的载药量和稳定性差、制剂涉及的耗时步骤以及其较差的扩大生产能力。因此，需要在这一领域做出未来的努力，以使 Qu 纳米制剂达到临床水平。
