The first line therapy of patients with Parkinson’s disease, a neurodegenerative disorder caused by the degeneration of dopaminergic neurons, is levodopa (L-dopa) given orally. Recently, the presence of natural L-dopa in the seed of Mucuna pruriens, a tropical legume in the Fabaceae family, was reported and it showed superior efficiency compared with synthetic L-dopa. Therefore, this study aimed to examine the phytochemical compounds, particularly for natural L-dopa, in M. pruriens seed extract and subsequently prepare a nanogel containing the extract prior to incorporation into a jelly formulation for use as a functional food in elderly patients with Parkinson’s disease. The results show that M. pruriens seed extract contains phenolic compounds, flavonoids, tannins, alkaloids, terpenoids, and saponins. The quantitative analysis performed by the HPLC method revealed that spray-dried M. pruriens seed extract contained 5.59 ± 0.21% L-dopa. M. pruriens seed extract possesses a ferric-reducing antioxidant power and shows free-radical scavenging activity, determined by DPPH and ABTS methods, suggesting a distinctive antioxidant ability of the extract. M. pruriens seed extract at 10 ng/mL did not show cytotoxicity against a neuronal cell line (SH-SY5Y cells), kidney cells (HEK293 cells), or Caco-2 cells. Nanogel of M. pruriens seed extract prepared by ionic gelation had the hydrodynamic diameter, polydispersity index and zeta potential value of 384.53 ± 11.24 nm, 0.38 ± 0.05, and −11.23 ± 1.15 mV, respectively. The transepithelial transport of L-dopa in M. pruriens seed-extract nanogel through Caco-2 cells was measured. Nanogel containing M. pruriens seed extract at the concentration of 10 ng/mL exhibited neuroprotective activity. A jelly formulation containing M. pruriens seed-extract nanogel was successfully developed. The prepared jelly exhibited the acceptable physical and microbiological stabilities upon 6 months of the stability test. The half-life of natural L-dopa in jelly were 3.2, 0.9, and 0.6 years for storage conditions at 4, 30, and 40 °C, respectively, indicating the thermal degradation of natural L-dopa. The prepared jelly containing natural L-dopa from M. pruriens seed extract with the prominent antioxidant activity is a promising option for elderly patients suffering from Parkinson’s disease.

中文翻译：

---

含有黧豆种子提取物的天然左旋多巴纳米凝胶凝胶的开发用于帕金森病的神经保护

帕金森病患者的一线治疗是口服左旋多巴（左旋多巴），这是一种由多巴胺能神经元退化引起的神经退行性疾病。最近，据报道，豆科热带豆科植物黧豆种子中存在天然左旋多巴，与合成左旋多巴相比，它显示出更高的效率。因此，本研究的目的是检测植物化学化合物，特别是天然左旋多巴，在M. pruriens种子提取物中，随后制备含有该提取物的纳米凝胶，然后将其掺入果冻制剂中，用作老年帕金森病患者的功能性食品疾病。结果表明，M. pruriens种子提取物含有酚类化合物、类黄酮、单宁、生物碱、萜类和皂苷。通过 HPLC 方法进行的定量分析表明，喷雾干燥的M. pruriens种子提取物含有 5.59 ± 0.21% L-多巴。M. pruriens种子提取物具有降低铁的抗氧化能力并显示出自由基清除活性，通过DPPH和ABTS方法测定，表明该提取物具有独特的抗氧化能力。10 ng/mL 的M. pruriens种子提取物对神经元细胞系（SH-SY5Y 细胞）、肾细胞（HEK293 细胞）或 Caco-2 细胞没有显示细胞毒性。M. pruriens 纳米凝胶离子凝胶法制备的种子提取物的流体动力学直径、多分散指数和 zeta 电位值分别为 384.53 ± 11.24 nm、0.38 ± 0.05 和 -11.23 ± 1.15 mV。测量了 L-多巴在M. pruriens种子提取物纳米凝胶中通过 Caco-2 细胞的跨上皮转运。含有浓度为 10 ng/mL 的M. pruriens种子提取物的纳米凝胶表现出神经保护活性。含有M. pruriens的果冻配方种子提取物纳米凝胶研制成功。经6个月的稳定性测试，制备的果冻表现出可接受的物理和微生物稳定性。在 4、30 和 40°C 的储存条件下，果冻中天然左旋多巴的半衰期分别为 3.2、0.9 和 0.6 年，表明天然左旋多巴的热降解。制备的含有来自毛豆藤种子提取物的天然左旋多巴具有突出的抗氧化活性的果冻是患有帕金森病的老年患者的有希望的选择。