L-dopa, a dopaminergic agonist, is the gold standard for the treatment of Parkinson’s disease. However, due to the long-term toxicity and adverse effects of using L-dopa as the first-line therapy for Parkinson’s disease, a search for alternative medications is an important current challenge. Traditional Ayurvedic medicine has suggested the use of Mucuna pruriens Linn. (Fabaceae) as an anti-Parkinson’s agent. The present study aimed to quantify the amount of L-dopa in M. pruriens seed extract by HPLC analysis. The cytotoxicity and neuroprotective properties of M. pruriens aqueous extract were investigated by two in vitro models including the serum deprivation method and co-administration of hydrogen peroxide assay. The results showed the significant neuroprotective activities of M. pruriens seed extracts at a concentration of 10 ng/mL. In addition, the effects of L-dopa and M. pruriens seed extract on in vitro acetylcholinesterase activities were studied. M. pruriens seed extract demonstrated acetylcholinesterase inhibitory activity, while synthetic L-dopa enhanced the activity of the enzyme. It can be concluded that the administration of M. pruriens seed might be effective in protecting the brain against neurodegenerative disorders such as Parkinson’s and Alzheimer’s diseases. M. prurience seed extract containing L-dopa has shown less acetylcholinesterase activity stimulation compared with L-dopa, suggesting that the extract might have a superior benefit for use in the treatment of Parkinson’s disease.

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.