Development of an extraction method of mucuna pruriens seeds for a chemically and physically stable extract

Abstract

Levodopa (L-DOPA) is a drug for the treatment of Parkinson's disease (PD). Currently, it derives from chemical synthesis and plants, especially Mucuna Pruriens (MP) seeds. The results of clinical studies found using the L-DOPA-containing MP for the treatment of PD could reduce side effects more than the synthetic one but patients must take MP powder in high amounts per a single dose which may cause inconvenience. Therefore, using the extract can help in the reduction of the dose. Unfortunately, the water extract from the MP seeds can be easily degraded physically and chemically; especially the physical appearance e.g., darkening color, melting, or a solid lump. Moreover, the reduction of L-DOPA content in the extract was commonly observed. Therefore, it is necessary to develop an extraction procedure to solve these problems. This study aimed to modify the extraction of MP using the traditional acidification approach to obtain a higher stable MP extract by comparing the extraction efficiency of a set of previously studied acid solutions (hydrochloric acid, citric acid, and ascorbic acid) and acid extraction from Phyllanthus emblica water (PE), which has antioxidant effects and is also useful in treating PD as well. From the comparative extraction results of the two strains of MP seeds, it was found that the amount of levodopa was not statistically different. While using the sonication-assisted extraction method can improve the extraction efficiency. When comparing different acid solutions used for extraction, it was found that PE yielded an extract with a similar amount of levodopa as using hydrochloric acid as the control solution, and also helps to maintain the quality of the extract when stored under the accelerated condition for 12 months. In addition, qualitative analysis of chemicals in PEW and MP extracted with PE by HPTLC and HPLC techniques revealed that L-DOPA in the MP extract did not interfere with the chemicals in PEW. All these studies showed that PEW is beneficial for the L-DOPA extraction process and is a safe natural solvent. The obtained extract can be used as a starting material for herbal products.