Immunomodulation of Parkinson's disease using Mucuna pruriens (Mp)

Abstract

Immune control is associated with nigrostriatal neuroprotection for Parkinson's disease (PD); though its direct cause and effect relationships have not yet been realized and modulating the immune system for therapeutic gain has been openly discussed. While the pathobiology of PD remains in study, neuroinflammation is thought to speed nigrostriatal degeneration. The neuroinflammatory cascade associated with PD begins with aggregation of misfolded or post-translationally modified α-synuclein (α-syn). Such aggregation results in neuronal cell death and the presence of chronically activated glia (microglia and astroglia), leading to the production of proinflammatory cytokines like tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6, and enzymes such as nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and cyclooxygenase-2 (COX-2). These changes in the glial phenotype can affect the central nervous system (CNS) microenvironment by producing a pro-inflammatory milieu that speeds PD pathogenesis. Mucuna pruriens (Mp) is the most popular drug in Ayurveda, the Indian system of medicine. Several reports have suggested that it possesses analgesic, anti-inflammatory, anti-neoplastic, anti-epileptic and anti-microbial activities. Mp contain L-DOPA and ursolic acid which has an anti-inflammatory property. There are very few literatures which show the immunomodulatory activity of Mp in PD, several researchers have tried to work on the immunomodulatory activity of Mp in some other diseases. The results of several studies show that Mp modulate the immune components like TNF-α, IL-6, IFN-λ, IL-1β, iNOS and IL-2 in the CNS. It also modulates the activity of the transcription factor NF-kB which plays an important role in the progression of the PD. Thus, by altering these cytokines or transcription factors, Mp protects or prevents the progression of PD. Thus in this review we try to explore the immunomodulatory activity of Mp in PD.

Keywords: Astroglia; Microglia; Mucuna pruriens (Mp); Neuroinflammation; Ursolic acid (UA).