Mucuna pruriens (L.) DC. seed extract inhibits lipopolysaccharide-induced inflammatory responses in BV2 microglial cells

Ethnopharmacological relevance: Inflammation caused by activated microglia is known to be associated with neurodegenerative diseases, e.g., Parkinson's disease (PD) and Alzheimer's disease (AD). Inhibiting the inflammatory process can be considered a potential strategy for the treatment of inflammation-associated diseases. Mucuna pruriens (L.) DC. (Leguminosae) has long been used in Thailand, India, China and other tropical countries to treat several diseases including PD. M. pruriens seeds have been found to possess a variety of pharmacological properties including antioxidant and anti-Parkinsonism effects. However, the anti-inflammatory effects of M. pruriens seeds during microglial activation have yet to be reported.

Aim of the study: The present study was performed to evaluate the anti-inflammatory effects of M. pruriens seed extract and elucidate its underlying mechanism using lipopolysaccharide (LPS)-stimulated BV2 microglial cells.

Materials and methods: BV2 microglial cells were pretreated with various concentrations of M. pruriens seed extract before being stimulated with LPS. The levels of inflammatory mediators were analyzed by Griess assay and enzyme-linked immunoassay (ELISA). The protein expression levels of inflammatory cytokines were determined by Western blot analysis. The translocation of nuclear factor-kappa B (NF-κB) was assessed by immunofluorescence microscopy.

Results: M. pruriens seed extract significantly inhibited the release of inflammatory mediators including nitric oxide (NO), IL-1β, IL-6, and TNF-α in LPS-stimulated BV2 microglial cells. The extract also decreased the protein expression of IL-1β, IL-6, and TNF-α. Moreover, M. pruriens seed extract inhibited the translocation of NF-κB.

Conclusions: M. pruriens seed extract could suppress inflammatory responses in LPS-activated BV2 microglial cells by inhibiting the NF-κB signaling pathway. These findings support the use of M. pruriens seeds in traditional and alternative medicine for the treatment of PD and other inflammation-associated diseases.

Keywords: Inflammation; Microglia; Mucuna pruriens (L.) DC.; Neurodegenerative diseases; Parkinson's disease.