Modulation of LPS-stimulated neuroinflammation in BV-2 microglia by Gastrodia elata: 4-hydroxybenzyl alcohol is the bioactive candidate.

Gastrodia elata Blume (Orchidaceae, GE) a traditional plant in Oriental countries is known for its enormous benefits to treat headaches, dizziness, vertigo and convulsive illnesses. In the present study, the ethnopharmacological role of GE in neuroinflammation mediated by activated microglia and the mechanisms underlying were reported. BV-2 microglia activated by lipopolysaccharide (LPS) was employed and the effects of GE on corresponding neuroinflammatory parameters were assessed. GE extract inhibited LPS-stimulated production of inflammatory cytokines and down regulated the c-Jun NH(2)-Terminal Kinase (JNK) and nuclear factor-kappa B (NF-κB) signaling pathways, which are known to be involved in neuroinflammation. Further, inhibition of NO and iNOS by 4-hydroxybenzyl alcohol (4-HBA), one of the active constituent of GE in LPS-stimulated BV-2 cells suggest that 4-HBA might be the bioactive candidate. GE extract and its active constituent 4-HBA could be further exploited to mitigate microglial activation and may be developed as a new therapeutic remedy in treating various neuroinflammatory diseases.