Role of cinnabar and realgar of WSHFD in protecting against LPS-induced neurotoxicity

Ethnopharmacological relevance: Wan-Sheng-Hua-Feng-Dan (WSHFD) is a traditional Chinese medicine used for the treatment of neurological disorders. Cinnabar (HgS) and realgar (As4S4) are included in WSHFD. Are they remedies or poisons? Aim of study: To investigate the role of cinnabar and realgar in the protective effects of WSHFD on lipopolysaccharide (LPS)-induced neurotoxicity. Materials and methods: Rat primary midbrain neuron-glia cultures were used to explore the effects of WSHFD on LPS-induced dopamine (DA) neurodegeneration. The experiment was randomly divided into control, LPS, LPS + removed (cinnabar and realgar in WSHFD were removed), LPS + reduced (cinnabar and realgar in WSHFD were reduced by 65%) and LPS + original (10% cinnabar and 10% realgar in WSHFD) groups. Dopaminergic neurotoxicity was assessed by [H-3]DA uptake assay and the quantification of tyrosine hydroxylase (TH)-positive neurons. Microglial activation was evaluated using an anti-OX-42 antibody. The release of intracellular reactive oxygen species (ROS) was quantified via the DCFH-DA probe. The transcripts and production of pro-inflammatory factors were examined by real-time RT-PCR analysis and ELISA, respectively. Results: WSHFD (original) significantly attenuated LPS-induced decrease of DA uptake capacity and TH-positive neuron number, inhibited microglial activation, decreased LPS-induced ROS production, ameliorated LPS-induced elevations of the mRNA expressions of TNF alpha, iNOS, IL-1 beta. and COX-2 and the subsequent production of TNF alpha, NO, IL-1 beta and PGE(2) in neuron-glia cultures. However, WSHFD (removed) and (reduced) failed to protect against LPS-induced neurotoxicity. Conclusion: Cinnabar and realgar were active ingredients of WSHFD in producing protective effects against LPS-induced neurotoxicity. (C) 2011 Elsevier Ireland Ltd. All rights reserved.