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

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? To investigate the role of cinnabar and realgar in the protective effects of WSHFD on lipopolysaccharide (LPS)-induced neurotoxicity. 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 [3H]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. 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 TNFα, iNOS, IL-1β and COX-2 and the subsequent production of TNFα, NO, IL-1β and PGE2 in neuron-glia cultures. However, WSHFD (removed) and (reduced) failed to protect against LPS-induced neurotoxicity. Cinnabar and realgar were active ingredients of WSHFD in producing protective effects against LPS-induced neurotoxicity.