Longxuetongluo capsule (LTC), derived from the total phenolic compounds of Chinese dragon’s blood, is now used to treatment of ischemic stroke in convalescence. The aim of this study is to explore the neuroprotective effect of LTC from the perspective of neuro-inflammation.
Cell viability and LDH release were measured by MTS and LDH assay kit. Pro-inflammatory mediators and cytokines production including NO, PGE2, IL-1β, IL-6 and TNF-α were detected by Elisa assay. Additionally, western blot was used to detect the expression of inflammatory proteins associated with the MAPKs, JAK/STAT, NF-κB and Nrf2/HO-1 signaling pathways. Moreover, immunofluorescence assay and EMSA were performed to determine the Nrf2 translocation and the binding-DNA activity of NF-κB, respectively.
LTC at 0.5-2 μg/ml significantly increased cell viability and decreased LDH, NO, PGE2, IL-1β, IL-6 and TNF-α production in Oxygen-Glucose Deprivation/Reoxygenation (OGD/R) and LPS-induced BV2 microglia cells. Meanwhile, LTC not only decreased the protein expressions of iNOS, COX-2, but also down-regulated phosphorylation of ERK1/2, p38, and up-regulated HO-1 expression via nuclear translocation of Nrf2. LTC can significantly inhibit the phosphorylation of JAK1/STAT3 and reduce the translocation of NF-κB from cytosol to nucleus as well as the binding-DNA activity. PC12 cell pretreated with LTC- condition medium (CM) significantly alleviated lipopolysaccharide (LPS)-induced neurotoxicity and increased PC12 cell viability in a dose-dependent manner.
The present study showed that LTC exhibited a strong anti-neuroinflammatory activity and neuroprotective effects on LPS-stimulated BV2 microglia cells and PC12 cells.