P7 Extract of Ligusticum chuanxiong Hort attenuates LPS-induced neuroinflammation in BV2 microglia via down-regulation of TLR4/MyD88 pathway

Abstract

Microglia is the main resident immunological macrophage-like cell in the central nervous system. Activated microglia release various pro-inflammatory cytokines to induce neuroinflammation in stroke and neurodegenerative disorders. Ligusticum chuanxiong Hort. (LC) is a very common herb widely used to treat cerebrovascular and cardiovascular diseases. The present study was to investigate the protective effects of LC extract against neuroinflammation in BV2 microglia induced by LPS. BV2 cells were treated with LPS 200 ng/mL for 24 h to induce an inflammatory response. MTT assay was used to measure cell viability. The content of NO in supernatant was measured by Griess reagent. The levels of IL-1β, IL-6, TNF-α, and ICAM-1 in supernatant were measured using ELISA kits. Western blotting was utilized to detect the expression of COX-2, TLR4, and MyD88. LC extract at concentrations of 30 and 100 μg/mL significantly decreased the production of related inflammatory factors induced by LPS, such as NO, IL-1β, IL-6, TNF-α and ICAM-1. In addition, LC extract also significantly inhibited the expression of COX-2, TLR4, and MyD88 in LPS-treated BV2 cells. These results suggest that the extract of LC attenuates LPS-induced neuroinflammation in BV2 microglia via down-regulation of the TLR4/MyD88 signalling pathway.