Mechanisms of Ligusticum chuanxiong (LCX) extracts in the suppression of proinflammatory cytokine expression in blood macrophages

Abstract

Inflammation plays an important role in the pathogenesis of many diseases including heart disease, stroke, Parkinson’s disease and Alzheimer’s disease. In addition to the current therapeutic agents, alternative approaches using herbal medicines for the treatment of these diseases have gained popularity. Since LCX is one of the most commonly used traditional Chinese medicines in China to treat cardiovascular and cerebrovascular diseases, we hypothesize that its ingredients are capable of exhibiting significant suppressive effects on the production of proinflammatory cytokines. To test this, we investigated the anti-inflammatory mechanisms of LCX in primary human macrophages (PBMac) and RAW264.7 mouse macrophage cell line (RAW) using lipopolysaccharide (LPS) as a model for inflammation. Here, we demonstrated that the ethanol extract of LCX significantly down-regulated the production of TNF-α as well as nitric oxide in LPSinduced PBMac and RAW cells, respectively. Furthermore, we showed that LPS-induced phosphorylation of signaling kinases including mitogen activated protein kinases (MAPK) were inhibited by LCX. Taken together, ethanol extracts isolated from LCX can modulate the inflammatory responses via the regulation of specific signaling kinase activities, which lead to reduced LPS induced cytokine expression in immune cells. Therefore, LCX is a potential drug candidate for treating inflammatory diseases.