Anti-inflammatory Mechanism of Action of Benzoylmesaconine in Lipopolysaccharide-Stimulated RAW264.7 Cells

Background: Benzoylmesaconine (BMA), the most abundant monoester alkaloid in Aconitum Plants, has some biological activities and is a potential therapeutic agent for inflammation-related diseases. However, the potential anti-inflammatory mechanisms of BMA have not been clarified.

Purpose: This study aimed to investigate the underlying molecular mechanisms of the anti-inflammatory action of this compound using lipopolysaccharide (LPS)-activated RAW264.7 macrophages.

Methods: The release of pro-inflammatory cytokines and mediators were detected by nitric oxide (NO) assays, Reactive Oxygen Species (ROS) assays, and enzyme-linked immunosorbent assays (ELISA) in LPS-activated RAW264.7 macrophage cells. Quantitative Real-Time PCR was used to measure the gene expression of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Cell viability was determined using a cell counting kit-8 (CCK-8) assay. The expression of iNOS, COX-2, mitogen-activated protein kinase (MAPK), and nuclear factor-κB (NF-κB)-related proteins were detected by western blot, and nuclear translocation of p65 was observed by immunofluorescence.

Results: BMA significantly decreased the production of IL-1β, IL-6, TNF-α, PGE₂, NO, and ROS and inhibited the protein and mRNA levels of COX-2 and iNOS in LPS-activated RAW264.7 macrophages. Moreover, LPS-induced phosphorylation of IκBα, JNK, p38, and ERK; degradation of IκBα; and nuclear translocation of p65 were significantly suppressed by BMA treatment.

Conclusion: These findings demonstrate that the anti-inflammatory effect of BMA was through the suppression of the NF-κB and MAPK signaling pathways and that it may be a therapeutic agent targeting specific signal transduction events required for inflammation-related diseases.