Abstract
Objective: Sinomenine (SIN), an alkaloid isolated from sinomenium acutum plant, possesses many pharmacological properties, such as anti-inflammation, anti-hyperalgesia, anti-allergy, anti-apoptosis, and anti-angiogenesis. In this study, we aimed to investigate the detailed molecular mechanisms associated with the anti-inflammatory activity of SIN in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages.
Methods: RAW264.7 cells were treated with LPS and/or indicated concentrations of SIN. Inflammatory cytokine production, such as TNF-α, IL-1β, and IL-6, was detected by ELISA. Expression of microRNA-155 (miR-155), SOCS1 and NF-κB was assessed by qRT-PCR and Western blot, separately. Simultaneously, miR-155 inhibitor and SOCS1 SiRNA were transfected to observe the regulative effects of SIN on the expression of miR-155, SOCS1, and NF-κB.
Results: Our result showed that SIN treatment significantly reduced LPS-induced inflammatory cytokine release, suppressed the expression of miR-155, enhanced SOCS1 expression at mRNA and protein levels, and prevented NF-ĸB transcription. Furthermore, transfection of miR-155 inhibitor and SOCS1 SiRNA emphasized that the regulation of miR-155, SOCS1, and NF-ĸB was associated with the anti-inflammatory activation of SIN in LPS-treated macrophages.
Conclusions: This study indicated that SIN alleviated LPS-induced inflammatory responses in RAW264.7 macrophages by downregulating miR-155 and upregulating SOCS1, at least partly, leading to the suppression of NF-ĸB transcription. These findings suggest that SIN might be developed as an alternative and promising drug for the treatment of inflammatory diseases.
Disclosure statement
The authors declare that they have no conflict of interest in this work.