Smilaxchina L. polyphenols inhibit LPS-induced macrophage M1 polarization to alleviate inflammation through NF-κB signaling pathway in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE

As an important component of the cell wall of Gram-negative bacteria, lipopolysaccharide (LPS) is an important inducer of inflammation in humans. Smilax china L. is known for its diverse bioactive functions, particularly its anti-inflammatory effects.

AIM OF THE STUDY

This study aimed to investigate the bioactive function of Smilax china L. polyphenols (SCLP) on LPS-induced inflammation.

MATERIALS AND METHODS

Inflammation in RAW264.7 macrophages and mice were induced using LPS. The cytotoxicity of SCLP was investigated by MTT assay. Inflammatory factors were detected by ELISA and RT-PCR. The expression of NF-κB pathway-related proteins was analyzed by Western Blotting.

RESULTS

The results demonstrated that SCLP significantly reduced the levels of pro-inflammatory factors (TNF-α, IL-1β, and IL-6) and inhibited M1 polarization of macrophages in both RAW264.7 macrophages and mice (p < 0.05). Western Blotting analysis revealed that the levels of NF-κB signaling pathway-associated proteins (p-p65, p-IKB, p-IKK) were significantly reduced (p < 0.05). Notably, SCLP significantly downregulated the expression of pro-apoptotic proteins, while upregulating the expression of anti-apoptotic proteins in RAW264.7 macrophages (p < 0.05). Additionally, the levels of antioxidant enzymes were enhanced in mice, suggesting a potential reduction in the inflammatory response.

CONCLUSIONS

These findings indicated that SCLP might inhibit LPS-induced M1 polarization through the NF-κB signaling pathway, thereby reducing inflammation. Consequently, SCLP might serve as a promising bioactive substance for preventing inflammation-related injury.