Macrophage Inflammation Alleviation by 20(S)-Protopanaxatriol by Inhibiting NLRP3 Inflammasome Activation

LIU Ya'nan; NIU Zhiqiang; LI Fu; HU Weicheng; ZHANG Ji

doi:10.13982/j.mfst.1673-9078.2025.2.0176

Abstract：The effects of 20(S)-protopanaxatriol(PPT)on NOD-like receptor thermal protein domain-associated protein 3(NLRP3)inflammasome activation induced by lipopolysaccharide(LPS)and adenosine triphosphate(ATP)were investigated to examine the role of PPT in alleviating macrophage inflammation.RAW264.7 cells were divided into a control group,an LPS group,an LPS+ATP group,and three PPT treatment groups(20,40,and 80 μmol/L).The mRNA expression levels of inducible nitric oxide synthase(iNOS),cyclooxygenase-2(COX-2),Interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and NLRP3 were significantly increased after LPS+ATP treatment.PPT treatment markedly downregulated the mRNA levels of iNOS,IL-1β,and NLRP3;however,there were no significant changes in those of COX-2 and TNF-α.Additionally,the expression levels of NLRP3,IL-1β,and cysteinyl aspartate-specific proteinase-1 in the cell lysate of the PPT treatment group were lower than those in the LPS+ATP group;however,PPT had no effect on the translocation of nuclear factor kappa-B.Enzyme-linked immunosorbent assay revealed that PPT significantly reduced IL-1β expression levels without affecting TNF-α levels.Scanning electron microscopy observation showed that PPT notably improved the inflammatory state of RAW264.7 cells.Specifically,there was a decrease in pseudopodia formation,whereas cell folds were smoothed resulting in rounded cells.This study demonstrated that PPT exhibits immunomodulatory and anti-inflammatory effects.PPT can regulate inflammation in macrophages by inhibiting NLRP3 inflammasome activation and subsequently reducing the expression level of IL-1β.This study provides a theoretical basis for exploring the mechanism by which PPT targets the NLRP3 inflammasome and its potential impact on related drug development.