Mechanistic study of anti-inflammatory effect of Fu-Fang-Yu-Jie granules through inhibition of NLRP3 inflammasome activation in BMDM
Objective:To investigate the effect of Fu-Fang-Yu-Jie(FFYJ)granules on LPS-induced inflammation model in bone marrow-derived macrophages(BMDM)and its intervention of FFYJ on nucleotide-bound oligomeric domain-like receptor protein 3(NLRP3)inflammatory signaling pathway in macrophages.Methods:Primary cells were extracted and isolated from the leg bone mar-row of C57BL/6 mice and BMDM macrophages were obtained after 7 days of induction with 50 ng/ml M-CSF.Groups included control group(Control),model group(LPS+ATP),FFYJ low dose group(FFYJ 50 µg/ml),FFYJ medium dose group(FFYJ 100 µg/ml),FFYJ high dose group(FFYJ 200 µg/ml)and positive drug dexamethasone group(DEX).BMDM in FFYJ treatment group and posi-tive drug group were pretreated for 1 hour before modeling.Lactate dehydrogenase(LDH)release assay was used to detect the level of LDH in the supernatant of each group of cells;ELISA was used to detect the level of inflammatory factors TNF-α,IL-6 and IL-1β in the supernatant of each group of cells;qRT-PCR was used to detect the levels of TNF-α,IL-6 and IL-1β in each group of cells;protein levels of NF-κB,p-NF-κB,NLRP3,Caspase-1 p45,Caspase-1 p20 and GSDMD-N in each group of cells were detected by Western blot;inverted fluorescence microscope was used to observe the cell pyroptosis of each group after Hoechst-PI staining.Results:Compared with control group,the levels of LDH,TNF-α,IL-6 and IL-1β in the supernatant of the model group were signifi-cantly higher(P<0.000 1);the mRNA levels of TNF-α,IL-6 and IL-1β in the model group were significantly higher(P<0.000 1);the protein levels of p-NF-κB,NLRP3,Caspase-1 p20 and GSDMD-N were significantly higher(P<0.05);and the number of PI-posi-tive cells was significantly higher(P<0.05).Compared with the model group,FFYJ and DEX significantly reduced the levels of LDH,TNF-α,IL-6 and IL-1β in the supernatant of BMDMs(P<0.05);down-regulated the mRNA levels of TNF-α,IL-6 and IL-1β in the cells(P<0.05);and inhibited the expressions of p-NF-κB,NLRP3,Caspase-1 p20 and GSDMD-N protein expressions(P<0.05);and significantly reduced the number of PI-positive cells(P<0.05).Conclusion:FFYJ exerts anti-inflammatory effects by inhibiting NLRP3 inflammasome activation in BMDM macrophages.