This study aims to investigate the effect of essential oil of Acori Tatarinowii Rhizoma on microglial pyroptosis and decipher the underlying mechanism. BV-2 cells were treated with 1 μg·mL~(-1) lipopolysaccharide(LPS) and 10 μmol·L~(-1) nigericin sodium salt for the modeling of pyroptosis. The cells were treated with different doses of essential oil of Acori Tatarinowii Rhizoma, and then the cell viability and apoptosis were examined by the CCK-8 assay and flow cytometry, respectively. The levels of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), and interleukin-18(IL-18) were measured by ELISA. The mRNA levels of nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing protein 3(NLRP3), apoptosis-associated speck-like protein containing CARD(ASC), and cysteine proteinase-1(caspase-1) were determined by qRT-PCR. The immunofluorescence assay was used to detect the expression of ionized calcium-binding adapter molecule 1(Iba-1) and NLRP3. Western blot was employed to determine the protein levels of B lymphocytoma-2(Bcl-2), Bcl-2 associated X protein(Bax), Iba-1, κB-inhibitor kinase beta(IKKβ), p-IKKβ(Y188), nuclear factor-κB p65(NF-κB p65), p-NF-κB(S536), NLRP3, ASC, caspase-1, cleaved caspase-1, gasdermin D(GSDMD), and GSDMD-N. The results showed that 8, 16, and 32 μg·mL~(-1) essential oil of Acori Tatarinowii Rhizoma increased the viability, increased the expression of Bcl-2/Bax, and reduced the apoptosis of the cells exposed to LPS and nigericin sodium salt. In addition, the essential oil inhibited the expression of Iba-1, lowered the levels of TNF-α, IL-1β, and IL-18, and down-regulated the mRNA levels of NLRP3, ASC, and caspase-1 as well as the protein levels of NLRP3, ASC, caspase-1, p-IKKβ(Y188)/IKKβ, p-NF-κB(S536)/NF-κB p65, cleaved caspase-1, and GSDMD-N. The results indicated that the essential oil of Acori Tatarinowii Rhizoma inhibited the NLRP3 inflammasome-mediated pyroptosis of microglia.
Keywords: NLRP3; essential oil of Acori Tatarinowii Rhizoma; microglia; neuroinflammation; pyroptosis.