Objective:To observe the inhibitory effects of proanthocyanidin on activation of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)inflammasome and phosphorylation of nuclear factor(NF)-κBp65 induced by lipopolysaccharide(LPS)and adenine nucleoside triphosphate(ATP)in mouse microglia(BV2). Methods:BV2 cells were stimulated with 1.0 μg/mL LPS and 2.5 μmol/L ATP,and treated with different concentrations of proanthocyanidin(0.1,1.0,2.5,5.0 μg/mL). Cell viability was determined by thiazolyl blue tetrazolium bromide(MTT)assay. Nitric oxide(NO)release was detected by colorimetry. The activity of lactate dehydrogenase(LDH)was measured by microenzyme labeling method. The secretion of interleukin(IL)-1β and IL-18 were determined by ELISA. Expression of NLRP3,apoptosis-associated speck-like protein containing a CARD(ASC),caspase-1,pro-caspase-1,p-NF-κBp65,NF-κBp65 were detected by Western blot. Results:The effect of different concentrations of proanthocyanidin on the survival rate of BV2 cells was not statistically significant compared with the control group(P > 0.05). Compared with the control group,LPS/ATP increased the secretions of NO,IL-1β,IL-18 and LDH activity(P < 0.05),and the expressions of NLRP3,ASC,pro-caspase-1,caspase-1,p-NF-κBp65(P < 0.05). Compared with the LPS/ATP group,proanthocyanidin reduced the secretions of NO,IL-1β,IL-18 and LDH activity of BV2 cells(P < 0.05). In addition,proanthocyanidin(1.0,2.5,5.0 μg/mL) decreased the expressions of NLRP3,ASC,pro-caspase-1 and caspase-1(P < 0.05). Similarly,NF-κB inhibitor BAY11-7082(5.0 μmol/L)reduced NF-κBp65 phosphorylation and the expressions of NLRP3,ASC,pro-caspase-1,and caspase-1(P < 0.05). Conclusion:Proanthocyanidin can inhibit secretion of inflammatory factor and activation of NLRP3 inflammasome induced by LPS/ATP,which is closely related to the inhibition of phosphorylation of NF-κBp65 by proanthocyanidin in LPS/ATP induced status.