Naringenin Produces Neuroprotection Against LPS Induced Dopamine Neurotoxicity Via The Inhibition Of Microglial NLRP3 Inflammasome Activation

Objective: To research the effect of naringenin(NAR)on LPS induced dopaminergic neurons damage and its potential mechanism.Methods: Rats were randomly divided into the following five groups(n=6): Control,NAR alone(100 mg/kg),Model(LPS 5 μg),LPS+NAR(50 mg/kg)and LPS+NAR(100 mg/kg).Rats were received a single LPS unilateral injection into the SN pars compacts,after seven daily intragastric administration of NAR,rats’ behavior was analyzed by Rotarod test.Then,the expression of TH,IBA-1,NLRP3 and caspase-1 were analyzed by Western Blot and Immunofluorescence.In vitro experiments,BV-2 cells were treated with different doses of NAR,and 1 hour later,LPS(1 μg/ml)was added to the medium for 24 h,then collect the culture medium and protein for later experiments.The production of IL-1β and IL-18 in culture medium were tested by ELISA,and the production of NO was detected by Griess reagent.The expression of IBA-1,NLRP3 and caspase-1 were detected by Western Blot.MN9 D cells were cocultured with BV2 cells to mimic the animal experiments.MTT assay was used to analyze the viability of MN9 D cells,and the expression of TH was detected by Western Blot.Results: Compared with model group,NAR(100 mg/kg)could significantly improve motor activity.The result of the pathological analysis also suggested that NAR could decrease the activation of microglia as well as the expression of NLRP3 Inflammasome.In addition,NAR also could suppress the expression of pro-inflammatory factor levels,such as IL-1β,IL-18 and NO,and the protection of NAR could be inhibited by siRNA NLRP3.Moreover,the co-cultures system with BV2 and MN9 D cells was used to find the protection of NAR must via microglia,while there is no effect of NAR were directly added to MN9 D cells.Conclusion: In this study,NAR could produces neuroprotection against LPS induced dopamine neurotoxicity via the inhibition of microglial NLRP3 inflammasome activation.