Pharmacodynamic Evaluation And Mechanism Of Tragaloside IV In The Treatment Of Parkinson's Disee

ObjectiveParkinson's disee(PD) is the second largest aging-associated neurodegenerative disease after Alzheimer's disee(AD),and various comprehensive factors contribute to the development of PD.The exact pathological mechanism has not yet been fully elucidated.At present,there is no ideal treatment for PD.The first-line anti-PD drug L-dopa can only relieve the motion symptoms of PD,but it can not delay the pathological process of PD,and long-term application will also lead to a series of side effects and even aggravate the disease process.Therefore,it is particularly important to elucidate the pathological mechanism of PD and find therapeutic drugs that can effectively alleviate the course of PD.Astragaloside IV has been shown to have significant antiinflammatory,anti-oxidative and other pharmacological effects.Recent studies have shown that NLRP3 inflammasome and Nrf2 play an important role in the pathogenesis of PD,studies have also confirmed that Nrf2 can negatively regulate the level of NLRP3.In this study,we explored the neuroprotective effect of astragaloside IV on NLRP3 inflammatory mediator-mediated neuroinflammation and Nrf2 as the entry point on the MPTP-induced PD animal models,then,we further explored the possible mechanism of Astragaloside IV in the LPS-induced BV2 microglia cell model.MethodsC57BL/6 mice with MPTP injection intraperitoneally(MPTP 18 mg/kg,i.p,4 times/day,2 h/d intervals)to establish an acute MPTP injury model in mice.One week before model establishment,different doses of(10 mg,40 mg/Kg/d)AS were given to the treatment group by oral gavage orally or by gavage.The rotarod test was performed on the 1st,3rd,and 5th days after MPTP injection,and the Y-maze test was used on the 6th day after MPTP injection to examine the mice's motor coordination and balance ability.The gavage treatment was continued during the behavioral experiment.After completion of the behavioral studies,the mesencephalon and striatum of the mice were isolated and later biochemical indicators were examined.The basic morphology of the dopaminergic neurons in the substantia nigra pars compacta was observed by Nissl staining;the expression of TH positive cells in the substantia nigra pars compacta and microglial activation were observed by immunofluorescence staining;the TH protein in the midbrain area was detected by Western blotting.NLRP3 inflammasome-associated proteins(NLRP3,Caspase-1,Pro-Caspase-1,ASC,pro-IL-1?,Il-1?)and inflammatory nuclear transcription factor NF-?B levels.The kit was used to measure the levels of SOD,GSH and GSHpx in the serum.In vivo,LPS-induced BV2 microglial cells were used to simulate microglial activation,and 10 ?mol/L and 40 ?mol/L of AS were used for drug intervention.Western blotting was used to detect the levels of NLRP3 inflammatory correlative protein(NLRP3,Caspase-1,proCaspase-1,pro-IL-1?,and Il-1?),inflammatory nuclear transcription factor NF-?B and Nrf2 levels.NF-?B levels and Nrf2 levels were observed by immunofluorescence staining.Reults1.AS can significantly improve the dysfunction of MPTP model mice and reduce MPTP-induced damage of dopaminergic neurons in the substantia nigra pars compacta;2.AS significantly inhibited MPTP-induced microglial hypersensitivity in the substantia nigra pars compacta.3.AS significantly inhibited the activation of NLRP3 inflammasome in BV2 microglial cells induced by MPTP model mice and decreased LPS-induced increase in NF-?B levels in vivo and in vitro.4.AS can significantly increase the antioxidation ability of MPTP model mice,and increase the Nrf2 level both in vivo and in vitro.ConclusionAS has a significant protective effect on MPTP-induced PD animal models of dopamine neurons,and its mechanism may be related to its inhibition of NLRP3 inflammatory mediator-mediated neuroinflammation and increased Nrf2 antioxidation.