Effect Of Dendrobium Nobile Lindl Alkaloids On The Phenotype Of Microglial Induced By Aβ_1-42

Objective: To observe the effect of dendrobium nobilis Lindl alkaloids(DNLA)on the transformation of M1 and M2 phenotypes in microglia cells by BV2 cell model.Methods: Using BV2 cells as the experimental carrier,MTT method was used to observe whether DNLA and Aβ1-42 had toxic effects on the microglia cells.To screen the optimal concentrations and times of Aβ1-42 stimulating microglia cells by MTT method were used for subsequent experiments.The expression levels of the inflammatory factor TNF-α and anti-inflammatory factor IL-10 secreted by microglia cells were detected by ELISA,and the expression levels of M1-phenotype marker CD86 and M2-phenotype marker Arg-1 in microglia cells were detected by western blotting(WB).The experiment was divided into five groups: control group,model group(1μM Aβ1-42),DNLA low,medium and high concentration group(0.0035μg/m L DNLA+1 μM Aβ1-42;0.035 μg/m L DNLA+1 μM Aβ1-42;0.035 μg/m L DNLA+1 μM Aβ1-42).Results: The results showed that compared with the control group,(0.0035 μg/m L、0.035 μg/m L、0.035 μg/m L)DNLA had no toxic effect on microglia(P>0.05).When BV2 cells were incubated with(1 μM、2.5 μM、5 μM)Aβ1-42 for 4 h and 8h incubated with 1μM Aβ1-42,1μM Aβ1-42 and 2.5 μM Aβ1-42 incubated 4 h,no significant damage was found in BV2 cells(P>0.05),while incubated with 1μM Aβ1-42,2.5 μM Aβ1-42 and 5μM Aβ1-42 for 8 h,all showed significant damage to BV2cells(P<0.05).Pre-administration of DNLA for 24 h can alleviate the injury induced by 1μM Aβ1-42 stimulation of BV2 cells(P<0.05).1μM Aβ1-42 can induce the increase of the content of inflammatory factor TNF-α and the expression of M1-phenotype marker CD86(P<0.05).DNLA at 0.0035 μg/m L significantly inhibited TNF-α release induced by 1 μM Aβ1-42 and the expression of M1-phenotype marker CD86(P<0.05).However,the reduction in the content of the anti-inflammatory factor IL-10 induced by 1μM Aβ1-42 can be effectively alleviated by 0.0035 μg/m L DNLA,and DNLA increases the expression of the M2-phenotype marker Arg-1 in a concentration-dependent manner.Conclusion:DNLA inhibited the increase of the inflammatory factor TNF-α release d by Aβ1-42-activated microglia and the M1 phenotype marker CD86,suggesting that D NLA inhibited the activation of the M1 phenotype of microglia.DNLA promoted the increased expression of anti-inflammatory factor IL-10 and the M2 phenotype marker Arg-1,suggesting that DNLA induced the M2 phenotype activation of microglia cells.