Study On The Basis Of Effective Substance And Underlying Mechanisms Of Schisandra Chinensis Furit Extract For Anti-acne

Acne is a common chronic skin disease,and anti-acne cosmetics are very popular which are widely used for acne prevention and treatment.Natural anti-acne additives have a broad market prospect as they have remarkable therapeutic effects with high safety.In China,plant resources are quite rich.However,only a few natural plant additives are known and added in anti-acne cosmetics so far.Therefore,it is important to set up a stable and efficient system for additive screen plant additives with high efficiency and low toxicity.Meanwhile,a better understanding of anti-acne mechanism for the natural plant extracts will benefit the further acne cosmetic application in industry.In this study,I established an in vitro anti-P.acnes and acne-associated inflammation model,and I successfully screened the potential anti-acne additive Schisandra chinensis furit extract(SFE)using this model.Schisandrin A,B and C(Sch A,B and C)were identified as the main functional components of SFE according to the qualitative and quantitative evaluation of SFE anti-inflammatory activity.The anti-inflammatory and anti-acne mechanisms of Sch A,B and C were studied in this project,including the effects on TLR2 mediated MAPK/NF-κB inflammatory pathway and caspase-1 dependent pyroptosis.These results provide theoretical evidence for the potential application of Sch A,B and C as the anti-acne cosmetic additives.In order to screen the additives for anti-inflammation and anti-acne cosmetics,P.acnes and co-culture of P.acnes and THP-1 cells(the ratio of P.acnes and THP-1 cell number was 100:1)were used as the anti-bacterial and anti-inflammation model,respectively.The anti-bacterial effects of plant extracts were determined using microdilution broth method.ELISA was used to examine the pro-inflammatory cytokine levels in P.aces-induced THP-1 cells pretreated with plant extracts.The results showed that SFE had prominent anti-acne activity,with a MIC value of 500μg/mL and an IL-1β inhibitory rate of 81.00%at 50 μg/mL.Here,HPLC qualitative and quantitative analyses of SFE were carried out,and the material basis for anti-inflammatory and anti-acne effects was clarified.Schisandrin A,B and C,schisandrol A and B were identified as the main components,accounting for 5.45%of the total SFE.Schisandrin A,B,and C significantly inhibited the secretion of proinflammataory cytokine IL-1β and chemokine IL-8 used the acne-associated inflammation model.Specifically,the inhibition rate was higher than 85.0%and 60.0%for cytokine IL-1β and chemokine IL-8，respectively,when the concentration of SFE was 20 μM.Schisandrin A,B,and C were responsible for the anti-acne effect of SFE through comparing anti-inflammatory activity of the mixture of these three lignans with the total SFE.Effects of the main active components of SFE on TLR2-mediated MAPK/NF-κB signaling pathway induced by P.acnes were investigated.Immunofluorescence staining,quantitative real-time PCR and western blotting analyses showed that schisandrin A,B and C could decrease the protein and mRNA expression level of TLR2 in THP-1 cells.Also,the influence of schisandrins on the downstream MAPK signaling pathway was evaluated.Schisandrin A suppressed the P.acnes-induced phosphorylation of ERK and JNK,with little effects on p3 8 phosphorylation.Schisandrin B reduced the phosphorylation levels of ERK and p38 but not JNK.Schisandrin C simultaneously inhibited the phosphorylation levels of ERK,JNK and p38.Furthermore,all three lignans were able to inhibit the nuclear translocation of NF-κB in THP-1 cells.Molecular mechanisms of Sch A,B,and C on caspase-1 dependent pyroptosis were studied using several methods,e.g.flow cytometry analysis,chemiluminescence,western blotting,ELISA,DNA gel electrophiresis,immunofluorescence staining,quantitative real-time PCR,plasma-optiacl emission spectrometry.These analyses showed that Sch A,B and C could protect THP-1 cells from P.acnes infection.These three lignans can also maintain the cell membrane integrity through preventing non-gradient DNA fragmentation.Additionally,all three lignans inhibited the NLRP3 inflammasome activation via inhibiting mitochondria ROS production,ATP release and K+ efflux.Furthermore,Sch A,B,and C inhibited P.acnes induced caspase-1 dependent pyroptosis by reducing NLRP3 amount,caspase-1 level and caspase-1 enzyme activity.This project discovered the functional components responsible for anti-acne activity in SFE,and molecular mechanism of Schisandra chinensis lignans against P.aches-related inflammation were described in vitro.Schisandrins reduced P.acnes-stimulated inflammatory response through regulation of the TLR2-mediated MAPK/NF-κB signaling pathway.In addition,schisandrins decreased the P.acnes-induced caspase-1 dependent pyroptosis by inhibiting the activation of NLRP3 inflammasome.Thus,schisandrins can be the candidate additives for anti-acne cosmetics.