| Objective: Salvia miltiorrhiza Bunge(Danshen),a widely used famous Chinese herb in clinical,has the traditional function of Huoxue Huayu.Modern investigations showed that tanshinones isolated from Danshen possess cardiovascular and cerebrovascular protective and anti-tumor effects.In this study,the protective effect and the underlying mechanisms of 15’,16’-dihydrotanshinone I(DHT)were studied in a dextran sulfate sodium(DSS)-induced experimental mouse model of ulcerative colitis(UC).Methods: Forty male C57BL/6J mice were randomly divided into four groups: control group(n = 8),model group(n = 12),DHT low dose group(10 mg / kg,n = 10),DHT high dose group(25 mg / kg,n = 10).The mice in the model group were given 1% Tween 80 three days by gavage,and the medication administration groups were given DHT in 1%Tween 80 three days by gavage.On the 4th day,the mice in the model group and medication administration group were given 5% DSS in drinking water for 7 consecutive days.The control group only received 1% Tween 80.Mice mental status,body weight changes,stool traits(loose stools,diarrhea,bloody stools)were observed and recorded daily,and the disease activity index(DAI)scores were calculated.Mice were killed on the8 th day and blood was collected to separate plasma,the colon was collected and measured.A small section of colon from each mouse was made paraffin-embedded sections and H&E staining was performed to investigate the pathological alterations.Immunohistochemistry was used to detect the expression of receptor interacting protein kinase 3(RIP3),cyclooxygenase-2(COX-2),inducible nitric oxide synthase(i NOS).The plasma levels of tumor necrosis factor(TNF-α),interleukin-1β(IL-1β),interleukin-6(IL-6)and high mobility group box 1 protein(HMGB1)and the content of myeloperoxidase(MPO)in colorectal mucosa were detected by enzyme linked immunosorbent assay(ELISA).Western blotting was used to detect the expression of receptor interacting protein kinase 1 (RIP1),RIP3,mixed lineage kinase domain-like(MLKL),cysteinyl aspartate specific proteinase(Caspase-8),COX-2,i NOS protein expression.Results: Compared with the control group,the body weight of the model group decreased from the 3rd to the 4th day and continued until the 7th day after DSS administration,and the DHT group improved.The length of the colon in the model group was significantly shortened,and in the DHT group increased compared with the model group.Mice in model group had diarrhea pus and bloody stools on day 4,which was significantly alleviated in DHT group.H & E staining showed that in the normal group,the colon tissues were normal without any pathological changes.In the model group,the structural integrity of the colon tissues of mice was destroyed with a large number of infiltration of inflammatory cells and even crypt abscesses and ulcers.The structures of colon in DHT group were significantly improved with decreased inflammatory cell infiltration and relatively normal structures.In addition,compared with the control group,the contents of MPO and HMGB1 in the model group were significantly increased and the levels in the DHT group were significantly decreased.The plasma levels of inflammatory cytokines TNF-α,IL-1β,IL-6 in the model group increased significantly,which were significantly decreased in DHT group.WB results showed that compared with the control group,the expression of RIP1,RIP3,MLKL,COX-2,i NOS was increased while the expression of Caspase-8 was decreased in the model group.DHT treatment partially reversed their expressions.Immunohistochemical staining showed that compared with the control group,the colon tissues of the model group showed strong brown staining,which suggested the increased expression of RIP3,COX-2 and i NOS and this increase was significantly inhibited by DHT.Conclusion: DHT can significantly improve the general state of DSS-induced ulcerative colitis in mice and reduce inflammation and pathological changes.The mechanism may be related to the reduction of inflammatory factors,inhibition of the expression of i NOS,COX-2,RIPs,and MLKL.This study provides experimental data support for revealing the pharmacodynamic material basis of traditional Chinese medicine Salvia miltiorrhiza. |
