Modulating effects of Astragalus polysaccharide on immune disorders via gut microbiota and the TLR4/NF-κB pathway in rats with syndrome of dampness stagnancy due to spleen deficiency

The syndrome of dampness stagnancy due to spleen deficiency(DSSD)is relatively common globally.Although the pathogenesis of DSSD remains unclear,evidence has suggested that the gut microbiota might play a significant role.Radix Astragali,used as both medicine and food,exerts the effects of tonifying spleen and qi.Astragalus polysaccharide(APS)comprises a macromolecule substance extracted from the dried root of Radix Astragali,which has many pharmacological functions.However,whether APS mitigates the immune disorders underlying the DSSD syndrome via regulating gut microbiota and the relevant mechanism remains unknown.Here,we used DSSD rats induced by high-fat and low-protein(HFLP)diet plus exhaustive swimming,and found that APS of moderate molecular weight increased the body weight gain and immune organ indexes,decreased the levels of interleukin-1β(IL-1β),IL-6,and endotoxin,and suppressed the Toll-like receptor 4/nuclear factor-κB(TLR4/NF-κB)pathway.Moreover,a total of 27 critical genera were significantly enriched according to the linear discriminant analysis effect size(LEfSe).APS increased the diversity of the gut microbiota and changed its composition,such as reducing the relative abundance of Pseudoflavonifractor and Paraprevotella,and increasing that of Parasutterella,Parabacteroides,Clostridium XIVb,Oscillibacter,Butyricicoccus,and Dorea.APS also elevated the contents of short-chain fatty acids(SCFAs).Furthermore,the correlation analysis indicated that 12 critical bacteria were related to the body weight gain and immune organ indexes.In general,our study demonstrated that APS ameliorated the immune disorders in DSSD rats via modulating their gut microbiota,especially for some bacteria involving immune and inflammatory response and SCFA production,as well as the TLR4/NF-κB pathway.This study provides an insight into the function of APS as a unique potential prebiotic through exerting systemic activities in treating DSSD.

Therapeutic Effect of Crocin on Diabetic Retinopathy in Rats Based on TLR4/My D88/NF-κB Pathway

Objective:To study the therapeutic effect of crocin on diabetic retinopathy(DR)in rats based on toll-like receptor 4(TLR4)/myeloid differentiation factor 88(My D88)/nuclear factor-κB(NF-κB)pathway.Methods:Thirty SPF SD rats were used in the experiment,which were randomly divided into DR group,control group and crocin group,with 10 rats in each group.The DR rat model was established by feeding the rats in both the DR group and crocin group with a high glucose and high fat diet,along with intraperitoneal injection(IP)of streptozotocin.Crocin IP was administered to the rats in the crocin group,whereas the rats in the DR group and control group received an equivalent dosage of saline IP for 12 weeks.A comparison was made among the three groups regarding retinal thickness,vascular permeability,expression of TLR4/My D88/NF-κB pathway protein,levels of inflammatory factors,and levels of Bcl-2,Bax,and Bcl-2/Bax.Results:The DR group and crocins group exhibited a lower retinal thickness compared to the control group,while the crocins group displayed a higher thickness than the DR group.The DR group and crocins group had higher retinal vascular permeability than the control group,and the crocins group had lower retinal vascular permeability than the DR group(P<0.05).TLR4,My D88,and P-NF-κB relative expressions were higher in the DR and crocin groups than in the control group,whereas TLR4,My D88,and P-NF-κB relative expressions were lower in the crocin group than in the DR group(P<0.05).The DR group and crocin group exhibited elevated levels of inflammatory cytokines compared to the control group,while the crocin group displayed decreased levels in comparison to the DR group(P<0.05).The DR group and crocin group exhibited lower levels of Bcl-2 and Bcl-2/Bax compared to the control group,whereas the control group displayed higher levels of Bax.The crocin group exhibited elevated levels of Bcl-2 and Bcl-2/Bax compared to the DR group,whereas the DR group displayed diminished levels of Bax(P<0.05).Conclusion:Crocin has the potential to enhance the retinal thickness and vascular permeability of DR rats,and the inhibition of the TLR4/My D88/NF-κB pathway by crocin could play a crucial role in impeding the advancement of DR.

Catalpol ameliorates LPS-induced endometritis by inhibiting inflammation and TLR4/NF-κB signaling

Catalpol is the main active ingredient of an extract from Radix rehmanniae,which in a previous study showed a protective effect against various types of tissue injury.However,a protective effect of catalpol on uterine inflammation has not been reported.In this study,to investigate the protective mechanism of catalpol on lipopolysaccharide(LPS)-induced bovine endometrial epithelial cells(bEECs)and mouse endometritis,in vitro and in vivo inflammation models were established.The Toll-like receptor 4(TLR4)/nuclear factor-κB(NF-κB)signaling pathway and its downstream inflammatory factors were detected by enzyme-linked immunosorbent assay(ELISA),quantitative real-time polymerase chain reaction(qRT-PCR),western blot(WB),and immunofluorescence techniques.The results from ELISA and qRT-PCR showed that catalpol dose-dependently reduced the expression of pro-inflammatory cytokines such as tumor necrosis factorα(TNF-α),interleukin(IL)-1β,and IL-6,and chemokines such as C-X-C motif chemokine ligand 8(CXCL8)and CXCL5,both in bEECs and in uterine tissue.From the experimental results of WB,qRT-PCR,and immunofluorescence,the expression of TLR4 and the phosphorylation of NF-κB p65 were markedly inhibited by catalpol compared with the LPS group.The inflammatory damage to the mouse uterus caused by LPS was greatly reduced and was accompanied by a decline in myeloperoxidase(MPO)activity.The results of this study suggest that catalpol can exert an anti-inflammatory impact on LPS-induced bEECs and mouse endometritis by inhibiting inflammation and activation of the TLR4/NF-κB signaling pathway.

蠲痹历节清方对改良痛风性关节模型大鼠滑膜的TLR4,NF-κB,PPARγ的影响

目的：观察蠲痹历节清方对改良痛风性关节炎大鼠滑膜组织中Toll样受体4（Toll-like receptors 4,TLR4）,核转录因子kappa B（nuclear factor-kappa B,NF-κB）,过氧化物酶体增殖物激活受体γ（peroxisome proliferator-activated receptorγ,PPARγ）的影响,探讨蠲痹历节清方治疗急性痛风性关节炎局部组织炎症的可能作用机制。方法：将42只SD雄性大鼠,按随机数字表法选取6只为正常组,30只为造模组,造模组采用改良痛风性关节炎造模后随机分为模型组,蠲痹历节清方高、中、低剂量组（4 400,2 200,1 100 mg·kg^-1）,依托考昔组（11 mg·kg^-1）,吡格列酮组（20 mg·kg^-1）,每组6只。正常组及模型组的大鼠以生理盐水灌胃20 mL·kg^-1。每组每只大鼠每日灌胃给药2次,连续2 d后处死大鼠,取受试右踝关节,分离出滑膜组织,分为两部分,一部分用于病理形态学观察,一部分用逆转录聚合酶链式反应（RT-PCR）检测TLR4,NF-κB p65,PPARγmRNA的表达水平,蛋白质免疫印迹法（Western blot）检测TLR4,NF-κB p65,PPARγ蛋白表达水平。结果：与正常组比较,模型组中TLR4和NF-κB mRNA和蛋白表达显著升高（P〈0.01）,PPARγmRNA和蛋白表达升高（P〈0.05）;与模型组比较,吡格列酮组及蠲痹历节清方高、中、低剂量组TLR4和NF-κB mRNA和蛋白的表达显著降低（P〈0.01）,PPARγmRNA和蛋白的表达显著升高（P〈0.05）。结论：蠲痹历节清方可能通过上调PPARγ表达,抑制TLR4,NF-κB表达从而抑制急性痛风性关节炎局部组织炎症。