Effects of Total Saponins from Dioscorea Nipponica Makino on Monosodium Urate-Induced M1-Polarized Macrophages through Arachidonic Acid Signaling Pathway: An in vitro Study / 中国结合医学杂志

OBJECTIVE@#To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino (TSDN) on the arachidonic acid pathway in monosodium urate (MSU) crystal-induced M1-polarized macrophages.@*METHODS@#M1 polarization of RAW264.7 cells were induced by 1 µ g/mL lipopolysaccharide (LPS). The methylthiazolyldiphenyl-tetrazolium bromide method was then used to screen the concentration of TSDN. MSU (500 µ g/mL) was used to induce the gouty arthritis model. Afterwards, 10 µ g/L TSDN and 8 µ mol/L celecoxib, which was used as a positive control, were added to the above LPS and MSU-induced cells for 24 h. The mRNA and protein expressions of cyclooxygenase (COX) 2, 5-lipoxygenase (5-LOX), microsomal prostaglandin E synthase derived eicosanoids (mPGES)-1, leukotriene B (LTB)4, cytochrome P450 (CYP) 4A, and prostaglandin E2 (PGE2) were tested by real-time polymerase chain reaction and Western blotting, respectively. The enzyme-linked immunosorbent assay was used to test the contents of M1 markers, including inducible nitric oxid synthase (NOS) 2, CD80, and CD86.@*RESULTS@#TSDN inhibited the proliferation of M1 macrophages and decreased both the mRNA and protein expressions of COX2, 5-LOX, CYP4A, LTB4, and PGE2 (P<0.01) while increased the mRNA and protein expression of mPGES-1 (P<0.05 or P<0.01). TSDN could also significantly decrease the contents of NOS2, CD80, and CD86 (P<0.01).@*CONCLUSION@#TSDN has an anti-inflammation effect on gouty arthritis in an in vitro model by regulating arachidonic acid signaling pathway.

Tetrahydropalmatine alleviated diabetic neuropathic pain by inhibiting activation of microglia via p38 MAPK signaling pathway / 中国中药杂志

Neuropathic pain is one of the common complications of diabetes. Tetrahydropalmatine(THP) is a main active component of Corydalis Rhizoma with excellent anti-inflammatory and pain-alleviating properties. This study aims to investigate the therapeutic effect of THP on diabetic neuropathic pain(DNP) and the underlying mechanism. High-fat and high-sugar diet(4 weeks) and streptozotocin(STZ, 35 mg·kg~(-1), single intraperitoneal injection) were employed to induce type-2 DNP in rats. Moreover, lipopolysaccharide(LPS) was used to induce the activation of BV2 microglia in vitro to establish an inflammatory cellular model. Fasting blood glucose(FBG) was measured by a blood glucose meter. Mechanical withdrawal threshold(MWT) was assessed with von Frey filaments, and thermal withdrawal latency(TWL) with hot plate apparatus. The protein expression levels of OX42, inducible nitric oxide synthase(iNOS), CD206, p38, and p-p38 were determined by Western blot, the fluorescence expression levels of OX42 and p-p38 in the dorsal horn of the rat spinal cord by immunofluorescence, the mRNA content of p38 and OX42 in rat spinal cord tissue by qRT-PCR, and levels of nitric oxide(NO), interleukin-1β(IL-1β), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), interleukin-10(IL-10), and serum fasting insulin(FINS) by enzyme-linked immunosorbent assay(ELISA). RESULTS:: showed that the mo-del group demonstrated significant decrease in MWT and TWL, with pain symptoms. THP significantly improved the MWT and TWL of DNP rats, inhibited the activation of microglia and p38 MAPK signaling pathway in rat spinal cord, and ameliorated its inflammatory response. Meanwhile, THP promoted the change of LPS-induced BV2 microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, suppressed the activation of the p38 MAPK signaling pathway, decreased the expression levels of inflammatory factors NO, IL-1β, IL-6, and TNF-α, and increased the expression level of anti-inflammatory factor IL-10. The findings suggested that THP can significantly ameliorate the pain symptoms of DNP rats possibly by inhibiting the inflammatory response caused by M1 polarization of microglia via the p38 MAPK pathway.

Mechanism of Total Saponins from Dioscoreae Nipponicae Rhizoma to Treat Gouty Arthritis by Regulating M1/M2 Polarization of Macrophages / 中国实验方剂学杂志

Objective:To illustrate the effect of M1/M2 polarization of macrophages on gouty arthritis models induced with monosodium urate and reveal the molecular mechanism of total saponins from Dioscoreae Nipponicae Rhizoma to treat gouty arthritis. Method:A total of 72 male SD rats were randomly divided into four groups： normal group， model group， total saponin group （160 mg·kg^-1）， celecoxib group （43.3 mg·kg^-1）， with 18 rats in each group. Gouty arthritis models were induced by injecting monosodium urate into ankle joints bilaterally. Histopathology changes of ankle joints were observed by hematoxylin-eosin（HE） staining. Immunohistochemistry method was used to detect the protein expression change of CD68， interleukin-4（IL-4）， inducible nitric oxide synthase （iNOS） and transforming growth factor-<italic>β</italic>₁（TGF-<italic>β</italic>₁）. Result:HE staining results showed that the inflammation of the model group was most obvious on the third day after modeling， and the disease was in the acute stage. On day 5， the inflammation was alleviated， and on day 8， the inflammation was still present but close to normal. The total saponin group and celecoxib group could improve the pathological changes of synovial tissue， and the effect of total saponin group was more obvious. Immunohistochemical results were as follows. Compared with the normal group. The expression of CD68 and iNOS in the model group increased on the 3rd，5th and 8th day of administration （<italic>P</italic><0.01）. Compared with the model group， the total saponins group could reduce the expression of CD68 and iNOS （<italic>P</italic><0.05，<italic>P</italic><0.01）on the 3rd day of administration， and significantly reduced them expression on the 5th and 8th days （<italic>P</italic><0.01）. Compared with the normal group， IL-4 and TGF-<italic>β</italic>₁ expression were increased in the model group when the drug was given for three days（<italic>P</italic><0.01）. Total saponin group could enhance IL-4 expression（<italic>P</italic><0.05）and decreased the TGF-<italic>β</italic>₁ expression（<italic>P</italic><0.01）. Compared with normal group， the expression of IL-4 in the model group decreased on the 5th and 8th day of administration （<italic>P</italic><0.01）， and the expression of TGF-<italic>β</italic>₁ in the model group decreased on the 5th day of administration（<italic>P</italic><0.01）. Compared with the model group， the total saponins group could increase the expression of IL-4 and TGF-<italic>β</italic>₁ at 5 d and 8 d after administration （<italic>P</italic><0.01）. Conclusion:Total saponins from Dioscoreae Nipponicae Rhizoma has the potential effect to treat gouty arthritis by regulating M1/M2 polarization.

Effect of leonurine on peritoneal macrophages M1/M2 phenotypic differentiation via inhibiting overactivation of NLRP3 inflammasome / 药学实践杂志

Objective To find the effect of leonurine on LPS-induced macrophages activation and its potential mechanism. Methods Mouse primary peritoneal macrophages were isolated and pretreated for 24 h with LPS and leonurine. MTT assay was used to detect the cell viability of macrophages. The production of IL-1β, IL-6, TNF-α and IL-18 in culture medium were tested by ELISA, and the production of NO was detected by Griess reagent. The mRNA expression of NLRP3, ASC, caspase-1, TNF-α, iNOS, Arg-1 and CD206 were detected by RT-PCR, and the protein expression of NLRP3, ASC and caspase-1 were detected by Western blotting. Results LPS can significantly increase the releases of NO、IL-1β、IL-6、TNF-α and IL-18 from macrophages. Leonurine can suppress the expression of pro-inflammatory factor levels, such as IL-1β (P<0.05), IL-18 (P<0.05), NO(P<0.05), IL-6(P<0.05) and TNF-α (P<0.05). Leonurine can decrease the activation of macrophage as well as the expression of NLRP3 Inflammasome.Protein expressions of NLRP3、ASC、caspase-1 were mitigated. Conclution Leonurine exerts beneficial effects through M1/M2 phenotypic differentiation of peritoneal macrophage via inhibiting overactivation of NLRP3 inflammasome. These findings suggest that leonurine might have a therapeutic potential for pelvic inflammatory disease.

Effect of Ermiaosan on M1/M2 Polarization of Bone Marrow Derived-macrophages / 中国实验方剂学杂志

Objective:To explore the effect of Ermiaosan（EMS） on the polarization of M1 by lipopolysaccharide（LPS）+interferon(IFN)-γ and M2 induced by interleukin(IL)-4+IL-13 in rat bone marrow-derived macrophages. Method:Macrophages from rat bone marrow were extracted in vitro, stimulated by macrophage colony stimulating factor(M-CSF), induced to macrophages (marked by F4/80), stimulated by LPS+IFN-γ and induced to polarize to M1，while stimulated by IL-4+IL-13 and induced to polarize to M2. After adding different concentrations of EMS (0.2，0.4，0.8 g·L-1), the phenotypes of M1 and M2 were detected by immunofluorescence, and the effect of EMS on M1(marked by CD68 and iNOS)/M2(marked by CD206 and Arginase) polarization of macrophages from rat bone marrow was detected. Result:Compared with control group, LPS + IFN-γ could increase the polarization of M1 (P<0.01)，while IL-4+IL-13 could increase the polarization of M2 (P<0.01); compared with LPS+IFN-γ/IL-4+IL-13 group, EMS (0.2，0.4，0.8 g·L-1) could inhibit the polarization of M1 induced by LPS+IFN -γ for 24 hours (P<0.05), but had no significant effect on polarization of M2 induced by IL-4+IL-13. Conclusion:EMS can inhibit M1 polarization induced by LPS+IFN - γ, but has no effect on M2 polarization induced by IL-4+IL-13.

S1P₁ Regulates M1/M2 Polarization toward Brain Injury after Transient Focal Cerebral Ischemia

M1/M2 polarization of immune cells including microglia has been well characterized. It mediates detrimental or beneficial roles in neuroinflammatory disorders including cerebral ischemia. We have previously found that sphingosine 1-phospate receptor subtype 1 (S1P₁) in post-ischemic brain following transient middle cerebral artery occlusion (tMCAO) can trigger microglial activation, leading to brain damage. Although the link between S1P₁ and microglial activation as a pathogenesis in cerebral ischemia had been clearly demonstrated, whether the pathogenic role of S1P₁ is associated with its regulation of M1/M2 polarization remains unclear. Thus, this study aimed to determine whether S1P₁ was associated with regulation of M1/M2 polarization in post-ischemic brain. Suppressing S1P₁ activity with its functional antagonist, AUY954 (5 mg/kg, p.o.), attenuated mRNA upregulation of M1 polarization markers in post-ischemic brain at 1 day and 3 days after tMCAO challenge. Similarly, suppressing S1P₁ activity with AUY954 administration inhibited M1-polarizatioin-relevant NF-κB activation in post-ischemic brain. Particularly, NF-κB activation was observed in activated microglia of post-ischemic brain and markedly attenuated by AUY954, indicating that M1 polarization through S1P₁ in post-ischemic brain mainly occurred in activated microglia. Suppressing S1P₁ activity with AUY954 also increased mRNA expression levels of M2 polarization markers in post-ischemic brain, further indicating that S1P₁ could also influence M2 polarization in post-ischemic brain. Finally, suppressing S1P₁ activity decreased phosphorylation of M1-relevant ERK1/2, p38, and JNK MAPKs, but increased phosphorylation of M2-relevant Akt, all of which were downstream pathways following S1P₁ activation. Overall, these results revealed S1P₁-regulated M1/M2 polarization toward brain damage as a pathogenesis of cerebral ischemia.