Ferulic acid alleviates sciatica by inhibiting neuroinflammation and promoting nerve repair via the TLR4/NF-κB pathway.

INTRODUCTION: Sciatica causes intense pain. No satisfactory therapeutic drugs exist to treat sciatica. This study aimed to probe the potential mechanism of ferulic acid in sciatica treatment. METHODS: Thirty-two SD rats were randomly divided into 4 groups: sham operation, chronic constriction injury (CCI), mecobalamin, and ferulic acid. We conducted RNA sequencing, behavioral tests, ELISA, PCR, western blotting, and immunofluorescence analysis. TAK-242 and JSH23 were administered to RSC96 and GMI-R1 cells to explore whether ferulic acid can inhibit apoptosis and alleviate inflammation. RESULTS: RNA sequencing showed that TLR4/NF-κB pathway is involved in the mechanism of sciatica. CCI induced cold and mechanical hyperalgesia; destroyed the sciatic nerve structure; increased IL-1ß, IL-6, TNF-α, IL-8, and TGF-ß protein levels and IL-1ß, IL-6, TNF-α, TGF-ß, TLR4, and IBA-1 mRNA levels; and decreased IL-10 and INF-γ protein levels and IL-4 mRNA levels. Immunohistochemistry showed that IBA-1, CD32, IL-1ß, iNOS, nNOS, COX2, and TLR4 expression was increased while S100ß and Arg-1 decreased. CCI increased TLR4, IBA-1, IL-1ß, iNOS, Myd88, p-NF-κB, and p-p38MAPK protein levels. Treatment with mecobalamin and ferulic acid reversed these trends. Lipopolysaccharide (LPS) induced RSC96 cell apoptosis by reducing Bcl-2 and Bcl-xl protein and mRNA levels and increasing Bax and Bad mRNA and IL-1ß, TLR4, Myd88, p-NF-κB, and p-p38MAPK protein levels, while ferulic acid inhibited cell apoptosis by decreasing IL-1ß, TLR4, Myd88, p-NF-κB, and p-p38MAPK levels and increasing Bcl-2 and Bcl-xl levels. In GMI-R1 cells, Ferulic acid attenuated LPS-induced M1 polarization by decreasing the M1 polarization markers IL-1ß, IL-6, iNOS, and CD32 and increasing the M2 polarization markers CD206, IL-4, IL-10 and Arg-1. After LPS treatment, IL-1ß, iNOS, TLR4, Myd88, p-p38MAPK, and p-NF-κB levels were obviously increased, and Arg-1 expression was reduced, while ferulic acid reversed these changes. CONCLUSION: Ferulic acid can promote injured sciatic nerve repair by reducing neuronal cell apoptosis and inflammatory infiltration though the TLR4/NF-κB pathway.

Protective effect of paeoniflorin on H2O2 induced Schwann cells injury based on network pharmacology and experimental validation.

This study was to investigate the protective effect of paeoniflorin (PF) on hydrogen peroxide-induced injury. Firstly, "SMILES" of PF was searched in Pubchem and further was used for reverse molecular docking in Swiss Target Prediction database to obtain potential targets. Injury-related molecules were obtained from GeenCards database, and the predicted targets of PF for injury treatment were selected by Wayne diagram. For mechanism analysis, the protein-protein interactions were constructed by String, and the KEGG analysis was conducted in Webgestalt. Then, cell viability and cytotoxicity assay were established by CCK8 assay. Also, the experimental cells were allocated to control, model (200 µmol·L-1 H2O2), SB203580 10 µmol·L-1 (200 µmol·L-1 H2O2+ SB203580 10 µmol·L-1), PF 50 µmol·L-1 (200 µmol·L-1 H2O2+ PF 50 µmol·L-1), and PF 100 µmol·L-1 (200 µmol·L-1 H2O2+ PF 100 µmol·L-1) groups. We measured the intracellular ROS, Hoechst 33258 staining, cell apoptosis, the levels of Bcl-xl, Bcl-2, Caspase-3, Cleaved-caspase3, Cleaved-caspase7, TRPA1, TRPV1, and the phosphorylation expression of p38MAPK. There are 96 potential targets that may be associated with PF for injury treatment. Then, we chose the "Inflammatory mediator regulation of TRP channels" pathway for the experimental verification from the first 10 KEGG pathway. In experimental verification, H2O2 decreased the cell viability moderately (P < 0.05), and 100 µmol·L -1 PF increased the cell viability significantly (P < 0.05). Depending on the difference of intracellular ROS fluorescence intensity, PF inhibited H 2O2-induced reactive oxygen species production in Schwann cells. In Hoechst 33258 staining, PF reversed the condensed chromatin and apoptotic nuclei following H2O2 treatment. Moreover, Flow cytometry results showed that PF could substantially inhibit H2O2 induced apoptosis (P < 0.05). Pretreatment with PF obviously reduced the levels of Caspase3, Cleaved-caspase3, Cleaved-caspase7, TRPA1, TRPV1, and the phosphorylation expression of p38MAPK after H 2O2 treatment (P < 0.05), increased the levels of Bcl-2, and Bcl-xl ( P < 0.05). PF inhibited Schwann cell injury and apoptosis induced by hydrogen peroxide, which mechanism was linked to the inhibition of phosphorylation of p38MAPK.

[Similarities and differences between Ginkgo biloba and Panax notoginseng in treatment of ischemic cerebrovascular disease].

Ginkgo biloba and Panax notoginseng are both herb medicines for cerebrovascular disease, and play an active role in treating ischemic cerebrovascular disease(ICVD). Their mechanisms of action include antioxidant stress, nerve protection, vascular protection. According to the comparative study of literatures, G. biloba has a certain protective effect from the early stage of free radical formation throughout the whole process of causing cell inflammation and apoptosis in antioxidant stress; while P. notoginseng has mainly anti-inflammatory, anti-apoptosis effects. In the nerve protection and repair of nerve damage caused by glutamate, both could promote neurogenesis, repair damaged axons and protect nerve cells. In addition, G. biloba could also relieve neurotoxicity caused by glutamate damage, while P. notoginseng have a unique effect in repairing blood-brain barrier(BBB) and blood vessel regeneration. In clinic, they are used as auxiliary drugs in combination with thrombolytic therapy, and play curative effects in alleviating inflammation, eliminating edema, improving the cure rate and the prognosis. For cerebral diseases caused by chronic cerebral hypoperfusion, G. biloba could reduce inflammation and improve cognition. In addition, G. biloba could protect neurocyte by adjusting the secretion of dopamine in vivo, and has a certain effect on antidepressant diseases, which however needs further studies.