Anti-inflammatory effect of Mongolian drug Naru-3 on traumatic spinal cord injury and its mechanism of action

The mechanism of Traditional Mongolian medicine Daruqi particles on inflammation

Daruqi is a Traditional Mongolian medicine with anti-inflammatory, anti-bacterial, and immune-regulatory effects. However, the mechanisms of its activity were unclear. In the present study, we confirmed the anti-inflammation effect of Daruqi on inflammation induced by LPS using animal models. Then, THP-1 cells treated with LPS was used as a positive control to explore the effective component of Daruqi on inflammation. We identified that Oxymatrine was the essential effector of Daruqi. Furthermore, the mechanism of Oxymatrine on inflammation was verified through proteomics analyses and validation assays. Our results demonstrated that Oxymatrine significantly reduced the levels of inflammatory cytokine, including IL-8, IL-1α, and IL-1β, in LPS induced THP-1 cells. Based on tandem mass tag -labeled quantitative proteomics, 428 differentially expressed proteins were screened, involved in TNF signaling pathway, Ferroptosis, IL-17 signaling pathway, etc. Among these differential expressed proteins (DEPs), 23 proteins were verified with parallel reaction monitoring analysis. The results showed that LPS treatment potentiated the protein level of PLEK, ACSL5 and CYBB, which could be reversed by Oxymatrine. By contrast, the protein expression of SPRYD4 and EMR2 was suppressed after LPS treatment, which could be rescued by Oxymatrine. In summary, Oxymatrine has excellent protective effects in LPS induced THP-1 cells. The five proteins, including PLEK, ACSL5, CYBB, SPRYD4 and EMR2, might serve as the targets of Oxymatrine, and as candidates regulating inflammation in future therapies.

Naru-3 inhibits inflammation, synovial hyperplasia, and neovascularization in collagen-induced arthritis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Naru-3 is a prescribed formulation based on the theory of Mongolian medicine for the treatment of rheumatoid arthritis (RA). Naru-3 consists of three medicinal agents: Aconitum kusnezoffii Reichb (caowu), Terminalia chebula Retz (hezi), and Piper longum L (biba). These medicinal agents are widely distributed in the Mongolian area of China and have been used to treat rheumatism for centuries.

BACKGROUND

Mongolian medicine Naru-3 is commonly prescribed to treat RA, but its mechanism of action is unknown.

METHODS

A rat collagen-induced arthritis (CIA) model was established to investigate the mechanism of Naru-3. Rats were treated with Naru-3, Etanercept (ETN), and sodium carboxymethylcellulose (CMC) for four weeks. After treatment was terminated, paw thickness, ankle diameter, and arthritis index (AI) were scored. Synovial hyperplasia was evaluated using hematoxylin and eosin (H&E) staining and two-dimensional ultrasonography. Synovitis and neovascularization were assayed using power Doppler imaging (PDI) and contrast-enhanced ultrasonography (CEUS). Levels of vascular endothelial growth factor (VEGF), interleukin (IL)-1, and CD31 in the serum or synovium were detected using ELISA and immunohistochemistry analyses.

RESULTS

Naru-3 and ETN alleviated the symptoms of CIA as evidenced by diminished paw thickness, ankle diameter, and AI scores. Mechanistically, Naru-3 inhibited synovial hyperplasia, synovitis, and neovascularization by diminishing systemic and local inflammation, as indicated by the relative expression of CD31, VEGF and IL-1 in the serumor synovium. After four weeks of treatment, no significant neovascularization was observed in the Naru-3 group, but neovascularization and synovitis occurred in the ETN group, as demonstrated by H&E staining, PDI, and CEUS examination.

CONCLUSION

Naru-3 inhibited inflammation, synovial hyperplasia, and neovascularization and alleviates RA in our CIA rat model. No symptom recurrence was observed four weeks after drug treatment.

Piperine treating sciatica through regulating inflammation and MiR-520a/P65 pathway

Although the etiology of sciatica remains uncertain, there is increasing evidence that the disease process of sciatica is associated with the levels of inflammatory factors. Piperine, an alkaloid isolated from Piper nigrum, has previously been demonstrated to inhibit inflammation and analgesic effects. The purpose of this study is to verify the regulatory relationship between miR-520a and p65 and to explore how miR-520a/P65 affects the level of cytokines under the action of piperine, so as to play a therapeutic role in sciatica. Through ELISA experiment, we confirmed that four inflammatory factors (IL-1β, TNF-α, IL-10, TGF-β1) can be used as evaluation indexes of sciatica. The differentially expressed miRNA was screened as miR-520a, by microarray technology, and the downstream target of miR-520a was P65 by bioinformatics. Real-time fluorescence quantitative PCR confirmed that the expression of miR-520a was negatively correlated with pro-inflammatory cytokines, positively correlated with anti-inflammatory cytokines and negatively correlated with p65 expression at mRNA level. The expression of p65 was positively correlated with pro-inflammatory cytokines and negatively correlated with anti-inflammatory cytokines at the protein level verified by ELISA and Western blot. HE staining analysis showed that the nerve fibers were repaired by piprine, the vacuoles were significantly reduced, and the degree of nerve fiber damage was also improved. Immunohistochemical analysis showed that the expression of p65 decreased after administration of piperine. Dual-luciferase reporter gene assay confirmed that the luciferase signal decreased significantly after cotransfection of miR-520a mimics and p65 3'UTR recombinant plasmid. To sum up, in the rat model of non-compressed lumbar disc herniation, piperine plays a significant role in analgesia. MiR-520a can specifically and directly target P65, and piperine can promote the expression of miR-520a, then inhibit the expression of p65, down-regulate the pro-inflammatory factors IL-1β and TNF-α, and up-regulate the effects of anti-inflammatory factors IL-10 and TGF-β1, so as to treat sciatica.

Neonatal Rats Exhibit a Predominantly Anti-Inflammatory Response following Spinal Cord Injury

It has been reported that children may respond better than adults to a spinal cord injury (SCI) of similar severity. There are known biomechanical differences in the developing spinal cord that may contribute to this "infant lesion effect," but the underlying mechanisms are unknown. Using immunohistochemistry, we have previously demonstrated a different injury progression and immune cell response after a mild thoracic contusion SCI in infant rats, as compared to adult rats. Here, we investigated the acute inflammatory responses using flow cytometry and ELISA at 1 h, 24 h, and 1 week after SCI in neonatal (P7) and adult (9 weeks) rats, and locomotor recovery was examined for 6 weeks after injury. Adult rats exhibited a pronounced pro-inflammatory response characterized by neutrophils and M1-like macrophage infiltration and Th1 cytokine secretion. Neonatal rats exhibited a decreased pro-inflammatory response characterized by a higher proportion of M2-like macrophages and reduced Th1 cytokine responses, as compared to adults. These results suggest that the initial inflammatory response to SCI is predominantly anti-inflammatory in very young animals.

Interaction between piperine and genes associated with sciatica and its mechanism based on molecular docking technology and network pharmacology

Abstract

Piperine is the main active component of Piper longum L., which is also the main component of anti-sciatica Mongolian medicine Naru Sanwei pill. It has many pharmacological activities such as anti-inflammatory and immune regulation. This paper aims to preliminarily explore the potential mechanism of piperine in the treatment of sciatica through network pharmacology and molecular docking. TCMSP, ETCM database and literature mining were used to collect the active compounds of Piper longum L. Swiss TargetPrediction and SuperPred server were used to find the targets of compounds. At the same time, CTD database was used to collect the targets of sciatica. Then the above targets were compared and analyzed to select the targets of anti-sciatica in Piper longum L. The Go (gene ontology) annotation and KEGG pathway of the targets were enriched and analyzed by Metascape database platform. The molecular docking between the effective components and the targets was verified by Autodock. After that, the sciatica model of rats was established and treated with piperine. The expression level of inflammatory factors and proteins in the serum and tissues of rat sciatic nerve were detected by ELISA and Western blot. HE staining and immunohistochemistry were carried out on the sciatica tissues of rats. The results showed that Piper longum L. can regulate the development of sciatica and affect the expressions of PPARG and NF-kB1 through its active ingredient piperine, and there is endogenous interaction between PPARG and NF-kB1.

Graphic abstract

Antipruritic effects of electroacupuncture on morphine-induced pruritus model mice through the TLR2/4-MyD88-NF-κB pathway

Pruritus is one of the common side effects of intrathecal or epidural injection of opioids. The aim of this study was to test the antipruritic effect of acupuncture and its possible mechanism. We used electroacupuncture (EA), toll-like receptor (TLR)2/4 antagonist sparstolonin B (SsnB), and TLR2/4 agonist peptidoglycan (PGN) to precondition female wild-type BALB/c mice, and then prepared a morphine-induced pruritus model. The mRNA and protein expression levels of TLR2, TLR4, MyD88, and NF-κB were detected by RT-PCR and western blotting. The contents of interleukin (IL)-1, IL-6, IL-12, IL-10, and tumor necrosis factor-α in serum were measured by ELISA assays. Flow cytometry was performed to analyze the ratio of M1-phenotype to M2-phenotype macrophages. Our results showed that EA preconditioning improved pruritus; reduced the expressions of TLR2, TLR4, MyD88, and NF-κB both at the mRNA and protein levels (P<0.05); reduced the expression of proinflammatory cytokines IL-1, IL-6, IL-12, and tumor necrosis factor-α; and increased the expression of anti-inflammatory cytokine IL-10 (P<0.05). EA promoted M2-phenotype macrophage differentiation. Moreover, these results showed no significant difference between the SsnB group and the EA+SsnB group (P>0.05), but showed a significant difference between the PGN group and the EA+PGN group (P<0.05). Therefore, we propose that EA may be involved in the remission of pruritus in morphine-induced pruritus model mice through the TLR2/4-MyD88-NF-κB pathway. EA is a potential therapeutic treatment for pruritus.