Molecular mechanisms of the analgesic action of Wu-tou Decoction on neuropathic pain in mice revealed using microarray and network analysis

Study on analgesic effect of Shentong Zhuyu Decoction in neuropathic pain rats by network pharmacology and RNA-Seq

ETHNOPHARMACOLOGICAL RELEVANCE

Shentong Zhuyu Decoction (STZYD) is a traditional prescription for promoting the flow of Qi and Blood which is often used in the treatment of low back and leg pain clinicall with unclear mechanism. Neuropathic pain (NP) is caused by disease or injury affecting the somatosensory system. LncRNAs may play a key role in NP by regulating the expression of pain-related genes through binding mRNAs or miRNAs sponge mechanisms.

AIM OF THE STUDY

To investigate the effect and potential mechanism of STZYD on neuropathic pain.

METHODS

Chronic constriction injury (CCI) rats, a commonly used animal model, were used in this study. The target of STZYD in NP was analyzed by network pharmacology, and the analgesic effect of STZYD in different doses (H-STZYD, M-STZYD, L-STZYD) on CCI rats was evaluated by Mechanical withdrawal thresholds (MWT) and thermal withdrawal latency (TWL). Meanwhile, RNA-seq assay was used to detect the changed mRNAs and lncRNAs in CCI rats after STZYD intervention. GO analysis, KEGG pathway analysis, and IPA analysis were used to find key target genes and pathways, verified by qPCR and Western Blot. The regulatory effect of lncRNAs on target genes was predicted by co-expression analysis and ceRNA network construction.

RESULTS

We found that STZYD can improve hyperalgesia in CCI rats, and H-STZYD has the best analgesic effect. The results of network pharmacological analysis showed that STZYD could play an analgesic role in CCI rats through the MAPK/ERK/c-FOS pathway. By mRNA-seq and lncRNA-seq, we found that STZYD could regulate the expression of Cnr1, Cacng5, Gucy1a3, Kitlg, Npy2r, and Grm8, and inhibited the phosphorylation level of ERK in the spinal cord of CCI rats. A total of 27 lncRNAs were associated with the target genes and 30 lncRNAs, 83 miRNAs and 5 mRNAs participated in the ceRNA network.

CONCLUSION

STZYD has the effect of improving hyperalgesia in CCI rats through the MAPK/ERK/c-FOS pathway, which is related to the regulation of lncRNAs to Cnr1 and other key targets.

Protective effect of Huangqi-Guizhi-Wuwutang against cyclophosphamide-induced spermatogenesis dysfunction in mice by promoting steroid hormone biosynthesis

ETHNOPHARMACOLOGICAL RELEVANCE

The primary adverse effect of cyclophosphamide (CTX) chemotherapy to cancer in male patients of reproductive age is a significant impairment of reproductive function. Huangqi-Guizhi-Wuwutang (HGW), a classical traditional Chinese medicine formula, is designed to exert a salutary effect on qi and promote blood circulation, thereby eliminating blood stasis and promoting spermatogenesis, and it has been recorded as a treatment for oligospermia. However, its potential in mitigating the adverse impact of CTX on male spermatogenesis remains unexplored.

AIM OF THE STUDY

The present investigation aims to elucidate the potential protective effects and underlying mechanisms of HGW against CTX - induced spermatogenic dysfunction in mice.

MATERIAL AND METHODS

C57BL/6J mice that received intraperitoneal injections of CTX were employed to induce dysfunction in spermatogenesis. Pharmacological experimentation was conducted to evaluate the potential effect of HGW in mitigating spermatogenic toxicity induced by CTX. Additionally, mRNA sequencing was utilized to identify genes exhibiting differential expression between the untreated and HGW treated groups, thereby elucidating the comprehensive underlying mechanisms involved. The most significantly enriched potential pathways were identified and subsequently validated in vivo.

RESULTS

The administration of HGW significantly increased the testicular index, epididymal index, sperm concentration and sperm motility in mice with spermatogenesis dysfunction. Furthermore, HGW effectively ameliorated the observed tissue damage in pathological sections of the testes, elevated serum levels of inhibin B (INH-B) and testosterone (T), while reduced levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) compared to the Model group. An analysis on the genes associated with HGW treatment for CTX-induced oligospermia revealed a significantly enhanced functional enrichment in steroid hormone biosynthesis signaling pathways. Experimental results demonstrated that HGW significantly enhanced cellular activity and T levels in TM3 cell injury model using phosphoramide mustard (PM, the active ingredient of CTX invivo) and upregulates protein expression of key enzymes involved in hormonal steroid synthesis within testicular tissues, including 3β-hydroxysteroid dehydrogenase (3β-HSD), steroidogenic acute regulatory protein (StAR), cytochrome P450 family 17 subfamily A member 1 (CYP17A1) and sytochrome P450 family 11 subfamily A member 1 (CYP11A1).

CONCLUSION

Our data has demonstrated the effectiveness of HGW in improving CTX-induced spermatogenic dysfunction by enhancing hormonal steroid synthesis in a model system, indicating the potential chemoprotective effects of HGW against CTX-induced spermatotoxicity.

Wutou decoction attenuates the synovial inflammation of collagen-induced arthritis rats via regulating macrophage M1/M2 type polarization

ETHNOPHARMACOLOGICAL RELEVANCE

Thousands of years of clinical practice in the treatment of joint-related diseases support the efficacy and safety of Wutou decoction (WTD). Nevertheless, the lack of pharmacological evidence and unclear mechanisms make it difficult for WTD to become a recognized complementary therapy for the treatment of rheumatoid arthritis (RA).

AIM OF THE STUDY

This study aimed to investigate the effect of WTD against synovial inflammation in RA and whether this effect depends on the regulation of macrophage polarization.

MATERIALS AND METHODS

Sprague-Dawley rats were used to establish the collagen-induced arthritis (CIA) model. WTD with low and high doses was administered for 45 days. RAW264.7 cells were stimulated by lipopolysaccharide (LPS) or interleukin (IL)-4 to polarize M1 and M2 macrophages, which were pre-treated with WTD extract for 4 h. The anti-arthritic and anti-inflammatory effects of WTD were studied using arthritis score, histopathological staining, immunostaining, and enzyme-linked immunosorbent assay (ELISA). The polarization state of RAW264.7 cells and related pro/anti-inflammatory cytokines was detected by ELISA, reverse transcription quantitative polymerase chain reaction and western blotting. Western blotting and immunofluorescence were used to investigate the effect of WTD on nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and peroxisome proliferator-activated receptors γ (PPARγ) activation both in vivo and in vitro.

RESULTS

WTD significantly reduced the arthritis score and the pathological damage of the knee joint and decreased the expression of tumor necrosis factor alpha (TNF-α), IL-6 in serum, TNF-α, IL-1β, monocyte chemoattractant protein-1 (MCP-1), and matrix metalloproteinase-3 (MMP3) in the knee synovium. WTD inhibited M1 type polarization and promoted M2 type polarization, both in vitro and in vivo, and reduced the expression of pro-inflammatory cytokines while increasing the expression of anti-inflammatory cytokines. Experiments showed that WTD inhibited the phosphorylation of NF-κB and downstream p38 in the synovium of CIA rats and LPS-induced M1 type polarized RAW264.7 cells. In addition, PPARγ expression in the synovium of CIA rats was mainly located in the cytoplasm, and WTD treatment increased the nuclear translocation of PPARγ, which was further verified in RAW264.7 cells.

CONCLUSIONS

NF-κB and PPARγ regulating M1 and M2 macrophage polarization and subsequent secretion of pro-inflammatory and anti-inflammatory cytokines are the underlying mechanisms of WTD that ameliorate RA synovial inflammation.

An exploratory study on the mechanism of Huangqi Guizhi Wuwu Decoction in the treatment of neuropathic pain

Huangqi Guizhi Wuwu Decoction (HGWD) has a definite effect on neuropathic pain (NP), whereas the specific mechanism has not been elucidated. The components and targets in HGWD were collected and identified through System Pharmacology Database (Traditional Chinese Medicine Database and Analysis Platform). Genecards and Online Mendelian Inheritance in Man databases were used to search for NP-related genes. The Venn diagram was drawn to get the intersection target. Cytoscape 3.8.0 software was used to construct the compound-disease-target-pathway networks. STRING database was applied to analyze protein-protein interaction of potential targets. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were used to identify the function of genes related to NP. Finally, molecular docking was performed to visualize the binding mode and affinity between proteins and active ingredients. According to the intersection target of the Venn diagram, the network graph is constructed by Cytoscape and the results show the five compounds, β-sitosterol, (+)-catechin, quercetin, Stigmasterol, kaempferol, and 15 genes (CASP3, FOS, GSK3B, HSP90AA1, IKBKB, IL6, MAPK8, RELA, ICAM1, SELE, ELK1, HSPB1, PRKACA, PRKCA, RAF1) were highly correlated with NP. KEGG and GO of 15 genes results that TNF, IL-17 and MAPK signaling pathway were Significantly related to the pathological mechanism of NP. Molecular docking showed that core genes in this network were IL-6 (TNF and IL-17 signaling pathways), ICAM1 (TNF signaling pathway), and CASP3 (three signal pathways). This study found that the five active compounds, three core genes, and three signaling pathways may be the key to the treatment of NP by HGWD.

A comprehensive strategy to clarify the pharmacodynamic constituents and mechanism of Wu-tou decoction based on the constituents migrating to blood and their in vivo process under pathological state

ETHNOPHARMACOLOGICAL RELEVANCE

As a traditional Chinese medicine (TCM) formula, Wu-tou decoction has been used for treating rheumatoid arthritis (RA) for more than a thousand years. Identifying pharmacodynamic constituents (PCs) of WTD and exploring their in vivo process are very meaningful for promoting the modernization of TCM. However, the pathological state might change this process.

AIM OF THE STUDY

Hence, it is necessary and significant to compare the process in vivo of drugs both in normal and disease state and clarify their action mechanism.

MATERIALS AND METHODS

Taking Wu-tou decoction (WTD) as the research object, a comprehensive strategy based on liquid chromatography coupled with mass spectrometry (LC-MS) was developed to identify PCs, clarify and compare their absorption and distribution in normal and model rats, and then explore the potential mechanism of TCM. Firstly, the PCs in WTD were identified. Then, the pharmacokinetics (PK) and tissue distribution of these ingredients were studied. Finally, the constituents with the difference between normal and model rats were selected for target network pharmacological analysis to clarify the mechanism.

RESULTS

A total of 27 PCs of WTD were identified. The absorption and distribution of 20 PCs were successfully analyzed. In the disease state, the absorption and distribution of all these components were improved to have better treatment effects. The results of target network pharmacological analysis indicated that PTGS1, PTGS2, ABCB1, SLC6A4, CHRM2, ESR1, ESR2, CDK2, TNF and IL-6 are 10 key targets for WTD against RA. The regulatory effects of WTD on the expression of PTGS2 and TNF were further verified. Pathway enrichment analysis showed that the key mechanism of WTD against RA is to reduce inflammation and regulate the immune response.

CONCLUSION

These results indicated that this strategy could better understand the in vivo process and mechanism of WTD under the pathological state. Furthermore, this strategy is also appropriate for other TCM.

Compounds of traditional Chinese medicine and neuropathic pain

Neuropathic pain (NP) has become a serious global health issue and a huge clinical challenge without available effective treatment. P2 receptors family is involved in pain transmission and represents a promising target for pharmacological intervention. Traditional Chinese medicine (TCM) contains multiple components which are effective in targeting different pathological mechanisms involved in NP. Different from traditional analgesics, which target a single pathway, TCMs take the advantage of multiple components and multiple targets, and can significantly improve the efficacy of treatment and contribute to the prediction of the risks of NP. Compounds of TCM acting at nucleotide P2 receptors in neurons and glial cells could be considered as a potential research direction for moderating neuropathic pain. This review summarized the recently published data and highlighted several TCMs that relieved NP by acting at P2 receptors.

A novel view of the problem of Osteoarthritis in experimental rat model

Introduction: The article presents the results of the functional tests to improve the assessment of MIA-induced osteoarthritis development and the effectiveness of NSAID therapy.

Materials and methods: In the study, 26 male SD rats were used. MIA-induced osteoarthritis was simulated in the right knee joint. After an intra-articular injection of MIA, the animals were treated with ibuprofen and meloxicam. Pain assessment was studied in the following functional tests: incapacitance (hind limb weight bearing) test, von Frey test (mechanical allodynia), grip strength test, and knee diameter measurement. At the end of the study, a histological analysis of the knee joint was performed.

Results and discussion: An intra-articular MIA injection reduced 1.5 times the paw withdrawal threshold. In the rats that suffered MIA-induced osteoarthritis, the difference between the diameters of the intact and injected joints was 1.05 mm, compared to 0.03 mm difference in the control group. Hind limb weight bearing asymmetry was 89.5% when simulating MIA-induced osteoarthritis. The muscular hind limb grip strength in rats with MIA-induced osteoarthritis was significantly reduced on 3rd and 7th days after simulating osteoarthritis. Ibuprofen and meloxicam showed significant efficacy in all the above tests, although ibuprofen effectiveness was more pronounced than that of meloxicam.

Conclusion: The following functional tests were identified as the most significant and sufficient to assess the development of MIA-induced osteoarthritis and analgesic efficacy of NSAIDs: incapacitance test, allodynia test (von Frey filaments), measurement of hind limb grip strength and measurement of the diameter of the inflamed knee joint. The histological analysis made it possible to confirm the correspondence of the physiological response and pathological changes in the knee joint.

Exploring and characterizing a novel combination of paeoniflorin and talatizidine for the treatment of rheumatoid arthritis

Wutou Decoction (WTD) achieves favorable therapeutic response in treating rheumatoid arthritis (RA), especially for wind-cold-dampness stimulating RA. However, its material basis and molecular mechanisms remain unclear. To address this problem, the main bioactive compounds (BACs) of WTD against RA and the candidate targets were identified in the current study via transcriptional regulatory network analysis, computational structure-based methods, as well as in vivo and in vitro experimental validations. As a result, we successfully established a RA rat model named AIA-S, which simulated the clinical manifestations and pathological changes of wind-cold-dampness stimulating RA, and also displayed the distinctive characteristics and biological basis of inflammatory-immune system imbalance and abnormal energy metabolism changes. In addition, ALOX15B-PPAR-γ-PTGS2-FGF2-IL-1β-c-JUN-MMP13-TGF-β1 signal axis, involved into thermogenesis and energy metabolism, as well as maintaining the balance of inflammation-immune system, was identified as a candidate target of WTD against RA, according to the transcriptional regulatory network analysis on "RA-related gene-WTD-effective gene interaction network". Moreover, Paeoniflorin (PAE) and Talatizidine (TLT) were demonstrated to be the main BACs of WTD against RA for the following reasons: firstly, both PAE and TLT were the BACs of WTD according to ADME analysis in silico and the pharmacokinetics analysis in vivo. Secondly, both PAE and TLT were able to bind with PPAR-γ, c-JUN, MMP13 and TGF-β1, which were the candidate targets of WTD against RA, with the strong binding affinity. Thirdly, the PAE and TLT combination exerted significant therapeutic effects on AIA-S rats through reversing the imbalance of inflammatory-immune system, and the disturbance of thermogenesis and energy metabolism, which were similar to WTD. More importantly, the administration of TLT or PAE alone didn't exert as prominently therapeutic effects as that of the two-BAC-combination did. Fourthly, the PAE and TLT combination promoted adipogenesis and lipogenesis by upregulating the PPAR-γ-induced lipogenic proteins. In conclusion, this study identified PAE and TLT as the main BACs of WTD in alleviating the severity of RA, and also developed a novel combination of PAE and TLT as a promising candidate drug for RA therapy.

Antineuropathic pain actions of Wu-tou decoction resulted from the increase of neurotrophic factor and decrease of CCR5 expression in primary rat glial cells

Wu-tou decoction (WTD), a classic Traditional Chinese medicine formula, has been extensively used in the treatment of neuropathic pain (NP) such as chronic inflammatory pain, trigeminal neuralgia, and cancer-induced pain. Our previous studies have shown that the severity of mechanical allodynia and thermo hypersensitivity in NP rats are reduced by WTD, of which analgesic candidates are paeoniflorin (Pae) and liquiritin (Liq). The aim of this study was to clarify the molecular mechanisms of WTD, Pae and Liq against NP based on the primary rat glial cells in vitro. The gene expression levels of neurotrophic factors such as nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and Artemin and C-C chemokine receptor type 5 (CCR5) were augmented by inflammatory cytokines, while chemokines increased only CCR5 gene expression. The constitutive and cytokine-augmented neurotrophic factor gene expression was enhanced by WTD, Pae, and Liq through PI3K- and PKA-dependent pathways in rat glial cells, leading to the increase of NGF and BDNF production. Furthermore, the CCR5 gene expression under basal and chemokine-treated conditions was suppressed by these reagents, in which signal pathway(s) was independent on the activation of PI3K and PKA. Moreover, there was no cytotoxicity in the WTD, Pae, and Liq treatments in glial cells. Thus, these results provide a novel evidence that WTD may exert the anti-NP actions by predominantly increasing the production of neurotrophic factors through PI3K- and PKA-signaling pathways in rat glial cells. Furthermore, Pae and Liq may play as analgesic candidates in WTD-mediated NP management.

Functional roles of lncRNAs and its potential mechanisms in neuropathic pain

Neuropathic pain (NP) is ranked as one of the major forms of chronic pain and emerges as a direct consequence of a lesion or disease affecting the somatosensory nervous system. Despite great advances into the mechanisms of NP, clinical practice is still not satisfactory. Fortunately, progress in elucidating unique features and multiple molecular mechanisms of long non-coding RNAs (lncRNAs) in NP has emerged in the past 10 years, suggesting that novel therapeutic strategies for pain treatment may be proposed. In this review, we will concentrate on recent studies associated with lncRNAs in NP. First, we will describe the alterations of lncRNA expression after spinal cord injury (SCI) and peripheral nerve injury (PNI), and then we illustrate the role of some specific lncRNAs in detail, which may offer new insights into our understanding of the etiology and pathophysiology of NP. Finally, we put special emphasis on the altered expression of lncRNAs in the diverse biological process of NP. Recent advances we summarized above in the development of NP may facilitate translation of these findings from bench to bedside in the future.

The Chinese Medicine Wu-Tou Decoction Relieves Neuropathic Pain by Inhibiting Hippocampal Microglia Activation

The comorbidity between the nociceptive and mental syndromes adds to the refractoriness of neuropathic pain (NP). Wu-Tou decoction (WTD) has been prescribed for chronic pain for thousands of years in China. Recently, we reported that WTD was helpful for hippocampus and co-curative for the nociceptive, depressive and anxiety behaviors in the spinal cord ligation (SNL) mice. However, the mechanism underlying the rescue of hippocampus, as well as the roles hippocampus assumed in co-curation remain unexplored. In this study, we validated that in SNL mice, the long-lasting damages to limbic system were mainly limited to hippocampus. In addition, hippocampal neurons were proven sensitive to harms induced by microglia and rescued by WTD, which in sum indicated hippocampal microglia as the critical modulator of co-curation. To validate this hypothesis the hippocampal microglia were mal-activated in shamed mice, in which the atrophy of hippocampus and the development of NP syndromes were consolidated and proven rescued by WTD. On the contrary, in the SNL mice, the failure to control hippocampal microglia was sufficient to void all the rescues mediated by WTD. In sum, our study points out that the effective modulation of microglia in hippocampus is of pivotal importance for the co-curation by WTD.