β-Sitosterol Alleviates Neuropathic Pain by Affect Microglia Polarization through Inhibiting TLR4/NF-κB Signaling Pathway

The active ingredient β-sitosterol in the anti-inflammatory agents alleviates perianal inflammation in rats by inhibiting the expression of Srebf2, activating the PPAR signaling pathway, and altering the composition of gut microbiota

BACKGROUND

Anti-inflammatory herbal formulations are common in traditional Chinese medicine for clearing heat and detoxifying; however, the specific active components and their mechanisms remain unclear.

OBJECTIVE

This study investigates the role of Sitosterol in alleviating perianal inflammation and its underlying mechanisms.

METHODS

Sitosterol was identified as a key active ingredient through the TCMSP database. Its structure was analyzed using PubChem, target genes were explored with STITCH, and KEGG pathways related to Srebf2 were revealed by STRING. An animal model of perianal inflammation was induced with 75 % acetic acid and treated with Sitosterol, water, normal saline, or antibiotics. The effects on gut microbiota were assessed using 16S rRNA sequencing, and inflammation was evaluated through HE stains, IHC, and TUNEL assays. In vitro, LPS-treated Caco-2 cells were used to measure proliferation, apoptosis, and cytokine levels, with PPAR pathway involvement examined using GW6471.

RESULTS

Sitosterol emerged as the primary active ingredient targeting Srebf2, with KEGG analysis highlighting the PPAR signaling pathway. In rats, Sitosterol reduced weight loss, inflammatory cell infiltration, edema, and vasodilation in perianal tissue. Additionally, it decreased PCNA levels, increased apoptosis, and elevated serum levels of IL-1β, IL-6, and TNF-α, particularly at high doses compared to antibiotics. Sitosterol also restored gut microbiota. Srebf2 knockdown improved tissue conditions and modulated cytokine levels, effects that were countered by GW6471. In LPS-treated Caco-2 cells, Sitosterol reversed reductions in cell viability and proliferation and modulated the expression of proteins and cytokines.

CONCLUSION

Sitosterol restores gut microbiota composition and further alleviates perianal inflammation in rats by inhibiting Srebf2 expression and activating the PPAR signaling pathway.

β-Sitosterol Mitigates Apoptosis, Oxidative Stress and Inflammatory Response by Inactivating TLR4/NF-кB Pathway in Cell Models of Diabetic Nephropathy

Podocyte injury plays a pivotal role in the pathogenesis of diabetic nephropathy (DN), leading to proteinuria formation. β-Sitosterol is a natural compound with anti-inflammatory, anti-diabetic, nephroprotective and antioxidant properties. The studyaimed to explore whether and how β-Sitosterol protected podocytes against high glucose (HG)-induced inflammatory andoxidative injury. DN cell models were established by stimulating podocytes or renal tubular epithelial cells (HK-2) cells with 25 mM glucose. Cell viability and apoptosis were evaluated using cell counting kit-8 assays and flow cytometry analyses. Westernblotting was used to quantify protein levels of genes related to podocyte injury, HK-2 cell damage, inflammation, and TLR4/NF-кB pathway. Contents of oxidative stress biomarkers were evaluated by corresponding commercial kits while proinflammatorycytokine levels were determined by enzyme-linked immunosorbent assay. Immunofluorescence staining was performed todetect intracellular levels of reactive oxygen species (ROS) and Nrf2 nuclear translocation. Experimental results revealed that HG treatment induced podocyte dysfunction by impairing cell viability while accelerating theapoptosis, and the changes were reversed by β-sitosterol treatment. Moreover, β-sitosterol repressed HG-evoked oxidative stressby reducing ROS and malondialdehyde (MDA) levels while increasing activities of antioxidant enzymes. The reduction ofproinflammatory cytokines mediated by β-sitosterol in HG-stimulated podocytes suggested the anti-inflammatory role of β-sitosterol. Additionally, the activation of the TLR4/NF-кB signaling induced by HG was inhibited by β-sitosterol in podocytes.Inactivation of the TLR4 using TAK-242 enhanced the protective effects of β-sitosterol against HG-mediated oxidative stressand inflammation. Similarly, β-sitosterol also protected HK-2 cells from HG-induced oxidative stress, inflammation, andapoptosis. In summary, β-sitosterol exerts anti-inflammatory, anti-oxidative, and anti-apoptotic activities in HG-induced podocytes or HK-2 cells by inhibiting TLR4/NF-кB signaling.

Haloxylon salicornicum Phytochemicals Suppress NF-κB, iNOS and Pro-Inflammatory Cytokines in Lipopolysaccharide-Induced Macrophages

Haloxylon salicornicum is traditionally used for the treatment of several disorders associated with inflammation. Despite it is a defense response against tissue injury and infections, inflammation can become a chronic condition that can negatively impact the body. This study investigated the effect of H. salicornicum phytochemicals nuclear factor-kappaB (NF-κB), inducible nitric oxide synthase (iNOS) and cytokines release by lipopolysaccharide (LPS)-challenged macrophages in vitro. The binding affinity of the tested phytochemical towards NF-κB and iNOS was investigated using molecular docking. Ten compounds (four coumarins, three sterols and three flavonoids) were isolated from the ethanolic extract of H. salicornicum. Treatment of LPS-challenged macrophages with the compounds resulted in remarkable decrease in NF-κB p65 and iNOS mRNA abundance. All compounds suppressed the production of nitric oxide (NO) and the pro-inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-6) from macrophages challenged with LPS. Molecular docking revealed the ability of the isolated phytochemicals to bind NF-κB p65 and iNOS. In conclusion, H. salicornicum is a rich source of phytochemicals with anti-inflammatory properties. The anti-inflammatory efficacy of H. salicornicum phytoconstituents is mediated via their ability to modulate NF-κB and iNOS, and suppress the release of NO, TNF-α, and IL-6 from macrophages.

Network Pharmacology Suggests Mechanisms for Therapeutic Effects of Caulis Sinomenii on Avian Gout

Avian gout (AG) is detrimental to the survival and production performance of poultry and effective drugs are lacking. Caulis sinomenii has shown clinical efficacy against arthritis and may have potential value in AG prevention and treatment. In the present study, the components and targets of C. sinomenii and AG-related targets were identified using relevant databases. The common targets, target interactions, and signaling pathways involved in the prevention and treatment of AG by C. sinomenii were determined using software to explore the potential mechanisms of action. Sixteen components of C. sinomenii, eight of which were active ingredients with 351 targets and 2993 AG-related targets, were identified using several databases. A total of 156 common targets were associated with 202 biological processes and 34 pathways. Toll-like receptor 4 (TLR4) and prostaglandin endoperoxide synthase 2 were core targets. These targets may exert therapeutic effects on AG through four pathways: the nucleotide-binding oligomerization domain (NOD)-like receptor, mammalian target of rapamycin, TLR, and mitogen-activated protein kinase signaling pathways. In summary, C. sinomenii has potential therapeutic efficacy against AG through multicomponent, multi-target, and multi-pathway mechanisms.

Pharmacological Effects of Paeonia lactiflora Focusing on Painful Diabetic Neuropathy

Painful diabetic neuropathy (PDN) is a highly prevalent complication in patients suffering from diabetes mellitus. Given the inadequate pain-relieving effect of current therapies for PDN, there is a high unmet medical need for specialized therapeutic options. In traditional Chinese medicine (TCM), various herbal formulations have been implemented for centuries to relieve pain, and one commonly used plant in this context is Paeonia lactiflora (P. lactiflora). Here, we summarize the chemical constituents of P. lactiflora including their pharmacological mechanisms-of-action and discuss potential benefits for the treatment of PDN. For this, in silico data, as well as preclinical and clinical studies, were critically reviewed and comprehensively compiled. Our findings reveal that P. lactiflora and its individual constituents exhibit a variety of pharmacological properties relevant for PDN, including antinociceptive, anti-inflammatory, antioxidant, and antiapoptotic activities. Through this multifaceted and complex combination of various pharmacological effects, relevant hallmarks of PDN are specifically addressed, suggesting that P. lactiflora may represent a promising source for novel therapeutic approaches for PDN.

TLR4 induced TRPM2 mediated neuropathic pain

Ion channels play an important role in mediating pain through signal transduction, regulation, and control of responses, particularly in neuropathic pain. Transient receptor potential channel superfamily plays an important role in cation permeability and cellular signaling. Transient receptor potential channel Melastatin 2 (TRPM2) subfamily regulates Ca2+ concentration in response to various chemicals and signals from the surrounding environment. TRPM2 has a role in several physiological functions such as cellular osmosis, temperature sensing, cellular proliferation, as well as the manifestation of many disease processes such as pain process, cancer, apoptosis, endothelial dysfunction, angiogenesis, renal and lung fibrosis, and cerebral ischemic stroke. Toll-like Receptor 4 (TLR4) is a critical initiator of the immune response to inflammatory stimuli, particularly those triggered by Lipopolysaccharide (LPS). It activates downstream pathways leading to the production of oxidative molecules and inflammatory cytokines, which are modulated by basal and store-operated calcium ion signaling. The cytokine production and release cause an imbalance of antioxidant enzymes and redox potential in the Endoplasmic Reticulum and mitochondria due to oxidative stress, which results from TLR-4 activation and consequently induces the production of inflammatory cytokines in neuronal cells, exacerbating the pain process. Very few studies have reported the role of TRPM2 and its association with Toll-like receptors in the context of neuropathic pain. However, the molecular mechanism underlying the interaction between TRPM2 and TLR-4 and the quantum of impact in acute and chronic neuropathic pain remains unclear. Understanding the link between TLR-4 and TRPM2 will provide more insights into pain regulation mechanisms for the development of new therapeutic molecules to address neuropathic pain.

Exploring the molecular mechanism of Xuebifang in the treatment of diabetic peripheral neuropathy based on bioinformatics and network pharmacology

Background

Xuebifang (XBF), a potent Chinese herbal formula, has been employed in managing diabetic peripheral neuropathy (DPN). Nevertheless, the precise mechanism of its action remains enigmatic.

Purpose

The primary objective of this investigation is to employ a bioinformatics-driven approach combined with network pharmacology to comprehensively explore the therapeutic mechanism of XBF in the context of DPN.

Study design and Methods

The active chemicals and their respective targets of XBF were sourced from the TCMSP and BATMAN databases. Differentially expressed genes (DEGs) related to DPN were obtained from the GEO database. The targets associated with DPN were compiled from the OMIM, GeneCards, and DrugBank databases. The analysis of GO, KEGG pathway enrichment, as well as immuno-infiltration analysis, was conducted using the R language. The investigation focused on the distribution of therapeutic targets of XBF within human organs or cells. Subsequently, molecular docking was employed to evaluate the interactions between potential targets and active compounds of XBF concerning the treatment of DPN.

Results

The study successfully identified a total of 122 active compounds and 272 targets associated with XBF. 5 core targets of XBF for DPN were discovered by building PPI network. According to GO and KEGG pathway enrichment analysis, the mechanisms of XBF for DPN could be related to inflammation, immune regulation, and pivotal signalling pathways such as the TNF, TLR, CLR, and NOD-like receptor signalling pathways. These findings were further supported by immune infiltration analysis and localization of immune organs and cells. Moreover, the molecular docking simulations demonstrated a strong binding affinity between the active chemicals and the carefully selected targets.

Conclusion

In summary, this study proposes a novel treatment model for XBF in DPN, and it also offers a new perspective for exploring the principles of traditional Chinese medicine (TCM) in the clinical management of DPN.