Chrysin Is Immunomodulatory and Anti-Inflammatory against Complete Freund's Adjuvant-Induced Arthritis in a Pre-Clinical Rodent Model

Inhibition of DNA polymerase eta-mediated translesion DNA synthesis with small molecule sensitises ovarian cancer stem-like cells to chemotherapy

BACKGROUND AND PURPOSE

Chemoresistance and tumour relapse pose significant challenges in achieving successful chemotherapy outcomes. Targeting DNA polymerase eta (Pol ƞ)-mediated mutagenic translesion DNA synthesis (TLS) has emerged as a promising strategy for improving chemotherapy. However, the identification of small molecule inhibitors targeting Pol ƞ -mediated TLS with high in vivo efficacy remains a challenge.

EXPERIMENTAL APPROACH

The small molecule was identified through in silico screening. Pol η inhibitory potential of the identified small molecule was validated by a fluorescent-based reporter strand displacement assay. Flow cytometry was conducted to analyse the CD44 + CD117 + cancer stem-like cell (CSC) population and live-dead cell population. Xenograft mouse models were used to test the CSC sensitising potential.

KEY RESULTS

We screened and identified chrysin as a small-molecule inhibitor that sensitises ovarian cancer stem-like cells to cisplatin treatment by inhibiting Pol ƞ -mediated TLS. Chrysin effectively inhibits Pol ƞ expression, mitigates cancer stem-like cell enrichment and enhances cisplatin-induced cell death both in vitro and in vivo. Furthermore, chrysin treatment reduces spontaneous and cisplatin-induced mutagenesis. Pre-treatment with chrysin attenuates cisplatin-induced haematological toxicity and suppresses tumour growth in human ovarian cancer xenografts.

CONCLUSIONS AND IMPLICATIONS

These results establish chrysin as a novel class of TLS inhibitors and highlight its potential as a chemotherapy adjuvant for overcoming chemoresistance and improving treatment outcomes in ovarian cancer.

Chrysin ameliorates pain through regulation of the serum metabolomics in the rats

Background

Chrysin is a natural flavonoid that exhibits various pharmacological activities including pain relief. However, the effects of chrysin on changes of metabolic profiles during pain remain unclear. The aim of this study was to analyze the biomarkers related to pain in serum and to evaluate the analgesic properties of chrysin in a rat model of pain.

Methods

Male Wister rats were divided into four groups (n = 5). Pain was induced by injecting 50 μL of formalin into the hind paw. Chrysin and diclofenac (10 mg/kg, intraperitoneal injection) was administered to the intact and pain groups. All injections were given 30 minutes before pain induction. Immediately, the behavioral test was performed. Then the serum sample was separated for 1HNMR-based metabolite analysis.

Results

Chrysin treatment alleviated the paw licking events, flinching response, and pain score. The integrated analyses further revealed three major metabolic changes including glycine-serine-threonine, taurine-hypotaurine, and arginine by comparing the serums from intact operated rats, pain rats, and pain rats treated with chrysin, and suggested that chrysin may improve pain by regulating the biosynthesis of these metabolic pathways.

Conclusions

These findings provide insights into metabolic pathways involved in pain and the analgesic effects of chrysin and may help to identify potential targets for the anti-pain properties of chrysin.

Herbal Immunostimulants and Their Phytochemicals: Exploring Morinda citrifolia, Echinacea purpurea, and Phyllanthus niruri

The rising prevalence of infectious diseases and immune-related disorders underscores the need for effective and accessible therapeutic solutions. Herbal immunostimulants derived from medicinal plants offer promising alternatives, enhancing immune responses with lower toxicity and fewer side effects than synthetic drugs. This review explores the immunostimulatory potential of Morinda citrifolia, Echinacea purpurea, and Phyllanthus niruri, focusing on their bioactive compounds, mechanisms of action, and therapeutic relevance. These plants modulate innate and adaptive immune responses by activating macrophages, dendritic cells, and lymphocytes while regulating cytokine production to maintain immune homeostasis. Their immunomodulatory effects are linked to key signaling pathways, including NF-κB, MAPK, and JAK/STAT. In vitro and in vivo studies highlight their potential to strengthen immune responses and control inflammation, making them promising candidates for managing infectious and immune-related diseases. However, further research is needed to standardize formulations, determine optimal dosages, and validate safety and efficacy in clinical settings. Addressing these gaps will support the integration of herbal immunostimulants into evidence-based healthcare as sustainable and accessible immune-enhancing strategies.

Anticancer Activity of Ether Derivatives of Chrysin

Chrysin, a naturally occurring flavonoid, exhibits a broad spectrum of biological activities, including showing anticancer properties. However, its clinical application is limited by poor bioavailability and low solubility. The introduction of an amine, amide, ester, or alkoxy group to a flavone skeleton influences the biological activity. This review also discusses hybrid compounds, such as the chrysin-porphyrin hybrid, which are characterized by higher biological activity and better bioavailability properties than single molecules. This review concentrates on the anticancer activity of chrysin and its derivatives against the most popular cancers, such as breast, lung, prostate, and gastrointestinal tumors.

Peptide BG From Bitter Gourd (Momordica Charantia) Improves Adjuvant-Induced Arthritis by Modulating the Necroptosis/Neutrophil Extracellular Traps/Inflammation Axis and the Gut Microbiota

Background: BG is a novel bioactive peptide derived from bitter gourd (Momordica charantia), known for its anti-inflammatory and immunomodulatory properties. In the present study, our objective is to investigate the functional roles and mechanisms of BG in the context of rheumatoid arthritis (RA). Methods: A rat model of adjuvant-induced arthritis (AIA) was established by administering complete Freund's adjuvant (CFA). The viability of BG-mediated AIA was evaluated by assessing changes in rat body weight, joint swelling, ankle joint pathology, inflammation, necroptosis, the formation of neutrophil extracellular traps (NETs), and gut microbiota. Results: The results of the study showed that peptide BG was effective in improving weight loss, joint swelling, serum IgM-rheumatoid factor (IgM-RF) level, and pathological injury of ankle joint in rats with AIA. BG administration resulted in a decrease in erythrocyte sedimentation rate, serum C-reactive protein (CRP), and inflammatory factor (interferon-γ (IFN-γ), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α)) in AIA rats. Additionally, the administration of CFA resulted in an increase in the protein levels of myeloperoxidase (MPO), neutrophil elastase (NE), citrullinated histone H3 (CitH3), peptidyl arginine deiminase 4 (PAD4), p-mixed lineage kinase domain-like (p-MLKL), and cleaved caspase 8. However, this increase was found to be inhibited by BG treatment. Furthermore, it has been found that peptide BG possesses the capacity to regulate the species composition structure of the intestinal microbiota, thereby, facilitating the reestablishment of microbial diversity and equilibrium. Conclusion: Peptide BG has demonstrated efficacy in ameliorating AIA through its regulation of the necroptosis/NETs/inflammation axis and the gut microbiota. This finding underscores the potential of BG as a promising therapeutic intervention for RA.

Anti-arthritic effect of spirocyclopiperazinium bromide DXL-A-24 in CFA-induced arthritic rats and its mechanism

This study aimed to investigate the effect of spirocyclopiperazinium bromide DXL-A-24 on complete Freund's adjuvant (CFA)-induced arthritis and its underlying mechanism in rats. A rheumatoid arthritis model was established by the intradermal injection of CFA into the paws of rats. Mechanical withdrawal threshold (MWT), thermal withdrawal latency (TWL), ankle swelling and paw edema were used to evaluate the effects of DXL-A-24. Bone erosion and bone mineral density (BMD) were observed using micro-computed tomography. Receptor blocking test, western blotting, and enzyme-linked immunosorbent assay were performed to explore the mechanisms. Administration of DXL-A-24 (1, 0.5, 0.25 mg/kg, i.g.) dose-dependently increased the MWT and TWL, while alleviating ankle and paw swelling in CFA rats. The effects were blocked by peripheral α7 nicotinic or M4 muscarinic receptor antagonists. DXL-A-24 improved bone erosion and BMD, as well as downregulated the overexpression of Cav3.2, pJAK2, pSTAT3, pIκBα, pNF-κB p65, c-Fos and TNF-α proteins that were induced by CFA. In conclusion, this study shows, for the first time, that DXL-A-24 improves bone erosion and BMD and exhibits obvious anti-arthritic effects in CFA rats. The mechanism may be related to activating the peripheral α7 nicotinic and M4 muscarinic receptors, reducing Cav3.2 expression, and suppressing JAK2/STAT3 and IκBα/NF-κB p65 inflammatory signaling pathways, ultimately inhibiting inflammation-related proteins TNF-α and c-Fos.

Synthesis and biological evaluation of chrysin derivatives containing α-lipoic acid for the treatment of inflammatory bowel disease

This study introduces newly discovered chrysin derivatives that show potential as candidate molecules for treating inflammatory bowel disease (IBD). Compound 4b, among the synthesized compounds, displayed significant inhibitory effects on monocyte adhesion to colon epithelium induced by TNF-α, with an IC50 value of 4.71 μM. Further mechanistic studies demonstrated that 4b inhibits the production of reactive oxygen species (ROS) and downregulates the expression of ICAM-1 and MCP-1, key molecules involved in monocyte-epithelial adhesion, as well as the transcriptional activity of NF-κB. In vivo experiments have shown that compound 4b exhibits a dose-dependent inhibition of 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats, thereby validating its effectiveness as a colitis inhibitor in animal models. These results indicate that 4b shows considerable promise as a therapeutic agent for managing IBD.

Analysis of anti-rheumatic activity of Nyctanthes arbor-tristis via in vivo and pharmacovigilance approaches

Introduction: Rheumatoid arthritis (RA) is an immune-mediated disease associated with chronic inflammation of numerous joints. Nyctanthes arbor-tristis (NAT) is a traditional remedy for RA, a chronic inflammatory disorder. Aim: The current project aims to demonstrate the role of the NAT extracts in sub-acute toxicity, pharmacovigilance, and anti-rheumatic biomarkers. Method: Hydroethanolic extract (1:1) of plant leaves was prepared by using the reflux method. The safety of the dose was evaluated in Sprague-Dawley rats, and the anti-inflammatory effects of NAT on RA symptoms, including paw volumes, body weight, arthritic index, withdrawal latency, hematology and serological test, radiology, and histopathology, were evaluated in Freund's complete adjuvant (FCA)-induced arthritis Sprague-Dawley rat models. The inflammatory (TNF-α and COX-2) and anti-inflammatory markers (IL-10) were analyzed in control and experimental groups. Result: The study showed that 500 mg/kg BW NAT leaf extract was found to be least toxic without showing any subacute toxicity symptoms. The pharmacovigilance study highlighted the potential side effects of NAT, such as drowsiness, sedation, and lethargy, at high dosages. Treatment with the plant extract mitigated paw edema, restored the immune organ and body weights, and ameliorated the level of blood parameters such as hemoglobin, red blood cells, platelets, white blood cells, aspartate aminotransferase (AST), alanine transaminase (ALT), C-reactive proteins, and rheumatoid factor. Treatment with the plant extracts also reduced the level of cyclooxygenase 2 and TNF-α and increased the level of IL-10 in the serum of arthritic rats dose-dependently. Radiographic analysis of the ankle joint showed an improvement in the hind legs. Histological examination of the ankle joints revealed that the plant extract treatment decreased pannus formation, inflammation, and synovial hyperplasia in arthritic animals. Conclusion: NAT 500 mg/kg could serve as a promising therapeutic option for the treatment of inflammatory arthritis.