Oral administration with diosgenin enhances the induction of intestinal T helper 1-like regulatory T cells in a murine model of food allergy

Network pharmacology-based investigation of the pharmacological mechanisms of diosgenin in nonalcoholic steatohepatitis

The prevalence of nonalcoholic steatohepatitis (NASH) is rising annually, posing health and economic challenges, with limited treatments available. Diosgenin, a natural steroidal compound found in various plants, holds potential as a therapeutic candidate. Recent studies have confirmed diosgenin's anti-inflammatory and metabolism-modulating properties. However, its therapeutic effects on NASH and the underlying mechanisms are still unclear. This study aims to explore diosgenin's protective effects and pharmacological mechanisms against NASH using network pharmacology, molecular docking, and experimental validation. We gathered potential targets of diosgenin and NASH from various databases to generate protein-protein interaction (PPI) networks. GO and KEGG pathway enrichment analyses identified key targets and mechanisms. Molecular docking confirmed the binding capacity between diosgenin and core target proteins. Additionally, a NASH cell model was developed to validate the pharmacological effects of diosgenin. Our investigation identified nine key targets (ALB, AKT1, TP53, VEGFA, MAPK3, EGFR, STAT3, CASP3, IGF1) that interact with diosgenin. Molecular docking indicated potential bindings interactions, while enrichment analyses revealed that diosgenin may enhance fatty acid metabolism via the PI3K-Akt pathway. Cellular experiments confirmed that diosgenin activates this pathway, reduces SCD1 expression, and decreases triglyceride and IL-6 levels. Our study elucidates that diosgenin may ameliorate triglyceride deposition and inflammation through the PI3K-Akt pathway.

Inulin-gel-based oral immunotherapy remodels the small intestinal microbiome and suppresses food allergy

Despite the potential of oral immunotherapy against food allergy, adverse reactions and loss of desensitization hinder its clinical uptake. Dysbiosis of the gut microbiota is implicated in the increasing prevalence of food allergy, which will need to be regulated to enable for an effective oral immunotherapy against food allergy. Here we report an inulin gel formulated with an allergen that normalizes the dysregulated ileal microbiota and metabolites in allergic mice, establishes allergen-specific oral tolerance and achieves robust oral immunotherapy efficacy with sustained unresponsiveness in food allergy models. These positive outcomes are associated with enhanced allergen uptake by antigen-sampling dendritic cells in the small intestine, suppressed pathogenic type 2 immune responses, increased interferon-γ+ and interleukin-10+ regulatory T cell populations, and restored ileal abundances of Eggerthellaceae and Enterorhabdus in allergic mice. Overall, our findings underscore the therapeutic potential of the engineered allergen gel as a suitable microbiome-modulating platform for food allergy and other allergic diseases.

Prospects of yam (Dioscorea) polysaccharides: Structural features, bioactivities and applications

Yam (Dioscorea) is a tuber crop cultivated for food security, revenue, and medicinal purposes. It has been used to treat diabetes, asthma, diarrhea, and other diseases. The main active ingredients in yam, polysaccharides, are regarded to be the important reason for its widespread applications. Now, a comprehensive review of research developments of yam polysaccharides (YPs) was presented to explore their prospects. We outlined the structural characteristics, biological activities, structure-activity relationships, and potential applications. Around 13 neutral components and 17 acidic components were separated. They exhibited various bioactivities, including immunomodulatory, hypoglycemic, hypolipidemic, antioxidant, gastrointestinal protective, anti-fatigue, and senile disease treatment activities, as well as prebiotic effect. Structure-activity relationships illustrated that unique structural properties, chemical modifications, and carried biopolymers could influence the bioactivities of YPs. The potential applications in medicine, food, and other fields have also been summarized.

Therapeutic potential and research progress of diosgenin for lipid metabolism diseases

Diosgenin, a steroidal saponin, is a natural product found in many plants. Diosgenin has a wide range of pharmacological activities, and has been used to treat cancer, nervous system diseases, inflammation, and infections. Numerous studies have shown that diosgenin has potential therapeutic value for lipid metabolism diseases via various pathways and mechanisms, such as controlling lipid synthesis, absorption, and inhibition of oxidative stress. These mechanisms and pathways have provided ideas for researchers to develop related drugs. In this review, we focus on data from animal and clinical studies, summarizing the toxicity of diosgenin, its pharmacological mechanism, recent research advances, and the related mechanisms of diosgenin as a drug for the treatment of lipid metabolism, especially in obesity, hyperlipidemia, nonalcoholic fatty liver disease, atherosclerosis, and diabetes. This systematic review will briefly describe the advantages of diosgenin as a potential therapeutic drug and seek to enhance our understanding of the pharmacological mechanism, recipe-construction, and the development of novel therapeutics against lipid metabolism diseases.

Emerging immune and cell death mechanisms in stroke: Saponins as therapeutic candidates

The complexity of the ischemic cascade is based on the integrated crosstalk of every cell type in the neurovascular unit. Depending on the features of the ischemic insult, several cell death mechanisms are triggered, such as apoptosis, necroptosis, ferroptosis/oxytosis, ETosis or pyroptosis, leading to reactive astrogliosis. However, emerging evidence demonstrates a dual role for the immune system in stroke pathophysiology, where it exerts both detrimental and also beneficial functions. In this review, we discuss the relevance of several cell death modalities and the dual role of the immune system in stroke pathophysiology. We also provide an overview of some emerging immunomodulatory therapeutic strategies, amongst which saponins, which are promising candidates that exert multiple pharmacological effects.

•

Several cell death mechanisms coexist in stroke pathophysiology.

•

Neurons are more vulnerable to necroptosis than glial cells.

•

Inhibitors of receptor-interacting protein kinases and of ferroptosis induce neuroprotection.

•

Saponins exert modulatory effects on inflammation and neuronal cell death in stroke.

Regulatory T Cell Plasticity and Stability and Autoimmune Diseases

CD4⁺CD25⁺ regulatory T cells (Tregs) are a class of CD4⁺ T cells with immunosuppressive functions that play a critical role in maintaining immune homeostasis. However, in certain disease settings, Tregs demonstrate plastic differentiation, and the stability of these Tregs, which is characterized by the stable expression or protective epigenetic modifications of the transcription factor Foxp3, becomes abnormal. Plastic Tregs have some features of helper T (Th) cells, such as the secretion of Th-related cytokines and the expression of specific transcription factors in Th cells, but also still retain the expression of Foxp3, a feature of Tregs. Although such Th-like Tregs can secrete pro-inflammatory cytokines, they still possess a strong ability to inhibit specific Th cell responses. Therefore, the plastic differentiation of Tregs not only increases the complexity of the immune circumstances under pathological conditions, especially autoimmune diseases, but also shows an association with changes in the stability of Tregs. The plastic differentiation and stability change of Tregs play vital roles in the progression of diseases. This review focuses on the phenotypic characteristics, functions, and formation conditions of several plastic Tregs and also summarizes the changes of Treg stability and their effects on inhibitory function. Additionally, the effects of Treg plasticity and stability on disease prognosis for several autoimmune diseases were also investigated in order to better understand the relationship between Tregs and autoimmune diseases.

Influence of different erythrocyte storage times on the macrophage response in haemorrhagic shock mice

Objective

To investigate the characteristics of the macrophage response to transfusion of erythrocytes kept at different storage times in the mouse model of haemorrhagic shock.

Methods

Erythrocytes were isolated from mice and stored for 7, 21 or 35 days and samples injected intravenously into haemorrhagic shock mice. Changes in macrophages, inflammatory cytokines and T cell differentiation were assessed using flow cytometry or enzyme-linked immunosorbent assay (ELISA). In a second experiment, haemorrhagic shock mice were injected with 21D-erythrocytes and the expression of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), arginine -1 (Arg-1) and inducible nitrous oxide (iNOS) determined.

Results

The proportion of M1-polarized macrophages was greatest in the 21D group while M2 macrophages tended to increase with the erythrocyte storage time. Levels of inflammatory cytokines and T helper 1 (Th1) cells increased in proportion to erythrocytes storage time. Most regulatory T cells (Treg) were found at 21D. Arg-1 expression was significantly increased in a group that received an heme oxygenase 1 (HO-1) agonist and significantly decreased in a group that received an HO-1 inhibitor but there were no differences in the expression of iNOS or Nrf2.

Conclusion

21D storage time may be an important time point for erythrocyte storage and immunity response and Arg-1 may have a role in the macrophage response to erythrocyte infusion.

Diosgenin inhibits the epithelial-mesenchymal transition initiation in osteosarcoma cells via the p38MAPK signaling pathway

Diosgenin is an important basic raw material for the production of steroid hormone drugs. It can be isolated and purified from a variety of traditional Chinese medicines or plants. Modern molecular biological studies have shown that diosgenin inhibits various tumor cells migration and invasion ability to varying degrees in vitro and in vivo. The aim of the present study was to observe the inhibitory effects of diosgenin on the invasive and metastatic capabilities of osteosarcoma cells and to determine the association between the effects of diosgenin on the epithelial-mesenchymal transition (EMT). Wound healing and Transwell assays were used to observe the inhibitory effects of diosgenin on the invasion and migration of two osteosarcoma cell lines. Immunofluorescence was used to observe changes in transforming growth factor β1 (TGF-β1) protein expression levels in the osteosarcoma cells following drug administration. EMT-associated proteins, including TGFβ1, E-cadherin and vimentin were detected by western blotting, which demonstrated that the drug may inhibit the initiation of EMT in osteosarcoma cells. Western blot analysis of the expression of all the proteins in the mitogen-activated protein kinase (MAPK) pathway demonstrated that the drug inhibited the MAPK signaling pathway. The primary mechanism of action of diosgenin was the inhibition of the phosphorylated p38 (pP38) protein. Through a combination of inhibitors of the p38MAPK signaling pathway and detection of the downstream EMT marker protein E-cadherin by quantitative PCR, pP38 was confirmed to be a target of diosgenin in the inhibition of EMT in the osteosarcoma cells via the MAPK molecular signaling pathway. Diosgenin may exhibit utility as an auxiliary drug for the clinical reduction of metastasis in patients with osteosarcoma.

Outstanding animal studies in allergy I. From asthma to food allergy and anaphylaxis

PURPOSE OF REVIEW

Animal models published within the past 18 months on asthma, food allergy and anaphylaxis, all conditions of rising public health concern, were reviewed.

RECENT FINDINGS

While domestic animals spontaneously develop asthma, food allergy and anaphylaxis, in animal models, divergent sensitization and challenge routes, dosages, intervals and antigens are used to induce asthmatic, food allergic or anaphylactic phenotypes. This must be considered in the interpretation of results. Instead of model antigens, gradually relevant allergens such as house dust mite in asthma, and food allergens like peanut, apple and peach in food allergy research were used. Novel engineered mouse models such as a mouse with a T-cell receptor for house dust mite allergen Der p 1, or with transgenic human hFcγR genes, facilitated the investigation of single molecules of interest. Whole-body plethysmography has become a state-of-the-art in-vivo readout in asthma research. In food allergy and anaphylaxis research, novel techniques were developed allowing real-time monitoring of in-vivo effects following allergen challenge. Networks to share tissues were established as an effort to reduce animal experiments in allergy which cannot be replaced by in-vitro measures.

SUMMARY

Natural and artificial animal models were used to explore the pathophysiology of asthma, food allergy and anaphylaxis and to improve prophylactic and therapeutic measures. Especially the novel mouse models mimicking molecular aspects of the complex immune network in asthma, food allergy and anaphylaxis will facilitate proof-of-concept studies under controlled conditions.