Immuno-stimulatory activity of Astragalus polysaccharides in cyclophosphamide-induced immunosuppressed mice by regulating gut microbiota

Astragalus Polysaccharide Enhances Voriconazole Metabolism under Inflammatory Conditions through the Gut Microbiota

Background and Aims

Voriconazole (VRC), a widely used antifungal drug, often causes hepatotoxicity, which presents a significant clinical challenge. Previous studies demonstrated that Astragalus polysaccharide (APS) can regulate VRC metabolism, thereby potentially mitigating its hepatotoxic effects. In this study, we aimed to explore the mechanism by which APS regulates VRC metabolism.

Methods

First, we assessed the association of abnormal VRC metabolism with hepatotoxicity using the Roussel Uclaf Causality Assessment Method scale. Second, we conducted a series of basic experiments to verify the promotive effect of APS on VRC metabolism. Various in vitro and in vivo assays, including cytokine profiling, immunohistochemistry, quantitative polymerase chain reaction, metabolite analysis, and drug concentration measurements, were performed using a lipopolysaccharide-induced rat inflammation model. Finally, experiments such as intestinal biodiversity analysis, intestinal clearance assessments, and Bifidobacterium bifidum replenishment were performed to examine the ability of B. bifidum to regulate the expression of the VRC-metabolizing enzyme CYP2C19 through the gut-liver axis.

Results

The results indicated that APS does not have a direct effect on hepatocytes. However, the assessment of gut microbiota function revealed that APS significantly increases the abundance of B. bifidum, which could lead to an anti-inflammatory response in the liver and indirectly enhance VRC metabolism. The dual-luciferase reporter gene assay revealed that APS can hinder the secretion of pro-inflammatory mediators and reduce the inhibitory effect on CYP2C19 transcription through the nuclear factor-κB signaling pathway.

Conclusions

The study offers valuable insights into the mechanism by which APS alleviates VRC-induced liver damage, highlighting its immunomodulatory influence on hepatic tissues and its indirect regulatory control of VRC-metabolizing enzymes within hepatocytes.

Role of traditional Chinese medicine in age-related macular degeneration: exploring the gut microbiota's influence

The pathogenesis of age-related macular degeneration (AMD), a degenerative retinopathy, remains unclear. Administration of anti-vascular endothelial growth factor agents, antioxidants, fundus lasers, photodynamic therapy, and transpupillary warming has proven effective in alleviating symptoms; however, these interventions cannot prevent or reverse AMD. Increasing evidence suggests that AMD risk is linked to changes in the composition, abundance, and diversity of the gut microbiota (GM). Activation of multiple signaling pathways by GM metabolites, including lipopolysaccharides, oxysterols, short-chain fatty acids (SCFAs), and bile acids (BAs), influences retinal physiology. Traditional Chinese medicine (TCM), known for its multi-component and multi-target advantages, can help treat AMD by altering GM composition and regulating the levels of certain substances, such as lipopolysaccharides, reducing oxysterols, and increasing SCFA and BA contents. This review explores the correlation between GM and AMD and interventions for the two to provide new perspectives on treating AMD with TCM.

Medicinal Herbs: Promising Immunomodulators for the Treatment of Infectious Diseases

Humans are constantly at high risk of emerging pandemics caused by viral and bacterial infections. The emergence of new pandemics is mainly caused by evolved viruses and bacteria that are highly resistant to existing medications. The rapid evolution of infectious agents demands the urgent investigation of new therapeutic strategies to prevent and treat these infections at an early stage. One of these therapeutic strategies includes the use of medicinal herbs for their antibacterial and antiviral properties. The use of herbal medicines as remedies is very ancient and has been employed for centuries. Many studies have confirmed the antimicrobial activities of herbs against various pathogens in vitro and in vivo. The therapeutic effect of medicinal herbs is mainly attributed to the natural bioactive molecules present in these plants such as alkaloids, flavonoids, and terpenoids. Different mechanisms have been proposed for how medicinal herbs enhance the immune system and combat pathogens. Such mechanisms include the disruption of bacterial cell membranes, suppression of protein synthesis, and limitation of pathogen replication through the inhibition of nucleic acid synthesis. Medicinal herbs have been shown to treat a number of infectious diseases by modulating the immune system's components. For instance, many medicinal herbs alleviate inflammation by reducing pro-inflammatory cytokines (e.g., tumor necrosis factor-alpha (TNF-α), interleukin-1, IL-6) while promoting the production of anti-inflammatory cytokines (e.g., IL-10). Medicinal herbs also play a role in defense against viral and intracellular infections by enhancing the proliferation and functions of natural killer cells, T-helper-1 cells, and macrophages. In this review, we will explore the use of the most common herbs in preventing and treating infectious and non-infectious diseases. Using current and recently published studies, we focus on the immunomodulatory and therapeutic effects induced by medicinal herbs to enhance immune responses during diseases.

UHPLC-MS-Based Metabolomics Reveal the Potential Mechanism of Armillaria mellea Acid Polysaccharide in and Its Effects on Cyclophosphamide-Induced Immunosuppressed Mice

Armillaria mellea (Vahl) P. Kumm is commonly used for food and pharmaceutical supplements due to its immune regulatory function, and polysaccharides are one of its main components. The aim of this research is to study the immunological activity of the purified acidic polysaccharide fraction, namely, AMPA, isolated from Armillaria mellea crude polysaccharide (AMP). In this study, a combination of the immune activity of mouse macrophages in vitro and serum metabonomics in vivo was used to comprehensively explore the cell viability and metabolic changes in immune-deficient mice in the AMPA intervention, with the aim of elucidating the potential mechanisms of AMPA in the treatment of immunodeficiency. The in vitro experiments revealed that, compared with LPS-induced RAW264.7, the AMPA treatment elevated the levels of the cellular immune factors IL-2, IL-6, IgM, IgA, TNF-α, and IFN-γ; promoted the expression of immune proteins; and activated the TLR4/MyD88/NF-κB signaling pathway to produce immunological responses. The protein expression was also demonstrated in the spleen of the cyclophosphamide immunosuppressive model in vivo. The UHPLC-MS-based metabolomic analysis revealed that AMPA significantly modulated six endogenous metabolites in mice, with the associated metabolic pathways of AMPA for treating immunodeficiency selected as potential therapeutic biomarkers. The results demonstrate that phosphorylated acetyl CoA, glycolysis, and the TCA cycle were mainly activated to enhance immune factor expression and provide immune protection to the body. These experimental results are important for the development and application of AMPA as a valuable health food or drug that enhances immunity.

Atractylodes lancea Rhizome Polysaccharide Alleviates Immunosuppression and Intestinal Mucosal Injury in Mice Treated with Cyclophosphamide

Plant-derived polysaccharides, such as Atractylodes lancea rhizome polysaccharide (ALP), are good immune regulators. However, the immune regulatory mechanism of the ALP is unknown. This study aimed to evaluate the effects of ALP on the intestinal mucosal barrier and intestinal mucosal immunity of immunosuppressed mice. We also compared the activity of raw Atractylodes lancea rhizome polysaccharide (SALP) with wheat bran processed bran-fried Atractylodes lancea rhizome polysaccharide (FALP; both at 1.2 g/kg/d for mice). Our results showed that ALP effectively increased the immune organ index and blood cell count, stimulated the secretion of cytokines, and promoted the expression of occludin and zonula occludens-1 (ZO-1). ALP also promoted the expression of T cells and the secretion of sIgA. Furthermore, ALP alleviated the gut microbiota disorder in Cy-treated mice and increased the relative abundances of Lactobacillus and Faecalibaculum. ALP reversed the decrease in the level of SCFAs and promoted the expression of G protein-coupled receptor 43 (GPR43). To our knowledge, this study was the first to explore how the ALP protects the intestinal mucosal barrier and enhances intestinal mucosal immunity by alleviating the gut microbiota imbalance and metabolic disorders of SCFAs. FALP was more therapeutic than SALP, suggesting that FALP could be developed as a promising functional food component.