Naringenin is a Potential Immunomodulator for Inhibiting Liver Fibrosis by Inhibiting the cGAS-STING Pathway

Progress of cGAS-STING signaling pathway-based modulation of immune response by traditional Chinese medicine in clinical diseases

The cGAS-STING signaling pathway is a critical component of the innate immune response, playing a significant role in various diseases. As a central element of this pathway, STING responds to both endogenous and exogenous DNA stimuli, triggering the production of interferons and pro-inflammatory cytokines to enhance immune defenses against tumors and pathogens. However, dysregulated activation of the STING pathway is implicated in the pathogenesis of multiple diseases, including autoinflammation, viral infections, and cancer. Traditional Chinese Medicines (TCMs), which have a long history of use, have been associated with positive effects in disease prevention and treatment. TCM formulations (e.g., Lingguizhugan Decoction, Yi-Shen-Xie-Zhuo formula) and active compounds (e.g., Glabridin, Ginsenoside Rd) can modulate the cGAS-STING signaling pathway, thereby influencing the progression of inflammatory, infectious, or oncological diseases. This review explores the mechanisms by which TCMs interact with the cGAS-STING pathway to regulate immunity, focusing on their roles in infectious diseases, malignancies, and autoimmune disorders.

Inhibition of hepatic stellate cell activation by nutraceuticals: an emphasis on mechanisms of action

Liver diseases emerge as a serious threat to humans worldwide due to increasing morbidity and mortality. Liver disease related deaths accounts for one third of all disease related death globally. A simple fatty liver if unattended advances further to liver fibrosis, cirrhosis and hepatocellular carcinoma. During liver fibrogenesis, hepatic stellate cells gets activated into myofibroblast like cells and exhibit proliferative and fibrogenic features. Targeting these activated hepatic stellate cells offer promising therapeutic approach towards liver fibrosis management. To date there is no Food and Drug Administration approved treatments for liver fibrosis. However, a large number of clinical trials are being conducted employing monoclonal antibodies, drugs, dietary supplements and herbal medicines. A vast number of research findings demonstrated nutraceuticals to be effective against experimental liver fibrosis both in vitro and in vivo. Nutraceuticals typically regulate key signaling pathways in activated hepatic stellate cells and exhibit anti-fibrotic effect. In this review, the mechanistic action of nutraceuticals targeting activated hepatic stellate cells were summarized to establish them as a possible therapeutic candidate for liver fibrosis.

Flavonoids in natural products for the therapy of liver diseases: progress and future opportunities

The liver is the largest, important organ and the site for essential biochemical reactions in the human body. It has the function to detoxify toxic substances and synthesize useful biomolecules. Liver diseases related complications represent a significant source of morbidity and mortality worldwide, creating a substantial economic burden. Oxidative stress, excessive inflammation, and dysregulated energy metabolism significantly contributed to liver diseases. Therefore, discovery of novel therapeutic drugs for the treatment of liver diseases are urgently required. For centuries, flavonoids and their preparations which have the beneficial health effects in chronic diseases have been used to treat various human illnesses. Flavonoids mainly include flavones, isoflavones, flavanols, dihydroflavones, dihydroflavonols, anthocyanins and chalcones. The primary objective of this review is to assess the efficacy and safety of flavonoids, mainly from a clinical point of view and considering clinically relevant end-points. We summarized the recent progress in the research of hepatoprotective and molecular mechanisms of different flavonoids bioactive ingredients and also outlined the networks of underlying molecular signaling pathways. Further pharmacology and toxicology research will contribute to the development of natural products in flavonoids and their derivatives as medicines with alluring prospect in the clinical application.

Naringenin alleviates liver fibrosis by triggering autophagy-dependent ferroptosis in hepatic stellate cells

Inhibition of activated hepatic stellate cells (HSCs) is a promising approach for treating liver fibrosis, and the ferroptosis has emerged as a pivotal mechanism to achieve this inhibition. The effects of naringenin, a flavonoid with anti-inflammatory properties, have not been thoroughly examined in liver fibrosis. Therefore, we used cholestasis model to study the effect of naringenin on liver fibrosis. Our findings demonstrated a significant exacerbation of liver tissue damage and fibrosis in mice subjected to bile duct ligation (BDL), accompanied by a substantial upregulation of fibrogenesis-related gene expression. Notably, naringenin administration markedly alleviated liver injury and fibrosis in these mice. Furthermore, naringenin exhibited inhibitory effects on the activation of HSCs, concurrently inducing ferroptosis. Importantly, naringenin significantly increased autophagic activity in HSCs. This effect was counteracted by co-administration of the autophagy inhibitor 3-MA, leading to a notable reduction in naringenin-induced HSC ferroptosis. In BDL model mice, naringenin demonstrated a mitigating effect on liver fibrosis, suggesting a potential correlation with naringenin-induced ferroptosis of HSCs. These results provide novel insights into the molecular mechanisms of naringenin-induced ferroptosis and highlight autophagy-dependent ferroptosis as a promising therapeutic strategy for liver fibrosis.

Update on the STING Signaling Pathway in Developing Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a prevalent chronic liver condition with limited treatment options. Inflammation caused by metabolic disturbances plays a significant role in NAFLD development. Stimulator of interferon gene (STING), a critical regulator of innate immunity, induces the production of interferons and other pro-inflammatory factors by recognizing cytoplasmic DNA to defend against pathogen infection. The STING-mediated signaling pathway appears to play a vital role in hepatic inflammation, metabolic disorders, and even carcinogenesis. Promisingly, pharmacological interventions targeting STING have shown improvements in the pathological state of NAFLD. Macrophages, dendritic cells, natural killer cells, and T cell pathways regulated by STING present potential novel druggable targets for NAFLD treatment. Further research and development in this area may offer new therapeutic options for managing NAFLD effectively.

Human diet-derived polyphenolic compounds and hepatic diseases: From therapeutic mechanisms to clinical utilization

This review focuses on the potential ameliorative effects of polyphenolic compounds derived from human diet on hepatic diseases. It discusses the molecular mechanisms and recent advancements in clinical applications. Edible polyphenols have been found to play a therapeutic role, particularly in liver injury, liver fibrosis, NAFLD/NASH, and HCC. In the regulation of liver injury, polyphenols exhibit anti-inflammatory and antioxidant effects, primarily targeting the TGF-β, NF-κB/TLR4, PI3K/AKT, and Nrf2/HO-1 signaling pathways. In the regulation of liver fibrosis, polyphenolic compounds effectively reverse the fibrotic process by inhibiting the activation of hepatic stellate cells (HSC). Furthermore, polyphenolic compounds show efficacy against NAFLD/NASH by inhibiting lipid oxidation and accumulation, mediated through the AMPK, SIRT, and PPARγ pathways. Moreover, several polyphenolic compounds exhibit anti-HCC activity by suppressing tumor cell proliferation and metastasis. This inhibition primarily involves blocking Akt and Wnt signaling, as well as inhibiting the epithelial-mesenchymal transition (EMT). Additionally, clinical trials and nutritional evidence support the notion that certain polyphenols can improve liver disease and associated metabolic disorders. However, further fundamental research and clinical trials are warranted to validate the efficacy of dietary polyphenols.

m6A methylation-induced NR1D1 ablation disrupts the HSC circadian clock and promotes hepatic fibrosis

The roles of nuclear receptor subfamily 1 group d member 1 (NR1D1) and the circadian clock in liver fibrosis remain unclear. Here, we showed that liver clock genes, especially NR1D1, were dysregulated in mice with carbon tetrachloride (CCl4)-induced liver fibrosis. In turn, disruption of the circadian clock exacerbated experimental liver fibrosis. NR1D1-deficient mice were more sensitive to CCl4-induced liver fibrosis, supporting a critical role of NR1D1 in liver fibrosis development. Validation at the tissue and cellular levels showed that NR1D1 was primarily degraded by N6-methyladenosine (m6A) methylation in a CCl4-induced liver fibrosis model, and this result was also validated in rhythm-disordered mouse models. In addition, the degradation of NR1D1 further inhibited the phosphorylation of dynein-related protein 1-serine site 616 (DRP1S616), resulting in weakened mitochondrial fission function and increased mitochondrial DNA (mtDNA) release in hepatic stellate cell (HSC), which in turn activated the cGMP-AMP synthase (cGAS) pathway. Activation of the cGAS pathway induced a local inflammatory microenvironment that further stimulated liver fibrosis progression. Interestingly, in the NR1D1 overexpression model, we observed that DRP1S616 phosphorylation was restored, and cGAS pathway was also inhibited in HSCs, resulting in improved liver fibrosis. Taken together, our results suggest that targeting NR1D1 may be an effective approach to liver fibrosis prevention and management.

Qingchang Wenzhong Decoction reduce ulcerative colitis in mice by inhibiting Th17 lymphocyte differentiation

BACKGROUND

Qingchang Wenzhong Decoction (QCWZD), a chinese herbal prescription, is widely used for ulcerative colitis (UC). Nevertheless, the active ingredients and mechanism of QCWZD in UC have not yet been explained clearly.

PURPOSE

This research focuses on the identification of the effective ingredients of QCWZD and the prediction and verification of their potential targets.

METHODS

The UC mice were established by adding 3.0% dextran sulfate sodium (DSS) to sterile water for one week. Concurrently, mice in the treatment group were gavage QCWZD or mesalazine. LC-MS analyzed the main components absorbed after QCWZD treatment, and network pharmacology predicted their possible targets. ELISA, qPCR, immunohistochemistry and immunofluorescence experiments were used to evaluate the colonic inflammation level and the intestinal barrier completeness. The percentage of Th17 and Treg lymphocytes was detected by flow cytometry.

RESULTS

After QCWZD treatment, twenty-seven compounds were identified from the serum. In addition, QCWZD treatment significantly reduced the increased myeloperoxidase (MPO) and inflammatory cell infiltration caused by DSS in the colonic. In addition, QCWZD can reduce the secretion of inflammatory factors in serum and promote the expression of mRNAs and proteins of occludin and ZO-1. Network pharmacology analysis indicated that inhibiting IL-6-STAT3 pathway may be necessary for QCWZD to treat UC. Flow cytometry analysis showed that QCWZD can restore the normal proportion of Th17 lymphocytes in UC mice. Mechanistically, QCWZD inhibited the phosphorylation of JAK2-STAT3 pathway, reducing the transcriptional activation of RORγT and IL-17A.

CONCLUSIONS

Overall, for the first time, our work revealed the components of QCWZD absorbed into blood, indicated that the effective ingredients of QCWZD may inhibit IL-6-STAT3 pathway and inhibit the differentiation of Th17 lymphocytes to reduce colon inflammation.