Glycyrrhizin Attenuates Carcinogenesis by Inhibiting the Inflammatory Response in a Murine Model of Colorectal Cancer

Acute Lung Injury and the NLRP3 Inflammasome

Acute lung injury (ALI) manifests through harm to the capillary endothelium and alveolar epithelial cells, arising from a multitude of factors, leading to scattered interstitial alterations, pulmonary edema, and subsequent acute hypoxic respiratory insufficiency. Acute lung injury (ALI), along with its more serious counterpart, acute respiratory distress syndrome (ARDS), carry a fatality rate that hovers around 30-40%. Its principal pathological characteristic lies in the unchecked inflammatory reaction. Currently, the main strategies for treating ALI are alleviation of inflammation and prevention of respiratory failure. Concerning the etiology of ALI, NLRP3 Inflammasome is essential to the body's innate immune response. The composition of this inflammasome complex includes NLRP3, the pyroptosis mediator ASC, and pro-caspase-1. Recent research has reported that the inflammatory response centered on NLRP3 inflammasomes plays a key part in inflammation in ALI, and may hence be a prospective candidate for therapeutic intervention. In the review, we present an overview of the ailment characteristics of acute lung injury along with the constitution and operation of the NLRP3 inflammasome within this framework. We also explore therapeutic strategies targeting the NLRP3 inflammasome to combat acute lung injury.

Anchang Yuyang Decoction inhibits experimental colitis-related carcinogenesis by regulating PPAR signaling pathway and affecting metabolic homeostasis of host and microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammatory bowel disease (IBD) presents a risk of carcinogenesis, which escalates with the duration of IBD. Persistent histological inflammation is considered to be the driving factor of colitis carcinogenesis. Effective control of inflammation is helpful to prevent and treat colitis-related colorectal cancer (CAC). Anchang Yuyang Decoction (AYD), a traditional Chinese medicine (TCM) formula, is originated from the ancient prescription of TCM for treating colitis and colorectal cancer. AYD has demonstrated efficacy in treating IBD and potential anti-carcinogenic properties.

AIM OF THE STUDY

This research aims to assess the therapeutic efficacy of AYD in ameliorating experimental colitis-related carcinogenesis induced by AOM/DSS. It further seeks to elucidate its potential mechanisms by integrating multiple omics sequencing approaches.

MATERIALS AND METHODS

A rat model for colitis-related carcinogenesis was developed using azoxymethane (AOM)/dextran sulfate sodium (DSS). UPLC-MS identified AYD's chemical constituents. Rats were administered varying doses of AYD (18.37, 9.19 and 4.59 g/kg) orally for 53 days, with mesalazine as a positive control. The study evaluated anti-carcinogenic effects by examining adenoma number, adenoma load, abnormal crypt foci (ACF), histopathological damage, and tumor-related protein expression. Anti-inflammatory and reparative effects were assessed through body weight, disease activity index (DAI), colon length, spleen index, inflammatory cytokine levels, and tight junction protein expression. The effects on intestinal microbiota and host metabolism were explored through 16S rRNA sequencing, targeted short-chain fatty acid (SCFA) metabonomics, and non-targeted colon metabolomics. Potential AYD targets were identified through transcriptomic sequencing and validated by qRT-PCR and western blotting.

RESULTS

AYD significantly reduced adenoma number, adenoma load, neoplasm-associated lesions, ACF, and tumor-related protein expression (e.g., p53, PCNA) in AOM/DSS-induced rats, thus impeding colitis-related carcinogenesis progression. AYD also alleviated histopathological damage and inflammation, promoting intestinal mucosal barrier repair. Furthermore, AYD modulated intestinal flora structure, enhanced SCFA production, and regulated colon metabolites. Transcriptomic sequencing revealed a significant impact on the peroxisome proliferator-activated receptor (PPAR) signaling pathway. Subsequent qRT-PCR and western blotting experiments indicated AYD's influence in up-regulating PPAR-γ and down-regulating PPAR-α, PPAR-β/δ, and related proteins (thrombomodulin [Thbd], fatty acid binding protein 5 [Fabp5], stearoyl-CoA desaturase 2 [Scd2], phospholipid transfer protein [Pltp]).

CONCLUSIONS

This study demonstrates AYD's ability to inhibit experimental colitis-related carcinogenesis induced by AOM/DSS. Its mechanism likely involves modulation of the PPAR signaling pathway, impacting intestinal microbiota and host metabolic equilibrium.

Directing in Vitro Selection towards G-quadruplex-forming Aptamers to Inhibit HMGB1 Pathological Activity

In the search for novel, effective inhibitors of High-Mobility Group Box1 (HMGB1)-a protein involved in various inflammatory and autoimmune diseases as well as in cancer-we herein discovered a set of anti-HMGB1 G-quadruplex(G4)-forming aptamers by using an in vitro selection procedure applied to a doped library of guanine-rich oligonucleotides. The selected DNA sequences were then studied in a pseudo-physiological buffer mimicking the extracellular medium, where HMGB1 exerts its pathological activity, using spectroscopic, electrophoretic, and chromatographic techniques. All the oligonucleotides proved to fold into monomeric G4s and in some cases also dimeric species, stable at physiological temperature. Remarkably, the protein preferentially recognized the sequences forming dimeric parallel G4 structures, as evidenced by a properly designed chemiluminescent binding assay which also highlighted a good selectivity of these aptamers for HMGB1. Moreover, all aptamers showed anti-HMGB1 activity, inhibiting protein-induced cell migration. The acquired data allowed identifying L12 as the best anti-HMGB1 aptamer, featured by high thermal and enzymatic stability, no toxicity at least up to 5 μM concentration on healthy cells, along with potent anti-HMGB1 activity (IC50 ca. 28 nM) and good binding affinity for the protein, thus indicating it as a very promising lead candidate for in vivo studies.

Tracing the pathways and mechanisms involved in the anti-breast cancer activity of glycyrrhizin using bioinformatics tools and computational methods

A complete investigation to understand the pathways that could be affected by glycyrrhizin (licorice), as anti-breast cancer (BC) agent, has not been performed to date. This study aims to investigate the pathways involved in the anti-cancer activity of glycyrrhizin against BC. For this purpose, the target genes of glycyrrhizin were obtained from the ChEMBL database. The BC-associated genes for three types of BC (breast carcinoma, malignant neoplasm of breast, and triple-negative breast neoplasms) were retrieved from DisGeNET. The target genes of glycyrrhizin and the BC-associated genes were compared, and the genes with disease specificity index (DSI) > 0.6 were selected for further evaluation using in silico methods. The protein-protein interaction (PPI) network was constructed, and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed. The potential complexes were further evaluated using molecular dynamics (MD) simulation. The results revealed that among 80 common genes, ten genes had DSI greater than 0.6, which included POLK, TACR2, MC3R, TBXAS1, HH1R, SLCO4A1, NPY2R, ADRA2C, ADRA1A, and SLCO2B1. The binding affinity of glycyrrhizin to the cognate proteins and binding characteristics were assessed using molecular docking and binding free energy calculations (MM/GBSA). POLK, TBXAS1, and ADRA1A showed the highest binding affinity with -8.9, -9.3, and -9.6 kcal/mol, respectively. The final targets had an association with BC at several stages of tumor growth. By affecting these targets, glycyrrhizin could influence and control BC efficiently. MD simulation suggested the pathways triggered by the complex glycyrrhizin-ADRA1A were more likely to happen.Communicated by Ramaswamy H. Sarma.

Sweeteners and the Gut Microbiome: Effects on Gastrointestinal Cancers

Worldwide, the demand for natural and synthetic sweeteners in the food industry as an alternative to refined sugar is increasing. This has prompted more research to be conducted to estimate its safety and effects on health. The gut microbiome is critical in metabolizing selected sweeteners which might affect overall health. Recently, more studies have evaluated the relationship between sweeteners and the gut microbiome. This review summarizes the current knowledge regarding the role played by the gut microbiome in metabolizing selected sweeteners. It also addresses the influence of the five selected sweeteners and their metabolites on GI cancer-related pathways. Overall, the observed positive effects of sweetener consumption on GI cancer pathways, such as apoptosis and cell cycle arrest, require further investigation in order to understand the underlying mechanism.

Inhibitory Effect of Zinc on Colorectal Cancer by Granzyme B Transcriptional Regulation in Cytotoxic T Cells

Zinc is one of the essential trace elements and is involved in various functions in the body. Zinc deficiency is known to cause immune abnormalities, but the mechanism is not fully understood. Therefore, we focused our research on tumor immunity to elucidate the effect of zinc on colorectal cancer and its mechanisms. Mice were treated with azoxymethane (AOM) and dextran sodium sulfate (DSS) to develop colorectal cancer, and the relationship between zinc content in the diet and the number and area of tumors in the colon was observed. The number of tumors in the colon was significantly higher in the no-zinc-added group than in the normal zinc intake group, and about half as many in the high-zinc-intake group as in the normal-zinc-intake group. In T-cell-deficient mice, the number of tumors in the high-zinc-intake group was similar to that in the normal-zinc-intake group, suggesting that the inhibitory effect of zinc was dependent on T cells. Furthermore, we found that the amount of granzyme B transcript released by cytotoxic T cells upon antigen stimulation was significantly increased by the addition of zinc. We also showed that granzyme B transcriptional activation by zinc addition was dependent on calcineurin activity. In this study, we have shown that zinc exerts its tumor-suppressive effect by acting on cytotoxic T cells, the center of cellular immunity, and increases the transcription of granzyme B, one of the key molecules in tumor immunity.

Glycyrrhizae Radix et Rhizoma: The popular occurrence of herbal medicine applied in classical prescriptions

Glycyrrhizae Radix et Rhizoma is a well-known herbal medicine with a wide range of pharmacological functions that has been used throughout Chinese history. This review presents a comprehensive introduction to this herb and its classical prescriptions. The article discusses the resources and distribution of species, methods of authentication and determination chemical composition, quality control of the original plants and herbal medicines, dosages use, common classical prescriptions, indications, and relevant mechanisms of the active content. Pharmacokinetic parameters, toxicity tests, clinical trials, and patent applications are discussed. The review will provide a good starting point for the research and development of classical prescriptions to develop herbal medicines for clinical use.

Glycyrrhizin mitigates acute lung injury by inhibiting the NLRP3 inflammasome in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhiza glabra L. is a widely used traditional Chinese medicine with antipyretic, detoxification, antibacterial and therapeutic effects against various diseases, including liver diseases. Glycyrrhizin (GL), the most significant active ingredient of Glycyrrhiza glabra L., exerts anti-inflammatory activity. However, the anti-inflammatory effect of GL remains to be determined.

AIM OF THIS STUDY

Consequently, this research was carried out to discover the effects and mechanism of action of GL on ALI.

MATERIALS AND METHODS

Cell experiments established an in vitro model of LPS-induced RAW 264.7 macrophages to verify the mechanism. The levels of NO, PEG₂, and inflammatory cytokines were estimated by ELISA. The expression levels of proteins related to the NF-κB signalling pathway and NLRP3 inflammasome were determined by Western blotting. The nuclear translocation of NF-κB p65 and ASC was tested through immunofluorescence analysis. The inhibitory effect of NLRP3 inhibitor MCC950 on macrophage was evaluated. Male BALB/C mice were selected to establish the ALI model. The experiment was randomly divided into five groups: control, ALI, GLL, GLH, and DEX. Pathological alterations were explored by H&E staining. The weight ratios of lung W/D, MPO, and inflammatory cytokines were evaluated by ELISA. The expression levels of proteins related to the NF-κB signalling pathway or NLRP3 inflammasome were analysed by Western blotting.

RESULTS

Here, we demonstrate that GL attenuates inflammation, nitric oxide, IL-18, IL-1β, TNF-α, IL-6, and PGE₂ levels and alveolar epithelial barrier permeability in macrophages and mice challenged with LPS. In addition, GL inhibits NLRP3 inflammasome initiation and activation and NF-κB signalling pathway activation.

CONCLUSION

This research demonstrates that GL may alleviate ALI inflammation by interfering with the NF-κB/NLRP3 inflammasome signalling pathway.

Cellular Carcinogenesis: Role of Polarized Macrophages in Cancer Initiation

Simple Summary

Inflammation is a hallmark of many cancers. Macrophages are key participants in innate immunity and important drivers of inflammation. When chronically polarized beyond normal homeostatic responses to infection, injury, or aging, macrophages can express several pro-carcinogenic phenotypes. In this review, evidence supporting polarized macrophages as endogenous sources of carcinogenesis is discussed. In addition, the depletion or modulation of macrophages by small molecule inhibitors and probiotics are reviewed as emerging strategies in cancer prevention.

Abstract

Inflammation is an essential hallmark of cancer. Macrophages are key innate immune effector cells in chronic inflammation, parainflammation, and inflammaging. Parainflammation is a form of subclinical inflammation associated with a persistent DNA damage response. Inflammaging represents low-grade inflammation due to the dysregulation of innate and adaptive immune responses that occur with aging. Whether induced by infection, injury, or aging, immune dysregulation and chronic macrophage polarization contributes to cancer initiation through the production of proinflammatory chemokines/cytokines and genotoxins and by modulating immune surveillance. This review presents pre-clinical and clinical evidence for polarized macrophages as endogenous cellular carcinogens in the context of chronic inflammation, parainflammation, and inflammaging. Emerging strategies for cancer prevention, including small molecule inhibitors and probiotic approaches, that target macrophage function and phenotype are also discussed.

Anti-Cancer Properties of Stevia rebaudiana; More than a Sweetener

Stevia rebaudiana Bertoni is a perennial shrub from Paraguay that is nowadays widely cultivated, since it is increasingly being utilized as a sugar substitute in various foodstuffs due to its sweetness and minimal caloric content. These properties of the plant’s derivatives have spurred research on their biological activities revealing a multitude of benefits to human health, including antidiabetic, anticariogenic, antioxidant, hypotensive, antihypertensive, antimicrobial, anti-inflammatory and antitumor actions. To our knowledge, no recent reviews have surveyed and reported published work solely on the latter. Consequently, our main objective was to present a concise, literature-based review of the biological actions of stevia derivatives in various tumor types, as studied in in vitro and in vivo models of the disease. With global cancer estimates suggesting a 47% increase in cancer cases by 2040 compared to 2020, the data reviewed in this article should provide a better insight into Stevia rebaudiana and its products as a means of cancer prevention and therapy within the context of a healthy diet.

Oncopreventive and oncotherapeutic potential of licorice triterpenoid compound glycyrrhizin and its derivatives: Molecular insights

Licorice (Glycyrrhiza glabra) is a well-known natural herb used to treat different ailments since ancient times. Glycyrrhizin (GL), which is the primary triterpenoid compound of licorice extract, has been known to have broad-spectrum pharmacological effects. GL is cleaved into glucuronide and the aglycone, glycyrrhetinic acid (GA), which exists in two stereoisomeric forms: 18α- and 18β-GA. It is well documented that GL and GA have great potential as anti-inflammatory, anticancer, antiviral, anti-diabetic, antioxidant, and hepatoprotective agents. Studies undertaken during the coronavirus disease 2019 pandemic suggest that GL is effective at inhibiting the viral replication of severe acute respiratory syndrome coronavirus 2. The anticancer effects of GL and GA involve modulating various signaling pathways, such as the phosphatase and tensin homolog/phosphatidylinositol 3-kinase/protein kinase B pathway, the mitogen-activated protein kinase, and the mammalian target of rapamycin/signal transducer and activator of transcription 3, which are mainly involved in regulating cancer cell death, oxidative stress, and inflammation. The potential of GL and GA in preventing cancer development and suppressing the growth and invasion of different cancer types has been reviewed in this paper. This review also provides molecular insights on the mechanism of action for the oncopreventive and oncotherapeutic effects of GL and its derivative, GA, which could help develop more specific forms of these agents for clinical use.

Pharmacological Inhibition of HMGB1 Prevents Muscle Wasting

Background: Cachexia is a multifactorial disorder characterized by weight loss and muscle wasting, making up for about 20% of cancer-related death. However, there are no effective drugs to combat cachexia at present.

Methods: In this study, the effect of CT26 exosomes on C2C12 myotubes was observed. We compared serum HMGB1 level in cachexia and non-cachexia colon cancer patients. We further explored HMGB1 expression level in CT26 exosome. We added recombinant HMGB1 to C2C12 myotubes to observe the effects of HMGB1 on C2C12 myotubes and detected the expression level of the muscle atrophy-related proteins. Then, we used the HMGB1 inhibitor glycyrrhizin to reverse the effects of HMGB1 on C2C12 myotubes. Finally, HMGB1 inhibitor glycyrrhizin was utilized to relieve cachexia in CT26 cachexia mouse model.

Results: Exosomes containing HMGB1 led to muscle atrophy with significantly decreased myotube diameter and increased expression of muscle atrophy-related proteins Atrogin1 and MuRF1. Further, we detected that HMGB1 induced the muscle atrophy mainly via TLR4/NF-κB pathway. Administration of the HMGB1 inhibitor glycyrrhizin could relieve muscle wasting in vitro and attenuate the progression of cachexia in vivo.

Conclusion: These findings demonstrate the cachectic role of HMGB1, whether it is soluble form of HMGB1 or secreted from tumor cells as part of exosomes. HMGB1 inhibitor glycyrrhizin might be a promising drug in colon cancer cachexia.

Plant-Derived Compounds as Promising Therapeutics for Vitiligo

Vitiligo is the most common depigmenting disorder characterized by white patches in the skin. The pathogenetic origin of vitiligo revolves around autoimmune destruction of melanocytes in which, for instance, oxidative stress is responsible for melanocyte molecular, organelle dysfunction and melanocyte specific antigen exposure as well as melanocyte cell death and thus serves as an important contributor for vitiligo progression. In recent years, natural products have shown a wide range of pharmacological bioactivities against many skin diseases, and this review focuses on the effects and mechanisms of natural compounds against vitiligo models. It is showed that some natural compounds such as flavonoids, phenols, glycosides and coumarins have a protective role in melanocytes and thereby arrest the depigmentation, and, additionally, Nrf2/HO-1, MAPK, JAK/STAT, cAMP/PKA, and Wnt/β-catenin signaling pathways were reported to be implicated in these protective effects. This review discusses the great potential of plant derived natural products as anti-vitiligo agents, as well as the future directions to explore.

Tumour Microenvironment Stress Promotes the Development of Drug Resistance

Multi-drug resistance (MDR) is a leading cause of cancer-related death, and it continues to be a major barrier to cancer treatment. The tumour microenvironment (TME) has proven to play an essential role in not only cancer progression and metastasis, but also the development of resistance to chemotherapy. Despite the significant advances in the efficacy of anti-cancer therapies, the development of drug resistance remains a major impediment to therapeutic success. This review highlights the interplay between various factors within the TME that collectively initiate or propagate MDR. The key TME-mediated mechanisms of MDR regulation that will be discussed herein include (1) altered metabolic processing and the reactive oxygen species (ROS)-hypoxia inducible factor (HIF) axis; (2) changes in stromal cells; (3) increased cancer cell survival via autophagy and failure of apoptosis; (4) altered drug delivery, uptake, or efflux and (5) the induction of a cancer stem cell (CSC) phenotype. The review also discusses thought-provoking ideas that may assist in overcoming the TME-induced MDR. We conclude that stressors from the TME and exposure to chemotherapeutic agents are strongly linked to the development of MDR in cancer cells. Therefore, there remains a vast area for potential research to further elicit the interplay between factors existing both within and outside the TME. Elucidating the mechanisms within this network is essential for developing new therapeutic strategies that are less prone to failure due to the development of resistance in cancer cells.

Biotransformation of the Phenolic Constituents from Licorice and Cytotoxicity Evaluation of Their Metabolites

Biotransformation of four bioactive phenolic constituents from licorice, namely licoisoflavanone (1), glycyrrhisoflavone (2), echinatin (3), and isobavachalcone (4), was performed by the selected fungal strain Aspergillus niger KCCM 60332, leading to the isolation of seventeen metabolites (5-21). Structures of the isolated compounds were determined on the basis of extensive spectroscopic methods, twelve of which (5-7, 10-17 and 19) have been previously undescribed. A series of reactions including hydroxylation, hydrogenation, epoxidation, hydrolysis, reduction, cyclization, and alkylation was observed in the biotransformation process. All compounds were tested for their cytotoxic activities against three different human cancer cell lines including A375P, MCF-7, and HT-29. Compounds 1 and 12 exhibited most considerable cytotoxic activities against all the cell lines investigated, while compounds 2 and 4 were moderately cytotoxic. These findings will contribute to expanding the chemical diversity of phenolic compounds, and compounds 1 and 12 may serve as leads for the development of potential cancer chemopreventive agents.