Quercetin inhibits growth of hepatocellular carcinoma by apoptosis induction in part via autophagy stimulation in mice

Therapeutic potentials and targeting strategies of quercetin on cancer cells: Challenges and future prospects

BACKGROUND

Every cell in the human body is vital because it maintains equilibrium and carries out a variety of tasks, including growth and development. These activities are carried out by a set of instructions carried by many different genes and organized into DNA. It is well recognized that some lifestyle decisions, like using tobacco, alcohol, UV, or multiple sexual partners, might increase one's risk of developing cancer. The advantages of natural products for any health issue are well known, and researchers are making attempts to separate flavonoid-containing substances from plants. Various parts of plants contain a phenolic compound called flavonoid. Quercetin, which belongs to the class of compounds known as flavones with chromone skeletal structure, has anti-cancer activity.

PURPOSE

The study was aimed at investigating the therapeutic action of the flavonoid quercetin on various cancer cells.

METHODS

The phrases quercetin, anti-cancer, nanoparticles, and cell line were used to search the data using online resources such as PubMed, and Google Scholar. Several critical previous studies have been included.

RESULTS

Quercetin inhibits various dysregulated signaling pathways that cause cancer cells to undergo apoptosis to exercise its anticancer effects. Numerous signaling pathways are impacted by quercetin, such as the Hedgehog system, Akt, NF-κB pathway, downregulated mutant p53, JAK/STAT, G1 phase arrest, Wnt/β-Catenin, and MAPK. There are downsides to quercetin, like hydrophobicity, first-pass effect, instability in the gastrointestinal tract, etc., because of which it is not well-established in the pharmaceutical industry. The solution to these drawbacks in the future is using bio-nanomaterials like chitosan, PLGA, liposomes, and silk fibroin as carriers, which can enhance the target specificity of quercetin. The first section of this review covers the specifics of flavonoids and quercetin; the second section covers the anti-cancer activity of quercetin; and the third section explains the drawbacks and conjugation of quercetin with nanoparticles for drug delivery by overcoming quercetin's drawback.

CONCLUSIONS

Overall, this review presented details about quercetin, which is a plant derivative with a promising molecular mechanism of action. They inhibit cancer by various mechanisms with little or no side effects. It is anticipated that plant-based materials will become increasingly relevant in the treatment of cancer.

Exploring the Geroprotective Potential of Nutraceuticals

Aging is the result of the accumulation of a wide variety of molecular and cellular damages over time, meaning that "the more damage we accumulate, the higher the possibility to develop age-related diseases". Therefore, to reduce the incidence of such diseases and improve human health, it becomes important to find ways to combat such damage. In this sense, geroprotectors have been suggested as molecules that could slow down or prevent age-related diseases. On the other hand, nutraceuticals are another set of compounds that align with the need to prevent diseases and promote health since they are biologically active molecules (occurring naturally in food) that, apart from having a nutritional role, have preventive properties, such as antioxidant, anti-inflammatory and antitumoral, just to mention a few. Therefore, in the present review using the specialized databases Scopus and PubMed we collected information from articles published from 2010 to 2023 in order to describe the role of nutraceuticals during the aging process and, given their role in targeting the hallmarks of aging, we suggest that they are potential geroprotectors that could be consumed as part of our regular diet or administered additionally as nutritional supplements.

Network medicine analysis for dissecting the therapeutic mechanism of consensus TCM formulae in treating hepatocellular carcinoma with different TCM syndromes

Introduction

Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality worldwide. Traditional Chinese Medicine (TCM) is widely utilized as an adjunct therapy, improving patient survival and quality of life. TCM categorizes HCC into five distinct syndromes, each treated with specific herbal formulae. However, the molecular mechanisms underlying these treatments remain unclear.

Methods

We employed a network medicine approach to explore the therapeutic mechanisms of TCM in HCC. By constructing a protein-protein interaction (PPI) network, we integrated genes associated with TCM syndromes and their corresponding herbal formulae. This allowed for a quantitative analysis of the topological and functional relationships between TCM syndromes, HCC, and the specific formulae used for treatment.

Results

Our findings revealed that genes related to the five TCM syndromes were closely associated with HCC-related genes within the PPI network. The gene sets corresponding to the five TCM formulae exhibited significant proximity to HCC and its related syndromes, suggesting the efficacy of TCM syndrome differentiation and treatment. Additionally, through a random walk algorithm applied to a heterogeneous network, we prioritized active herbal ingredients, with results confirmed by literature.

Discussion

The identification of these key compounds underscores the potential of network medicine to unravel the complex pharmacological actions of TCM. This study provides a molecular basis for TCM's therapeutic strategies in HCC and highlights specific herbal ingredients as potential leads for drug development and precision medicine.

Amentoflavone regulates the miR-124-3p/CAPN2 axis to promote mitochondrial autophagy in HCC cells

BACKGROUND

Hepatocellular carcinoma (HCC) is a disease with poor prognosis and high mortality. Amentoflavone (AF) possesses the characteristics of marginal toxicity, stable curative effect, and good anti-HCC activity. This study aimed to evaluate the molecular mechanism of AF inhibiting HCC and provide a new idea for HCC treatment.

METHODS

Clinical tissue of HCC was collected. AF was given with HCC cells, and transfected with corresponding vectors. MiR-124-3p expression in HCC clinical samples and cells was ascertained by qRT-PCR assay. HCC cells viability was identified by CCK-8 assay. LC3 protein expression was ascertained by immunofluorescence assay. The expressions of CAPN2, β-catenin and mitochondrial autophagy-related proteins were detected by western blot. Dual-luciferase reporter gene assay confirmed the targeting relationship of miR-124-3p and CAPN2.

RESULTS

MiR-124-3p expression was inhibited and CAPN2 expression was increased in HCC tissues and cells. AF decreased HCC cell viability, up-regulated miR-124-3p expression, and inhibited CAPN2 expression and β-catenin nuclear transcription. Moreover, AF could activate the mitochondrial autophagy of HCC cells. MiR-124-3p specifically regulated CAPN2 expression. This study found that CAPN2 could promote β-catenin nuclear translocation, thus activating wnt/β-catenin pathway to inhibit mitochondrial autophagy in HCC cells. MiR-124-3p mimics enhanced AF function in promoting mitochondrial autophagy in HCC cells. However, CAPN2 overexpression, miR-124-3p inhibitor and SKL2001 attenuated the effectiveness of AF.

CONCLUSION

This study confirmed that AF regulated miR-124-3p/CAPN2 axis to restraint β-catenin nuclear translocation and then inhibit the wnt/β-catenin pathway, thereby promoting mitochondrial autophagy in HCC.

Biological impact and therapeutic implication of tumor-associated macrophages in hepatocellular carcinoma

The tumor microenvironment is a complex space comprised of normal, cancer and immune cells. The macrophages are considered as the most abundant immune cells in tumor microenvironment and their function in tumorigenesis is interesting. Macrophages can be present as M1 and M2 polarization that show anti-cancer and oncogenic activities, respectively. Tumor-associated macrophages (TAMs) mainly have M2 polarization and they increase tumorigenesis due to secretion of factors, cytokines and affecting molecular pathways. Hepatocellular carcinoma (HCC) is among predominant tumors of liver that in spite of understanding its pathogenesis, the role of tumor microenvironment in its progression still requires more attention. The presence of TAMs in HCC causes an increase in growth and invasion of HCC cells and one of the reasons is induction of glycolysis that such metabolic reprogramming makes HCC distinct from normal cells and promotes its malignancy. Since M2 polarization of TAMs stimulates tumorigenesis in HCC, molecular networks regulating M2 to M1 conversion have been highlighted and moreover, drugs and compounds with the ability of targeting TAMs and suppressing their M2 phenotypes or at least their tumorigenesis activity have been utilized. TAMs increase aggressive behavior and biological functions of HCC cells that can result in development of therapy resistance. Macrophages can provide cell-cell communication in HCC by secreting exosomes having various types of biomolecules that transfer among cells and change their activity. Finally, non-coding RNA transcripts can mainly affect polarization of TAMs in HCC.

Advancements in Utilizing Natural Compounds for Modulating Autophagy in Liver Cancer: Molecular Mechanisms and Therapeutic Targets

Autophagy, an intrinsic catabolic mechanism that eliminates misfolded proteins, dysfunctional organelles, and lipid droplets, plays a vital function in energy balance and cytoplasmic quality control, in addition to maintaining cellular homeostasis. Liver cancer such as hepatocellular carcinoma (HCC) is one of the most common causes of cancer deaths globally and shows resistance to several anticancer drugs. Despite the rising incidence and poor prognosis of malignant HCC, the underlying molecular mechanisms driving this aggressive cancer remain unclear. Several natural compounds, such as phytochemicals of dietary and non-dietary origin, affect hepatocarcinogenesis signaling pathways in vitro and in vivo, which may help prevent and treat HCC cells. Current HCC cells treatments include chemotherapy, radiation, and surgery. However, these standard therapies have substantial side effects, and combination therapy enhances side effects for an acceptable therapeutic benefit. Therefore, there is a need to develop treatment strategies for HCC cells that are more efficacious and have fewer adverse effects. Multiple genetic and epigenetic factors are responsible for the HCC cells to become resistant to standard treatment. Autophagy contributes to maintain cellular homeostasis, which activates autophagy for biosynthesis and mitochondrial regulation and recycling. Therefore, modifying autophagic signaling would present a promising opportunity to identify novel therapies to treat HCC cells resistant to current standard treatments. This comprehensive review illustrates how natural compounds demonstrate their anti-hepatocellular carcinoma function through autophagy.

Research progress on antitumor effects of sea buckthorn, a traditional Chinese medicine homologous to food and medicine

Sea buckthorn (Hippophae Fructus), as a homologous species of medicine and food, is widely used by Mongolians and Tibetans for its anti-tumor, antioxidant and liver-protecting properties. In this review, the excellent anti-tumor effect of sea buckthorn was first found through network pharmacology, and its active components such as isorhamnetin, quercetin, gallic acid and protocatechuic acid were found to have significant anti-tumor effects. The research progress and application prospect of sea buckthorn and its active components in anti-tumor types, mechanism of action, liver protection, anti-radiation and toxicology were reviewed, providing theoretical basis for the development of sea buckthorn products in the field of anti-tumor research and clinical application.

Luteolin: A promising modulator of apoptosis and survival signaling in liver cancer

Due to the increasing incidence of cancer and the difficulties in determining the safety profile of existing therapeutic approaches, cancer research has recently become heavily involved in the search for new therapeutic approaches. The therapeutic significance of natural substances, especially flavonoids, against the onset and progression of cancer has been emphasized in traditional food-based medicine. Interestingly, the flavone luteolin possesses biological effects that have been linked to its anti-inflammatory, antioxidant, and anticancer effects. Luteolin interacts with several downstream chemicals and signaling pathways, including those involved in apoptosis, autophagy, cell cycle progression, and angiogenesis, to exert its anticancer effects on various cancerous cells. A complete understanding of both intrinsic and extrinsic apoptotic pathways, autophagy, and, most critically, the nanodelivery of luteolin in liver cancer is provided in the current review.

Lipid nanoparticles of quercetin (QU-Lip) alleviated pancreatic microenvironment in diabetic male rats: The interplay between oxidative stress - unfolded protein response (UPR) - autophagy, and their regulatory miRNA

BACKGROUND

Autophagy is a well-preserved mechanism essential in minimizing endoplasmic reticulum stress (ER)-related cell death. Defects in β-cell autophagy have been linked to type 1 diabetes, particularly deficits in the secretion of insulin, boosting ER stress sensitivity and possibly promoting pancreatic β-cell death. Quercetin (QU) is a potent antioxidant and anti-diabetic flavonoid with low bioavailability, and the precise mechanism of its anti-diabetic activity is still unknown. Aim This study aimed to design an improved bioavailable form of QU (liposomes) and examine the impact of its treatment on the alleviation of type 1 diabetes induced by STZ in rats.

METHODS

Seventy SD rats were allocated into seven equal groups 10 rats of each: control, STZ, STZ + 3-MA, STZ + QU-Lip, and STZ + 3-MA + QU-Lip. Fasting blood glucose, insulin, c-peptide, serum IL-6, TNF-α, pancreatic oxidative stress, TRAF-6, autophagy, endoplasmic reticulum stress (ER stress) markers expression and their regulatory microRNA (miRNA) were performed. As well as, docking analysis for the quercetin, ER stress, and autophagy were done. Finally, the histopathological and immunohistochemical analysis were conducted.

SIGNIFICANCE

QU-Lip significantly decreased glucose levels, oxidative, and inflammatory markers in the pancreas. It also significantly downregulated the expression of ER stress and upregulated autophagic-related markers. Furthermore, QU-Lip significantly ameliorated the expression of several MicroRNAs, which both control autophagy and ER stress signaling pathways. However, the improvement of STZ-diabetic rats was abolished upon combination with an autophagy inhibitor (3-MA). The findings suggest that QU-Lip has therapeutic promise in treating type 1 diabetes by modulating ER stress and autophagy via an epigenetic mechanism.

Selected Flavonols Targeting Cell Death Pathways in Cancer Therapy: The Latest Achievements in Research on Apoptosis, Autophagy, Necroptosis, Pyroptosis, Ferroptosis, and Cuproptosis

The complex and multi-stage processes of carcinogenesis are accompanied by a number of phenomena related to the potential involvement of various chemopreventive factors, which include, among others, compounds of natural origin such as flavonols. The use of flavonols is not only promising but also a recognized strategy for cancer treatment. The chemopreventive impact of flavonols on cancer arises from their ability to act as antioxidants, impede proliferation, promote cell death, inhibit angiogenesis, and regulate the immune system through involvement in diverse forms of cellular death. So far, the molecular mechanisms underlying the regulation of apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis, and cuproptosis occurring with the participation of flavonols have remained incompletely elucidated, and the results of the studies carried out so far are ambiguous. For this reason, one of the therapeutic goals is to initiate the death of altered cells through the use of quercetin, kaempferol, myricetin, isorhamnetin, galangin, fisetin, and morin. This article offers an extensive overview of recent research on these compounds, focusing particularly on their role in combating cancer and elucidating the molecular mechanisms governing apoptosis, autophagy, necroptosis, pyroptosis, ferroptosis, and cuproptosis. Assessment of the mechanisms underlying the anticancer effects of compounds in therapy targeting various types of cell death pathways may prove useful in developing new therapeutic regimens and counteracting resistance to previously used treatments.

Exploring the mechanism of bioactive components of Prunella vulgaris L. in treating hepatocellular carcinoma based on network pharmacology

In traditional Chinese Medicine, Prunella vulgaris L. (PVL) is potentially effective in the treatment of some human malignancies including hepatocellular carcinoma (HCC). However, the detailed mechanism of action remains unclear. The purpose of this study was to decipher the constitutes of the bioactive ingredients of PVL, and its mechanism against HCC using network pharmacology and in vitro experiments. The bioactive components of PVL were obtained by Traditional Chinese Medicine System Pharmacology Database and Analysis platform database, and the targets of bioactive components of PVL was investigated by Swiss Target Prediction database. HCC related targets were obtained from GEO database, GeneCards database and DisGeNET database, and the gene ontology function annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted for annotating the biological function of gene targets. A protein-protein interaction network was constructed using STRING database. Molecular docking of key bioactive ingredients was performed using AutoDock Vina. Cell proliferation and apoptosis were detected by cell counting kit-8 and flow cytometry, respectively. The expression level of the target genes of PI3K/Akt pathway were detected by qPCR. In the present work, 11 bioactive components of PVL were screened out, which acted on 177 potential targets. In addition, 13,517 genes were strongly associated with HCC pathogenesis, of which 158 targets are overlapped with PVL's targets. KEGG results identified 39 signaling pathways closely associated with the 158 targets. Molecular docking showed that the main bioactive components of PVL, kaempferol, morin, quercetin, luteolin, and spinasterol, had good binding activity with the core proteins in cancer biology such as AKT1, EGFR, SRC, ESR1, and PPARG. In vitro assays showed that quercetin, one of the main components of PVL extracts effectively inhibited HCC cell proliferation, and promoted apoptosis, which may be associated with PI3K/AKT signaling pathway. In summary, PVL may regulate HCC progression by regulating core targets such as AKT1, EGFR, SRC, ESR1, and PPARG, and acting on PI3K-Akt signaling pathway.

A Strategy based on Bioinformatics and Machine Learning Algorithms Reveals Potential Mechanisms of Shelian Capsule against Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a prevalent and life-threatening form of cancer, with Shelian Capsule (SLC), a traditional Chinese medicine (TCM) formulation, being recommended for clinical treatment. However, the mechanisms underlying its efficacy remain elusive. This study sought to uncover the potential mechanisms of SLC in HCC treatment using bioinformatics methods.

METHODS

Bioactive components of SLC were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), and HCC-related microarray chip data were sourced from the Gene Expression Omnibus (GEO) database. The selection criteria for components included OB ≧ 30% and DL ≧ 0.18. By integrating the results of differential expression analysis and weighted gene co-expression network analysis (WGCNA), disease-related genes were identified. Therapeutic targets were determined as shared items between candidate targets and disease genes. Protein-protein interaction (PPI) network analysis was conducted for concatenated genes, with core protein clusters identified using the MCODE plugin. Machine learning algorithms were applied to identify signature genes within therapeutic targets. Subsequently, immune cell infiltration analysis, single-cell RNA sequencing (sc-RNA seq) analysis, molecular docking, and ADME analysis were performed for the screened genes.

RESULTS

A total of 153 SLC ingredients and 170 candidate targets were identified, along with 494 HCCrelated disease genes. Overlapping items between disease genes and drug candidates represented therapeutic genes, and PPI network analysis was conducted using concatenated genes. MCODE1 and MCODE2 cluster genes underwent Disease Ontology (DO), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Four signature genes (TOP2A, CYP1A2, CYP2B6, and IGFBP3) were identified from 28 therapeutic genes using 3 machine learning algorithms, with ROC curves plotted. Molecular docking validated the interaction modes and binding abilities between signature genes and corresponding compounds, with free binding energy all <-7 kcal/mol. Finally, ADME analysis revealed similarities between certain SLC components and the clinical drugs Sorafenib and Lenvatinib.

CONCLUSION

In summary, our study revealed that the mechanism underlying the anti-HCC effects of SLC involves interactions at three levels: components (quercetin, beta-sitosterol, kaempferol, baicalein, stigmasterol, and luteolin), pathways (PI3K-Akt signaling pathway, TNF signaling pathway, and IL-17 signaling pathway), and targets (TOP2A, CYP1A2, CYP2B6, and IGFBP3). This study provides preliminary insights into the potential pharmacological mechanisms of SLC in HCC treatment, aiming to support its clinical application and serve as a reference for future laboratory investigations.

Dietary antioxidant quercetin overcomes the acquired resistance of Sorafenib in Sorafenib-resistant hepatocellular carcinoma cells through epidermal growth factor receptor signaling inactivation

Sorafenib (SOR) is a molecular targeting agent commonly utilized as a primary treatment for advanced and inoperable hepatocellular carcinoma (HCC). Regrettably, the effectiveness of SOR is frequently hindered by the resistance of multiple HCC cases. The current investigation endeavors to examine the potential of the natural product quercetin (QUE) in reversing the acquired resistance of SOR-resistant cells, known as Huh7R, to SOR. Moreover, this study aims to elucidate the underlying molecular mechanism that contributes to this phenomenon. The results demonstrated that QUE significantly impeded proliferation and stimulated apoptosis in Huh7R cells, while also suppressing the growth of transplanted tumors. The impact of QUE enhanced the efficacy of SOR treatment for Huh7R. Additionally, bioinformatic and western blot analyses indicated that the underlying mechanisms may be associated with EGFR tyrosine kinase inhibitor resistance, the PI3K-AKT signaling pathway, and HCC. Furthermore, molecular docking and dynamics simulation assays revealed that QUE exhibited strong affinity and stability towards its hub targets, EGFR and AKT1. It is noteworthy that the activation of EGFR by its ligand, EGF, mitigated the effects of co-treatment with QUE and SOR. These findings suggest that QUE might potentially serve as a therapeutic agent in treating as well as facilitating SOR against Huh7R cells, which has substantial clinical and research implications for the treatment of acquired resistance to SOR in HCC.

Identification of peanut skin components for treating hepatocellular carcinoma via network pharmacology and in vitro experiments

Peanut skin (PS) contains various flavonoids and phenols that have antitumor and antioxidant effects. However, no research has been conducted on PS and hepatocellular carcinoma (HCC). Therefore, this study sought to explore the potential mechanism of PS in treating HCC. PS was searched for in the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and SYMMAP databases. HCC targets were searched for in five major databases. Protein-protein interaction network, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes analyses were performed. Molecular docking and molecular dynamics simulation were used for verification. Furthermore, in vitro experiments were used to verify the regulation of PS on human HCC (HepG2) cells. Ten ingredients and 95 common targets were identified for PS and HCC, respectively. The key targets of ingredients mainly relate to pathways such as hepatitis B, lipid and atherosclerosis, advanced glycation end products (AGEs)-AGE receptors (RAGEs) signaling pathway in diabetic complications, interleukin-17 (IL-17) signaling pathway, mitogen activated kinase-like protein (MAPK) signaling pathway, the PI3K-Akt signaling pathway. In addition, the molecular docking and molecular dynamics simulation analysis indicated the ingredients had strong binding ability with the targets. Moreover, in vitro experiments confirmed that luteolin can promote the apoptosis of HepG2 cells by controlling the expression of phosphorylated protein-tyrosine kinase (p-AKT). This study provides preliminary evidence that PS produces a marked effect in regulating multiple signaling pathways in HCC through multiple ingredients acting on multiple core genes, including AKT serine/threonine kinase 1 (AKT1), MYC, caspase 3 (CASP3), estrogen receptor 1 (ESR1), epidermal growth factor receptor (EGFR), jun proto-oncogene(JUN), and provides the basis for follow-up research to verify the mechanism of action of PS in treating HCC.

A study related to the treatment of gastric cancer with Xiang-Sha-Liu-Jun-Zi-Tang based on network analysis

Purpose

Xiang-Sha-Liu-Jun-Zi-Tang(XSLJZT) is a common formula for the treatment of Gastric Cancer(GC) and is widely used in clinical practice, however, there is a lack of investigation into its mechanism.

Methods

We collected and organized drug and disease targets, constructed the "XSLJZT-Active Ingredient-Target" visualization network, and performed GO and KEGG functional enrichment analysis of crossover genes, followed by molecular docking of active ingredients and core targets. The best docked monomers were combined with weighted gene co-expression network analysis(WGCNA) and macroscopically analyzed by GO and KEGG enrichment techniques. The results of cluster gene difference analysis, ROC evaluation, and CIBERSORT immune infiltration analysis were evaluated and finally supported by cellular experiments.

Results

The main components of XSLJZT are quercetin, stigmasterol, and naringenin, effectively treat GC by targeting STAT3, TP53 and MAPK3, which are involved in IL-17, TNF and HIF-1 signaling pathways. The results of molecular docking showed that quercetin bound better to the core targets. We performed an in-depth analysis of this monomer and found that quercetin acts on the core targets of TP53, MMP9, TIMP1 and MYC, and is involved in two key signaling pathways, TNF and IL-17, thus effectively treating GC. The experimental results are consistent with our analysis that quercetin inhibits the proliferation of GC cells and promotes apoptosis, and TP53, MYC and TIMP1 are the quercetin targets for the treatment of GC.

Conclusion

The present study tentatively suggests that quercetin, the main active ingredient in XSLJZT, can exert a therapeutic effect on GC by targeting TIMP1.

Network pharmacology and bioinformatics were used to construct a prognostic model and immunoassay of core target genes in the combination of quercetin and kaempferol in the treatment of colorectal cancer

Purpose: CRC is a malignant tumor seriously threatening human health. Quercetin and kaempferol are representative components of traditional Chinese medicine (TCM). Previous studies have shown that both quercetin and kaempferol have antitumor pharmacological effects, nevertheless, the underlying mechanism of action remains unclear. To explore the synergy and mechanism of quercetin and kaempferol in colorectal cancer. Methods: In this study, network pharmacology, and bioinformatics are used to obtain the intersection of drug targets and disease genes. Training gene sets were acquired from the TCGA database, acquired prognostic-related genes by univariate Cox, multivariate Cox, and Lasso-Cox regression models, and validated in the GEO dataset. We also made predictions of the immune function of the samples and used molecular docking to map a model for binding two components to prognostic genes. Results: Through Lasso-Cox regression analysis, we obtained three models of drug target genes. This model predicts the combined role of quercetin and kaempferol in the treatment and prognosis of CRC. Prognostic genes are correlated with immune checkpoints and immune infiltration and play an adjuvant role in the immunotherapy of CRC. Conclusion: Core genes are regulated by quercetin and kaempferol to improve the patient's immune system and thus assist in the treatment of CRC.

Targeting Oxidative Stress with Polyphenols to Fight Liver Diseases

Reactive oxygen species (ROS) are important second messengers in many metabolic processes and signaling pathways. Disruption of the balance between ROS generation and antioxidant defenses results in the overproduction of ROS and subsequent oxidative damage to biomolecules and cellular components that disturb cellular function. Oxidative stress contributes to the initiation and progression of many liver pathologies such as ischemia-reperfusion injury (LIRI), non-alcoholic fatty liver disease (NAFLD), and hepatocellular carcinoma (HCC). Therefore, controlling ROS production is an attractive therapeutic strategy in relation to their treatment. In recent years, increasing evidence has supported the therapeutic effects of polyphenols on liver injury via the regulation of ROS levels. In the current review, we summarize the effects of polyphenols, such as quercetin, resveratrol, and curcumin, on oxidative damage during conditions that induce liver injury, such as LIRI, NAFLD, and HCC.

Apoptotic Mechanisms of Quercetin in Liver Cancer: Recent Trends and Advancements

Due to rising incidence rates of liver cancer and worries about the toxicity of current chemotherapeutic medicines, the hunt for further alternative methods to treat this malignancy has escalated. Compared to chemotherapy, quercetin, a flavonoid, is relatively less harmful to normal cells and is regarded as an excellent free-radical scavenger. Apoptotic cell death of cancer cells caused by quercetin has been demonstrated by many prior studies. It is present in many fruits, vegetables, and herbs. Quercetin targets apoptosis, by upregulating Bax, caspase-3, and p21 while downregulating Akt, PLK-1, cyclin-B1, cyclin-A, CDC-2, CDK-2, and Bcl-2. Additionally, it has been reported to increase STAT3 protein degradation in liver cancer cells while decreasing STAT3 activation. Quercetin has a potential future in chemoprevention, based on substantial research on its anticancer effects. The current review discusses quercetin's mechanisms of action, nanodelivery strategies, and other potential cellular effects in liver cancer.

Targeting and regulation of autophagy in hepatocellular carcinoma: revisiting the molecular interactions and mechanisms for new therapy approaches

Autophagy is an evolutionarily conserved process that plays a role in regulating homeostasis under physiological conditions. However, dysregulation of autophagy is observed in the development of human diseases, especially cancer. Autophagy has reciprocal functions in cancer and may be responsible for either survival or death. Hepatocellular carcinoma (HCC) is one of the most lethal and common malignancies of the liver, and smoking, infection, and alcohol consumption can lead to its development. Genetic mutations and alterations in molecular processes can exacerbate the progression of HCC. The function of autophagy in HCC is controversial and may be both tumor suppressive and tumor promoting. Activation of autophagy may affect apoptosis in HCC and is a regulator of proliferation and glucose metabolism. Induction of autophagy may promote tumor metastasis via induction of EMT. In addition, autophagy is a regulator of stem cell formation in HCC, and pro-survival autophagy leads to cancer cell resistance to chemotherapy and radiotherapy. Targeting autophagy impairs growth and metastasis in HCC and improves tumor cell response to therapy. Of note, a large number of signaling pathways such as STAT3, Wnt, miRNAs, lncRNAs, and circRNAs regulate autophagy in HCC. Moreover, regulation of autophagy (induction or inhibition) by antitumor agents could be suggested for effective treatment of HCC. In this paper, we comprehensively review the role and mechanisms of autophagy in HCC and discuss the potential benefit of targeting this process in the treatment of the cancer. Video Abstract.

Targets Involved in the Anti-Cancer Activity of Quercetin in Breast, Colorectal and Liver Neoplasms

Phytochemicals have long been effective partners in the fight against several diseases, including cancer. Among these, flavonoids are valuable allies for both cancer prevention and therapy since they are known to influence a large panel of tumor-related processes. Particularly, it was revealed that quercetin, one of the most common flavonoids, controls apoptosis and inhibits migration and proliferation, events essential for the development of cancer. In this review, we collected the evidence on the anti-cancer activity of quercetin exploring the network of interactions between this flavonol and the proteins responsible for cancer onset and progression focusing on breast, colorectal and liver cancers, owing to their high worldwide incidence. Moreover, quercetin proved to be also a potentiating agent able to push further the anti-cancer activity of common employed anti-neoplastic agents, thus allowing to lower their dosages and, above all, to sensitize again resistant cancer cells. Finally, novel approaches to delivery systems can enhance quercetin's pharmacokinetics, thus boosting its great potentiality even further. Overall, quercetin has a lot of promise, given its multi-target potentiality; thus, more research is strongly encouraged to properly define its pharmaco-toxicological profile and evaluate its potential for usage in adjuvant and chemoprevention therapy.

Systems Pharmacology-Based Strategy to Investigate the Mechanism of Ruangan Lidan Decoction for Treatment of Hepatocellular Carcinoma

epatocellular carcinoma (HCC) is one of the leading contributors to cancer mortality worldwide. Currently, the prevention and treatment of HCC remains a major challenge. As a traditional Chinese medicine (TCM) formula, Ruangan Lidan decoction (RGLD) has been proved to own the effect of relieving HCC symptoms. However, due to its biological effects and complex compositions, its underlying mechanism of actions (MOAs) have not been fully clarified yet. In this study, we proposed a pharmacological framework to systematically explore the MOAs of RGLD against HCC. We firstly integrated the active ingredients and potential targets of RGLD. We next highlighted 25 key targets that played vital roles in both RGLD and HCC disease via a protein-protein interaction (PPI) network and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Furthermore, an ingredient-target network of RGLD consisting of 216 ingredients with 306 targets was constructed, and multilevel systems pharmacology analyses indicated that RGLD could act on multiple biological processes related to the pathogenesis of HCC, such as cellular response to hypoxia and cell proliferation. Additionally, integrated pathway analysis of RGLD uncovered that RGLD might treat HCC through regulating various pathways, including MAPK signaling pathway, PI3K/Akt signaling pathway, TNF signaling pathway, and ERBB signaling pathway. Survival analysis results showed that HCC patients with low expression of VEGFA, HIF1A, CASP8, and TOP2A were related with a higher survival rate than those with high expression, indicating the potential clinical significance for HCC. Finally, molecular docking results of core ingredients and targets further proved the feasibility of RGLD in the treatment of HCC. Overall, this study indicates that RGLD may treat HCC through multiple mechanisms, which also provides a potential paradigm to investigate the MOAs of TCM prescription.

Natural-Product-Mediated Autophagy in the Treatment of Various Liver Diseases

Autophagy is essential for the maintenance of hepatic homeostasis, and autophagic malfunction has been linked to the pathogenesis of substantial liver diseases. As a popular source of drug discovery, natural products have been used for centuries to effectively prevent the progression of various liver diseases. Emerging evidence has suggested that autophagy regulation is a critical mechanism underlying the therapeutic effects of these natural products. In this review, relevant studies are retrieved from scientific databases published between 2011 and 2022, and a novel scoring system was established to critically evaluate the completeness and scientific significance of the reviewed literature. We observed that numerous natural products were suggested to regulate autophagic flux. Depending on the therapeutic or pathogenic role autophagy plays in different liver diseases, autophagy-regulative natural products exhibit different therapeutic effects. According to our novel scoring system, in a considerable amount of the involved studies, convincing and reasonable evidence to elucidate the regulatory effects and underlying mechanisms of natural-product-mediated autophagy regulation was missing and needed further illustration. We highlight that autophagy-regulative natural products are valuable drug candidates with promising prospects for the treatment of liver diseases and deserve more attention in the future.

Targeting of non-apoptotic cancer cell death mechanisms by quercetin: Implications in cancer therapy

The ultimate goal of cancer treatment is to kill cancer cells, based on the use of various therapeutic agents, such as chemotherapy, radiotherapy, or targeted therapy drugs. Most drugs exert their therapeutic effects on cancer by targeting apoptosis. However, alterations in apoptosis-related molecules and thus assisting cells to evade death, eventually lead to tumor cell resistance to therapeutic drugs. The increased incidence of non-apoptotic cell death modes such as induced autophagy, mitotic catastrophe, senescence, and necrosis is beneficial to overcoming multidrug resistance mediated by apoptosis resistance in tumor cells. Therefore, investigating the function and mechanism of drug-induced non-apoptotic cell death modes has positive implications for the development of new anti-cancer drugs and therapeutic strategies. Phytochemicals show strong potential as an alternative or complementary medicine for alleviating various types of cancer. Quercetin is a flavonoid compound widely found in the daily diet that demonstrates a significant role in inhibiting numerous human cancers. In addition to direct pro-tumor cell apoptosis, both in vivo and in vitro experiments have shown that quercetin exerts anti-tumor properties by triggering diverse non-apoptotic cell death modes. This review summarized the current status of research on the molecular mechanisms and targets through which quercetin-mediated non-apoptotic mode of cancer cell death, including autophagic cell death, senescence, mitotic catastrophe, ferroptosis, necroptosis, etc.

Isoliquiritigenin inhibits pancreatic cancer progression through blockade of p38 MAPK-regulated autophagy

BACKGROUND

Pancreatic cancer has been characterized by poor prognosis, early metastasis and dissatisfactory treatment outcome. The high basal level of autophagy in tumor cells leads to chemoresistance and tumor progression. Thus, it is imminent to explore novel effective chemotherapeutic adjuvants to increase patients' survival rate. Isoliquiritigenin (ISL) is a bioactive flavonoid obtained from the Traditional Chinese herbal medicine Glycyrrhiza glabra, and it possesses a broad range of pharmacological effects. In this study, the anti-cancer effect of ISL in pancreatic cancer treatment and the underlying mechanism are investigated.

METHODS

MTT assay, colony formation and EdU analysis were performed to explore the growth inhibition of ISL on pancreatic cancer cells. Apoptosis were analyzed using TUNEL and flow cytometry. The formations of autophagosomes were analyzed by immunofluorescence microscopy and transmission electron microscopy. RFP-GFP-LC3B probe was applied to detect the autophagy flux. To assess the structural interaction of ISL with p38 protein, molecular docking assays were performed. The molecular mechanism was elucidated by using western immunoblotting. Subsequently, the inhibition of ISL on tumor growth was determined in vivo using pancreatic tumor mice model.

RESULTS

ISL inhibited pancreatic cancer cell growth and induced apoptosis, both in vitro and in vivo. ISL caused accumulation of autophagosome through blockade of late stage autophagic flux. Moreover, autophagy inducer rapamycin enhanced ISL-evoked cell growth inhibition and promoted apoptosis, while inhibition of autophagosome formation by siAtg5 attenuated ISL-induced apoptosis. It is remarkable that ISL synergistically sensitized the cytotoxic effect of gemcitabine and 5-fluorouracil on pancreatic cancer cells as both drugs induced autophagy. Molecular docking analysis has indicated that ISL acted by direct targeting of p38 MAPK, which was confirmed by ISL-induced phosphorylation of p38. The autophagy flux induced by p38 inhibitor SB203580 was blocked by ISL, with further increasing toxicity of ISL in pancreatic cancer cells.

CONCLUSION

The results have revealed that ISL inhibited pancreatic cancer progression by blockade of autophagy through p38 MAPK signaling.

Exploring the potential targets of Sanshimao formula for hepatocellular carcinoma treatment by a method of network pharmacology combined with molecular biology

ETHNOPHARMACOLOGICAL RELEVANCE

The Sanshimao (SSM) formula is an effective prescription for hepatocellular carcinoma (HCC) therapy in the clinical setting. This prescription is made up of four herbals, Maorenshen, Shijianchuan, Shishangbai and Shidachuan, which are used for detoxification and removing blood stasis. However, its mechanism in the treatment of HCC remains ambiguous.

AIM OF THE STUDY

To explore the potential targets of SSM against HCC by network pharmacology analysis and verify the data using molecular biological methods.

MATERIALS AND METHODS

We screened active components and potential targets by data mining, constructed a network, and performed functional analysis and pathway enrichment to explore the therapeutic targets of SSM for HCC treatment. Then, the effects of SSM on HCC cells were studied to validate the data from network pharmacology analysis.

RESULTS

Eighty-eight common targets were obtained by mapping 932 HCC-related genes, and 325 targets corresponded to 11 active components of SSM. They were enriched in various biological processes, such as the response to inorganic substances, response to toxic substances and apoptotic signalling pathway, and multi-pathways involved pathways in cancer, EGFR tyrosine kinase inhibitor resistance, and AGE-RAGE signalling pathway in diabetic complications, as evaluated by the analysis of advanced functions and pathways. TP53, JUN, HSP90AA1, EGFR, AR and MAPK1 might be the core targets closely related to the effects of SSM on HCC according to PPI analysis. Treatment with SSM decreased cell viability and migration, promoted apoptosis and inhibited the EGFR/FAK/AKT signalling pathway.

CONCLUSION

This research preliminarily indicates that SSM treats HCC via multiple components and pathways. EGFR/FAK/AKT are promising therapeutic targets of SSM for HCC treatment. This provides objective evidence for further mechanistic research and the future development and clinical application of SSM in HCC patients.

Smp24, a Scorpion-Venom Peptide, Exhibits Potent Antitumor Effects against Hepatoma HepG2 Cells via Multi-Mechanisms In Vivo and In Vitro

Scorpion-venom-derived peptides have become a promising anticancer agent due to their cytotoxicity against tumor cells via multiple mechanisms. The suppressive effect of the cationic antimicrobial peptide Smp24, which is derived from the venom of ScorpioMaurus palmatus, on the proliferation of the hepatoma cell line HepG2 has been reported earlier. However, its mode of action against HepG2 hepatoma cells remains unclear. In the current research, Smp24 was discovered to suppress the viability of HepG2 cells while having a minor effect on normal LO2 cells. Moreover, endocytosis and pore formation were demonstrated to be involved in the uptake of Smp24 into HepG2 cells, which subsequently interacted with the mitochondrial membrane and caused the decrease in its potential, cytoskeleton reorganization, ROS accumulation, mitochondrial dysfunction, and alteration of apoptosis- and autophagy-related signaling pathways. The protecting activity of Smp24 in the HepG2 xenograft mice model was also demonstrated. Therefore, our data suggest that the antitumor effect of Smp24 is closely related to the induction of cell apoptosis, cycle arrest, and autophagy via cell membrane disruption and mitochondrial dysfunction, suggesting a potential alternative in hepatocellular carcinoma treatment.

Investigation of Anti-Liver Cancer Activity of the Herbal Drug FDY003 Using Network Pharmacology

Globally, liver cancer (LC) is the sixth-most frequently occurring and the second-most fatal malignancy, responsible for 0.83 million deaths annually. Although the application of herbal drugs in cancer therapies has increased, their anti-LC activity and relevant mechanisms have not been fully studied from a systems perspective. To address these issues, we conducted a system-perspective network pharmacological investigation into the activity and mechanisms underlying the action of the herbal drug. FDY003 reduced the viability of human LC treatment. FDY003 reduced the viability of human LC cells and elevated their chemosensitivity. There were a total of 16 potential bioactive chemical components in FDY003 and they had 91 corresponding targets responsible for the pathological processes in LC. These FDY003 targets were functionally involved in regulating the survival, proliferation, apoptosis, and cell cycle of LC cells. Additionally, we found that FDY003 may target key signaling cascades connected to diverse LC pathological mechanisms, namely, PI3K-Akt, focal adhesion, IL-17, FoxO, MAPK, and TNF pathways. Overall, this study contributed to integrative mechanistic insights into the anti-LC potential of FDY003.

Intracellular Pathways and Mechanisms of Colored Secondary Metabolites in Cancer Therapy

Despite the great advancements made in cancer treatment, there are still many unsatisfied aspects, such as the wide palette of side effects and the drug resistance. There is an obvious increasing scientific attention towards nature and what it can offer the human race. Natural products can be used to treat many diseases, of which some plant products are currently used to treat cancer. Plants produce secondary metabolites for their signaling mechanisms and natural defense. A variety of plant-derived products have shown promising anticancer properties in vitro and in vivo. Rather than recreating the natural production environment, ongoing studies are currently setting various strategies to significantly manipulate the quantity of anticancer molecules in plants. This review focuses on the recently studied secondary metabolite agents that have shown promising anticancer activity, outlining their potential mechanisms of action and pathways.

Mechanisms and network pharmacological analysis of Yangyin Fuzheng Jiedu prescription in the treatment of hepatocellular carcinoma

OBJECTIVE

To identify the key drugs of Yangyin Fuzheng Jiedu prescription (YFJP) and investigate their therapeutic effects against hepatocellular carcinoma (HCC) and the potential mechanism using network pharmacology.

METHODS

The H22 tumor-bearing mouse model was established. Thirty male BALB/c mice were divided randomly into five groups. The mice were orally treated with either disassembled prescriptions of YFJP or saline solution continuously for 14 days. The mice were weighed every 2 days during treatment and the appearance of tumors was observed by photographing. The tumor inhibition rate and the spleen and thymus indexes were calculated. Hematoxylin and eosin and immunohistochemical staining were performed to observe the histological changes and tumor-infiltrating lymphocytes. Cell apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining. The proportion of CD8⁺ T cells and the expression of programmed cell death protein 1 (PD-1), T cell immunoglobulin domain and mucin domain-3 (Tim-3), and T cell immunoreceptor with Ig and ITIM domains (TIGIT) were analyzed using flow cytometry. The production of serum cytokines was detected using the Milliplex® MAP mouse high sensitivity T cell panel kit. The active components of the key drugs and HCC-related target proteins were obtained from the corresponding databases. The putative targets for HCC treatment were screened by target mapping, and potential active components were screened by constructing a component-target network. The interactive targets of putative targets were obtained from the STRING database to construct the protein-protein interaction network. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes pathway enrichment analyses were performed based on potential targets. The gene-gene inner and component-target-pathway networks were constructed and analyzed to screen the key targets. Western blotting was used to evaluate the protein expression of the key targets in the tumor-bearing mouse model. The binding activity of the key targets and compounds was verified by molecular docking.

RESULTS

Among the three disassembled prescriptions of YFJP, the Fuzheng prescription (FZP) showed significant antitumor effects and inhibited weight loss during the treatment of H22 tumor-bearing mice. FZP increased the immune organ index and the levels of CD8⁺ and CD3⁺ T cells in the spleen and peripheral blood of H22 tumor-bearing mice. FZP also reduced the expression of PD-1, TIGIT, and TIM3 in CD8⁺ T cells and the production of IL-10, IL-4, IL-6, and IL-1β. Network pharmacology and experimental validation showed that the key targets of FZP in the treatment of HCC were PIK3CA, TP53, MAPK1, MAPK3, and EGFR. The therapeutic effect on HCC was evaluated based on HCC-related signaling pathways, including the PIK3-Akt signaling pathway, PD-L1 expression, and PD-1 checkpoint pathway in cancer. GO enrichment analysis indicated that FZP positively regulated the molecular functions of transferases and kinases on the cell surface through membrane raft, membrane microarea, and other cell components to inhibit cell death and programmed cell death.

CONCLUSION

FZP was found to be the key disassembled prescription of YFJP that exerted antitumor and immunoregulatory effects against HCC. FZP alleviated T cell exhaustion and improved the immunosuppressive microenvironment via HCC-related targets, pathways, and biological processes.

A renewed concept on the MAPK signaling pathway in cancers: Polyphenols as a choice of therapeutics

Abnormalities in the mitogen-activated protein kinase (MAPK) signaling pathway are a key contributor to the carcinogenesis process and have therefore been implicated in several aspects of tumorigenesis, including cell differentiation, proliferation, invasion, angiogenesis, apoptosis, and metastasis. This pathway offers multiple molecular targets that may be modulated for anticancer activity and is of great interest for several malignancies. Polyphenols from various dietary sources have been observed to interfere with certain aspects of this pathway and consequently play a substantial role in the development and progression of cancer by suppressing cell growth, inactivating carcinogens, blocking angiogenesis, causing cell death, and changing immunity. A good number of polyphenolic compounds have shown promising outcomes in numerous pieces of research and are currently being investigated clinically to treat cancer patients. The current study concentrates on the role of the MAPK pathway in the development and metastasis of cancer, with particular emphasis on dietary polyphenolic compounds that influence the different MAPK sub-pathways to obtain an anticancer effect. This study aims to convey an overview of the various aspects of the MAPK pathway in cancer development and invasion, as well as a review of the advances achieved in the development of polyphenols to modulate the MAPK signaling pathway for better treatment of cancer.

Active ingredients and molecular targets of Taraxacum mongolicum against hepatocellular carcinoma: network pharmacology, molecular docking, and molecular dynamics simulation analysis

Background

Taraxacum mongolicum (TM) is a widely used herb. Studies have reported that TM exhibits growth-inhibitory and apoptosis-inducing on multiple tumors, including hepatocellular carcinoma (HCC). The active ingredients, targets, and molecular mechanisms of TM against HCC need to be further elucidated.

Methods

We identified the active ingredients and targets of TM via HERB, PubChem, SwissADME, SwissTargetPrediction, and PharmMapper. We searched HCC targets from GeneCards, Comparative Toxicogenomics Database (CTD), and DisGeNET. Then, the intersection of drug targets and disease targets was uploaded to the STRING database to construct protein-protein interactions (PPI) networking whose topology parameters were analyzed in Cytoscape software to screen hub targets. Next, we used Metascape for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and we employed AutoDock vina, AMBER18 and PyMOL software along with several auxiliary tools for molecular docking and molecular dynamics (MD) simulation. Finally, based on the in silico findings, cellular experiments were conducted to investigate the effect of TM on HSP90AA1 gene expression.

Results

A total of 228 targets and 35 active ingredients were identified. Twenty two hub targets were selected through PPI networking construction for further investigation. The enrichment analysis showed that protein kinase binding, mitogenactivated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathways were mainly involved. Molecular docking and MD simulation results supported good interaction between HSP90 protein and Austricin/Quercetin. The in vitro assay showed that TM inhibited the proliferation of HepG2 cells and the expression of HSP90AA1 gene.

Conclusions

This study is the first to use network pharmacology, molecular docking, MD simulation and cellular experiments to elucidate the active ingredients, molecular targets, and key biological pathways responsible for TM anti-HCC, providing a theoretical basis for further research.

Quercetin encapsulated in Folic Acid-Modified Liposomes is therapeutic against osteosarcoma by non-Covalent binding to the JH2 Domain of JAK2 Via the JAK2-STAT3-PDL1

Osteosarcoma (OS) is a malignant solid tumor prone to lung metastasis that occurs in adolescents aged 15-19 years. Neoadjuvant chemotherapy and surgical treatment aimed at curing OS have gained limited progress over the last 30 years. Exploring new effective second-line therapies for OS patients is a serious challenge for researchers. Quercetin, a multiple biologically active polyphenolic flavonoid, has been used in tumor therapy. However, the exact mechanism of quercetin is still unknown, which limits the application of quercetin. In the current study, we found that quercetin could inhibit JAK2 through the JH2 domain in a non-covalent manner, resulting in the inhibition of OS proliferation and immune escape via the JAK2-STAT3-PD-L1 signaling axis. More importantly, to overcome the shortcomings of quercetin, including low water solubility and low oral availability, we encapsulated it with folic acid-modified liposomes. The transportation of quercetin by folic acid-modified liposomes may provide a feasible strategy to cure OS.

Application of Quercetin in the Treatment of Gastrointestinal Cancers

Many cellular signaling pathways contribute to the regulation of cell proliferation, division, motility, and apoptosis. Deregulation of these pathways contributes to tumor cell initiation and tumor progression. Lately, significant attention has been focused on the use of natural products as a promising strategy in cancer treatment. Quercetin is a natural flavonol compound widely present in commonly consumed foods. Quercetin has shown significant inhibitory effects on tumor progression via various mechanisms of action. These include stimulating cell cycle arrest or/and apoptosis as well as its antioxidant properties. Herein, we summarize the therapeutic effects of quercetin in gastrointestinal cancers (pancreatic, gastric, colorectal, esophageal, hepatocellular, and oral).

Quercetin Regulates Key Components of the Cellular Microenvironment during Early Hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is a health problem worldwide due to its high mortality rate, and the tumor microenvironment (TME) plays a key role in the HCC progression. The current ineffective therapies to fight the disease still warrant the development of preventive strategies. Quercetin has been shown to have different antitumor activities; however, its effect on TME components in preneoplastic lesions has not been fully investigated yet. Here, we aimed to evaluate the effect of quercetin (10 mg/kg) on TME components during the early stages of HCC progression induced in the rat. Histopathological and immunohistochemical analyses showed that quercetin decreases the size of preneoplastic lesions, glycogen and collagen accumulation, the expression of cancer stem cells and myofibroblasts markers, and that of the transporter ATP binding cassette subfamily C member 3 (ABCC3), a marker of HCC progression and multi-drug resistance. Our results strongly suggest that quercetin has the capability to reduce key components of TME, as well as the expression of ABCC3. Thus, quercetin can be an alternative treatment for inhibiting the growth of early HCC tumors.

Autophagy as a molecular target of quercetin underlying its protective effects in human diseases

Autophagy, known as a "self-eating" process, is associated with degradation of aged or damaged components and organelles. Generally, autophagy is a survival mechanism that provides energy during nutritional deprivation. This mechanism plays a remarkable role during the physiological condition by maintaining homeostasis and energy balance and several pathological conditions, particularly neurological disorders. Due to the critical role of autophagy in cancer, much attention has been made in the regulation of autophagy using both naturally occurring and synthetic drugs. Quercetin is a plant-derived chemical belonging to the family of flavonoids. Quercetin has valuable biological and therapeutic effects such as anti-tumor, antioxidant, anti-inflammatory, anti-diabetic, hepatoprotective, and cardioprotective. At the present review, we first provide an introduction about quercetin and autophagy with its related molecular pathways. We also describe how quercetin modulates autophagy mechanism to exert its therapeutic effects.

Targeting PI3K/Akt/mTOR Pathway by Different Flavonoids: A Cancer Chemopreventive Approach

Cancer is, globally, one of the main causes of death. Even though various therapies are available, they are still painful because of their adverse side effects. Available treatments frequently fail due to unpromising responses, resistance to classical anticancer drugs, radiation therapy, chemotherapy, and low accessibility to tumor tissues. Developing novel strategies to minimize adverse side effects, improve chemotherapy sensitivity, and control cancer progression is needed. Many studies have suggested small dietary molecules as complementary treatments for cancer patients. Different components of herbal/edible plants, known as flavonoids, have recently garnered attention due to their broad biological properties (e.g., antioxidant, antiviral, antimicrobial, anti-inflammatory, anti-mutagenic, anticancer, hepatoprotective, and cardioprotective). These flavonoids have shown anticancer activity by affecting different signaling cascades. This article summarizes the key progress made in this area and discusses the role of flavonoids by specifically inhibiting the PI3K/Akt/mTOR pathway in various cancers.

Cogent role of flavonoids as key orchestrators of chemoprevention of hepatocellular carcinoma: A review

Chemopreventive approaches with food-derived phytochemicals are progressively rising as a significant aspect of tumor management and control. Herein, we have showcased the major phytoconstituents belonging to the group of flavanoid, as anti-cancer agents used for the treatment and prevention of hepatocellular carcinoma (HCC). Sorafenib is the sole drug used for the treatment of advanced HCC, but its clinical application is limited because of its severe adverse effects and drug resistance. Diet-based chemoprevention seems to be the way forward for this disease of malignant nature. As HCC is derived from a chronic inflammatory milieu, the regular incorporation of bioactive phytochemicals in the diet will confer protection and prevent progression to hepatocarcinogenesis. Many preclinical studies proved that the health benefits of flavonoids confer cytotoxic potential against various types of cancers including hepatocellular carcinoma. As flavonoids with excellent safety profile are abundantly present in common vegetables and fruits, they can be better utilized for chemoprevention and chemosensitization in such chronic condition. This review highlights the plausible role of the eight most promising flavonoids (Curcumin, Kaempferol, Resveratrol, Quercetin, Silibinin, Baicalein, Galangin and Luteolin) as key orchestrators of chemoprevention in hepatocellular carcinoma with preclinical and clinical evidence. An attempt to address the challenges in its clinical translation is also included. This review also provides an insight into the close association of HCC and metabolic disorders which may further decipher the chemopreventive effect of dietary bioactive from a proof of concept to extensive clinical translation. PRACTICAL APPLICATIONS: According to GLOBOCAN 2020 database, it is estimated that 905,677 new cases of liver cancer and approximately 830,180 deaths related to that. The cancer incidence and mortality are almost similar as it is diagnosed at an advanced stage in patients where systemic drug therapy is the sole approach. Due to the emergence of multidrug resistance and drug-related toxicities, most of the patient can not adhere to the therapy regimen. Flavonoids are known to be a potential anticancer agent with an excellent safety profile. These are found to be effective preclinically against hepatocellular carcinoma through modulation of numerous pathways in hepatocarcinogenesis. But, the bioavailability issue, lack of well designed-validated clinical evidence, the possibility of food-drug interaction etc limit its clinical utility. The research inputs mainly to overcome pharmacokinetic issues along with suitable validation of efficacy and toxicity will be a critical point for establishing flavonoids as an effective, safe, affordable therapeutics.

Quercetin as a protective agent for liver diseases: A comprehensive descriptive review of the molecular mechanism

Quercetin is the major representative of the flavonoid subgroup of flavones, with good pharmacological activities for the treatment of liver diseases, including liver steatosis, fatty hepatitis, liver fibrosis, and liver cancer. It can significantly influence the development of liver diseases via multiple targets and multiple pathways via antifat accumulation, anti-inflammatory, and antioxidant activity, as well as the inhibition of cellular apoptosis and proliferation. Despite extensive research on understanding the mechanism of quercetin in the treatment of liver diseases, there are still no targeted therapies available. Thus, we have comprehensively searched and summarized the different targets of quercetin in different stages of liver diseases and concluded that quercetin inhibited inflammation of the liver mainly through NF-κB/TLR/NLRP3, reduced PI3K/Nrf2-mediated oxidative stress, mTOR activation in autophagy, and inhibited the expression of apoptotic factors associated with the development of liver diseases. In addition, quercetin showed different mechanisms of action at different stages of liver diseases, including the regulation of PPAR, UCP, and PLIN2-related factors via brown fat activation in liver steatosis. The compound inhibited stromal ECM deposition at the liver fibrosis stage, affecting TGF1β, endoplasmic reticulum stress (ERs), and apoptosis. While at the final liver cancer stage, inhibiting cancer cell proliferation and spread via the hTERT, MEK1/ERK1/2, Notch, and Wnt/β-catenin-related signaling pathways. In conclusion, quercetin is an effective liver protectant. We hope to explore the pathogenesis of quercetin in different stages of liver diseases through the review, so as to provide more accurate targets and theoretical basis for further research of quercetin in the treatment of liver diseases.

Endoplasmic Reticulum Stress and Autophagy in the Pathogenesis of Non-alcoholic Fatty Liver Disease (NAFLD): Current Evidence and Perspectives

PURPOSE OF REVIEW

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease with rising prevalence worldwide. Herein, we provide a comprehensive overview of the current knowledge supporting the role of ER stress and autophagy processes in NAFLD pathogenesis and progression. We also highlight the interrelation between these two pathways and the impact of ER stress and autophagy modulators on NAFLD treatment.

RECENT FINDINGS

The pathophysiological mechanisms involved in NAFLD progression are currently under investigation. The endoplasmic reticulum (ER) stress and the concomitant unfolded protein response (UPR) seem to contribute to its pathogenesis mainly due to high ER content in the liver which exerts significant metabolic functions and can be dysregulated. Furthermore, disruption of autophagy processes has also been identified in NAFLD. The crucial role of these two pathways in NAFLD is underlined by the fact that they have recently emerged as promising targets of therapeutic interventions. There is a greater need for finding the natural/chemical compounds and drugs which can modulate the ER stress pathway and autophagy for the treatment of NAFLD. Clarifying the inter-relation between these two pathways and their interaction with inflammatory and apoptotic mechanisms will allow the development of additional therapeutic options which can better target and reprogram the underlying pathophysiological pathways, aiming to attenuate NAFLD progression.

Manuka honey enhanced sensitivity of HepG2, hepatocellular carcinoma cells, for Doxorubicin and induced apoptosis through inhibition of Wnt/β-catenin and ERK1/2

Background

Recently, there is increasing awareness focused on the identification of naturally occurring anticancer agents derived from natural products. Manuka honey (MH) has been recognized for its biological properties as antimicrobial, antioxidant, and anticancer properties. However, its antiproliferative mechanism in hepatocellular carcinoma is not investigated. The current study focused mainly on investigating the molecular mechanism and synergistic effect of anticancer properties of MH on Doxorubicin (DOX)-mediated apoptotic cell death, using two different p53 statuses (HepG2 and Hep3B) and one non-tumorigenic immortalized liver cell line.

Results

MH treatment showed a proliferative inhibitory effect on tested cells in a dose-dependent manner with IC₅₀ concentration of (6.92 ± 0.005%) and (18.62 ± 0.07%) for HepG2 and Hep3B cells, respectively, and induced dramatic morphological changes of Hep-G2 cells, which considered as characteristics feature of apoptosis induction after 48 h of treatment. Our results showed that MH or combined treatments induced higher cytotoxicity in p53-wild type, HepG2, than in p53-null, Hep3B, cells. Cytotoxicity was not observed in normal liver cells. Furthermore, the synergistic effect of MH and Dox on apoptosis was evidenced by increased annexin-V-positive cells and Sub-G1 cells in both tested cell lines with a significant increase in the percentage of Hep-G2 cells at late apoptosis as confirmed by the flow cytometric analysis. Consistently, the proteolytic activities of caspase-3 and the degradation of poly (ADP-ribose) polymerase were also higher in the combined treatment which in turn accompanied by significant inhibitory effects of pERK1/2, mTOR, S6K, oncogenic β-catenin, and cyclin D1 after 48 h. In contrast, the MH or combined treatment-induced apoptosis was accompanied by significantly upregulated expression of proapoptotic Bax protein and downregulated expression of anti-apoptotic Bcl-2 protein after 48 h.

Conclusions

Our data showed a synergistic inhibitory effect of MH on DOX-mediated apoptotic cell death in HCC cells. To our knowledge, the present study provides the first report on the anticancer activity of MH and its combined treatment with DOX on HCC cell lines, introducing MH as a promising natural and nontoxic anticancer compound.

Natural products as geroprotectors: An autophagy perspective

Over the past decade, significant attention has been given to repurposing Food and Drug Administration approved drugs to treat age-related diseases. In contrast, less consideration has been given to natural bioactive compounds. Consequently, there have been limited attempts to translate these compounds. Autophagy is a fundamental biological pathway linked to aging, and numerous strategies to enhance autophagy have been shown to extend lifespan. Interestingly, there are a number of natural products that are reported to modulate autophagy, and here we describe a number of them that activate autophagy through diverse molecular and cellular mechanisms. Among these, Urolithin A, Spermidine, Resveratrol, Fatty Acids and Phospholipids, Trehalose and Lithium are featured in detail. Finally, we outline possible strategies to optimise and increase the translatability of natural products, with the overall aim of delaying the ageing process and improving human healthspan.

Quercetin induces pro-apoptotic autophagy via SIRT1/AMPK signaling pathway in human lung cancer cell lines A549 and H1299 in vitro

Background

Quercetin, a natural flavonoid compound, is a potent cancer therapeutic agent widely found in fruit and vegetables. It has been reported to induce growth inhibition and apoptosis in both A549 and H1299 human lung cancer cells. However, the effect of quercetin‐induced autophagy on apoptosis and the possible autophagy mechanism in A549 and H1299 cells have not yet been critically examined.

Methods

A549 and H1299 cells were treated with different concentrations of quercetin for 24 hours. Cell growth was measured by cell counting kit‐8 (CCK‐8) assay, whereas apoptosis was assessed by western blotting analysis of apoptotic proteins. The levels of proteins and genes involved in autophagy were determined by western blotting and reverse transcription polymerase chain reaction (RT‐PCR), respectively. Autophagosomes were also observed by transmission electron microscopy (TEM) and LC3 immunofluorescence.

Results

Quercetin inhibited cell viability and induced mitochondria‐dependent apoptosis in both A549 and H1299 cells in a dose‐dependent. Moreover, quercetin also promoted the expression of LC3‐II and beclin 1 and suppressed the expression of p62. The mRNA levels of LC3‐II, beclin 1, Atg5, Atg7, and Atg12 were upregulated by quercetin treatment. Autophagy inhibition with 3‐methyladenine could effectively inhibit quercetin‐induced apoptosis. In addition, quercetin dose‐dependently elevated the levels of SIRT1 protein and the pAMPK–AMPK ratio. Quercetin‐induced autophagy was attenuated by SIRT1 inhibitor EX527 and SirT1 knockdown by small interfering RNA (siRNA).

Conclusions

Quercetin‐induced autophagy contributes to apoptosis in A549 and H1299 lung cancer cells, which involved the SIRT1/AMPK signaling pathway.

Autophagy: Mechanisms and Therapeutic Potential of Flavonoids in Cancer

Autophagy, which is a conserved biological process and essential mechanism in maintaining homeostasis and metabolic balance, enables cells to degrade cytoplasmic constituents through lysosomes, recycle nutrients, and survive during starvation. Autophagy exerts an anticarcinogenic role in normal cells and inhibits the malignant transformation of cells. On the other hand, aberrations in autophagy are involved in gene derangements, cell metabolism, the process of tumor immune surveillance, invasion and metastasis, and tumor drug-resistance. Therefore, autophagy-targeted drugs may function as anti-tumor agents. Accumulating evidence suggests that flavonoids have anticarcinogenic properties, including those relating to cellular proliferation inhibition, the induction of apoptosis, autophagy, necrosis, cell cycle arrest, senescence, the impairment of cell migration, invasion, tumor angiogenesis, and the reduction of multidrug resistance in tumor cells. Flavonoids, which are a group of natural polyphenolic compounds characterized by multiple targets that participate in multiple pathways, have been widely studied in different models for autophagy modulation. However, flavonoid-induced autophagy commonly interacts with other mechanisms, comprehensively influencing the anticancer effect. Accordingly, targeted autophagy may become the core mechanism of flavonoids in the treatment of tumors. This paper reviews the flavonoid-induced autophagy of tumor cells and their interaction with other mechanisms, so as to provide a comprehensive and in-depth account on how flavonoids exert tumor-suppressive effects through autophagy.

Quercetin nanoformulations: a promising strategy for tumor therapy

Phytochemicals as dietary constituents are being widely explored for the prevention and treatment of various diseases. Quercetin, a major constituent of various dietary products, has attracted extensive interest due to its anti-proliferative capability, reversal of multidrug resistance, autophagy promotion and tumor microenvironment modulation on different cancer types. Although quercetin has shown potent medical value, its application as an antitumor drug is limited. Problems like poor solubility, bioavailability and stability, short half-life and weak tumor-targeting biodistribution make quercetin an unreliable candidate for cancer therapy. Nanoparticle based platforms have shown a number of advantages in delivering a hydrophobic drug like quercetin to diseased tissues. Quercetin nanoparticles have demonstrated high encapsulation efficiency, stability, sustained release, prolonged circulation time, improved accumulation at tumor sites and therapeutic efficiency. Moreover, a combination of quercetin with other diagnostic or therapeutic agents in one nanocarrier has achieved enhancements in detecting or treating tumors. In this review, we have tried to summarize the pharmacological activities of quercetin with regard to tumor cells and microenvironments in vitro and in vivo. Furthermore, various nanoformulations have been highlighted for quercetin delivery for cancer treatment. These results suggest that quercetin nanoparticles may be a promising antitumor therapeutic agent.

Quercetin Induces Apoptosis via Downregulation of Vascular Endothelial Growth Factor/Akt Signaling Pathway in Acute Myeloid Leukemia Cells

Acute myeloid leukemia (AML) is an aggressive haematological malignancy characterized by highly proliferative accumulation of immature and dysfunctional myeloid cells. Quercetin (Qu), one kind of flavonoid, exhibits anti-cancer property in multiple types of solid tumor, but its effect on acute myeloid leukemia is less studied, and the underlying mechanisms still largely unknown. This study aimed to explore the specific target and potential mechanism of quercetin-induced cell death in AML. First, we found that quercetin induces cell death in the form of apoptosis, which was caspase dependent. Second, we found that quercetin-induced apoptosis depends on the decrease of mitochondria membrane potential (MMP) and Bcl-2 proteins. With quantitative chemical proteomics, we observed the downregulation of VEGFR2 and PI3K/Akt signaling in quercetin-treated cells. Consistently, cell studies also identified that VEGFR2 and PI3K/Akt signaling pathways are involved in the action of quercetin on mitochondria and Bcl-2 proteins. The decrease of MMP and cell death could be rescued when PI3K/Akt signaling is activated, suggesting that VEGFR2 and PI3K/Akt exert as upstream regulators for quercetin effect on apoptosis induction in AML cells. In conclusion, our findings from this study provide convincing evidence that quercetin induces cell death via downregulation of VEGF/Akt signaling pathways and mitochondria-mediated apoptosis in AML cells.

Coptisine induces autophagic cell death through down-regulation of PI3K/Akt/mTOR signaling pathway and up-regulation of ROS-mediated mitochondrial dysfunction in hepatocellular carcinoma Hep3B cells

Coptisine is isoquinoline alkaloid derived from Coptidis Rhizoma and is known to have potential anti-cancer activity toward various carcinomas. Targeting autophagy is one of the main approaches for cancer therapy, but whether the anti-cancer efficacy of coptisine involves autophagy is still unclear. Therefore, this study investigated the effect of coptisine on autophagy in hepatocellular carcinoma (HCC) Hep3B cells, and identified the underlying mechanism. Our results showed that coptisine increased cytotoxicity and autophagic vacuoles in a concentration-dependent manner. Furthermore, the expressions of light chain 3 (LC3)-I/II, Beclin-1 and autophagy genes were markedly increased by coptisine, while the expression of p62 decreased. In addition, we found that pretreatment with bafilomycin A1, an inhibitor of autophagosome-lysosome fusion, markedly reduced coptisine-mediated autophagic cell death, but 3-methyladenine, an inhibitor for autophagosome formation did not. Moreover, our results showed that although coptisine up-regulated AMP-activated protein kinase (AMPK) that partially induced LC3-I/II, coptisine-mediated AMPK signaling did not directly regulate autophagic cell death. Additionally, we found that coptisine suppressed the phosphorylation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR), and this effect was notably enhanced by PI3K inhibitor LY294002. Meanwhile, coptisine significantly increased both the production of mitochondrial reactive oxygen species (ROS) and the recruitment of mitophagy-regulated proteins to mitochondria. Furthermore, N-acetylcysteine, a potential ROS scavenger, substantially suppressed the expression of mitophagy-regulated proteins and LC3 puncta by coptisine. Overall, our results demonstrate that coptisine-mediated autophagic cell death was regulated by PI3K/Akt/mTOR signaling and mitochondrial ROS production associated with mitochondrial dysfunction. Taken together, these findings suggest that coptisine exerts its anti-cancer effects through induction of autophagy in HCC Hep3B cells.