Caffeine enhances the anti-tumor effect of 5-fluorouracil via increasing the production of reactive oxygen species in hepatocellular carcinoma

Caffeine in Hepatocellular Carcinoma: Cellular Assays, Animal Experiments, and Epidemiological Investigation

The use of caffeine in treating various liver diseases has made substantial progress in the past decade owing to advances in science, technology, and medicine. However, whether caffeine has a preventive effect on hepatocellular carcinoma (HCC) and its mechanism are still worth further investigation. In this review, we summarize and analyze the efficacy and safety of caffeine in the prevention of HCC. We conducted a review of articles published in PubMed and Web of Science in the past 2 decades until December 6, 2023, which were searched for using the terms "Caffeine" and "Hepatocellular Carcinoma." Studies have found that coffee intake is negatively correlated with HCC risk, especially caffeinated coffee. Recent studies have found that caffeine has beneficial effects on liver health, decreasing levels of enzymes responsible for liver damaging and slowing the progression of hepatic fibrosis and cirrhosis. Caffeine also acts against liver fibrosis through adenosine receptors (ARs), which promote tissue remodeling by inducing fibrin and collagen production. Additionally, new studies have found that moderate consumption of caffeinated beverages can decrease various the levels of various collagens in patients with chronic hepatitis C. Furthermore, polyphenolic compounds in coffee can improve fat homeostasis, reduce oxidative stress, and prevent liver steatosis and fibrosis. Moreover, many in vitro studies have shown that caffeine can protect liver cells and inhibit the activation and proliferation of hepatic stellate cells. Taken together, we describe the benefits of caffeine for liver health and highlight its potential values as a drug to prevent various hepatic diseases. As a protective agent of liver inflammation, non-selective AR inhibitor caffeine can inhibit the growth of HCC cells by inhibiting adenosine and AR binding to initiate immune response, providing a basis for the future development of caffeine as an adjuvant drug against HCC.

Efficient chemosensitizing and antimetastatic combinations of a naturally occurring trans-ferulic acid with different chemotherapies on an in vitro hepatocellular carcinoma model

Trans-ferulic acid (TFA) is a polyphenolic compound present in many dietary supplements. The aim of this study was to get better chemotherapeutic outcomes through treatment protocols for human hepatocellular carcinoma (HCC). This study focused on the exploration of the in vitro influence of a combination of TFA with 5-fluorouracil (5-FU), doxorubicin (DOXO), and cisplatin (CIS) on HepG2 cell line. Treatment with 5-FU, DOXO, and CIS alone down-regulated oxidative stress and alpha-fetoprotein (AFP), and decreased cell migration through the depression of metalloproteinases (MMP-3, MMP-9, and MMP-12) expression. Co-treatment with TFA synergized the effects of these chemotherapies by decreased MMP-3, MMP-9, and MMP-12 expression, and gelatinolytic activity of both MMP-9 and MMP-2 in cancer cells. TFA significantly reduced the elevated levels of AFP and NO, and depressed cell migration ability (metastasis) in HepG2 groups. Co-treatment with TFA elevated the chemotherapeutic potency of 5-FU, DOXO, and CIS in managing HCC.

Overview of Caffeine Effects on Human Health and Emerging Delivery Strategies

Caffeine is a naturally occurring alkaloid found in various plants. It acts as a stimulant, antioxidant, anti-inflammatory, and even an aid in pain management, and is found in several over-the-counter medications. This naturally derived bioactive compound is the best-known ingredient in coffee and other beverages, such as tea, soft drinks, and energy drinks, and is widely consumed worldwide. Therefore, it is extremely important to research the effects of this substance on the human body. With this in mind, caffeine and its derivatives have been extensively studied to evaluate its ability to prevent diseases and exert anti-aging and neuroprotective effects. This review is intended to provide an overview of caffeine's effects on cancer and cardiovascular, immunological, inflammatory, and neurological diseases, among others. The heavily researched area of caffeine in sports will also be discussed. Finally, recent advances in the development of novel nanocarrier-based formulations, to enhance the bioavailability of caffeine and its beneficial effects will be discussed.

Critical Review in Designing Plant-Based Anticancer Nanoparticles against Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), accounting for 85% of liver cancer cases, continues to be the third leading cause of cancer-related deaths worldwide. Although various forms of chemotherapy and immunotherapy have been investigated in clinics, patients continue to suffer from high toxicity and undesirable side effects. Medicinal plants contain novel critical bioactives that can target multimodal oncogenic pathways; however, their clinical translation is often challenged due to poor aqueous solubility, low cellular uptake, and poor bioavailability. Nanoparticle-based drug delivery presents great opportunities in HCC therapy by increasing selectivity and transferring sufficient doses of bioactives to tumor areas with minimal damage to adjacent healthy cells. In fact, many phytochemicals encapsulated in FDA-approved nanocarriers have demonstrated the ability to modulate the tumor microenvironment. In this review, information about the mechanisms of promising plant bioactives against HCC is discussed and compared. Their benefits and risks as future nanotherapeutics are underscored. Nanocarriers that have been employed to encapsulate both pure bioactives and crude extracts for application in various HCC models are examined and compared. Finally, the current limitations in nanocarrier design, challenges related to the HCC microenvironment, and future opportunities are also discussed for the clinical translation of plant-based nanomedicines from bench to bedside.

Synergistic Effects of Caffeine in Combination with Conventional Drugs: Perspectives of a Drug That Never Ages

Plants have been known since ancient times for their healing properties, being used as preparations against human diseases of different etiologies. More recently, natural products have been studied and characterized, isolating the phytochemicals responsible for their bioactivity. Most certainly, there are currently numerous active compounds extracted from plants and used as drugs, dietary supplements, or sources of bioactive molecules that are useful in modern drug discovery. Furthermore, phytotherapeutics can modulate the clinical effects of co-administered conventional drugs. In the last few decades, the interest has increased even more in studying the positive synergistic effects between plant-derived bioactives and conventional drugs. Indeed, synergism is a process where multiple compounds act together to exert a merged effect that is greater than that of each of them summed together. The synergistic effects between phytotherapeutics and conventional drugs have been described in different therapeutic areas, and many drugs are based on synergistic interactions with plant derivatives. Among them, caffeine has shown positive synergistic effects with different conventional drugs. Indeed, in addition to their multiple pharmacological activities, a growing body of evidence highlights the synergistic effects of caffeine with different conventional drugs in various therapeutic fields. This review aims to provide an overview of the synergistic therapeutic effects of caffeine and conventional drugs, summarizing the progress reported to date.

Caffeine-Supplemented Diet Prevents Fatigue-Like Behavior in Tumor-Bearing Mice

Caffeine is a widely consumed stimulant, known for its positive effects on physical and mental performance. These effects are potentially beneficial for ameliorating cancer-related fatigue, which affects the quality of life of patients with cancer. This study aimed to determine the anti-fatigue and antitumor effects of caffeine in tumor-bearing mice. BALB/c mice were intravenously injected with C26 colon carcinoma cells and fed with normal or 0.05% caffeine-supplemented diet. Fatigue-like behavior was assessed by running performance using a treadmill test. Lung, blood, liver, muscle, and epididymal adipose tissue samples were collected on day 13 and examined. The antitumor effect of caffeine was assessed using subcutaneous tumor-bearing mice fed with 0.05% caffeine-supplemented diet, and the tumor volume was measured. C26 tumor-bearing mice showed fatigue-like behavior associated with hypoglycemia, depleted liver glycogen and non-esterified fatty acid (NEFA) levels. C26 tumor-bearing mice fed with 0.05% caffeine-supplemented diet showed improved running performance associated with restored NEFA levels. However, exacerbated hypoglycemia and liver glycogen levels after caffeine consumption may be due to tumor-induced catabolic signals, as the tumor volume was not affected. Collectively, caffeine may exert anti-fatigue effects through enhanced lipolysis leading to restored NEFA levels, which can be used as an alternative energy source.

Elevation of Anticancer Drug Toxicity by Caffeine in Spheroid Model of Human Lung Adenocarcinoma A549 Cells Mediated by Reduction in Claudin-2 and Nrf2 Expression

Claudin-2 (CLDN2), a component of tight junctions, is abnormally expressed in human lung adenocarcinoma tissue. CLDN2 contributes to chemoresistance in human lung adenocarcinoma-derived A549 cells, and it may be a target for cancer therapy. Here, we found that coffee ingredients, namely caffeine and theobromine, decreased the protein level of CLDN2 in human lung adenocarcinoma-derived A549 cells. In contrast, other components, such as theophylline and chlorogenic acid, had no effect. These results indicate that the 7-methyl group in methylxanthines may play a key role in the reduction in CLDN2 expression. The caffeine-induced reduction in the CLDN2 protein was inhibited by chloroquine, a lysosome inhibitor. In a protein-stability assay using cycloheximide, CLDN2 protein levels decreased faster in caffeine-treated cells than in vehicle-treated cells. These results suggest that caffeine accelerates the lysosomal degradation of CLDN2. The accumulation and cytotoxicity of doxorubicin were dose-dependently increased, which was exaggerated by caffeine but not by theophylline in spheroids. Caffeine decreased nuclear factor-erythroid 2-related factor 2 (Nrf2) levels without affecting hypoxia-inducible factor-1α levels. Furthermore, caffeine decreased the expression of Nrf2-targeted genes. The effects of caffeine on CLDN2 expression and anticancer-drug-induced toxicity were also observed in lung adenocarcinoma RERF-LC-MS cells. We suggest that caffeine enhances doxorubicin-induced toxicity in A549 spheroids mediated by the reduction in CLDN2 and Nrf2 expression.

Caffeine in liver diseases: Pharmacology and toxicology

We have previously shown that adenosine A1AR antagonists, adenosine A2aAR antagonists, and caffeine have significant inhibitory effects on the activation and proliferation of hepatic stellate cells in alcoholic liver fibrosis. Many recent studies have found that moderate coffee consumption is beneficial for various liver diseases. The main active ingredient of coffee is caffeine, which is a natural non-selective adenosine receptor antagonist. Moreover, numerous preclinical epidemiological studies and clinical trials have examined the association between frequent coffee consumption and the risk of developing different liver diseases. In this review, we summarize and analyze the prophylactic and therapeutic effects of caffeine on various liver diseases, with an emphasis on cellular assays, animal experiments, and clinical trials. To review the prevention and treatment effects of caffeine on different liver diseases, we searched all literature before 19 July 2022, using “caffeine” and “liver disease” as keywords from the PubMed and ScienceDirect databases. We found that moderate coffee consumption has beneficial effects on various liver diseases, possibly by inhibiting adenosine binding to its receptors. Caffeine is a potential drug for the prevention and treatment of various liver diseases.

Dietary sources, health benefits, and risks of caffeine

Dietary intake of caffeine has significantly increased in recent years, and beneficial and harmful effects of caffeine have been extensively studied. This paper reviews antioxidant and anti-inflammatory activities of caffeine as well as its protective effects on cardiovascular diseases, obesity, diabetes mellitus, cancers, and neurodegenerative and liver diseases. In addition, we summarize the side effects of long-term or excessive caffeine consumption on sleep, migraine, intraocular pressure, pregnant women, children, and adolescents. The health benefits of caffeine depend on the amount of caffeine intake and the physical condition of consumers. Moderate intake of caffeine helps to prevent and modulate several diseases. However, the long-term or over-consumption of caffeine can lead to addiction, insomnia, migraine, and other side effects. In addition, children, adolescents, pregnant women, and people who are sensitive to caffeine should be recommended to restrict/reduce their intake to avoid potential adverse effects.

Caffeine Induces G0/G1 Cell Cycle Arrest and Inhibits Migration through Integrin αv, β3, and FAK/Akt/c-Myc Signaling Pathway

Lung cancer is recognized as a major cause of mortality worldwide owing to its metastatic activity. Given the lack of solid information regarding the possible effects of caffeine, one of the most consumed natural psychoactive substances, on molecular signaling pathways implicated in the aggressive behavior of lung cancer, our study aimed to evaluate the effect and mechanism of caffeine on metastasis-related mechanisms. The results revealed that caffeine treatment at concentrations of 0–500 µM caused no direct cytotoxic effects on NCI-H23 cells. Treatment of cells with caffeine showed good potential to inhibit cell proliferation at 48 h and induced significant cell cycle arrest at the G0/G1 phase. Concerning metastasis, caffeine was shown to reduce filopodia formation, inhibit migration and invasion capability, and reduce the ability of cancer cells to survive and grow in an anchorage-independent manner. Moreover, caffeine could attenuate the formation of 3D tumor spheroids in cancer stem cell (CSC)-enriched populations. With regard to mechanisms, we found that caffeine significantly altered the integrin pattern of the treated cells and caused the downregulation of metastasis-associated integrins, namely, integrins αv and β3. Subsequently, the downstream signals, including protein signaling and transcription factors, namely, phosphorylated focal adhesion kinase (p-FAK), phosphorylated protein kinase B (p-Akt), cell division cycle 42 (Cdc42), and c-Myc, were significantly decreased in caffeine-exposed cells. Taken together, our novel data on caffeine-inhibiting mechanism in relation to metastasis in lung cancer could provide insights into the impact of caffeine intake on human diseases and conditions.

Antiinflammatory and antiinfective effect of caffeine in a mouse model of disseminated salmonellosis

Caffeine has been reported for its antiinflammatory properties by stimulating phagocytosis. In this study, we investigated the antiinflammatory and antiinfective potential of caffeine in murine macrophage cell cultures and Swiss mice infected with virulent Salmonella enterica serotype typhimurium. Peritoneal macrophages (pMØ) were treated with caffeine on 96-well plates for 24 hr and then infected with Salmonella for 4 hr. In another experiment, the pMØ were first infected with the bacterium for 4 hr and then treated with caffeine for 24 hr. In addition, Swiss mice were inoculated, intraperitoneally, with S. typhimurium and then received caffeine intravenously. Control groups received phosphate-buffered saline (PBS) or dexamethasone. We found that treatments with caffeine increased the macrophage cell viability and reduced the intracellular bacterial load. The administration of caffeine to Swiss mice reduced the infiltration of leukocytes into the peritoneal cavity after the bacterial challenge. Furthermore, the bacterial burdens in the peritoneal fluid, bloodstream, spleen, and liver were decreased by caffeine treatment. The expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), IL-6, and inducible nitric oxide synthase (iNOs) were down-regulated after infection in caffeine-treated mice. We can conclude that caffeine has both antiinflammatory and antiinfective properties that can be useful for management of bacterial infections along with antibiotics.

Phytochemicals as an Alternative or Integrative Option, in Conjunction with Conventional Treatments for Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma (HCC) is globally ranked as the sixth most diagnosed cancer, and the second most deadly cancer. To worsen matters, there are only limited therapeutic options currently available; therefore, it is necessary to find a reservoir from which new HCC treatments may be acquired. The field of phytomedicine may be the solution to this problem, as it offers an abundance of plant-derived molecules, which show capabilities of being effective against HCC proliferation, invasion, migration, and metastasis. In our review, we collect and analyze current evidence regarding these promising phytochemical effects on HCC, and delve into their potential as future chemotherapies. Additionally, information on the signaling behind these numerous phytochemicals is provided, in an attempt to understand their mechanisms. This review makes accessible the current body of knowledge pertaining to phytochemicals as HCC treatments, in order to serve as a reference and inspiration for further research into this subject.

Abstract

Hepatocellular carcinoma (HCC) is the most abundant form of liver cancer. It accounts for 75–85% of liver cancer cases and, though it ranks globally as the sixth most common cancer, it ranks second in cancer-related mortality. Deaths from HCC are usually due to metastatic spread of the cancer. Unfortunately, there are many challenges and limitations with the latest HCC therapies and medications, making it difficult for patients to receive life-prolonging care. As there is clearly a high demand for alternative therapy options for HCC, it is prudent to turn to plants for the solution, as their phytochemicals have long been used and revered for their many medicinal purposes. This review explores the promising phytochemical compounds identified from pre-clinical and clinical trials being used either independently or in conjunction with already existing cancer therapy treatments. The phytochemicals discussed in this review were classified into several categories: lipids, polyphenols, alkaloids, polysaccharides, whole extracts, and phytochemical combinations. Almost 80% of the compounds failed to progress into clinical studies due to lack of information regarding the toxicity to normal cells and bioavailability. Although large obstacles remain, phytochemicals can be used either as an alternative or integrative therapy in conjunction with existing HCC chemotherapies. In conclusion, phytochemicals have great potential as treatment options for hepatocellular carcinoma.

Coffeeberry Activates the CaMKII/CREB/BDNF Pathway, Normalizes Autophagy and Apoptosis Signaling in Nonalcoholic Fatty Liver Rodent Model

Nonalcoholic fatty liver disease (NAFLD) shows extensive liver cell destruction with lipid accumulation, which is frequently accompanied by metabolic comorbidities and increases mortality. This study aimed to investigate the effects of coffeeberry (CB) on regulating the redox status, the CaMKII/CREB/BDNF pathway, autophagy, and apoptosis signaling by a NAFLD rodent model senescence-accelerated mice prone 8 (SAMP8). Three-month-old male SAMP8 mice were divided into a control group and three CB groups (50, 100, and 200 mg/kg BW), and fed for 12 weeks. The results show that CB reduced hepatic malondialdehyde and carbonyl protein levels. CB significantly enhanced Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) and brain-derived neurotrophic factor (BDNF) and reduced the phospho-cAMP response element-binding protein (p-CREB)/CREB ratio. In addition, CB increased the silent information regulator T1 level, promoted Beclin 1 and microtubule-associated protein light chain 3 II expressions, and reduced phosphorylated mammalian target of rapamycin and its downstream p-p70s6k levels. CB also inhibited the expressions of apoptosis-related factors poly (ADP-ribose) polymerase-1 and the apoptosis-inducing factor. In conclusion, CB might protect the liver by reducing oxidative stress, activating the CaMKII/CREB/BDNF pathway, and improving autophagic and apoptotic expressions in a dose-dependent manner.

Natural products targeting into cancer hallmarks: An update on caffeine, theobromine, and (+)-catechin

Natural products have been studied to reveal new therapies against human dysfunctions since they present several medicinal properties. Caffeine, theobromine and (+)-catechin are remarkable natural agents in the class of methylxanthines and flavonoids. These bioactive molecules have several biological activities, for instance, antioxidant, anti-inflammatory, and antitumor capacity. In this sense, studies focusing on these molecules have been performed to discover new treatments against diseases, such as cancer. Cancer is a serious public health problem worldwide responsible for more than 70% of all deaths globally. Industrialized products associated with a sedentary lifestyle and a diet low in antioxidants are related to neoplasms development. Unfortunately, many types of cancers are extremely aggressive and untreatable since, in many cases, they are resistant to chemotherapy. Therefore, revealing new strategies to block cancer growth is one of the biggest challenges to science. In this context, despite the known anticancer actions of caffeine, theobromine and (+)-catechin, it is still essential to elucidate the causal antitumor mechanism of these molecules by analyzing the dysfunctional cancer pathways associated with the hallmarks of cancer. Hence, this review aims to describe the anticancer activity of caffeine, theobromine, and (+)-catechin against the different hallmarks and enabling characteristics of cancer.

MTIF2 impairs 5 fluorouracil-mediated immunogenic cell death in hepatocellular carcinoma in vivo: Molecular mechanisms and therapeutic significance

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related morbidity and mortality; it has been reported that immune cell infiltration is a prognosis factor. Here we identified genes that associated with tumor immune cell infiltrate; the underlying mechanism was verified by in vivo and in vitro experiment. In this study, Weighted correlation network analysis (WGCNA) and CIBERSORT tool were used to identify MTIF2 as the hub tumor immune infiltrating gene in HCC. To investigate the underlying role played by MTIF2, MTIF2 was knocked down by transfection of shRNA targeting MTIF2, CCK8, and EdU incorporation assay was used to evaluate the effect of MTIF2 on proliferation, wound heal assay and transwell assay was used to confirm its effect on cell migration. Ecto-calreticulin on the cell surface was evaluated by flow cytometry, ATP, and HMGB1 secretion were tested to the investigated effect of MTIF2 on the immunogenic cell death (ICD) process. We found that down-regulation of MTIF2 impaired proliferation and migration capacity of HCC cells, chemoresistance to 5-Fluorouracil (5-FU) weakened after MTIF2 was knocked down. Reduced release of damage-associated molecular patterns (DAMP) was observed after MTIF2 was overexpressed, which subsequently impaired dendritic cell (DC) maturation and proliferation of CD8 + T cells. Mechanically, the co-IP experiment confirmed that MTIF2 could interact with AIFM1, prevents AIFM1 induced transcription of caspase3, and finally suppress apoptosis. In vivo experiment also used to confirm our previously conclusion, our result indicated that MTIF2 overexpression suppresses tumor apoptosis and immune cell activity in the 5-FU therapy in vivo model, by suppression maturation of tumor-infiltrated DC. Collectively, our study confirmed that MTIF2 impair drug-induced immunogenic cell death in hepatocellular carcinoma cells.

Coffee in cancer chemoprevention: an updated review

INTRODUCTION

Chemoprevention of cancer refers to the use of natural or synthetic compounds to abolish or perturb a variety of steps in tumor initiation, promotion, and progression. This can be realized through different mechanisms, including activation of free radical scavenging enzymes, control of chronic inflammation, and downregulation of specific signaling pathways.

AREAS COVERED

The goal of this article is to critically review recent evidence on association between coffee and prevention of different types of cancer, with particular emphasis on the molecular mechanisms and the bioactive compounds involved in its anticancer activity.

EXPERT OPINION

Coffee is a mixture of different compounds able to decrease the risk of many types of cancer. However, its potential anticancer activity is not completely understood. Hundreds of biologically active components such as caffeine, chlorogenic acid, diterpenes are contained in coffee. Further research is needed to fully elucidate the molecular mechanisms underlying the anticancer effects of coffee and fully understand the role of different confounding factors playing a role in its reported anticancer activity.

6H2L, a novel synthetic derivative of bifendate, induces apoptosis in hepatoma cells via mitochondrial and MAPK pathway

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. Our previous study indicated that 6H2L, a novel synthetic bifendate derivative, shows multidrug resistance reversal activity, while its antitumor effect has not been revealed. Here, the potent antitumor effects of 6H2L on hepatoma cells both in vitro and in vivo were investigated. 6H2L inhibited cell viability of HepG2 and SMMC-7721 cells with less sensitivity to normal human liver L-02 cells. 6H2L induced apoptosis in hepatoma cells. It upregulated Bax expression, while simultaneously decreasing Bcl-2 expression. Further elucidation of the mechanism revealed that 6H2L induced mitochondrial dysfunction, with transmitochondrial membrane potential collapse and cytochrome c release, which activated caspase-9 and caspase-3 and subsequently cleaved PARP, suggesting that 6H2L induced apoptosis via triggering mitochondrial pathway. Moreover, 6H2L decreased the phosphorylation of ERK1/2, whereas it increased the expression of p-JNK and p-p38. Then, specific inhibitors of the mitogen-activated protein kinase (MAPK) pathway were employed to confirm the roles of the MAPK pathway in the apoptosis-inducing effects of 6H2L. Additionally, 6H2L obviously inhibited the tumor growth in H22-bearing ICR mice. Meanwhile, 6H2L remarkably up-regulated Bax while suppressing Bcl-2 in tumors. Importantly, neither significant weight loss, white blood cell (WBC) count, nor histopathological abnormalities of major organs were observed in the mice receiving 6H2L treatment, indicating that 6H2L exerted strong anticancer activities with low toxicity in vivo. In contrast, fluorouracil inhibited tumor growth with significant decreased body weight and WBC count. Taken together, these results suggested 6H2L is a potential therapeutic candidate for HCC.