Cancer therapeutics with epigallocatechin-3-gallate encapsulated in biopolymeric nanoparticles

Biomaterials as a new option for treating sensorineural hearing loss

Sensorineural hearing loss (SNHL) usually involves damage to complex auditory pathways such as inner ear cells and auditory nerves. The highly intricate and nuanced characteristics of these cells render their repair and regeneration extremely challenging, making it difficult to restore hearing to normal levels once it has been compromised. The effectiveness of traditional drugs is so minimal that they provide little help with the treatment. Fortunately, extensive experiments have demonstrated that combining biomaterials with conventional techniques significantly enhances drug effectiveness. This article reviews the research progress of biomaterials in protecting hair cells and the auditory nerve, repairing genes related to hearing, and developing artificial cochlear materials. By organizing the knowledge presented in this article, perhaps new insights can be provided for the clinical management of SNHL.

Natural products and derivatives for breast cancer treatment: From drug discovery to molecular mechanism

BACKGROUND

Breast cancer stands as the most common malignancy among women globally and a leading cause of cancer-related mortality. Conventional treatments, such as surgery, hormone therapy, radiotherapy, chemotherapy, and small-molecule targeted therapy, often fall short of addressing the complexity and heterogeneity of certain breast cancer subtypes, leading to drug resistance and metastatic progression. Thus, the search for novel therapeutic targets and agents is imperative. Given their low toxicity and abundant variety, natural products and their derivatives are increasingly considered valuable sources for small-molecule anticancer drugs.

PURPOSE

This review aims to elucidate the pharmacological impacts and underlying mechanisms of active compounds found in select natural products and their derivatives, primarily focusing on breast cancer treatment. It intends to underscore the potential of these substances in combating breast cancer and guide future research directions for the development of natural product-based therapeutics.

METHODS

We conducted comprehensive searches in electronic databases such as PubMed, Web of Science, and Scopus until October 2023, using keywords such as 'breast cancer', 'natural products', 'derivatives', 'mechanism', 'signaling pathways', and various keyword combinations.

RESULTS

The review presents a spectrum of phytochemicals, including but not limited to flavonoids, polyphenols, and alkaloids, and examines their actions in various animal and cellular models of breast cancer. The anticancer effects of these natural products and derivatives are manifested through diverse mechanisms, including induction of cell death via apoptosis and autophagy, and suppression of tumor angiogenesis.

CONCLUSION

An increasing array of natural products and their derivatives are proving effective against breast cancer. Future therapeutic strategies can benefit from strategic enhancement of the anticancer properties of natural compounds, optimization for targeted action, improved bioavailability, and minimized side effects. The forthcoming research on natural products should prioritize these facets to maximize their therapeutic potential.

Bibliometric and visual analysis in the field of tea in cancer from 2013 to 2023

Objective

Tea has been utilized in cancer research and is progressively gaining wider recognition, with its roles in cancer prevention and treatment being increasingly affirmed. The objective of this study is to investigate the current state and research hotspots in the field of tea's involvement in cancer research from 2013 to 2023, aiming to offer reference and direction for future studies.

Methods

We analyzed 4,789 articles published between 2013 and 2022 from the Web of Science database using VOSviewer, R software, and CiteSpace software.

Result

Tea-related cancer research showed an overall upward trend, with China leading in publications, followed by the United States, India, Japan, and Italy. China also had significant international collaborations, notably with Harvard University and the Egyptian Knowledge Bank. The 'Journal of Agricultural and Food Chemistry' was the most cited journal. Key topics included 'green tea,' 'cancer,' 'in vitro,' 'oxidative stress,' and 'apoptosis.' Research focused on tea's pharmacological effects, anticancer properties, mechanisms of natural compounds (e.g., polyphenols and EGCG), antioxidant and antimicrobial properties, and molecular mechanisms in cancer treatment.

Conclusion

Tea's potential as an anti-cancer medication is gaining global recognition. Our study provides a comprehensive analysis of tea-related cancer research from 2013 to 2023, guiding future investigations in this field.

Single-step assembly of lipid-gelatin-epigallocatechin-3-gallate hybrid nanoparticles for cancer therapy

OBJECTIVE

Novel core-shell lipid-gelatin-epigallocatechin-3-gallate hybrid nanoparticles (LGE-N) were prepared to increase the stability and antitumor efficacy of epigallocatechin-3-gallate (EGCG).

METHODS

The LGE-N was prepared by a single-step double-emulsion method, in which EGCG-gelatin nanoparticles were formed and stabilized in the inner phase by gelatinization. The cytotoxicity of EGCG solution (EGCG-S) and LGE-N were assessed by a standard 3-(4, 5-dimethylthiazol- 2-yl)-2, 5-diphenyltetrazolium bromide assay.

RESULTS

The obtained LGE-N had a spherical shape, with relatively high encapsulation efficiency (92.30 ± 1.63%), drug loading capacity (11.09 ± 0.62%) and controlled drug release. In-vitro cytotoxicity studies revealed that LGE-N exhibited a lower half maximal inhibitory concentration compared with EGCG-S in MCF-7 (a breast carcinoma cell line) cells. When labeled with a fluorescent probe, Dir, LGE-N was shown to accumulate much more in tumor. In addition, the LGE-N achieved potent antitumor efficacy at a dose of 5 mg/kg in 4T1-implanted mice.

CONCLUSION

Our study highlights the unique EGCG-entrapped lipid-gelatin hybrid nanoparticles, which may be a powerful strategy for further cancer therapy.

Emerging strategies to fabricate polymeric nanocarriers for enhanced drug delivery across blood-brain barrier: An overview

Blood-brain barrier (BBB) serves as an essential interface between central nervous system (CNS) and its periphery, allowing selective permeation of ions, gaseous molecules, and other nutrients to maintain metabolic functions of brain. Concurrently, it restricts passage of unsolicited materials from bloodstream to CNS which could otherwise lead to neurotoxicity. Nevertheless, in the treatment of neurodegenerative diseases such as Parkinson's, Alzheimer's, diffuse intrinsic pontine glioma, and other brain cancers, drugs must reach CNS. Among various materials developed for this purpose, a few judiciously selected polymeric nanocarriers are reported to be highly prospective to facilitate BBB permeation. However, the challenge of transporting drug-loaded nanomaterials across this barrier remains formidable. Herein a concise analysis of recently employed strategies for designing polymeric nanocarriers to deliver therapeutics across BBB is presented. Impacts of 3Ss, namely, size, shape, and surface charge of polymeric nanocarriers on BBB permeation along with different ligands used for nanoparticle surface modification to achieve targeted delivery have been scrutinized. Finally, we elucidated future research directions in the context of designing smart polymeric nanocarriers for BBB permeation. This work aims to guide researchers engaged in polymeric nanocarrier design, helping them navigate where to begin, what challenges to address, and how to proceed effectively.

Epigallocatechin gallate-loaded tetrahedral DNA nanostructures as a novel inner ear drug delivery system

The study of drug delivery systems to the inner ear is a crucial but challenging field. The sensory organ (in the inner ear) is protected by the petrous bone labyrinth and the membranous labyrinth, both of which need to be overcome during the drug delivery process. The requirements for such a delivery system include small size, appropriate flexibility and biodegradability. DNA nanostructures, biomaterials that can arrange multiple functional components with nanometer precision, exhibit characteristics that are compatible with the requirements for inner ear drug delivery. Herein, we report the development of a novel inner ear drug delivery system based on epigallocatechin gallate (EGCG)-loaded tetrahedral DNA nanostructures (TDNs, EGCG@TDNs). The TDNs self-assembled via base-pairing of four single-stranded DNA constructs and EGCG was loaded into the TDNs through non-covalent interactions. Cy5-labeled TDNs (Cy5-TDNs) were significantly internalized by the House Ear Institute-Organ of Corti 1 cell line, and this endocytosis was energy-, clathrin-, and micropinocytosis-dependent. Cy5-TDNs penetrated the round window membrane (RWM) rapidly in vivo. Local application of EGCG@TDNs onto the RWM of guinea pigs in a single dose continuously released EGCG over 4 hours. Drug concentrations in the perilymph were significantly elevated compared with the administration of free EGCG at the same dose. EGCG@TDNs were found to have favorable biocompatibility and strongly affected the RSL3-induced down-regulation of GPX4 and the generation of reactive oxygen species, on the basis of 2',7'-dichlorodihydrofluorescein diacetate staining. JC-1 staining suggested that EGCG@TDNs successfully reversed the decrease in mitochondrial membrane potential induced by RSL-3 in vitro and rescued cells from apoptosis, as demonstrated by the analysis of Annexin V-FITC/PI staining. Further functional studies showed that a locally administered single-dose of EGCG@TDNs effectively preserved spiral ganglion cells in C57/BL6 mice after noise-induced hearing loss. Hearing loss at 5.6 and 8 kHz frequencies was significantly attenuated when compared with the control EGCG formulation. Histological analyses indicated that the administration of TDNs and EGCG@TDNs did not induce local inflammatory responses. These favorable histological and functional effects resulting from the delivery of EGCG by TDNs through a local intratympanic injection suggest potential for therapeutic benefit in clinical applications.

Influence of Molecular Structures on Fluorescence of Flavonoids and Their Detection in Mammalian Cells

Flavonoids are being increasingly applied for the treatment of various diseases due to their anti-cancer, anti-oxidant, anti-inflammatory, and anti-viral properties. However, it is often challenging to detect their presence in cells and tissues through bioimaging, as most of them are not fluorescent or are too weak to visualize. Here, fluorescence possibilities of nine naturally occurring analogous flavonoids have been investigated through UV/visible spectroscopy, molecular structure examination, fluorescent images in mammalian cells and their statistical analysis employing aluminum chloride and diphenylboric acid 2-aminoethyl ester as fluorescence enhancers. It is found that, in order to form a stable fluorescent complex with an enhancer, flavonoids should have a keto group at C4 position and at least one -OH group at C3 or C5 position. Additionally, the presence of a double bond at C2–C3 can stabilize extended quinonoid structure at the cinnamoyl moiety, which thereby enhances the complex stability. A possible restriction to the free rotation of ring B around C1′–C2 single bond can contribute to the further enhancement of fluorescence. Thus, these findings can act as a guide for distinguishing flavonoids capable of exhibiting fluorescence from thousands of their analogues. Finally, using this technique, flavonoids are detected in neuroblastoma cells and their time course assay is conducted via fluorescence imaging. Their cellular uptake efficiency is found to be high and differential in nature and their distribution throughout the cytoplasm is clearly detected.

Epigallocatechin gallate: Phytochemistry, bioavailability, utilization challenges, and strategies

Epigallocatechin gallate (EGCG), a green tea catechin, has gained the attention of current study due to its excellent health-promoting effects. It possesses anti-obesity, antimicrobial, anticancer, anti-inflammatory activities, and is under extensive investigation in functional foods for improvement. It is susceptible to lower stability, lesser bioavailability, and lower absorption rate due to various environmental, processing, formulations, and gastrointestinal conditions of the human body. Therefore, it is the foremost concern for the researchers to enhance its bioactivity and make it the most suitable therapeutic compound for its clinical applications. In the current review, factors affecting the bioavailability of EGCG and the possible strategies to overcome these issues are reviewed and discussed. This review summarizes structural modifications and delivery through nanoparticle-based approaches including nano-emulsions, encapsulations, and silica-based nanoparticles for effective use of EGCG in functional foods. Moreover, recent advances to enhance EGCG therapeutic efficacy by specifically targeting its molecules to increase its bioavailability and stability are also described. PRACTICAL APPLICATIONS: The main green tea constituent EGCG possesses several health-promoting effects making EGCG a potential therapeutic compound to cure ailments. However, its low stability and bioavailability render its uses in many disorders. Synthesizing EGCG prodrugs by structural modifications helps against its low bioavailability and stability by overcoming premature degradation and lower absorption rate. This review paper summarizes various strategies that benefit EGCG under different physiological conditions. The esterification, nanoparticle approaches, silica-based EGCG-NPs, and EGCG formulations serve as ideal EGCG modification strategies to deliver superior concentrations with lesser toxicity for its efficient penetration and absorption across cells both in vitro and in vivo. As a result of EGCG modifications, its bioactivities would be highly improved at lower doses. The protected or modified EGCG molecule would have enhanced potential effects and stability that would contribute to the clinical applications and expand its use in various food and cosmetic industries.

Structure-Based Varieties of Polymeric Nanocarriers and Influences of Their Physicochemical Properties on Drug Delivery Profiles

Carriers are equally important as drugs. They can substantially improve bioavailability of cargos and safeguard healthy cells from toxic effects of certain therapeutics. Recently, polymeric nanocarriers (PNCs) have achieved significant success in delivering drugs not only to cells but also to subcellular organelles. Variety of natural sources, availability of different synthetic routes, versatile molecular architectures, exploitable physicochemical properties, biocompatibility, and biodegradability have presented polymers as one of the most desired materials for nanocarrier design. Recent innovative concepts and advances in PNC-associated nanotechnology are providing unprecedented opportunities to engineer nanocarriers and their functions. The efficiency of therapeutic loading has got considerably increased. Structural design-based varieties of PNCs are widely employed for the delivery of small therapeutic molecules to genes, and proteins. PNCs have gained ever-increasing attention and certainly paves the way to develop advanced nanomedicines. This article presents a comprehensive investigation of structural design-based varieties of PNCs and the influences of their physicochemical properties on drug delivery profiles with perspectives highlighting the inevitability of incorporating both the multi-stimuli-responsive and multi-drug delivery properties in a single carrier to design intelligent PNCs as new and emerging research directions in this rapidly developing area.

Recent advances in lipid-engineered multifunctional nanophytomedicines for cancer targeting

Cancer is a leading cause of death in many countries around the world. However, the efficacy of current treatments available for variety of cancers is considered to be suboptimal due to the pathophysiological challenges associated with the disease which limits the efficacy of the anticancer drugs. Moreover, the vulnerability towards off-target effects and high toxicity also limits the use of drugs for the treatment of cancers. Besides, the biopharmaceutical challenges like poor water solubility and permeability of the drugs, along with the absence of active targeting capability further decreases the utility of drugs in cancer therapy. As a result of these deficiencies, the current therapeutic strategies face noncompliance to patients for providing meaningful benefits after administration. With the advancements in nanotechnology, there has been a paradigm shift in the modalities for cancer treatment with the help of phytomedicine-based nanosized drug delivery systems coupled with variegated surface-engineering strategies for targeted drug delivery. Among these delivery systems, lipid-based nanoparticles are considered as one of the highly biocompatible, efficient and effective systems extensively explored for anticancer drug delivery. These include diverse range of systems including liposomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipidic carriers and supramolecular carriers, which alters pharmacokinetic and biodistribution of the drugs for active targeting to the desired site of action by overcoming the biopharmaceutical challenges associated with anticancer drug delivery. The present review endeavours to provide a comprehensive account on the recent advances in the application of lipid-based nanostructured systems for improving the pharmacotherapeutic performance of phytomedicines for cancer targeting application.

Another look at dietary polyphenols: challenges in cancer prevention and treatment

Cancer is a pathology that impacts in a profound manner people all over the world. The election strategy against cancer often uses chemotherapy and radiotherapy, which more often than not can present many side effects and not always reliable efficacy. By contrast, it is widely known that a diet rich in fruit and vegetables has a protective effect against cancer insurgence and development. Polyphenols are generally believed to be responsible for those beneficial actions, at least partially. In this review, we highlight the metabolic interaction between polyphenols and our metabolism and discuss their potential for anticancer prevention and therapy.

Novel Perbutyrylated Glucose Derivatives of (-)-Epigallocatechin-3-Gallate Inhibit Cancer Cells Proliferation by Decreasing Phosphorylation of the EGFR: Synthesis, Cytotoxicity, and Molecular Docking

Lung cancer is one of the most commonly occurring cancer mortality worldwide. The epidermal growth factor receptor (EGFR) plays an important role in cellular functions and has become the new promising target. Natural products and their derivatives with various structures, unique biological activities, and specific selectivity have served as lead compounds for EGFR. D-glucose and EGCG were used as starting materials. A series of glucoside derivatives of EGCG (7-12) were synthesized and evaluated for their in vitro anticancer activity against five human cancer cell lines, including HL-60, SMMC-7721, A-549, MCF-7, and SW480. In addition, we investigated the structure-activity relationship and physicochemical property-activity relationship of EGCG derivatives. Compounds 11 and 12 showed better growth inhibition than others in four cancer cell lines (HL-60, SMMC-7721, A-549, and MCF), with IC50 values in the range of 22.90-37.87 μM. Compounds 11 and 12 decreased phosphorylation of EGFR and downstream signaling protein, which also have more hydrophobic interactions than EGCG by docking study. The most active compounds 11 and 12, both having perbutyrylated glucose residue, we found that perbutyrylation of the glucose residue leads to increased cytotoxic activity and suggested that their potential as anticancer agents for further development.

Synthesis, cytotoxicity, and molecular docking of methylated (–)-epigallocatechin-3-gallate-4β-triazolopodophyllotoxin derivatives as novel antitumor agents

A series of novel methylated (–)-epigallocatechin-3-gallate-4β-triazolopodophyllotoxin derivatives is synthesized by utilizing the click reaction. Evaluation of their cytotoxicity against a panel of five human cancer cell lines (HL-60, SMMC-7721, A-549, MCF-7, and SW480) using the MTT assay shows that most of these compounds exhibit weak cytotoxicity. It is observed that compound 12 shows the highest activity against A-549 cells with an IC50 value of 10.27 ± 0.90 μM. Molecular docking results suggested that this compound 12 has a higher binding affinity for epidermal growth factor receptor than for tubulin. Our findings support the utility of compound 12 as a novel compound for the further development of anticancer agents.

Polyphenol-Containing Nanoparticles: Synthesis, Properties, and Therapeutic Delivery

Polyphenols, the phenolic hydroxyl group-containing organic molecules, are widely found in natural plants and have shown beneficial effects on human health. Recently, polyphenol-containing nanoparticles have attracted extensive research attention due to their antioxidation property, anticancer activity, and universal adherent affinity, and thus have shown great promise in the preparation, stabilization, and modification of multifunctional nanoassemblies for bioimaging, therapeutic delivery, and other biomedical applications. Additionally, the metal-polyphenol networks, formed by the coordination interactions between polyphenols and metal ions, have been used to prepare an important class of polyphenol-containing nanoparticles for surface modification, bioimaging, drug delivery, and disease treatments. By focusing on the interactions between polyphenols and different materials (e.g., metal ions, inorganic materials, polymers, proteins, and nucleic acids), a comprehensive review on the synthesis and properties of the polyphenol-containing nanoparticles is provided. Moreover, the remarkable versatility of polyphenol-containing nanoparticles in different biomedical applications, including biodetection, multimodal bioimaging, protein and gene delivery, bone repair, antibiosis, and cancer theranostics is also demonstrated. Finally, the challenges faced by future research regarding the polyphenol-containing nanoparticles are discussed.

Frontiers in the treatment of glioblastoma: Past, present and emerging

Glioblastoma (GBM) is one of the most aggressive cancers of the brain. Despite extensive research over the last several decades, the survival rates for GBM have not improved and prognosis remains poor. To date, only a few therapies are approved for the treatment of GBM with the main reasons being: 1) significant tumour heterogeneity which promotes the selection of resistant subpopulations 2) GBM induced immunosuppression and 3) fortified location of the tumour in the brain which hinders the delivery of therapeutics. Existing therapies for GBM such as radiotherapy, surgery and chemotherapy have been unable to reach the clinical efficacy necessary to prolong patient survival more than a few months. This comprehensive review evaluates the current and emerging therapies including those in clinical trials that may potentially improve both targeted delivery of therapeutics directly to the tumour site and the development of agents that may specifically target GBM. Particular focus has also been given to emerging delivery technologies such as focused ultrasound, cellular delivery systems nanomedicines and immunotherapy. Finally, we discuss the importance of developing novel materials for improved delivery efficacy of nanoparticles and therapeutics to reduce the suffering of GBM patients.

Anticancer activity of flavonoids accompanied by redox state modulation and the potential for a chemotherapeutic strategy

Since researchers began studying the mechanism of flavonoids' anticancer activity, little attention has been focused on the modulation of redox state in cells as a potential chemotherapeutic strategy. However, recent studies have begun identifying that the anticancer effect of flavonoids occurs both in their antioxidative activity which scavenges ROS and their prooxidative activity which generates ROS. Against this backdrop, this study attempts to achieve a comprehensive analysis of the individual and separate study findings regarding flavonoids' modulation of redox state in cancer cells. It focuses on the mechanism behind the anticancer effect, and mostly on the modulation of redox potential by flavonoids such as quercetin, hesperetin, apigenin, genistein, epigallocatechin-3-gallate (EGCG), luteolin and kaempferol in both in vitro and animal models. In addition, the clinical applications of and bioavailability of flavonoids were reviewed to help build a treatment strategy based on flavonoids' prooxidative potential.

New tricks of old drugs: Repurposing non-chemo drugs and dietary phytochemicals as adjuvants in anti-tumor therapies

Combination therapy has long been applied to enhance therapeutic effect and deal with the occurrence of multi-drug resistance in cancer treatment. However, the overlapping toxicity of multiple anticancer drugs to healthy tissues and increasing financial burden on patients emerged as major concerns. As promising alternatives to chemo agents, repurposed non-chemo drugs and dietary phytochemicals have been investigated as adjuvants to conventional anti-tumor therapeutics, offering a safe and economic strategy for combination therapy. In this review, we aim to highlight the advances in research about combination therapy using conventional therapeutics and repurposed drugs or phytochemicals for an enhanced anti-tumor efficacy, along with the mechanisms involved in the synergism. Beyond these, we outlined the potential challenges and solutions for clinical translation of the proposed combination therapy, providing a safe and affordable strategy to improve the reach of cancer therapy to low income regions with such new tricks of old drugs.

Current Perspectives of the Applications of Polyphenols and Flavonoids in Cancer Therapy

The development of anticancer therapies that involve natural drugs has undergone exponential growth in recent years. Among the natural compounds that produce beneficial effects on human health, polyphenols have shown potential therapeutic applications in cancer due to their protective functions in plants, their use as food additives, and their excellent antioxidant properties. The possibility of combining conventional drugs-which are usually more aggressive than natural compounds-with polyphenols offers very valuable advantages such as the building of more efficient anticancer therapies with less side effects on human health. This review shows a wide range of trials in which polyphenolic compounds play a crucial role as anticancer medicines alone or in combination with other drugs at different stages of cancer: cancer initiation, promotion, and growth or progression. Moreover, the future directions in applications of various polyphenols in cancer therapy are emphasized.

Nutraceutical nanodelivery; an insight into the bioaccessibility/bioavailability of different bioactive compounds loaded within nanocarriers

Nanofoods is a current concept that is based on the application of nanotechnologies in the preparation of safe foods, with superior nutritional and sensory characteristics, and capable of providing multiple health benefits. In line with the principles of this concept, food scientists have focused on developing new types of nano biosystems that can contribute to increasing the bioavailability of bioactive compounds used in food fortification. Numerous research teams have investigated the main factors limiting oral bioavailability including: bioaccessibility, absorption and transformation of bioactive compounds and bioactive-loaded nanocarriers. The physicochemical processes involved in the factors limiting oral bioavailability have been extensively studied, such asthe release, solubility and interaction of bioactive compounds and nanocarriers during food digestion, transport mechanisms of bioactive compounds and nanoparticles through intestinal epithelial cells as well as the chemical and biochemical transformations in phase I and phase II reactions. In this comprehensive review, the physicochemical processes involved in the bioaccessibility/bioavailability of different encapsulated bioactive compounds, that play an important role in human health, will be explained including polyphenols, phytosterols, carotenoids, vitamins and minerals. In particular, the mechanisms involved in the cellular uptake of bioactive-loaded nanocarriers including transcellular transport (diffusion, endocytosis, pinocytosis, transcytosis, phagocytosis), paracellular transport (through the "tight junctions" between epithelial cells), and the active transport of bioactive compounds under the action of membrane transporters are highlighted.

Cancer Chemoprevention Using Nanotechnology-Based Approaches

Cancer research in pursuit of better diagnostic and treatment modalities has seen great advances in recent years. However, the incidence rate of cancer is still very high. Almost 40% of women and men are diagnosed with cancer during their lifetime. Such high incidence has not only resulted in high mortality but also severely compromised patient lifestyles, and added a great socioeconomic burden. In view of this, chemoprevention has gained wide attention as a method to reduce cancer incidence and its relapse after treatment. Among various stems of chemoprevention research, nanotechnology-based chemoprevention approaches have established their potential to offer better efficacy and safety. This review summarizes recent advances in nanotechnology-based chemoprevention strategies for various cancers with emphasis on lung and bronchial cancer, colorectal, pancreatic, and breast cancer and highlights the unmet needs in this developing field towards successful clinical translation.

Natural Compounds with Potential to Modulate Cancer Therapies and Self-Reactive Immune Cells

Cancer-related deaths are approaching 10 million each year. Survival statistics for some cancers, such as ovarian cancer, have remained unchanged for decades, with women diagnosed at stage III or IV having over 80% chance of a lethal cancer recurrence after standard first-line treatment (reductive surgery and chemotherapy). New treatments and adjunct therapies are needed. In ovarian cancer, as in other cancers, the immune response, particularly cytotoxic (CD8⁺) T cells are correlated with a decreased risk of recurrence. As well as completely new antigen targets resulting from DNA mutations (neo-antigens), these T cells recognize cancer-associated overexpressed, re-expressed or modified self-proteins. However, there is concern that activation of self-reactive responses may also promote off-target pathology. This review considers the complex interplay between cancer-reactive and self-reactive immune cells and discusses the potential uses for various leading immunomodulatory compounds, derived from plant-based sources, as a cancer therapy option or to modulate potential autoimmune pathology. Along with reviewing well-studied compounds such as curcumin (from turmeric), epigallocatechin gallate (EGCG, from green tea) and resveratrol (from grapes and certain berries), it is proposed that compounds from novel sources, for example, native Australian plants, will provide a useful source for the fine modulation of cancer immunity in patients.

Neuroprotection mediated by natural products and their chemical derivatives

Neuronal injuries can lead to various diseases such as neurodegenerative diseases, stroke, trauma, ischemia and, more specifically, glaucoma and optic neuritis. The cellular mechanisms that regulate neuronal death include calcium influx and calcium overload, excitatory amino acid release, oxidative stress, inflammation and microglial activation. Much attention has been paid to the effective prevention and treatment of neuroprotective drugs by natural products. This review summarizes the neuroprotective aspects of natural products, extracted from Panax ginseng, Camellia sinensis, soy and some other plants, and some of their chemical derivatives. Their antioxidative and anti-inflammatory action and their inhibition of apoptosis and microglial activation are assessed. This will provide new directions for the development of novel drugs and strategies to treat neurodegenerative diseases.

Synergistic inhibition of lung cancer cells by EGCG and NF-κB inhibitor BAY11-7082

Lung cancer has a poor 5-year survival rate and is the leading cause of cancer-related deaths worldwide. Thus, the development of more efficient therapeutic strategies is urgently needed. Many studies have shown that EGCG, a major polyphenol found in green tea, has potential anticancer effects. The present study aims to investigate the molecular mechanism of EGCG-mediated inhibition of proliferation in lung cancer cells and to explore the effects of combined treatment with EGCG and an NF-κB inhibitor, BAY11-7082, in A549 and H1299 cells both in vitro and in vivo. Our results showed that EGCG inhibits cell proliferation and migration and induces apoptosis in A549 and H1299 cells at relatively high concentrations (IC50=86.4 µM for A549 cells and 80.6 µM for H1299 cells). These effects are partially achieved via inhibition of the NF-κB signaling pathway. Combined treatment with EGCG and BAY11-7082, a potent NF-κB inhibitor, shows significant synergistic effects at relatively low concentrations. The inhibition rate reached approximately 50% in cells treated for 72 h with 20 µM EGCG and 5 µM (A549 cells) or 2.5 µM BAY11-7082 (H1299 cells). This synergistic anti-tumor effect was also observed in a xenograft model. These results indicated that EGCG inhibits lung cancer cell proliferation by suppressing NF-κB signaling. Coadministration of EGCG and BAY11-7082 has a synergistic effect both in vitro and in vivo and may serve as a novel therapeutic strategy for lung cancer.

Gut microbiota modulation with traditional Chinese medicine: A system biology-driven approach

With the development of system biology, traditional Chinese medicine (TCM) is drawing more and more attention nowadays. However, there are still many enigmas behind this ancient medical system because of the arcane theory and complex mechanism of actions. In recent decades, advancements in genome sequencing technologies, bioinformatics and culturomics have led to the groundbreaking characterization of the gut microbiota, a 'forgotten organ', and its role in host health and disease. Notably, gut microbiota has been emerging as a new avenue to understanding TCM. In this review, we will focus on the structure, composition, functionality and metabolites of gut microbiota affected by TCM so as to conversely understand its theory and mechanisms. We will also discuss the potential areas of gut microbiota for exploring Chinese material medica waste, Chinese marine material medica, add-on therapy and personalized precise medication of TCM. The review will conclude with future perspectives and challenges of gut microbiota in TCM intervention.

Dietary flavonoids: Nano delivery and nanoparticles for cancer therapy

Application of nanotechnologies to cancer therapy might increase solubility and/or bioavailability of bioactive compounds of natural or synthetic origin and offers other potential benefits in cancer therapy, including selective targeting. In the present review we aim to evaluate in vivo studies on the anticancer activity of nanoparticles (NPs) obtained from food-derived flavonoids. From a systematic search a total of 60 studies were identified. Most of the studies involved the flavanol epigallocatechin-3-O-gallate and the flavonol quercetin, in both delivery and co-delivery (with anti-cancer drugs) systems. Moreover, some studies investigated the effects of other flavonoids, such as anthocyanins aglycones anthocyanidins, flavanones, flavones and isoflavonoids. NPs inhibited tumor growth in both xenograft and chemical-induced animal models of cancerogenesis. Encapsulation improved bioavailability and/or reduced toxicity of both flavonoids and/or co-delivered drugs, such as doxorubicin, docetaxel, paclitaxel, honokiol and vincristine. Moreover, flavonoids have been successfully applied in molecular targeted nanosystems. Selectivity for cancer cells involves pH- and/or reactive oxygen species-mediated mechanisms. Furthermore, flavonoids are good candidates as drug delivery for anticancer drugs in green synthesis systems. In conclusion, although human studies are needed, NPs obtained from food-derived flavonoids have promising anticancer effects in vivo.

Isocitrate dehydrogenase 1-mutated cancers are sensitive to the green tea polyphenol epigallocatechin-3-gallate

Background

Mutations in isocitrate dehydrogenase 1 (IDH1) occur in various types of cancer and induce metabolic alterations resulting from the neomorphic activity that causes production of D-2-hydroxyglutarate (D-2-HG) at the expense of α-ketoglutarate (α-KG) and NADPH. To overcome metabolic stress induced by these alterations, IDH-mutated (IDH^mut) cancers utilize rescue mechanisms comprising pathways in which glutaminase and glutamate dehydrogenase (GLUD) are involved. We hypothesized that inhibition of glutamate processing with the pleiotropic GLUD-inhibitor epigallocatechin-3-gallate (EGCG) would not only hamper D-2-HG production, but also decrease NAD(P)H and α-KG synthesis in IDH^mut cancers, resulting in increased metabolic stress and increased sensitivity to radiotherapy.

Methods

We performed ¹³C-tracing studies to show that HCT116 colorectal cancer cells with an IDH1^R132H knock-in allele depend more on glutaminolysis than on glycolysis for the production of D-2-HG. We treated HCT116 cells, HCT116-IDH1^R132H cells, and HT1080 cells (carrying an IDH1^R132C mutation) with EGCG and evaluated D-2-HG production, cell proliferation rates, and sensitivity to radiotherapy.

Results

Significant amounts of ¹³C from glutamate accumulate in D-2-HG in HCT116-IDH1^wt/R132H but not in HCT116-IDH1^wt/wt. Preventing glutamate processing in HCT116-IDH1^wt/R132H cells with EGCG resulted in reduction of D-2-HG production. In addition, EGCG treatment decreased proliferation rates of IDH1^mut cells and at high doses sensitized cancer cells to ionizing radiation. Effects of EGCG in IDH-mutated cell lines were diminished by treatment with the IDH1^mut inhibitor AGI-5198.

Conclusions

This work shows that glutamate can be directly processed into D-2-HG and that reduction of glutamatolysis may be an effective and promising new treatment option for IDH^mut cancers.

Electronic supplementary material

The online version of this article (10.1186/s40170-019-0198-7) contains supplementary material, which is available to authorized users.

Targeting Cancer Via Resveratrol-Loaded Nanoparticles Administration: Focusing on In Vivo Evidence

Resveratrol (RSV) is a polyphenol endowed with potential therapeutic effects in chronic diseases, particularly in cancer, the second leading cause of death worldwide in the twenty-first century. The advent of nanotechnology application in the field of drug delivery allows to overcome the constrains associated with the conventional anticancer treatments, in particular chemotherapy, reducing its adverse side effects, off target risks and surpassing cancer multidrug chemoresistance. Moreover, the use of nanotechnology-based carriers in the delivery of plant-derived anticancer agents, such as RSV, has already demonstrated to surpass the poor water solubility, instability and reduced bioavailability associated with phytochemicals, improving their therapeutic activity, thus prompting pharmaceutical developments. This review highlights the in vivo anticancer potential of RSV achieved by nanotherapeutic approaches. First, RSV physicochemical, stability and pharmacokinetic features are described. Thereupon, the chemotherapeutic and chemopreventive properties of RSV are underlined, emphasizing the RSV numerous cancer molecular targets. Lastly, a comprehensive analysis of the RSV-loaded nanoparticles (RSV-NPs) developed and administered in different in vivo cancer models to date is presented. Nanoparticles (NPs) have shown to improve RSV solubility, stability, pharmacokinetics and biodistribution in cancer tissues, enhancing markedly its in vivo anticancer activity. RSV-NPs are, thus, considered a potential nanomedicine-based strategy to fight cancer; however, further studies are still necessary to allow RSV-NP clinical translation.

Effects and mechanisms of tea for the prevention and management of cancers: An updated review

Tea is a traditional and popular beverage worldwide, and the consumption of tea has been demonstrated to possess many health benefits, such as cardiovascular protection, anti-obesity, anti-diabetes, and anticancer. Epidemiological studies have shown that the consumption of tea is inversely associated with the risk of several cancers. In addition, experimental studies have revealed that the anticancer actions of tea are mainly attributed to tea polyphenols, such as epigallocatechin-3-gallate and theaflavins. Both in vitro and in vivo studies have demonstrated that the possible anticancer mechanisms are the inhibition on proliferation, anti-angiogenesis, induction of apoptosis, suppression on metastasis, inhibition on cancer stem cells, and modulation on gut microbiota. Its synergetic anticancer effects with drugs or other compounds could promote anticancer therapies. Furthermore, clinical trials have elucidated that intervention of tea phytochemicals is effective in the prevention of several cancers. This paper is an updated review for the prevention and management of cancers by tea based on the findings from epidemiological, experimental and clinical studies, and special attention is paid on the mechanisms of action.

Recent progress on biocompatible nanocarrier-based genistein delivery systems in cancer therapy

Diets with naturally occuring chemopreventive agents are showing good potentials in serving dual purposes: firstly, for maintaining health, and secondly, for emerging as most puissant cost-effective strategy against chronic diseases like cancer. Genistein, one of the active soy isoflavone, is gaining attention due to its ability to impede carcinogenic processes by regulating wide range of associated molecules and signalling mechanisms. Epidemiologic and preclinical evidences suggest that sufficient consumption of soy-based food having genistein can be correlated to the reduction of cancer risk. However, certain adverse effects like poor oral bioavailability, low aqueous solubility and inefficient pharmacokinetics have pushed it down in the list of phytoconstituents currently undergoing successful clinical trials. In order to maximise the utilisation of therapeutic benefits of this phytoestrogen, suitable drug carrier designs are required. Recently, nanocarriers, mainly composed of polymeric materials, are progressively and innovatively exploited with the aim to improve pharmacokinetics and pharmacodynamics of genistein. Here, we have briefly reviewed (a) the targeted molecular mechanisms of geinstein, (b) nanopolymeric approaches opted so far in designing carriers and (c) the reasons behind their restricted clinical applications. Finally, some mechanism-based approaches are proposed presenting genistein as the future paradigm in cancer therapy.

Enhanced oral bioavailability of EGCG using pH-sensitive polymeric nanoparticles: characterization and in vivo investigation on nephrotic syndrome rats

Objective

Chronic kidney disease (CKD) is characterized by progressive loss of renal functions. At present, there are only limited therapeutic strategies to slow down the progress of CKD and there is an urgent need to develop new therapeutic strategies to treat CKD patients. Numerous research evidence supports the potential role of EGCG in the renal protection of CKD. However, the clinical use is still limited due to the poor oral bioavailability. The aim of this study was to develop pH-sensitive polymeric nanoparticles of EGCG to improve this deficiency.

Materials and methods

EGCG-loaded nanoparticles (EGCG NPs) were prepared by an improved emulsion evaporation method. The formulation prepared was in spherical with uniform sizes, high encapsulation efficiencies and drug loading. The therapeutic efficacy of EGCG NPs on chronic kidney disease was investigated on model of rat Nephrotic syndrome by measuring urinary protein excretion and kidney pathology score.

Results

The mean particle size was found to be 91.3±0.8 nm and the encapsulation efficiency% and drug loading% of the formulation were 80.8%±1.6% and 6.3%±1.4%, respectively. The powder X-ray diffraction and differential scanning calorimetry of EGCG NPs showed that EGCG existed in amorphous form in NPs. The release of EGCG from NPs exhibited the lower burst release at pH 1.2 (<10%) and with the increase of pH value, the release of EGCG also gradually increased. During the observation period (24 hours), the total release amount was almost 68%. EGCG NPs could significantly modify the pharmacokinetic profile and increase the bioavailability of EGCG by more than 2.4-fold in comparison with the EGCG powder group. At the end of the fourth and sixth week, proteinuria excretion of nephrotic syndrome rats treated with EGCG NPs was significantly lower than those treated with EGCG powder, and kidney pathology scores in EGCG NPs treated rats were also significantly lower than EGCG powder treated rats.

Conclusion

The results of pharmacodynamics showed that compared with EGCG powder treatment group, EGCG NPs treatment group had better efficacy and reduce kidney damage.

Effects of the Green Tea Polyphenol Epigallocatechin-3-Gallate on Glioma: A Critical Evaluation of the Literature

The review discusses the effects of Epigallocatechin-3-gallate Gallate (EGCG) on glioma as a basis for future research on clinical application of EGCG. Epidemiological studies on the effects of green tea or EGCG on the risk of glioma is inconclusive due to the limited number of studies, the inclusion of all tea types in these studies, and the focus on caffeine rather than EGCG. In vivo experiments using EGCG monotherapy are inconclusive. Nevertheless, EGCG induces cell death, prevents cellular proliferation, and limits invasion in multiple glioma cell lines. Furthermore, EGCG enhances the efficacy of anti-glioma therapies, including irradiation, temozolomide, carmustine, cisplatin, tamoxifen, and TNF-related apoptosis-inducing ligand, but reduces the effect of bortezomib. Pro-drugs, co-treatment, and encapsulation are being investigated to enhance clinical applicability of EGCG. Mechanisms of actions of EGCG have been partly elucidated. EGCG has both anti-oxidant and oxidant properties. EGCG inhibits pro-survival proteins, such as telomerase, survivin, GRP78, PEA15, and P-gp. EGCG inhibits signaling of PDGFR, IGF-1R, and 67LR. EGCG reduces invasiveness of cancer cells by inhibiting the activities of various metalloproteinases, cytokines, and chemokines. Last, EGCG inhibits some NADPH-producing enzymes, thus disturbing redox status and metabolism of glioma cells. In conclusion, EGCG may be a suitable adjuvant to potentiate anti-glioma therapies.

Neuroprotective Effects and Mechanisms of Tea Bioactive Components in Neurodegenerative Diseases

As the population ages, neurodegenerative diseases such as Parkinson's disease (PD) and Alzheimer's disease (AD) impose a heavy burden on society and families. The pathogeneses of PD and AD are complex. There are no radical cures for the diseases, and existing therapeutic agents for PD and AD have diverse side effects. Tea contains many bioactive components such as polyphenols, theanine, caffeine, and theaflavins. Some investigations of epidemiology have demonstrated that drinking tea can decrease the risk of PD and AD. Tea polyphenols can lower the morbidity of PD and AD by reducing oxidative stress and regulating signaling pathways and metal chelation. Theanine can inhibit the glutamate receptors and regulate the extracellular concentration of glutamine, presenting neuroprotective effects. Additionally, the neuroprotective mechanisms of caffeine and theaflavins may contribute to the ability to antagonize the adenosine receptor A2AR and the antioxidant properties, respectively. Thus, tea bioactive components might be useful for neuronal degeneration treatment in the future. In the present paper, the neuro protection and the mechanisms of tea and its bioactive components are reviewed. Moreover, the potential challenges and future work are also discussed.

Antitumor activities of Quercetin and Green Tea in xenografts of human leukemia HL60 cells

Quercetin is one of the most abundant flavonoids, present in fruits and vegetables and has been shown to have multiple properties capable of reducing cell growth in cancer cells. Green tea is a widely consumed beverage, known for a potential source of free radical scavenging and anti-cancer activities. Herein, we investigate the in vivo antitumor efficacy of quercetin and green tea in human leukemia. Human tumors were xenografted into NOD/SCID mice. Quercetin and green tea reduced tumor growth in HL-60 xenografts accompanied by decreased expression of anti-apoptotic proteins, BCL-2, BCL-XL and MCL-1 and increased expression of BAX, a pro-apoptotic protein. Moreover, caspase-3 was activated to a greater extent after quercetin and green tea treatment. Quercetin and green tea also mediated G1 phase cell cycle arrest in HL-60 xenografts. Treatment with quercetin and green tea induced conversion of LC3-I to LC3-II as well as activation of autophagy proteins, suggesting that quercetin and green tea initiate the autophagic progression. We have provided evidence that quercetin and green tea induces signaling at the level of apoptosis, cell cycle and autophagy which converge to antigrowth effects in HL-60 xenograft mice suggesting that these compounds may be a compelling ally in cancer treatment.

Epigallocatechin gallate-zinc oxide co-crystalline nanoparticles as an anticancer drug that is non-toxic to normal cells

Decreased uptake and cellular accumulation of zinc is a common characteristic in cancer of the liver, pancreas and prostate, because these malignant cells are intolerant to the physiological concentrations of zinc. A tea polyphenol, epigallocatechin-3-gallate (EGCG), can enhance the cytotoxicity of zinc ions to cancer, but the application of this is limited by the low stability of EGCG. In this work, we have prepared a material that can simultaneously preserve the EGCG stability and facilitate zinc uptake and accumulation in cancer cells, under conditions that are not harmful to normal cells. Thus, we co-crystallize zinc oxide with EGCG to obtain hybrid EGCG-ZnO crystalline nanoparticles of 16.5 ± 5.3 nm in diameter. The EGCG-ZnO particles effectively kill PC-3 prostate adenocarcinoma cells at concentrations that are not cytotoxic to normal cells, WI-38 human embryonic lung fibroblasts. The EGCG-ZnO particles are two times more cytotoxic against PC-3 cells than the standard ZnO particles. In PC-3 cells, the EGCG-ZnO particles are taken up by endocytosis, followed by lysosomal disruption to release zinc and EGCG into the cytoplasm, finally resulting in nuclear accumulation of zinc.

A tea polyphenol, epigallocatechin-3-gallate (EGCG), can enhance cytotoxicity of Zinc in cancer cells. Here we synthesize hybrid EGCG-ZnO nanoparticles that can kill PC-3 prostate cancer cells at concentrations that are not toxic to normal cells.

Increased Loading, Efficacy and Sustained Release of Silibinin, a Poorly Soluble Drug Using Hydrophobically-Modified Chitosan Nanoparticles for Enhanced Delivery of Anticancer Drug Delivery Systems

Conventional delivery of anticancer drugs is less effective due to pharmacological drawbacks such as lack of aqueous solubility and poor cellular accumulation. This study reports the increased drug loading, therapeutic delivery, and cellular accumulation of silibinin (SLB), a poorly water-soluble phenolic compound using a hydrophobically-modified chitosan nanoparticle (pCNP) system. In this study, chitosan nanoparticles were hydrophobically-modified to confer a palmitoyl group as confirmed by 2,4,6-Trinitrobenzenesulfonic acid (TNBS) assay. Physicochemical features of the nanoparticles were studied using the TNBS assay, and Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analyses. The FTIR profile and electron microscopy correlated the successful formation of pCNP and pCNP-SLB as nano-sized particles, while Dynamic Light Scattering (DLS) and Field Emission-Scanning Electron Microscopy (FESEM) results exhibited an expansion in size between pCNP and pCNP-SLB to accommodate the drug within its particle core. To evaluate the cytotoxicity of the nanoparticles, a Methylthiazolyldiphenyl-tetrazolium bromide (MTT) cytotoxicity assay was subsequently performed using the A549 lung cancer cell line. Cytotoxicity assays exhibited an enhanced efficacy of SLB when delivered by CNP and pCNP. Interestingly, controlled release delivery of SLB was achieved using the pCNP-SLB system, conferring higher cytotoxic effects and lower IC₅₀ values in 72-h treatments compared to CNP-SLB, which was attributed to the hydrophobic modification of the CNP system.

Green Tea Catechins for Prostate Cancer Prevention: Present Achievements and Future Challenges

Green tea catechins (GTCs) are a family of chemically related compounds usually classified as antioxidant molecules. Epidemiological evidences, supported by interventional studies, highlighted a more than promising role for GTCs in human prostate cancer (PCa) chemoprevention. In the last decades, many efforts have been made to gain new insights into the mechanism of action of GTCs. Now it is clear that GTCs' anticancer action can no longer be simplistically limited to their direct antioxidant/pro-oxidant properties. Recent contributions to the advancement of knowledge in this field have shown that GTCs specifically interact with cellular targets, including cell surface receptors, lipid rafts, and endoplasmic reticulum, modulate gene expression through direct effect on transcription factors or indirect epigenetic mechanisms, and interfere with intracellular proteostasis at various levels. Many of the effects observed in vitro are dose and cell context dependent and take place at concentrations that cannot be achieved in vivo. Poor intestinal absorption together with an extensive systemic and enteric metabolism influence GTCs' bioavailability through still poorly understood mechanisms. Recent efforts to develop delivery systems that increase GTCs' overall bioavailability, by means of biopolymeric nanoparticles, represent the main way to translate preclinical results in a real clinical scenario for PCa chemoprevention.