Anticancer Effects of Green Tea and the Underlying Molecular Mechanisms in Bladder Cancer

The Association between Tea Consumption and Bladder Cancer Risk Based on the Bladder Cancer Epidemiology and Nutritional Determinants (BLEND) International Consortium

OBJECTIVES

Evidence regarding the association between tea consumption and bladder cancer (BC) risk is inconsistent. This study aimed to increase our knowledge of the association by using international data from the Bladder Cancer Epidemiology and Nutritional Determinants Consortium.

METHODS

Individual data on 2,347 cases and 6,871 controls from 15 case-control studies with information on black, green, herbal, or general tea was pooled. The association was estimated using multilevel multivariable logistic regression analysis adjusted for multiple (non-)dietary factors.

RESULTS

Association between tea consumption and BC risk was observed (odds ratio, OR = 0.72, 95% confidence interval, 95% CI = 0.65-0.80) compared to non-tea drinkers. Stratified analyses based on gender and smoking status yielded similar results. Stratified analysis showed no significant association between black or green tea consumption and BC risk across models, while herbal tea consumption was linked to a reduced BC risk (OR = 0.59, 95% CI = 0.36-0.96). As daily tea consumption increased within a suitable range (<5.67 cups/day), BC risk decreased.

CONCLUSIONS

Camellia sinensis tea showed no association with BC risk, while herbal tea was inversely linked to BC incidence. Despite some significant findings in the selected strata, further studies are required to clarify the underlying mechanisms.

Green synthesis of silver nanoparticles using the BT5 tea cultivar of Bangladesh: unveiling molecular mechanisms of anti-cancer activity in mice model

Silver nanoparticles (AgNPs) have sparked widespread interest due to their remarkable physiochemical capabilities, and they are now being used as a beneficial tool in the biomedical field. However, typical synthesis processes generate dangerous compounds that raise environmental and safety concerns. This is one of the main reasons for choosing a greener synthesis approach. The BT5 cultivar of green tea, which is high in phenolic and flavonoid compounds and has strong antioxidant activity (IC50 ≈ 97.8 μg mL-1), was used in an eco-friendly way to produce AgNPs. The green synthesis approach was confirmed by the rapid color change (light to dark brown) of AgNO3 solution upon the addition of the BT5 extract. Several methods were performed to characterize the synthesized BT5-AgNPs, using UV-vis spectroscopy (λ max = 424 nm), FTIR, DLS, zeta potential (-39.8 ± 0.45 mV), TGA, XRD (crystalline size = 11.25 nm), and FE-SEM (35 ± 8.36 nm). BT5-AgNPs showed strong antiproliferative properties inimical to Ehrlich-Lettre ascites carcinoma cells (EAC) of the Swiss albino variety of mice model, with low-concentration treatment (1 mg kg-1) resulting in 52.15% cell growth inhibition. Fluorescence microscopy using DAPI staining revealed morphological alterations via heterochromatization and karyorrhexis. Gene expression analysis revealed upregulation of hallmark genes p53 and BAX and Bcl2 downregulation in the low- and high-concentration groups, indicating activation of the apoptotic pathway. Most likely due to cytotoxic effects and altered cellular responses, a higher dosage (5 mg kg-1) resulted in slightly lower efficacy.

Catechins in cancer therapy: integrating traditional and complementary approaches

Catechin is a group of bioactive flavonoids found in various plant sources such as tea, cocoa, and fruits. Recent studies have suggested that catechins has significant potential in preventing and treating cancer. Catechin exhibits a variety of biological activities that may contribute to its anticancer effects, including antioxidant, anti-inflammatory, and pro-apoptotic properties. Studies have demonstrated that catechin can inhibit cancer cell proliferation, induce cell cycle arrest, and promote apoptosis across multiple cancer types, including skin, breast, lung, liver, prostate, and colon cancers. Furthermore, catechin has shown the ability to inhibit angiogenesis, a critical process for tumor growth and metastasis, by restricting new blood vessel formation. Catechin's impact on cancer extends beyond its direct effects on cancer cells. It modulates various signaling pathways involved in cancer progression, such as those associated with cell survival, inflammation, and metastasis. Despite these promising findings, additional research is needed to clarify the precise mechanisms of catechin's anticancer action, optimal dosing strategies, and long-term safety in cancer prevention and treatment. This review will explore the current research landscape on tea polyphenols, particularly catechin, and their potential role in cancer prevention and therapy.

Molecular Mechanisms of Phthalate-Induced Hepatic Injury and Amelioration by Plant-Based Principles

Phthalates are the emerging environmental toxicants derived from phthalic acid and its constituents, which are moderately present in plastics and many personal care products. Phthalate exposure occurs through various environmental factors, including air, water, and soil, with absorption facilitated via ingestion, inhalation, and dermal contact. Upon exposure, phthalates become bioavailable within the biological systems and undergo biotransformation and detoxification processes in the liver. The physicochemical properties of phthalates indicate their lipophilicity, environmental persistence, and bioaccumulation potential, influencing their absorption, distribution, and hepatic biotransformation. The prolonged exposure to phthalates adversely influences the biological redox system by altering the levels of the enzymatic and non-enzymatic antioxidants, molecular signaling pathways, and causing hepatic pathogenesis. The strategies to combat phthalate-induced toxicity include avoiding exposure to these compounds and using plant-based bioactive molecules such as polyphenols, which possess therapeutic potential as antioxidants, suppress inflammatory cascades, prevent oxidative damage, and stabilize cellular integrity. This review presents a comprehensive and updated account of the chemical, biochemical, immunological, and toxicological properties of phthalates, along with novel plant-based therapeutic strategies to mitigate the phthalate-induced adverse effects on living systems.

Potential of Natural Products in the Treatment of Glioma: Focus on Molecular Mechanisms

Despite the waning of traditional treatments for glioma due to possible long-term issues, the healing possibilities of substances derived from nature have been reignited in the scientific community. These natural substances, commonly found in fruits and vegetables, are considered potential alternatives to pharmaceuticals, as they have been shown in prior research to impact pathways surrounding cancer progression, metastases, invasion, and resistance. This review will explore the supposed molecular mechanisms of different natural components, such as berberine, curcumin, coffee, resveratrol, epigallocatechin-3-gallate, quercetin, tanshinone, silymarin, coumarin, and lycopene, concerning glioma treatment. While the benefits of a balanced diet containing these compounds are widely recognized, there is considerable scope for investigating the efficacy of these natural products in treating glioma.

Formation of ZnS quantum dots using green tea extract: applications to protein binding, bio-sensing, anti-bacterial and cell cytotoxicity studies

Biocompatible quantum dots (QDs) have attracted a lot of attention due to their potential biological applications (drug delivery, sensing and diagnosis). Here, we have synthesized 2-4 nm sized biocompatible zinc sulphide (ZnS) QDs using a plant leaf extract as an immobilizing and stabilizing agent via a green route. We have investigated the biological effects of ZnS QDs in a variety of applications, including (1) anti-bacterial activity, (2) cell cytotoxicity, (3) bio-sensing and (4) protein binding. Studies on the anti-bacterial activity of the as-synthesized ZnS QDs against E. coli and E. faecalis inhibited bacterial growth effectively and showed a cytotoxic effect on the HeLa cell line. The biosynthesized ZnS QDs act as a fluorescence probe to detect bilirubin and rifampicin (RFP) with a wide linear range, high sensitivity, good selectivity, and a low limit of detection (LOD), with LOD values of 22.12 ± 0.25 ng mL^-1 and 122.37 ± 0.42 ng mL^-1, respectively. In a biological matrix, the QDs can form a complex with biomacromolecules; therefore, we studied the interaction between a carrier protein (HSA) and the as-synthesized ZnS QDs. The surface functionalized and nano-sized ZnS-GT QDs were observed to form complexes with the human serum albumin (HSA) protein and quenched the intrinsic fluorescence of HSA through static and dynamic quenching modes. The binding affinity was observed to be of the order of 10⁵ M^-1 for the HSA-ZnS-GT QD interactions, which can be considered as a reversible mode of binding. The effect of the ZnS QDs on other ligands and protein interactions was also studied. Enhanced binding affinities for HSA-quercetin ((5.994 ± 0.139) × 10⁵ M^-1) and HSA-luteolin ((3.068 ± 0.127) × 10⁵ M^-1) interactions were also observed in the presence of ZnS-GT QDs.

Epigallocatechin-3-gallate improves the biocompatibility of bone substitutes in dental pulp stem cells

BACKGROUND

The Biocompatibility between osteoprogenitor cells and bone substitutes is necessary for cell differentiation and osteogenesis. The aim of this study was to assess the in vitro effect of bovine (Geistlich BioOss®), porcine (OsteoBiol Gen-Os®) and beta-tricalcium phosphate (Cerasorb M®) bone substitutes, and their combination with polyphenol epigallocatechin-3-gallate (EGCG), upon cultured dental pulp stem cells (DPSCs).

METHODS

The DPSCs were isolated from third molars extracted from healthy individuals and seeded with 5 mg/ml of Bio-Oss® (BO), Gen-Os® (GO) and Cerasorb® (CE) in combination with EGCG 1 μM. The effects were evaluated based on cell viability / cytotoxicity assay (MTT, cell viability staining test), cell migration, scanning electron microscopy (SEM), and alkaline phosphatase (ALP) activity.

RESULTS

BO and CE produced negative effects upon cell viability and migration, and GO and CE resulted in deficient cell adhesion. On the other hand, all the biomaterials exerted no negative effects upon ALP activity. Interestingly, the addition of EGCG reverted the cytotoxic effect and the loss of migration capacity in the BO and CE groups, and improved cell adhesion in the GO and CE groups. Furthermore, EGCG promoted an overall increased in ALP activity.

CONCLUSION

The addition of EGCG to the tested biomaterials BO, GO and CE reverts their negative impact on DPSCs, and improves their biocompatibility with cultured DPSCs. The use of EGCG, thus, appears to be a promising strategy for restoring and enhancing the osteoconductive properties of BO, GO and CE in bone regeneration treatments.

Resveratrol, Epigallocatechin Gallate and Curcumin for Cancer Therapy: Challenges from Their Pro-Apoptotic Properties

Plant-derived bioactive compounds are gaining wide attention for their multiple health-promoting activities and in particular for their anti-cancer properties. Several studies have highlighted how they can prevent cancer initiation and progression, improve the effectiveness of chemotherapy, and, in some cases, limit some of the side effects of chemotherapy agents. In this paper, we provide an update of the literature on the anti-cancer effects of three extensively studied plant-derived compounds, namely resveratrol, epigallocatechin gallate, and curcumin, with a special focus on the anti-cancer molecular mechanisms inducing apoptosis in the major types of cancers globally.

Evaluation of tea (Camellia sinensis L.) phytochemicals as multi-disease modulators, a multidimensional in silico strategy with the combinations of network pharmacology, pharmacophore analysis, statistics and molecular docking

Tea (Camellia sinensis L.) is considered as to be one of the most consumed beverages globally and a reservoir of phytochemicals with immense health benefits. Despite numerous advantages, tea compounds lack a robust multi-disease target study. In this work, we presented a unique in silico approach consisting of molecular docking, multivariate statistics, pharmacophore analysis, and network pharmacology approaches. Eight tea phytochemicals were identified through literature mining, namely gallic acid, catechin, epigallocatechin gallate, epicatechin, epicatechin gallate (ECG), quercetin, kaempferol, and ellagic acid, based on their richness in tea leaves. Further, exploration of databases revealed 30 target proteins related to the pharmacological properties of tea compounds and multiple associated diseases. Molecular docking experiment with eight tea compounds and all 30 proteins revealed that except gallic acid all other seven phytochemicals had potential inhibitory activities against these targets. The docking experiment was validated by comparing the binding affinities (Kcal mol^-1) of the compounds with known drug molecules for the respective proteins. Further, with the aid of the application of statistical tools (principal component analysis and clustering), we identified two major clusters of phytochemicals based on their chemical properties and docking scores (Kcal mol^-1). Pharmacophore analysis of these clusters revealed the functional descriptors of phytochemicals, related to the ligand-protein docking interactions. Tripartite network was constructed based on the docking scores, and it consisted of seven tea phytochemicals (gallic acid was excluded) targeting five proteins and ten associated diseases. Epicatechin gallate (ECG)-hepatocyte growth factor receptor (PDB id 1FYR) complex was found to be highest in docking performance (10 kcal mol^-1). Finally, molecular dynamic simulation showed that ECG-1FYR could make a stable complex in the near-native physiological condition.

Tea Polyphenols and Their Preventive Measures against Cancer: Current Trends and Directions

Cancer is exerting an immense strain on the population and health systems all over the world. Green tea because of its higher simple catechin content (up to 30% on dry weight basis) is greatly popular as an anti-cancer agent which is found to reduce the risks of cancer as well as a range of other diseases. In addition, several in vitro and in vivo studies have shown that green tea possesses copious health benefits like anti-diabetic, anti-obese, anti-inflammatory, neuro-protective, cardio-protective, etc. This review highlights the anti-carcinogenic effects of green tea catechins integrating the recent information to gain a clear concept. Special emphasis was given to the effectiveness of green tea polyphenols (GTP) in the prevention of cancer. Overall, green tea has been found to be effective to reduce the risks of breast cancer, ovarian cancer, liver cancer, colorectal cancer, skin cancer, prostate cancer, oral cancer, etc. However, sufficient information was not found to support that green tea consumption reduces the risk of lung cancer, esophageal cancer, or stomach cancer. The exciting data integrated into this article will increase interest in future researchers to garner more fruitful information on the relevant topics.

Green Tea Catechins: Nature’s Way of Preventing and Treating Cancer

Green tea’s (Camellia sinensis) anticancer and anti-inflammatory effects are well-known. Catechins are the most effective antioxidants among the physiologically active compounds found in Camellia sinesis. Recent research demonstrates that the number of hydroxyl groups and the presence of specific structural groups have a substantial impact on the antioxidant activity of catechins. Unfermented green tea is the finest source of these chemicals. Catechins have the ability to effectively neutralize reactive oxygen species. The catechin derivatives of green tea include epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG). EGCG has the greatest anti-inflammatory and anticancer potential. Notably, catechins in green tea have been explored for their ability to prevent a variety of cancers. Literature evidence, based on epidemiological and laboratory studies, indicates that green tea catechins have certain properties that can serve as the basis for their consideration as lead molecules in the synthesis of novel anticancer drugs and for further exploration of their role as pharmacologically active natural adjuvants to standard chemotherapeutics. The various sections of the article will focus on how catechins affect the survival, proliferation, invasion, angiogenesis, and metastasis of tumors by modulating cellular pathways.

Camellia sinensis L. Alleviates Pulmonary Inflammation Induced by Porcine Pancreas Elastase and Cigarette Smoke Extract

Cigarette smoke (CS) is the major factor in the development of chronic obstructive pulmonary disease (COPD), the third leading cause of death worldwide. Furthermore, although Camellia sinensis (CN) has been known as an anti-inflammatory material, the effect of CN has not yet been known on pulmonary inflammation in COPD. Thus, we investigated the protective effects of Camellia sinensis L. extract (CLE) against pulmonary inflammation in porcine pancreas elastase (PPE) and a cigarette smoke extract (CSE)-induced COPD mouse model. Oral administration of CLE suppressed the symptoms such as infiltration of immune cells, cytokines/chemokines secretion, mucus hypersecretion, and injuries of the lung parenchyma. Increased inflammatory responses in COPD are mediated by various immune cells such as airway epithelial cells, neutrophils, and alveolar macrophages. Thus, we investigated the effect and mechanisms of CLE in H292, HL-60, and MH-S cells. The CLE inhibited the expression of IL-6, IL-8, MUC5AC and MUC5B on CSE/LPS-stimulated H292 cells and also suppressed the formation of neutrophil extracellular traps and secretion of neutrophil elastase by inhibiting reactive oxygen species in PMA-induced HL-60 cells. In particular, the CLE suppressed the release of cytokines and chemokines caused by activating the nuclear factor kappa-light-chain-enhancer of activated B via the activation of nuclear factor erythroid-2-related factor 2 and the heme oxygenase-1 pathway in CSE/LPS-stimulated MH-S cells. Therefore, we suggest that the CLE administration be the effective approach for treating or preventing chronic pulmonary diseases such as COPD induced by CS.

Naringenin: A potential flavonoid phytochemical for cancer therapy

Naringenin is an important phytochemical which belongs to the flavanone group of polyphenols, and is found mainly in citrus fruits like grapefruits and others such as tomatoes and cherries plus medicinal plants derived food. Available evidence demonstrates that naringenin, as herbal medicine, has important pharmacological properties, including anti-inflammatory, antioxidant, neuroprotective, hepatoprotective, and anti-cancer activities. Collected data from in vitro and in vivo studies show the inactivation of carcinogens after treatment with pure naringenin, naringenin-loaded nanoparticles, and also naringenin in combination with anti-cancer agents in various malignancies, such as colon cancer, lung neoplasms, breast cancer, leukemia and lymphoma, pancreatic cancer, prostate tumors, oral squamous cell carcinoma, liver cancer, brain tumors, skin cancer, cervical and ovarian cancer, bladder neoplasms, gastric cancer, and osteosarcoma. Naringenin inhibits cancer progression through multiple mechanisms, like apoptosis induction, cell cycle arrest, angiogenesis hindrance, and modification of various signaling pathways including Wnt/β-catenin, PI3K/Akt, NF-ĸB, and TGF-β pathways. In this review, we demonstrate that naringenin is a natural product with potential for the treatment of different types of cancer, whether it is used alone, in combination with other agents, or in the form of the naringenin-loaded nanocarrier, after proper technological encapsulation.

Rutin prevents cardiac oxidative stress and inflammation induced by bisphenol A and dibutyl phthalate exposure via NRF-2/NF-κB pathway

AIM

Environmental pollutants such as plastic-component substances (phthalates and bisphenol A) that coexist in natural ecosystems have been linked to an increase in the occurrence of human health hazards, particularly cardiovascular health. This study was designed to investigate single and combined cardio-toxic effects of dibutyl phthalate and bisphenol-A and the possible interventional role of rutin.

MATERIALS AND METHODS

Forty-two rats were randomized into 7 groups of 6 animals each and were treated as follows for 28 days: Control (0.1% DMSO), Bisphenol-A (BPA, 25 mg/kg, p.o), Dibutyl phthalate (DBP, 25 mg/kg, p.o), BPA + Rutin (25 mg/kg, Rt 50 mg/kg), DBP + Rt (25 mg/kg, Rt 50 mg/kg), BPA + DBP, BPA + DBP + Rt. Cardiac lipid peroxidation, antioxidants and inflammatory markers activities were measured.

KEY FINDINGS

The result showed that BPA reduced the superoxide dismutase (SOD) activity, DBP and DBP+ BPA reduced the catalase (CAT) activity, DBP reduced glutathione (GSH) and nuclear factor erythroid 2-related factor 2 (Nrf2) while malondialdehyde (MDA) increased in DBP + BPA group. Also, DBP increased tissue C-reactive protein (CRP); DBP, DBP + BPA increased tissue nuclear factor kappa B (NF-κB); DBP + BPA increased plasma CRP; BPA increased plasma NF-κB. However, rutin efficiently reduced MDA level, CRP and NF-κB; increasing SOD, GSH and Nrf2 levels in DBP and BPA exposed rats.

SIGNIFICANCE

These results revealed that bisphenol and dibutyl phthalate exposure caused oxidative stress and inflammation in the heart through Nrf2/NF-κB signaling pathway while oral administration of rutin prevents these effects via upregulation of Nrf2 and suppression of NF-κB signaling pathway.

Recent insights on tea metabolites, their biosynthesis and chemo-preventing effects: A review

Tea manufactured from the cultivated shoots of Camellia sinensis (L.) O. Kuntze is the most commonly consumed nonalcoholic drink around the world. Tea is an agro-based, environmentally sustainable, labor-intensive, job-generating, and export-oriented industry in many countries. Tea includes phenolic compounds, flavonoids, alkaloids, vitamins, enzymes, crude fibers, protein, lipids, and carbohydrates, among other biochemical constituents. This review described the nature of tea metabolites, their biosynthesis and accumulation with response to various factors. The therapeutic application of various metabolites of tea against microbial diseases, cancer, neurological, and other metabolic disorders was also discussed in detail. The seasonal variation, cultivation practices and genetic variability influence tea metabolite synthesis. Tea biochemical constituents, especially polyphenols and its integral part catechin metabolites, are broadly focused on potential applicability for their action against various diseases. In addition to this, tea also contains bioactive flavonoids that possess health-beneficial effects. The catechin fractions, epigallocatechin 3-gallate and epicatechin 3-gallate, are the main components of tea that has strong antioxidant and medicinal properties. The synergistic function of natural tea metabolites with synthetic drugs provides effective protection against various diseases. Furthermore, the application of nanotechnologies enhanced bioavailability, enhancing the therapeutic potential of natural metabolites against numerous diseases and pathogens.

Biocompatible silver nanoparticles: An investigation into their protein binding efficacies, anti-bacterial effects and cell cytotoxicity studies

Green synthesis of silver nanoparticles (AgNPs) has garnered tremendous interest as conventional methods include the use and production of toxic chemicals, products, by-products and reagents. In this regard, the synthesis of AgNPs using green tea (GT) extract and two of its components, (-)-epigallocatechin gallate (EGCG) and (+)-catechin (Ct) as capping/stabilizing agents, is reported. The synthesized AgNPs showed antibacterial activity against the bacterial strains Staphylococcus aureus and Escherichia coli, along with anticancer activity against HeLa cells. After administering nanoparticles to the body, they come in contact with proteins and results in the formation of a protein corona; hence we studied the interactions of these biocompatible AgNPs with hen egg white lysozyme (HEWL) as a carrier protein. Static quenching mechanism was accountable for the quenching of HEWL fluorescence by the AgNPs. The binding constant (K b) was found to be higher for EGCG-AgNPs ((2.309 ± 0.018) × 104 M-1) than for GT-AgNPs and Ct-AgNPs towards HEWL. EGCG-AgNPs increased the polarity near the binding site while Ct-AgNPs caused the opposite effect, but GT-AgNPs had no such observable effects. Circular dichroism studies indicated that the AgNPs had no such appreciable impact on the secondary structure of HEWL. The key findings of this research included the synthesis of AgNPs using GT extract and its constituent polyphenols, and showed significant antibacterial, anticancer and protein-binding properties. The -OH groups of the polyphenols drive the in situ capping/stabilization of the AgNPs during synthesis, which might offer new opportunities having implications for nanomedicine and nanodiagnostics.

Anti-Cancer and Anti-Inflammatory Activities of Three New Chromone Derivatives from the Marine-Derived Penicillium citrinum

Three new and uncommon chromone analogs, epiremisporine F (1), epiremisporine G (2), and epiremisporine H (3), were isolated from marine-origin Penicillium citrinum. Among the isolated compounds, compounds 2–3 remarkably suppressed fMLP-induced superoxide anion generation by human neutrophils, with IC₅₀ values of 31.68 ± 2.53, and 33.52 ± 0.42 μM, respectively. Compound 3 exhibited cytotoxic activities against human colon carcinoma (HT-29) and non-small lung cancer cell (A549) with IC₅₀ values of 21.17 ± 4.89 and 31.43 ± 3.01 μM, respectively, and Western blot assay confirmed that compound 3 obviously induced apoptosis of HT-29 cells, via Bcl-2, Bax, and caspase 3 signaling cascades.

Bladder Hyperactivity Induced by Oxidative Stress and Bladder Ischemia: A Review of Treatment Strategies with Antioxidants

Overactive bladder (OAB) syndrome, including frequency, urgency, nocturia and urgency incontinence, has a significantly negative impact on the quality-of-life scale (QoL) and can cause sufferer withdrawal from social activities. The occurrence of OAB can result from an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidant-induced oxidative stress. Several animal models, such as bladder ischemia/reperfusion (I/R), partial bladder outlet obstruction (PBOO) and ovarian hormone deficiency (OHD), have suggested that cyclic I/R during the micturition cycle induces oxidative stress, leading to bladder denervation, bladder afferent pathway sensitization and overexpression of bladder-damaging molecules, and finally resulting in bladder hyperactivity. Based on the results of previous animal experiments, the present review specifically focuses on four issues: (1) oxidative stress and antioxidant defense system; (2) oxidative stress in OAB and biomarkers of OAB; (3) OAB animal model; (4) potential nature/plant antioxidant treatment strategies for urinary dysfunction with OAB. Moreover, we organized the relationships between urinary dysfunction and oxidative stress biomarkers in urine, blood and bladder tissue. Reviewed information also revealed the summary of research findings for the effects of various antioxidants for treatment strategies for OAB.

Oxidation of Hydrogen Sulfide by Quinones: How Polyphenols Initiate Their Cytoprotective Effects

We have shown that autoxidized polyphenolic nutraceuticals oxidize H₂S to polysulfides and thiosulfate and this may convey their cytoprotective effects. Polyphenol reactivity is largely attributed to the B ring, which is usually a form of hydroxyquinone (HQ). Here, we examine the effects of HQs on sulfur metabolism using H₂S- and polysulfide-specific fluorophores (AzMC and SSP4, respectively) and thiosulfate sensitive silver nanoparticles (AgNP). In buffer, 1,4-dihydroxybenzene (1,4-DB), 1,4-benzoquinone (1,4-BQ), pyrogallol (PG) and gallic acid (GA) oxidized H₂S to polysulfides and thiosulfate, whereas 1,2-DB, 1,3-DB, 1,2-dihydroxy,3,4-benzoquinone and shikimic acid did not. In addition, 1,4-DB, 1,4-BQ, PG and GA also increased polysulfide production in HEK293 cells. In buffer, H₂S oxidation by 1,4-DB was oxygen-dependent, partially inhibited by tempol and trolox, and absorbance spectra were consistent with redox cycling between HQ autoxidation and H₂S-mediated reduction. Neither 1,2-DB, 1,3-DB, 1,4-DB nor 1,4-BQ reduced polysulfides to H₂S in either 21% or 0% oxygen. Epinephrine and norepinephrine also oxidized H₂S to polysulfides and thiosulfate; dopamine and tyrosine were ineffective. Polyphenones were also examined, but only 2,5-dihydroxy- and 2,3,4-trihydroxybenzophenones oxidized H₂S. These results show that H₂S is readily oxidized by specific hydroxyquinones and quinones, most likely through the formation of a semiquinone radical intermediate derived from either reaction of oxygen with the reduced quinones, or from direct reaction between H₂S and quinones. We propose that polysulfide production by these reactions contributes to the health-promoting benefits of polyphenolic nutraceuticals.

Pharmacological Effects and Potential Clinical Usefulness of Polyphenols in Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is arguably the most common benign disease among men. This disease is often associated with lower urinary tract symptoms (LUTS) in men and significantly decreases the quality of life. Polyphenol consumption reportedly plays an important role in the prevention of many diseases, including BPH. In recent years, in addition to disease prevention, many studies have reported the efficacy and safety of polyphenol treatment against various pathological conditions in vivo and in vitro. Furthermore, numerous studies have also revealed the molecular mechanisms of the antioxidant and anti-inflammatory effects of polyphenols. We believe that an improved understanding of the detailed pharmacological roles of polyphenol-induced activities at a molecular level is important for the prevention and treatment of BPH. Polyphenols are composed of many members, and their biological roles differ. In this review, we first provide information regarding the pathological roles of oxidative stress and inflammation in BPH. Next, the antioxidant and anti-inflammatory effects of polyphenols, including those of flavonoids and non-flavonoids, are discussed. Finally, we talk about the results and limitations of previous clinical trials that have used polyphenols in BPH, with particular focus on their molecular mechanisms of action.

Camellia Sinensis Mouthwashes in Oral Care: a Systematic Review

Herbal products are increasingly growing in the oral care market. Some of the related herbal compounds in this field have considerable clinical evidence for use in mouthwashes in their background. Camellia sinensis or tea plant has attracted numerous researchers of dentistry and pharmaceutical sciences, in recent years, for its biologic and medicinal properties. The effects such as anti-septic, anti-oxidative, and anti-inflammatory activities have made this plant a suitable candidate for preparation of mouthwashes. In this systematic review, we tried to find, evaluate, and categorize the sparse evidence in medical literature about Camellia sinensis mouthwashes. We explored three scientific databases with keywords including tea, dental care, Camellia sinensis, and mouthwashes and found 69 relevant studies including 41 randomized controlled trials (RCTs), which are generally proposing anti-microbial, anti-plaque, and analgesic indications for these tea formulations. Considering the main trend in clinical evidence and favorable safety profile, Camellia sinensis products are able to act as antiseptic, anti-plaque, and anti-inflammatory agents and can be used as useful mouthwashes in the future clinical studies and practice.

Present Status, Limitations and Future Directions of Treatment Strategies Using Fucoidan-Based Therapies in Bladder Cancer

Bladder cancer (BC) is a common urological cancer, with poor prognosis for advanced/metastatic stages. Various intensive treatments, including radical cystectomy, chemotherapy, immune therapy, and radiotherapy are commonly used for these patients. However, these treatments often cause complications and adverse events. Therefore, researchers are exploring the efficacy of natural product-based treatment strategies in BC patients. Fucoidan, derived from marine brown algae, is recognized as a multi-functional and safe substrate, and has been reported to have anti-cancer effects in various types of malignancies. Additionally, in vivo and in vitro studies have reported the protective effects of fucoidan against cancer-related cachexia and chemotherapeutic agent-induced adverse events. In this review, we have introduced the anti-cancer effects of fucoidan extracts in BC and highlighted its molecular mechanisms. We have also shown the anti-cancer effects of fucoidan therapy with conventional chemotherapeutic agents and new treatment strategies using fucoidan-based nanoparticles in various malignancies. Moreover, apart from the improvement of anti-cancer effects by fucoidan, its protective effects against cancer-related disorders and cisplatin-induced toxicities have been introduced. However, the available information is insufficient to conclude the clinical usefulness of fucoidan-based treatments in BC patients. Therefore, we have indicated the aspects that need to be considered regarding fucoidan-based treatments and future directions for the treatment of BC.

Green tea polyphenolic antioxidants oxidize hydrogen sulfide to thiosulfate and polysulfides: A possible new mechanism underpinning their biological action

Matcha and green tea catechins such as (−)-epicatechin (EC), (−)-epigallocatechin (EGC) and (−)-epigallocatechin gallate (EGCG) have long been studied for their antioxidant and health-promoting effects. Using specific fluorophores for H₂S (AzMC) and polysulfides (SSP4) as well as IC-MS and UPLC-MS/MS-based techniques we here show that popular Japanese and Chinese green teas and select catechins all catalytically oxidize hydrogen sulfide (H₂S) to polysulfides with the potency of EGC > EGCG >> EG. This reaction is accompanied by the formation of sulfite, thiosulfate and sulfate, consumes oxygen and is partially inhibited by the superoxide scavenger, tempol, and superoxide dismutase but not mannitol, trolox, DMPO, or the iron chelator, desferrioxamine. We propose that the reaction proceeds via a one-electron autoxidation process during which one of the OH-groups of the catechin B-ring is autooxidized to a semiquinone radical and oxygen is reduced to superoxide, either of which can then oxidize HS⁻ to thiyl radicals (HS^•) which react to form hydrogen persulfide (H₂S₂). H₂S oxidation reduces the B-ring back to the hydroquinone for recycling while the superoxide is reduced to hydrogen peroxide (H₂O₂). Matcha and catechins also concentration-dependently and rapidly produce polysulfides in HEK293 cells with the potency order EGCG > EGC > EG, an EGCG threshold of ~300 nM, and an EC₅₀ of ~3 μM, suggesting green tea also acts as powerful pro-oxidant in vivo. The resultant polysulfides formed are not only potent antioxidants, but elicit a cascade of secondary cytoprotective effects, and we propose that many of the health benefits of green tea are mediated through these reactions. Remarkably, all green tea leaves constitutively contain small amounts of H₂S₂.

Rutin ameliorates copper sulfate-induced brain damage via antioxidative and anti-inflammatory activities in rats

Excessive exposure to Copper (Cu) may result in Cu toxicity and adversely affect health outcomes. We investigated the protective role of rutin on Cu-induced brain damage. Experimental rats were treated as follows: group I: control; group II: Cu-sulfate: 200 mg/kg; group III: Cu-sulfate, and rutin 100 mg/kg; and group IV: rutin 100 mg/kg, for 7 weeks. Cu only treatment significantly decreased body weight gain, while rutin cotreatment reversed this decrease. Cu treatment increased malondialdehyde, nitric oxide level, and myeloperoxidase activity and decreased superoxide dismutase and catalase activities in rat brain. Immunohistochemistry showed that COX-2, iNOS, and Bcl-2 proteins were strongly expressed, while Bax was mildly expressed in the brain of Cu-treated rats. Furthermore, brain histology revealed degenerated neurons, and perforated laminae of cerebral cortex in the Cu-only treated rats. Interestingly, coadministration of Cu and rutin reduced the observed histological alteration, improved inflammatory and antioxidant biomarkers, thereby protecting against Cu-induced brain damage via antioxidative and anti-inflammatory mechanisms.

Molecular Mechanisms of the Anti-Cancer Effects of Isothiocyanates from Cruciferous Vegetables in Bladder Cancer

Bladder cancer (BC) is a representative of urological cancer with a high recurrence and metastasis potential. Currently, cisplatin-based chemotherapy and immune checkpoint inhibitors are used as standard therapy in patients with advanced/metastatic BC. However, these therapies often show severe adverse events, and prolongation of survival is unsatisfactory. Therefore, a treatment strategy using natural compounds is of great interest. In this review, we focused on the anti-cancer effects of isothiocyanates (ITCs) derived from cruciferous vegetables, which are widely cultivated and consumed in many regions worldwide. Specifically, we discuss the anti-cancer effects of four ITC compounds—allyl isothiocyanate, benzyl isothiocyanate, sulforaphane, and phenethyl isothiocyanate—in BC; the molecular mechanisms underlying their anti-cancer effects; current trends and future direction of ITC-based treatment strategies; and the carcinogenic potential of ITCs. We also discuss the advantages and limitations of each ITC in BC treatment, furthering the consideration of ITCs in treatment strategies and for improving the prognosis of patients with BC.

Valorisation of Camellia sinensis branches as a raw product with green technology extraction methods

This work deals with the study of tea stalks from pruning debris using environmental friendly extraction technology to offer new healthy properties. In the manufacturing tea industry, tea trees require to be pruned every year and most of their remains are discarded as a waste with no economic value. Microwave aqueous extraction and pressurized hot water extraction process (autohydrolysis) were used to recover bioactive compounds from the tea branches. Operating at a fixed solid: liquid ratio (1:15), the effect of the maximum heating temperatures from 140 to 220 °C was studied. Liquid extracts were analysed for total phenolic, oligosaccharides, protein, mineral and heavy metals content, as well as for antioxidant capacity. The antitumoral possibilities were also determined for selected samples. The obtained results indicated that both processes could be used as an alternative to recover bioactive compounds from tea wastes, although microwave-assisted extraction allowed saving time when compared with autohydrolysis processing. The temperature exhibited a relevant effect on the total phenolic content and antioxidant capacity, decreasing with the microwave treatment and increasing with the autohydrolysis temperature. The obtained extracts could be adequate for incorporation in food and non-food fields.

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Tea pruning remains were valorised using green extractions by microwave (MW) and autohydolysis (AH).

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MW and AH were efficient technologies to recover bioactive compounds.

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Values above 40 mg gallic acid equivalents/g extract and 0.10 g Trolox/g extract were identified.

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Future applications in cosmetics, pharmacy or food industries should be explored.

Molecular Insights into Potential Contributions of Natural Polyphenols to Lung Cancer Treatment

Naturally occurring polyphenols are believed to have beneficial effects in the prevention and treatment of a myriad of disorders due to their anti-inflammatory, antioxidant, antineoplastic, cytotoxic, and immunomodulatory activities documented in a large body of literature. In the era of molecular medicine and targeted therapy, there is a growing interest in characterizing the molecular mechanisms by which polyphenol compounds interact with multiple protein targets and signaling pathways that regulate key cellular processes under both normal and pathological conditions. Numerous studies suggest that natural polyphenols have chemopreventive and/or chemotherapeutic properties against different types of cancer by acting through different molecular mechanisms. The present review summarizes recent preclinical studies on the applications of bioactive polyphenols in lung cancer therapy, with an emphasis on the molecular mechanisms that underlie the therapeutic effects of major polyphenols on lung cancer. We also discuss the potential of the polyphenol-based combination therapy as an attractive therapeutic strategy against lung cancer.

Natural Compounds as New Cancer Treatments

Cancer is still a global challenge worldwide with a high impact not only on human health, causing morbidity and mortality, but also on economics [...].

A Review of Oxidative Stress and Urinary Dysfunction Caused by Bladder Outlet Obstruction and Treatments Using Antioxidants

Urinary dysfunction is a common pathological condition that can significantly decrease the quality of life. Bladder outlet obstruction (BOO) is a major cause of urinary dysfunction, and various lower urinary tract diseases including benign prostatic hyperplasia and urethral stricture disease cause BOO. According to the results of a variety of animal experiments on partial BOO (PBOO), there is a general agreement that ischemic conditions and repeated ischemia/reperfusion of the bladder are closely associated with BOO-induced bladder damage, and that increased oxidative stress by ischemia/reperfusion plays a crucial role in the pathological mechanisms underlying urinary dysfunction. Changes in biomarkers of oxidative stress in PBOO animal models support this association between oxidative stress and urinary dysfunction. Oxidative stress is defined as an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidants. Therefore, organizing the knowledge on the state of oxidative stress, changes in biomarkers, and biological roles of antioxidants in systemic and bladder tissues is essential to understand the detailed pathological characteristics of the urinary dysfunction caused by PBOO. Furthermore, information on drugs and supplements that have antioxidant effects is important for defining treatment strategies for urinary dysfunction with PBOO. In this review, we paid special attention to the following three issues; (1) changes in oxidative stress, including its biomarkers, (2) antioxidant status, and (3) previous reports on treatment strategies involving agents with antioxidative activity for urinary dysfunction caused by BOO. In particular, we provide systematic information on the detailed mechanisms underlying the antioxidative effects of agents used to treat PBOO. In addition, we show present research issues and research limitations, as well as suggest possible future antioxidant treatment strategies for patients with PBOO.

The acute effect of a single dose of green tea on the quality and quantity of tears in normal eye subjects

Objective

The study aimed to investigate the acute effect of a single dose of green tea on the quality and quantity of tears in normal eye subjects.

Methods

Forty normal eye subjects (22 men and 18 women) aged 19–39 years were enrolled in the study. Also, an age matching control group (20 males and 20 females) was enrolled for comparison. McMonnies dry eye symptoms questionnaire and slit lamp were used for the exclusion criteria determination. Phenol red thread (PRT) test was performed on both eyes of each subject. A tear sample was collected from the lower tear meniscus of the right eye of each subject for the tear ferning (TF) test, which was performed before (30 minutes) and after (60 minutes) drinking green tea.

Results

The median PRT measurement after green tea consumption was lower (median [IQR]=23.50 [8.00] mm) compared to that before consumption (median [IQR]=27.00 [8.75] mm). In contrast, the median TF grade was significantly higher following green tea consumption than that before consumption (median [IQR]=2.65 [1.23] vs 1.50 [0.88] mm, respectively). The results show that TF grades increased in 97.5%, and the red phenol thread scores decreased in 80% of the subjects after green tea consumption compared to those before consumption. The PRT readings and TF grades were significantly different (P<0.05) before and after green tea consumption.

Conclusion

Drinking green tea could have a significant effect on the eye tear film quality. Tear quality appeared to decrease after green tea consumption.

Inhibitory Effects of (-)-Epigallocatechin-3-gallate on Esophageal Cancer

There is epidemiological evidence showing that drinking green tea can lower the risk of esophageal cancer (EC). The effect is mainly attributed to tea polyphenols and their most abundant component, (−)-epigallocatechin-3-gallate (EGCG). The possible mechanisms of tumorigenesis inhibition of EGCG include its suppressive effects on cancer cell proliferation, angiogenesis, DNA methylation, metastasis and oxidant stress. EGCG modulates multiple signal transduction and metabolic signaling pathways involving in EC. A synergistic effect was also observed when EGCG was used in combination with other treatment methods.

Oral Intake of Royal Jelly Has Protective Effects Against Tyrosine Kinase Inhibitor-Induced Toxicity in Patients with Renal Cell Carcinoma: A Randomized, Double-Blinded, Placebo-Controlled Trial

Background: Although tyrosine kinase inhibitors (TKIs) are still recommended as the standard therapy in renal cell carcinoma (RCC), the high frequency of adverse events is a weakness of this therapy. Because royal jelly (RJ) possesses anti-inflammatory and antioxidant properties, we assessed its protective effects on TKI-induced toxicities in RCC patients. Methods: We enrolled 33 patients with advanced RCC who were assigned to start TKI therapy in combination with a randomized, double-blinded, placebo-controlled RJ trial consisting of a placebo group with 17 subjects and an RJ group with 16 subjects. Results: Fatigue and anorexia frequencies in the RJ group were significantly lower than in the placebo group (p = 0.003 and 0.015, respectively). A statistically significant correlation between RJ and fatigue or anorexia was detected in sunitinib-treated patients. The dose reduction- or discontinuation-free periods were significantly longer (p = 0.013) in the RJ group than in the placebo group. Furthermore, similar observations were made in sunitinib-treated patients (p = 0.016). Conclusions: Our clinical trial showed that RJ exerted protective effects against TKI-induced fatigue and anorexia and lowered TKI dose reduction or discontinuation. Hence, RJ is beneficial for maintaining the quality of life and medication compliance in TKI-treated RCC patients.

Anti-Cancer and Protective Effects of Royal Jelly for Therapy-Induced Toxicities in Malignancies

Royal jelly (RJ) is a glandular secretion produced by worker honeybees and is a special food for the queen honeybee. It results in a significant prolongation of the lifespan of the queen honeybee compared with the worker honeybees through anti-inflammatory, anti-oxidant and anti-microbial activities. Consequently, RJ is used as cosmetic and dietary supplement throughout the world. In addition, in vitro studies and animal experiments have demonstrated that RJ inhibits cell proliferation and stimulates apoptosis in various types of malignant cells and affects the production of various chemokines, anti-oxidants and growth factors and the expression of cancer-related molecules in patients with malignancies, especially in patients treated with anti-cancer agents. Therefore, RJ is thought to exert anti-cancer effects on tumor growth and exhibit protective functions against drug-induced toxicities. RJ has also been demonstrated to be useful for suppression of adverse events, the maintenance of the quality of life during treatment and the improvement of prognosis in animal models and patients with malignancies. To understand the mechanisms of the beneficial effects of RJ, knowledge of the changes induced at the molecular level by RJ with respect to cell survival, inflammation, oxidative stress and other cancer-related factors is essential. In addition, the effects of combination therapies of RJ and other anti-cancer agents or natural compounds are important to determine the future direction of RJ-based treatment strategies. Therefore, in this review, we have covered the following five issues: (1) the anti-cancer effects of RJ and its main component, 10-hydroxy-2-decenoic acid; (2) the protective effects of RJ against anti-cancer agent-induced toxicities; (3) the molecular mechanisms of such beneficial effects of RJ; (4) the safety and toxicity of RJ; and (5) the future directions of RJ-based treatment strategies, with a discussion on the limitations of the study of the biological activities of RJ.