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

Researches on the tender leaf identification and mechanically perceptible plucking finger for high-quality green tea

BACKGROUND

Intelligent identification and precise plucking are the keys to intelligent tea harvesting robots, which are currently of increasing significance. Aiming at plucking tender leaves for high-quality green tea production, in this study, a tender leaf identification algorithm and a mechanically perceptible plucking finger have been proposed.

RESULTS

Based on the segmentation algorithm and color features, the tender leaf identification algorithm shows an average identification accuracy of over 92.8%. The mechanically perceptible plucking finger plucks tender leaves in a way that a human hand does, aiming to maintain the high quality of tea products. Though finite element analysis, we determine the ideal size of grippers and the location of strain gauge attachment on a gripper to enable the employment of feedback control of desired gripping force. As revealed in our experiments, the success rate of tender leaf plucking reaches 92.5%, demonstrating the effectiveness of our design.

CONCLUSION

The results show that the tender leaf identification algorithm and the mechanically perceptible plucking finger are effective for identification of tender leaves and plucking, providing a foundation for the development of an intelligent tender leaf plucking robot. © 2024 Society of Chemical Industry.

Depolymerization of oyster glycosaminoglycans for the enhancement of α-glucosidase inhibition and its application in hypoglycemic studies

Glycosaminoglycans are a class of naturally occurring macromolecular heteropolysaccharides with α-glucosidase inhibitory effects, which play an essential role in regulating postprandial hyperglycemia. However, the significant molecular weight hinders their inhibitory activity. In this study, oyster glycosaminoglycans were used for purification and depolymerization studies to obtain oyster glycosaminoglycan oligosaccharides (OGAG-Oli) and to study their inhibitory activity against α-glucosidase in vitro and hypoglycemic effect on hyperglycemic zebrafish in vivo. The results showed that the OGAG-Oli with optimal α-glucosidase inhibition obtained by the β-elimination mechanism of chondroitinase ABC had a molecular weight of about 2400 Da with five disaccharide repeating units, and their inhibitory effect on α-glucosidase was significantly enhanced with an IC50 value of 0.12 mg/mL, which was related to the strong binding capacity with α-glucosidase as evidenced by molecular docking. FT-IR and NMR results showed that the conformation of OGAG-Oli was predominantly in the α-configuration, which indicated that its inhibitory effect on α-glucosidase mainly depended on the α-glucosidic bond therein. The enzymatic depolymerization process of glycosaminoglycans was optimized, and the process conditions were determined as phosphate buffer solution pH 8.0, reaction time 3 h, reaction temperature 30 °C, chondroitin enzyme ABC activity 0.5 mU. The hypoglycemic ability of OGAG-Oli was evaluated in diabetic zebrafish, and the results showed that OGAG-Oli at a high-dose (0.12 mg/g, bw/d) could extremely significantly reduce fasting blood glucose in zebrafish, with an effect close to that of acarbose (p > 0.05), and exceptionally significantly (p < 0.01) reduced the elevation of TC, TG, and LDL-C caused by prolonged hyperglycemia, and extremely significantly (p < 0.01) increased the HDL-C level. This study showed that the structurally modified oyster glycosaminoglycans had intense α-glucosidase inhibitory activity, and exhibited biological activity of reducing glucose uptake and consequently improving body weight and lipid metabolism in diabetic zebrafish. As a bioactive ingredient of natural origin, this study provides a theoretical basis for the development and utilization of glycosaminoglycans with hypoglycemic effects in foods and drugs.

Angiogenesis, a key point in the association of gut microbiota and its metabolites with disease

The gut microbiota is a complex and dynamic ecosystem that plays a crucial role in human health and disease, including obesity, diabetes, cardiovascular diseases, neurodegenerative diseases, inflammatory bowel disease, and cancer. Chronic inflammation is a common feature of these diseases and is closely related to angiogenesis (the process of forming new blood vessels), which is often dysregulated in pathological conditions. Inflammation potentially acts as a central mediator. This abstract aims to elucidate the connection between the gut microbiota and angiogenesis in various diseases. The gut microbiota influences angiogenesis through various mechanisms, including the production of metabolites that directly or indirectly affect vascularization. For example, short-chain fatty acids (SCFAs) such as butyrate, propionate, and acetate are known to regulate immune responses and inflammation, thereby affecting angiogenesis. In the context of cardiovascular diseases, the gut microbiota promotes atherosclerosis and vascular dysfunction by producing trimethylamine N-oxide (TMAO) and other metabolites that promote inflammation and endothelial dysfunction. Similarly, in neurodegenerative diseases, the gut microbiota may influence neuroinflammation and the integrity of the blood-brain barrier, thereby affecting angiogenesis. In cases of fractures and wound healing, the gut microbiota promotes angiogenesis by activating inflammatory responses and immune effects, facilitating the healing of tissue damage. In cancer, the gut microbiota can either inhibit or promote tumor growth and angiogenesis, depending on the specific bacterial composition and their metabolites. For instance, some bacteria can activate inflammasomes, leading to the production of inflammatory factors that alter the tumor immune microenvironment and activate angiogenesis-related signaling pathways, affecting tumor angiogenesis and metastasis. Some bacteria can directly interact with tumor cells, activating angiogenesis-related signaling pathways. Diet, as a modifiable factor, significantly influences angiogenesis through diet-derived microbial metabolites. Diet can rapidly alter the composition of the microbiota and its metabolic activity, thereby changing the concentration of microbial-derived metabolites and profoundly affecting the host's immune response and angiogenesis. For example, a high animal protein diet promotes the production of pro-atherogenic metabolites like TMAO, activating inflammatory pathways and interfering with platelet function, which is associated with the severity of coronary artery plaques, peripheral artery disease, and cardiovascular diseases. A diet rich in dietary fiber promotes the production of SCFAs, which act as ligands for cell surface or intracellular receptors, regulating various biological processes, including inflammation, tissue homeostasis, and immune responses, thereby influencing angiogenesis. In summary, the role of the gut microbiota in angiogenesis is multifaceted, playing an important role in disease progression by affecting various biological processes such as inflammation, immune responses, and multiple signaling pathways. Diet-derived microbial metabolites play a crucial role in linking the gut microbiota and angiogenesis. Understanding the complex interactions between diet, the gut microbiota, and angiogenesis has the potential to uncover novel therapeutic targets for managing these conditions. Therefore, interventions targeting the gut microbiota and its metabolites, such as through fecal microbiota transplantation (FMT) and the application of probiotics to alter the composition of the gut microbiota and enhance the production of beneficial metabolites, present a promising therapeutic strategy.

Thermochemical reactions in tea drying shape the flavor of tea: A review

Drying is the final and essential step in tea processing. It contributes a lot to the formation of tea flavor quality by a series of complicated and violent thermochemical reactions, such as degradation reaction, Maillard reaction, redox reaction, isomerization reaction, etc. However, the mechanism of specific thermochemical reaction is unclear. Here, by comprehensively summarizing the thermochemical reactions of the main chemicals, including polyphenols, lipids, amino acids and carbohydrates, etc., during tea drying with particularly focus on their contributions of thermal drying on the flavor including color, aroma, and taste, we found that thermal degradation is the dominant thermochemical reaction, directly affecting the taste and color of tea, and thermal oxidation of lipids and Maillard reaction mainly contribute to form tea aroma. More interesting was that high temperature enhanced nucleophilicity of phenolics, allowing them to easily trap carbonyl substances to form small molecular adducts (i.e. EPSFs) or polymers, which could interfere other thermochemical reactions, and then alter the flavor quality of tea. Over all, this review provides updated scientific evidence for in-depth exploration of thermochemical reactions towards tea precision processing.

Non-cytotoxic levels of resveratrol enhance the anticancer effects of cisplatin by increasing the methyltransferase activity of CARM1 in human cancer cells

BACKGROUND

Resveratrol (RSVL) is a plant-derived polyhydroxyphenolic compound with excellent anticancer properties, alone or in combination with other chemotherapeutic drugs. However, the anticancer mechanism of RSVL is diverse and high concentrations are often required for RSVL to exert its anticancer effect, which would also adversely affect normal cells.

PURPOSE

The main objective of this study is to investigate the molecular mechanism of how non-cytotoxic concentrations of RSVL enhance the anticancer effect of cisplatin involving a newly identified RSVL-binding protein.

METHODS

Cell viability of cell lines from three cancer types exposed to RSVL and/or cisplatin was measured by NBB staining assay. RSVL-binding proteins were identified using RSVL-bound CNBr-activated Sepharose 4B beads coupled with LC-MS/MS, and the binding between RSVL and novel RSVL-binding protein was further confirmed with an in vitro pull-down assay. The expression of proteins was examined by immunoblot analysis, and the activity of methyltransferase was evaluated by in vitro methylation assay. The methylation level of H3R17 in the gene promoter was investigated using ChIP-qPCR. Bioinformatics analysis was conducted to identify pathway enrichment of genes, predict drug sensitivity, and analyze the survival of cancer patients.

RESULTS

Low doses of RSVL might promote cancer cell growth whereas high doses of RSVL showed cytotoxic effects on normal cells. When co-treated with a lower cisplatin dose, non-cytotoxic RSVL levels showed synergistic anticancer effects. Here, coactivator-associated arginine methyltransferase 1 (CARM1) was identified as a novel RSVL-binding protein, and we showed that the upregulation of CARM1 increased the sensitivity of cancer cells to RSVL. Interestingly, we found that CARM1 was essential in the RSVL-induced sensitivity of cisplatin. Further molecular mechanistic studies revealed that RSVL could stabilize CARM1 protein, resulting in the upregulation and increased methyltransferase activity of CARM1. Additionally, we showed that the methylation levels of H3R17 in the promoter of p21, a downstream gene of CARM1 involving cell cycle arrest, were significantly increased after RSVL treatment. Finally, data from our bioinformatics analysis suggested that CARM1 could be utilized as a potential biomarker for chemotherapeutic drug sensitivity and prognosis in cancers.

CONCLUSIONS

This study identified CARM1 as a RSVL-binding protein for the first time and elucidated the potential roles of CARM1 in enhancing the efficacy of cisplatin by low doses of RSVL, which could have important clinical implications.

Functional Tea Extract Inhibits Cell Growth, Induces Apoptosis, and Causes G0/G1 Arrest in Human Hepatocellular Carcinoma Cell Line Possibly through Reduction in Telomerase Activity

The functional tea CFT-1 has been introduced into China as a nutraceutical beverage according to the "Healthy China" national project. The effects on human hepatocellular carcinoma (HCC) cells remain unclear and were investigated with the functional tea extract (purity > 98%). The morphological changes in the cells were observed with microscopes. Cell proliferation, migration, cycle distribution, and apoptotic effects were assessed by MTT, Transwell assays, and flow cytometry, respectively, while telomerase inhibition was evaluated with telomerase PCR ELISA assay kits. The CFT-1 treatment resulted in cell shrinkage, nuclear pyknosis, and chromatin condensation. CFT-1 suppressed the growth of Hep3B cells with IC50 of 143 μg/mL by inducing apoptosis and G0/G1 arrest in Hep3B cells. As for the molecular mechanism, CFT-1 treatment can effectively reduce the telomerase activity. The functional tea extract inhibits cell growth in human HCC by inducing apoptosis and G0/G1 arrest, possibly through a reduction in telomerase activity. These results indicate that CFT-1 extract exhibited in vitro anticancer activities and provided insights into the future development and utilization of CFT-1 as functional foods to inhibit the proliferation of HCC cells.

Investigating the potential causal association between consumption of green tea and risk of lung cancer: a study utilizing Mendelian randomization

Background

Lung cancer is the most common global cancer in terms of incidence and mortality. Its main driver is tobacco smoking. The identification of modifiable risk factors isa public health priority. Green tea consumption has been examined in epidemiological studies, with inconsistent findings. Thus, we aimed to apply Mendelian randomization to clarify any causal link between green tea consumption and the risk of lung cancer.

Methods

We utilized a two-sample Mendelian randomization (MR) approach. Genetic variants served as instrumental variables. The goal was to explore a causal link between green tea consumption and different lung cancer types. Green tea consumption data was sourced from the UK Biobank dataset, and the genetic association data for various types of lung cancer were sourced from multiple databases. Our analysis included primary inverse-variance weighted (IVW) analyses and various sensitivity test.

Results

No significant associations were found between green tea intake and any lung cancer subtypes, including non-small cell lung cancer (adenocarcinoma and squamous cell carcinoma) and small cell lung cancer. These findings were consistent when applying multiple Mendelian randomization methods.

Conclusion

Green tea does not appear to offer protective benefits against lung cancer at a population level. However, lung cancer's complex etiology and green tea's potential health benefitssuggest more research is needed. Further studies should include diverse populations, improved exposure measurements and randomized controlled trials, are warranted.

Inhibition of pathogenic microbes in oral infectious diseases by natural products: Sources, mechanisms, and challenges

The maintenance of oral health is of utmost importance for an individual's holistic well-being and standard of living. Within the oral cavity, symbiotic microorganisms actively safeguard themselves against potential foreign diseases by upholding a multifaceted equilibrium. Nevertheless, the occurrence of an imbalance can give rise to a range of oral infectious ailments, such as dental caries, periodontitis, and oral candidiasis. Presently, clinical interventions encompass the physical elimination of pathogens and the administration of antibiotics to regulate bacterial and fungal infections. Given the limitations of various antimicrobial drugs frequently employed in dental practice, the rising incidence of oral inflammation, and the escalating bacterial resistance to antibiotics, it is imperative to explore alternative remedies that are dependable, efficacious, and affordable for the prevention and management of oral infectious ailments. There is an increasing interest in the creation of novel antimicrobial agents derived from natural sources, which possess attributes such as safety, cost-effectiveness, and minimal adverse effects. This review provides a comprehensive overview of the impact of natural products on the development and progression of oral infectious diseases. Specifically, these products exert their influences by mitigating dental biofilm formation, impeding the proliferation of oral pathogens, and hindering bacterial adhesion to tooth surfaces. The review also encompasses an examination of the various classes of natural products, their antimicrobial mechanisms, and their potential therapeutic applications and limitations in the context of oral infections. The insights garnered from this review can support the promising application of natural products as viable therapeutic options for managing oral infectious diseases.

Analysis of differences in the accumulation of tea compounds under various processing techniques, geographical origins, and harvesting seasons

The processing techniques, geographical origins, and harvesting seasons have a significant impact on tea compound accumulation, leading to different flavor characteristics and consumer preferences for tea. Herein, six categories of tea involving 1329 samples revealed the distribution characteristics via compound accumulation, as well as the impact of production regions and harvesting seasons on flavor chemicals. With the increasing fermentation degree, the average content of tea polyphenols, catechins, and theanine in dark tea decreased by 57.78%, 94.64%, and 98.57% compared to green tea, respectively. The compounds in tea fluctuate with the geographical origins and seasons, with theanine and free amino acids being more accumulated in the Jiangnan tea region in spring tea, while total polyphenols and catechins were more abundant in Southwest China's tea region in summer and autumn tea. This study comprehensively understands the accumulation characteristics of tea compounds corresponding to processing techniques and the geographical origins of Chinese tea.

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

Cancer is a severe public health problem. Resveratrol is a famous natural compound that has various bioactivities, such as antioxidant, anti-inflammatory, antidiabetic and antiaging activities. Especially, resveratrol could prevent and treat various cancers, such as oral, thyroid, breast, lung, liver, pancreatic, gastric, colorectal, bladder, prostate and ovarian cancers. The underlying mechanisms have been widely studied, such as inhibiting cell proliferation, suppressing metastasis, inducing apoptosis, stimulating autophagy, modulating immune system, attenuating inflammation, regulating gut microbiota and enhancing effects of other anticancer drugs. In this review, we summarize effects and mechanisms of resveratrol on different cancers. This paper is helpful to develop resveratrol, crude extract containing resveratrol, or foods containing resveratrol into functional food, dietary supplements or auxiliary agents for prevention and management of cancers.

Bioactive phytocompounds for oral cancer prevention and treatment: A comprehensive and critical evaluation

The high incidence of oral cancer combined with excessive treatment cost underscores the need for novel oral cancer preventive and therapeutic options. The value of natural agents, including plant secondary metabolites (phytochemicals), in preventing carcinogenesis and representing expansive source of anticancer drugs have been established. While fragmentary research data are available on antioral cancer effects of phytochemicals, a comprehensive and critical evaluation of the potential of these agents for the prevention and intervention of human oral malignancies has not been conducted according to our knowledge. This study presents a complete and critical analysis of current preclinical and clinical results on the prevention and treatment of oral cancer using phytochemicals. Our in-depth analysis highlights anticancer effects of various phytochemicals, such as phenolics, terpenoids, alkaloids, and sulfur-containing compounds, against numerous oral cancer cells and/or in vivo oral cancer models by antiproliferative, proapoptotic, cell cycle-regulatory, antiinvasive, antiangiogenic, and antimetastatic effects. Bioactive phytochemicals exert their antineoplastic effects by modulating various signaling pathways, specifically involving the epidermal growth factor receptor, cytokine receptors, toll-like receptors, and tumor necrosis factor receptor and consequently alter the expression of downstream genes and proteins. Interestingly, phytochemicals demonstrate encouraging effects in clinical trials, such as reduction of oral lesion size, cell growth, pain score, and development of new lesions. While most phytochemicals displayed minimal toxicity, concerns with bioavailability may limit their clinical application. Future directions for research include more in-depth mechanistic in vivo studies, administration of phytochemicals using novel formulations, investigation of phytocompounds as adjuvants to conventional treatment, and randomized clinical trials.

Possible Mechanisms of Dark Tea in Cancer Prevention and Management: A Comprehensive Review

Tea is one of the most popular drinks in the world. Dark tea is a kind of post-fermented tea with unique sensory characteristics that is produced by the special fermentation of microorganisms. It contains many bioactive substances, such as tea polyphenols, theabrownin, tea polysaccharides, etc., which have been reported to be beneficial to human health. This paper reviewed the latest research on dark tea's potential in preventing and managing cancer, and the mechanisms mainly involved anti-oxidation, anti-inflammation, inhibiting cancer cell proliferation, inducing cancer cell apoptosis, inhibiting tumor metastasis, and regulating intestinal flora. The purpose of this review is to accumulate evidence on the anti-cancer effects of dark tea, the corresponding mechanisms and limitations of dark tea for cancer prevention and management, the future prospects, and demanding questions about dark tea's possible contributions as an anti-cancer adjuvant.

Health benefits, mechanisms of interaction with food components, and delivery of tea polyphenols: a review

Tea polyphenols (TPs) are the most important active component of tea and have become a research focus among natural products, thanks to their antioxidant, lipid-lowering, liver-protecting, anti-tumor, and other biological activities. Polyphenols can interact with other food components, such as protein, polysaccharides, lipids, and metal ions to further improve the texture, flavor, and sensory quality of food, and are widely used in food fields, such as food preservatives, antibacterial agents and food packaging. However, the instability of TPs under conditions such as light or heat and their low bioavailability in the gastrointestinal environment also hinder their application in food. In this review, we summarized the health benefits of TPs. In order to better use TPs in food, we analyzed the form and mechanism of interaction between TPs and main food components, such as polysaccharides and proteins. Moreover, we reviewed research into optimizing the applications of TPs in food by bio-based delivery systems, such as liposomes, nanoemulsions, and nanoparticles, so as to improve the stability and bioactivity of TPs in food application. As an effective active ingredient, TPs have great potential to be applied in functional food to produce benefits for human health.

The perception and influencing factors of astringency, and health-promoting effects associated with phytochemicals: A comprehensive review

Astringency as the complex sensory of drying or shrinking can be perceived from natural foods, including abundant phenolic compounds. Up to now, there have been two possible astringency perception mechanisms of phenolic compounds. The first possible mechanism involved chemosensors and mechanosensors and took salivary binding proteins as the premise. Although piecemeal reports about chemosensors, friction mechanosensor's perception mechanisms were absent. There might be another perception way because a part of astringent phenolic compounds also triggered astringency although they could not bind with salivary proteins, however, the specific mechanism was unclear. Structures caused the differences in astringency perception mechanisms and intensities. Except for structures, other influencing factors also changed astringency perception intensity and aimed to decrease it, which probably ignored the health-promoting effects of phenolic compounds. Therefore, we roundly summarized the chemosensor's perception processes of the first mechanism. Meanwhile, we speculated that friction mechanosensor's probably activated Piezo2 ion channel on cell membranes. Phenolic compounds directly binds with oral epithelial cells, activating Piezo2 ion channel probably the another astringency perception mechanism. Except for structure, the increase of pH values, ethanol concentrations, and viscosity not only lowered astringency perception but were beneficial to improve the bioaccessibility and bioavailability of astringent phenolic compounds, which contributed to stronger antioxidant, anti-inflammatory, antiaging and anticancer effects.

Epigenetic drugs as new emerging therapeutics: What is the scale's orientation of application and challenges?

Epigenetics is the study of heritable changes in gene expression or function without altering the DNA sequence. Important factors are part of epigenetic events, such as methylation, DNA histone rearrangements, nucleosome transposition, and non-coding RNAs. Dysregulated epigenetic mechanics are associated with various cancers' initiation, development, and metastasis. It is known that the occurrence and development of cancer can be controlled by regulating unexpected epigenetic events. Epi-drugs are used singly or in combination with chemotherapy and enhance antitumor activity, reduce drug resistance, and stimulate the host immune response. Despite these benefits, epigenetic therapy as a single therapy or in combination with other drugs leads to adverse effects. This review article introduces and compares the advantages, disadvantages, and side effects of using these drugs for the first time since their introduction. Also, this article describes the mechanism of action of various epigenetic drugs. Recommendations for future use of epigenetic drugs as cancer therapeutics are suggested as an overall conclusion.

A review on matcha: Chemical composition, health benefits, with insights on its quality control by applying chemometrics and multi-omics

This review discussed the origin, manufacturing process, chemical composition, factors affecting quality and health benefits of matcha (Camellia sinensis), and the application of chemometrics and multi-omics in the science of matcha. The discussion primarily distinguishes between matcha and regular green tea with processing and compositional factors, and demonstrates beneficial health effects of consuming matcha. Preferred Reporting Items for Systematic Reviews and Meta-Analyses was adopted to search for relevant information in this review. Boolean operators were incorporated to explore related sources in various databases. Notably, climate, cultivar, maturity of tea leaves, grinding process and brewing temperature impact on the overall quality of matcha. Besides, sufficient shading prior to harvesting significantly increases the contents of theanine and chlorophyll in the tea leaves. Furthermore, the ground whole tea leaf powder delivers matcha with the greatest benefits to the consumers. The health promoting benefits of matcha are mainly contributed by its micro-nutrients and the antioxidative phytochemicals, specifically epigallocatechin-gallate, theanine and caffeine. Collectively, the chemical composition of matcha affected its quality and health benefits significantly. To this end, more studies are required to elucidate the biological mechanisms of these compounds for human health. Chemometrics and multi-omics technologies are useful to fill up the research gaps identified in this review.

Food groups and urologic cancers risk: a systematic review and meta-analysis of prospective studies

BACKGROUND

To assess the association between 12 food groups intake and the risk of urologic cancers.

METHODS

We scanned PubMed and Web of Science databases up to April 1st, 2023, and 73 publications met the inclusion criteria in the meta-analysis. We used a random effects model to estimate the summary risk ratios (RRs) and 95% confidence intervals (95% CI).

RESULTS

In the linear dose-response meta-analysis, an inverse association was found between each additional daily 100 g of fruits [RR: 0.89, 95%CI = (0.83, 0.97)], 100 g of vegetables [RR: 0.92, 95%CI = (0.85, 0.99)], 12 g of alcohol [RR: 0.91, 95%CI = (0.88, 0.94)] and 1 cup of coffee [RR: 0.95, 95%CI = (0.83, 0.97)] intake and the risk of renal cell carcinoma. Conversely, each additional daily 100 g of red meat intake was positively associated with renal cell carcinoma [RR: 1.41, 95%CI = (1.03, 2.10)]. Inverse associations were observed between each additional daily 50 g of egg [RR: 0.73, 95%CI = (0.62, 0.87)] and each additional daily 1 cup of tea consumption and bladder cancer risk [RR: 0.97, 95%CI = (0.94, 0.99)]. There were no significant associations for nonlinear dose-response relationships between 12 food groups and urological cancers.

CONCLUSION

Our meta-analysis strengthens the evidence that appropriate intake of specific food groups, such as fruits, vegetables, alcohol, tea, and coffee, is associated with the risk of renal cell carcinoma or bladder cancer. More studies are required to fill the knowledge gap on the links between various food groups and urologic cancers because the evidence was less credible in this meta-analysis.

SYSTEMATIC REVIEW REGISTRATION

This study was registered on PROSPERO (CRD42022340336).

PAHs, PCBs and OCPs in olive oil during the fruit ripening period of olive fruits

Because of their possible carcinogenic effects, it is crucial to determine levels of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in olive oils. However, there are a few studies about these pollutants' levels in olive oils and no other studies reported PAHs, PCBs and OCPs at the same time and during the ripening period of olives in olive oils. A modified clean-up technique was successfully applied for eliminating lipidic components. Additionally, this study does not just report the concentrations of these pollutants but also inspects the sources depending on the actual sampling site. Also, PCBs and OCPs carcinogenic risks in olive oil were reported for the first time in the literature. This study aims to present levels, carcinogenic risks, sources and concentration changes during the ripening period of these pollutants in olive oil. For this purpose, fruit samples for oil extraction were collected between the beginning of the fruit ripening and harvest period. Obtained olive oils from the fruits were extracted and cleaned up using the QuEChERS method. GC-MS and GC-ECD were used for the quantitative analysis of the targeted pollutants. The average concentrations for ∑₁₆PAHs, ∑₃₇PCBs and ∑₁₀OCPs were 222.48 ± 133.76 μg/kg, 58.26 ± 21.64 μg/kg and 25.48 ± 19.55 μg/kg, respectively. During the harvest period, the concentrations were in a decreasing trend. Calculated carcinogenic risks were above acceptable limits for all groups and traffic, wood-coal burning, atmospheric transport and previous uses were the main sources. Results of the source determination indicated that some possible sources could be prevented with regulations and precautions.

Therapeutic actions of tea phenolic compounds against oxidative stress and inflammation as central mediators in the development and progression of health problems: A review focusing on microRNA regulation

Many health problems including chronic diseases are closely associated with oxidative stress and inflammation. Tea has abundant phenolic compounds with various health benefits including antioxidant and anti-inflammatory properties. This review focuses on the present understanding of the impact of tea phenolic compounds on the expression of miRNAs, and elucidates the biochemical and molecular mechanisms underlying the transcriptional and post-transcriptional protective actions of tea phenolic compounds against oxidative stress- and/or inflammation-mediated diseases. Clinical studies showed that drinking tea or taking catechin supplement on a daily basis promoted the endogenous antioxidant defense system of the body while inhibiting inflammatory factors. The regulation of chronic diseases based on epigenetic mechanisms, and the epigenetic-based therapies involving different tea phenolic compounds, have been insufficiently studied. The molecular mechanisms and application strategies of miR-27 and miR-34 involved in oxidative stress response and miR-126 and miR-146 involved in inflammation process were preliminarily investigated. Some emerging evidence suggests that tea phenolic compounds may promote epigenetic changes, involving non-coding RNA regulation, DNA methylation, histone modification, ubiquitin and SUMO modifications. However, epigenetic mechanisms and epigenetic-based disease therapies involving phenolic compounds from different teas, and the potential cross-talks among the epigenetic events, remain understudied.

Effects of natural spring water on the sensory attributes and physicochemical properties of tea infusions

The sensory quality of tea is influenced by water quality, with natural spring water (NSW) gaining much attention for its natural and healthy qualities. The effects of NSW on the sensory attributes, physicochemical composition, and antioxidant capacity of Chinese tea were investigated. Tea brewed with pure water was the most resistant to oxidation and darkening. NSW with low total dissolved solids (TDS) was most suitable for brewing unfermented or mildly fermented teas, improving their sensory quality. The simulated green tea infusion system was used to investigate further the dramatic darkening of tea infusions in NSW. Exposure of infusions to air promoted the degradation, epimerization, and oxidative polymerization of catechins, and further formed theabrownins which darkened the tea infusions. These findings enabled tea consumers to choose the most suitable NSW for brewing Chinese teas and illustrated the darkening mechanism of tea infusion in high pH/TDS water.

Insights into the key quality components in Se-Enriched green tea and their relationship with Selenium

Selenium-enriched green tea (Se-GT) is of increasing interest because of its health benefits, but its quality components obtained limited research. In this study, Enshi Se-enriched green tea (ESST, high-Se green tea), Pingli Se-enriched green tea (PLST, low-Se green tea), and Ziyang green tea (ZYGT, common green tea) were subjected to sensory evaluation, chemical analysis, and aroma profiling. Chemical profiles in Se-GT were consistent with the taste attributes of the sensory analysis. 9 volatiles were identified as key odorants of Se-GT based on multivariate analysis. Correlations between Se and quality components were further assessed and highly Se-related compounds contents in these three tea samples were compared. The results showed that most amino acids and non-gallated catechins were highly negatively correlated with Se, while gallated catechins exhibited strong positive correlation with Se. And there were strong and significant associations between the key aroma compounds and Se. Moreover, 11 differential markers were found between Se-GTs and common green tea, including catechin, serine, glycine, threonine, l-theanine, alanine, valine, isoleucine, leucine, histidine, and lysine. These findings provide great potential for quality evaluation of Se-GT.

Gut microbiota-mediated metabolism of green tea catechins and the biological consequences: An updated review

Multiple beneficial effects have been attributed to green tea catechins (GTCs). However, the bioavailability of GTCs is generally low, with only a small portion directly absorbed in the small intestine. The majority of ingested GTCs reaches the large intestinal lumen, and are extensively degraded via biotransformation by gut microbiota, forming many low-molecular-weight metabolites such as phenyl-γ-valerolactones, phenolic acids, butyrate, and acetate. This process not only improves the overall bioavailability of GTC-derived metabolites but also enriches the biological activities of GTCs. Therefore, the intra- and inter-individual differences in human gut microbiota as well as the resulting biological contribution of microbial metabolites are crucial for the ultimate health benefits. In this review, the microbial degradation of major GTCs was characterized and an overview of the in vitro models used for GTC metabolism was summarized. The intra- and inter-individual differences of human gut microbiota composition and the resulting divergence in the metabolic patterns of GTCs were highlighted. Moreover, the potential beneficial effects of GTCs and their gut microbial metabolites were also discussed. Overall, the microbial metabolites of GTCs with higher bioavailability and bioactive potency are key factors for the observed beneficial effects of GTCs and green tea consumption.

Absorption, metabolism, bioactivity, and biotransformation of epigallocatechin gallate

Epigallocatechin gallate (EGCG), a typical flavone-3-ol polyphenol containing eight free hydroxyl groups, is associated with a variety of bioactivities, such as antioxidant, anti-inflammatory, anti-cancer, and antibacterial activities. However, the poor bioavailability of EGCG restricts its use. In this review, we discuss the processes involved in the absorption and metabolism of EGCG, with a focus on its metabolic interactions with the gut microbiota. Next, we summarize the bioactivities of some key metabolites, describe the biotransformation of EGCG by different microorganisms, and discuss its catabolism by specific bacteria. A deeper understanding of the absorption, metabolism, and biotransformation of EGCG may enable its disease-preventive and therapeutic properties to be better utilized. This review provides a theoretical basis for further development and utilization of EGCG and its metabolites for improving the gut microbiota and physiological health.

Anticancer applications of phytochemicals in gastric cancer: Effects and molecular mechanism

Gastric cancer (GC) is the fourth most common malignant cancer and is a life-threatening disease worldwide. Phytochemicals have been shown to be a rational, safe, non-toxic, and very promising approach to the prevention and treatment of cancer. It has been found that phytochemicals have protective effects against GC through inhibiting cell proliferation, inducing apoptosis and autophagy, suppressing cell invasion and migration, anti-angiogenesis, inhibit Helicobacter pylori infection, regulating the microenvironment. In recent years, the role of phytochemicals in the occurrence, development, drug resistance and prognosis of GC has attracted more and more attention. In order to better understand the relationship between phytochemicals and gastric cancer, we briefly summarize the roles and functions of phytochemicals in GC tumorigenesis, development and prognosis. This review will probably help guide the public to prevent the occurrence and development of GC through phytochemicals, and develop functional foods or drugs for the prevention and treatment of gastric cancer.

A Tea Plant (Camellia sinensis) FLOWERING LOCUS C-like Gene, CsFLC1, Is Correlated to Bud Dormancy and Triggers Early Flowering in Arabidopsis

Flowering and bud dormancy are crucial stages in the life cycle of perennial angiosperms in temperate climates. MADS-box family genes are involved in many plant growth and development processes. Here, we identified three MADS-box genes in tea plant belonging to the FLOWERING LOCUS C (CsFLC) family. We monitored CsFLC1 transcription throughout the year and found that CsFLC1 was expressed at a higher level during the winter bud dormancy and flowering phases. To clarify the function of CsFLC1, we developed transgenic Arabidopsis thaliana plants heterologously expressing 35S::CsFLC1. These lines bolted and bloomed earlier than the WT (Col-0), and the seed germination rate was inversely proportional to the increased CsFLC1 expression level. The RNA-seq of 35S::CsFLC1 transgenic Arabidopsis showed that many genes responding to ageing, flower development and leaf senescence were affected, and phytohormone-related pathways were especially enriched. According to the results of hormone content detection and RNA transcript level analysis, CsFLC1 controls flowering time possibly by regulating SOC1, AGL42, SEP3 and AP3 and hormone signaling, accumulation and metabolism. This is the first time a study has identified FLC-like genes and characterized CsFLC1 in tea plant. Our results suggest that CsFLC1 might play dual roles in flowering and winter bud dormancy and provide new insight into the molecular mechanisms of FLC in tea plants as well as other plant species.

Kaempferol as a potential neuroprotector in Alzheimer's disease

Alzheimer's disease (AD), the most prevalent neurodegenerative disorder, is largely associated with cognitive disability, amnesia, and abnormal behavior, which accounts for about two third of people with dementia worldwide. A growing body of research demonstrates that AD is connected to several factors, such as aberrant accumulation of amyloid-beta (Aβ), increase in the hyperphosphorylation of Tau protein, and the formation of neurofibrillary tangles, mitochondrial dysfunction, and inordinate production of reactive oxygen species (ROS). Despite remarkable efforts to realize the etiology and pathophysiology of AD, until now, scientists have not developed and introduced medications that can permanently cease the progression of AD. Thus, nowadays, research on the role of natural products in the treatment and prevention of AD has attracted great attention. Kaempferol (KMP), one of the prominent members of flavonols, exerts its ameliorative actions via attenuating oxidative stress and inflammation, reducing Aβ-induced neurotoxicity, and regulating the cholinergic system. Therefore, in this review article, we outlined the possible effects of KMP in the prevention and treatment of AD. PRACTICAL APPLICATIONS: Kaempferol (KMP) exerts its ameliorative actions against AD via attenuating oxidative stress and inflammation, reducing Aβ-induced neurotoxicity, and regulating the cholinergic system. The beneficial effects of KMP were addressed in both in vitro and in vivo studies; however, conducting further research can warrant its long-term effects as a safe agent. Therefore, after confirming its favorable functions in the prevention and treatment of AD, it could be used as a safe and effective agent.

Green Tea Catechins Attenuate Neurodegenerative Diseases and Cognitive Deficits

Neurodegenerative diseases exert an overwhelming socioeconomic burden all around the globe. They are mainly characterized by modified protein accumulation that might trigger various biological responses, including oxidative stress, inflammation, regulation of signaling pathways, and excitotoxicity. These disorders have been widely studied during the last decade in the hopes of developing symptom-oriented therapeutics. However, no definitive cure has yet been discovered. Tea is one of the world's most popular beverages. The same plant, Camellia Sinensis (L.).O. Kuntze, is used to make green, black, and oolong teas. Green tea has been most thoroughly studied because of its anti-cancer, anti-obesity, antidiabetic, anti-inflammatory, and neuroprotective properties. The beneficial effect of consumption of tea on neurodegenerative disorders has been reported in several human interventional and observational studies. The polyphenolic compounds found in green tea, known as catechins, have been demonstrated to have many therapeutic effects. They can help in preventing and, somehow, treating neurodegenerative diseases. Catechins show anti-inflammatory as well as antioxidant effects via blocking cytokines' excessive production and inflammatory pathways, as well as chelating metal ions and free radical scavenging. They may inhibit tau protein phosphorylation, amyloid beta aggregation, and release of apoptotic proteins. They can also lower alpha-synuclein levels and boost dopamine levels. All these factors have the potential to affect neurodegenerative disorders. This review will examine catechins' neuroprotective effects by highlighting their biological, pharmacological, antioxidant, and metal chelation abilities, with a focus on their ability to activate diverse cellular pathways in the brain. This review also points out the mechanisms of catechins in various neurodegenerative and cognitive diseases, including Alzheimer's, Parkinson's, multiple sclerosis, and cognitive deficit.

Health functions and related molecular mechanisms of ellagitannin-derived urolithins

Ellagitannins are vital bioactive polyphenols that are widely distributed in a variety of plant-based foods. The main metabolites of ellagitannins are urolithins, and current research suggests that urolithins provide a variety of health benefits. This review focused on the role of the gut bacteria in the conversion of ellagitannins to urolithins. Based on the results of in vitro and in vivo studies, the health benefits of urolithins, including antioxidant, anti-inflammatory, anti-cancer, anti-obesity, anti-diabetic, anti-aging, cardiovascular protective, neuroprotective, kidney protective, and muscle mass protective effects, were thoroughly outlined, with a focus on their associated molecular mechanisms. Finally, we briefly commented on urolithins' safety. Overall, urolithins' diverse health benefits indicate the potential utilization of ellagitannins and urolithins in the creation of functional foods and nutraceuticals to treat and prevent some chronic diseases.

Effects and Mechanisms of Curcumin for the Prevention and Management of Cancers: An Updated Review

Cancer is the leading cause of death in the world. Curcumin is the main ingredient in turmeric (Curcuma longa L.), and is widely used in the food industry. It shows anticancer properties on different types of cancers, and the underlying mechanisms of action include inhibiting cell proliferation, suppressing invasion and migration, promoting cell apoptosis, inducing autophagy, decreasing cancer stemness, increasing reactive oxygen species production, reducing inflammation, triggering ferroptosis, regulating gut microbiota, and adjuvant therapy. In addition, the anticancer action of curcumin is demonstrated in clinical trials. Moreover, the poor water solubility and low bioavailability of curcumin can be improved by a variety of nanotechnologies, which will promote its clinical effects. Furthermore, although curcumin shows some adverse effects, such as diarrhea and nausea, it is generally safe and tolerable. This paper is an updated review of the prevention and management of cancers by curcumin with a special attention to its mechanisms of action.

Anticancer Effects and Mechanisms of Berberine from Medicinal Herbs: An Update Review

Cancer has been a serious public health problem. Berberine is a famous natural compound from medicinal herbs and shows many bioactivities, such as antioxidant, anti-inflammatory, antidiabetic, anti-obesity, and antimicrobial activities. In addition, berberine shows anticancer effects on a variety of cancers, such as breast, lung, gastric, liver, colorectal, ovarian, cervical, and prostate cancers. The underlying mechanisms of action include inhibiting cancer cell proliferation, suppressing metastasis, inducing apoptosis, activating autophagy, regulating gut microbiota, and improving the effects of anticancer drugs. This paper summarizes effectiveness and mechanisms of berberine on different cancers and highlights the mechanisms of action. In addition, the nanotechnologies to improve bioavailability of berberine are included. Moreover, the side effects of berberine are also discussed. This paper is helpful for the prevention and treatment of cancers using berberine.

Effects of Different Green Teas on Obesity and Non-Alcoholic Fatty Liver Disease Induced by a High-Fat Diet in Mice

Non-alcoholic fatty liver disease (NAFLD) and obesity are serious public health problems. Green tea is widely consumed in the world and different green teas could possess different bioactivities. In this study, the effects of 10 selected green teas on obesity and NAFLD were evaluated and compared. The mice fed with a high-fat diet were intervened with green tea extract (200 mg/kg body weight) for 15 weeks. Most of these teas were first evaluated for their effects on obesity and NAFLD. The results showed that Selenium-Enriched Chaoqing Green Tea and Jieyang Chaoqing Tea showed the most prominent inhibition of obesity and body weight gains of mice in these two tea intervention groups and model groups were 5.3, 5.5, and 13.7 g, respectively. In addition, Jieyang Chaoqing Tea, Taiping Houkui Tea, and Selenium-Enriched Chaoqing Green Tea exerted the most notable effect on NAFLD, which was attributed to decreasing body weight, and lipid content and ameliorating oxidative stress. Furthermore, 13 phytochemicals were determined in these teas by high-performance liquid chromatography and the correlation analysis found that epigallocatechin gallate, gallocatechin, and epigallocatechin might contribute to the decrease of hepatic weight, while epicatechin might reduce oxidative stress. In general, several green teas could prevent the development of obesity and NAFLD and could be developed into functional foods. This study was also helpful for the public to select appropriate tea to prevent obesity and NAFLD.

Comparison of the chemical composition and antioxidant, anti-inflammatory, α-amylase and α-glycosidase inhibitory activities of the supernatant and cream from black tea infusion

Tea cream is a kind of turbid substance commonly existing in tea infusion and tea beverage upon cooling. Herein, a comparative study was conducted on the supernatant and cream from black tea infusion in terms of antioxidant, anti-inflammatory and enzyme inhibitory activities, and chemical composition. Ultraviolet-visible (UV-vis) spectrometry and high-performance liquid chromatography (HPLC) analysis showed that the contents of protein, polyphenols, theaflavins, thearubigins, theabrownins, and caffeine in cream were significantly higher than those in the supernatant. The contents of Al, Ca, Cu, and Fe elements in cream were higher than those in the supernatant. However, higher levels of monosaccharides and free amino acids were detected in the supernatant compared with cream. The ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) based metabolomics analysis revealed that the main marker compounds between the supernatant and the cream were organic acids, phenolic acids, and flavan-3-ols and their oxidation products, flavonol glycosides and amino acids. The cream showed better antioxidant and anti-inflammatory, as well as α-amylase and α-glycosidase inhibitory activities than the supernatant, because it contained higher contents of polyphenols than the supernatant. The present study expanded the new vision towards the cream of black tea infusion.

Dietary sources, health benefits, and risks of caffeine

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

Joint Effects of Cigarette Smoking and Green Tea Consumption with miR-29b and DNMT3B mRNA Expression in the Development of Lung Cancer

In tumor development, increased expression of DNA methyltransferase (DNMT) has been observed. In particular, cigarette smoke and tea polyphenols may influence DNMT3B mRNA expression by regulating microRNA (miR)-29b expression. Herein, we designed a case−control study to evaluate the joint effects of smoking and green tea consumption, with miR-29b and DNMT3B mRNA expression, in lung cancer development. A total of 132 lung cancer patients and 132 healthy controls were recruited to measure miR-29b and DNMT3B mRNA expression in whole blood. Results revealed that lung cancer patients had lower miR-29b expression (57.2 vs. 81.6; p = 0.02) and higher DNMT3B mRNA expression (37.2 vs. 25.8; p < 0.001) than healthy controls. Compared to non-smokers with both higher miR-29b and lower DNMT3B mRNA expression, smokers with both low miR-29b and higher DNMT3B mRNA expression had an elevated risk of lung cancer development (OR 5.12, 95% CI 2.64−9.91). Interactions of smoking with miR-29b or DNMT3B mRNA expression in lung cancer were significant. Interaction of green tea consumption with miR-29b expression and DNMT3B mRNA expression in lung cancer was also significant. Our study suggests that smokers and green tea nondrinkers with lower miR-29b expression and higher DNMT3B mRNA expression are more susceptible to lung cancer development.

Tea consumption and risk of bladder cancer in the Bladder Cancer Epidemiology and Nutritional Determinants (BLEND) Study: Pooled analysis of 12 international cohort studies

BACKGROUND & AIMS

Tea has been shown to be associated with reduced risk of several diseases including cardiovascular diseases, stroke, metabolic syndrome, and obesity. However, the results on the relationship between tea consumption and bladder cancer are conflicting. This research aimed to assess the association between tea consumption and risk of bladder cancer using a pooled analysis of prospective cohort data.

METHODS

Individual data from 532,949 participants in 12 cohort studies, were pooled for analyses. Cox regression models stratified by study centre was used to estimate hazard ratios (HR) and corresponding 95% CIs. Fractional polynomial regression models were used to examine the dose-response relationship.

RESULTS

A higher level of tea consumption was associated with lower risk of bladder cancer incidence (compared with no tea consumption: HR = 0.87, 95% C.I. = 0.77-0.98 for low consumption; HR = 0.86, 95% C.I. = 0.77-0.96 for moderate consumption; HR = 0.84, 95% C.I. = 0.75-0.95 for high consumption). When stratified by sex and smoking status, this reduced risk was statistically significant among men and current and former smokers. In addition, dose-response analyses showed a lower bladder cancer risk with increment of 100 ml of tea consumption per day (HR-increment = 0.97; 95% CI = 0.96-0.98). A similar inverse association was found among males, current and former smokers while never smokers and females showed non-significant results, suggesting potential sex-dependent effect.

CONCLUSIONS

Higher consumption of tea is associated with reduced risk of bladder cancer with potential interaction with sex and smoking status. Further studies are needed to clarify the mechanisms for a protective effect of tea (e.g. inhibition of the survival and proliferation of cancer cells and anti-inflammatory mechanisms) and its interaction with smoking and sex.

L-Theanine: A Unique Functional Amino Acid in Tea (Camellia sinensis L.) With Multiple Health Benefits and Food Applications

Tea (Camellia sinensis L.) is a very popular health drink and has attracted increasing attention in recent years due to its various bioactive substances. Among them, L-theanine, a unique free amino acid, is one of the most important substances in tea and endows tea with a special flavor. Moreover, L-theanine is also a bioactive compound with plenty of health benefits, including antioxidant, anti-inflammatory, neuroprotective, anticancer, metabolic regulatory, cardiovascular protective, liver and kidney protective, immune regulatory, and anti-obesity effects. Due to the unique characteristics and beneficial functions, L-theanine has potential applications in the development of functional foods. This review summarized the influencing factors of L-theanine content in teas, the main health benefits and related molecular mechanisms of L-theanine, and its applications in food, understanding of which can provide updated information for the further research of L-theanine.

Elderberry (Sambucus nigra L.): Bioactive Compounds, Health Functions, and Applications

Elderberry (Sambucus nigra L.) is rich in many bioactive compounds and exhibits diverse health functions, of which an understanding can be helpful for its better utilization in the food industry. This review mainly summarizes recent studies about the bioactive compounds and health functions of elderberry, highlighting the potential mechanism of action. In addition, the applications of elderberry in foods are also discussed. Elderberry contains diversely bioactive ingredients, such as (poly)phenolic compounds and terpenoid compounds. Recent studies report that some food processing methods can affect the content of bioactive compounds in elderberry. Additionally, elderberry exhibits various health functions in vitro and in vivo, including antioxidant, anti-inflammatory, anticancer, anti-influenza, antimicrobial, antidiabetic, cardiovascular protective, and neuroprotective activities, and their potential molecular mechanisms are associated with regulating some key signaling pathways and molecular targets. Up to now, there have been limited clinical trials supporting the health benefits of elderberry. Overall, elderberry is a promising dietary source of bioactive ingredients and has the potential to be developed into functional foods or nutraceuticals for preventing and treating certain chronic diseases.

Optimization of a tannase-assisted process for obtaining teas rich in theaflavins from Camelia sinensis leaves

This work aimed at optimizing the extraction of theaflavins for the development of a potentially functional tea beverage using different technological parameters as factors. Green tea leaves treated with tannase provided a beverage with significant higher amount (4.7-fold) of theaflavin (TF) compared to the pure withered leaf fermentation. For black tea, the optimized process conditions to produce a beverage with high TF (0.269 μg/mL) concentration were: 6 g of leaves/400 mL, a low fermentation temperature of 25 °C with the absence of buffer and pH control, an intermediate fermentation time (60 min) and a relatively low aeration rate (0.8-1.0 L/min). The tea liquid produced under optimized fermentation conditions appears to be ideal for making a black tea beverage with surplus summer tea leaves and brings economic benefits.

The Role of Bioactive Compounds in Natural Products Extracted from Plants in Cancer Treatment and Their Mechanisms Related to Anticancer Effects

Cancer is one of the greatest causes of death worldwide. With the development of surgery, radiotherapy, and medical agents, the outcomes of cancer patients have greatly improved. However, the underlying mechanisms of cancer are not yet fully understood. Recently, natural products have been proven to be beneficial for various conditions and have played important roles in the development of novel therapies. A substantial amount of evidence indicates that bioactive compounds could improve the outcomes of cancer patients via various pathways, such as endoplasmic reticulum stress, epigenetic modification, and modulation of oxidative stress. Here, we review the current evidence of bioactive compounds in natural products for the treatment of cancer and summarize the underlying mechanisms in this pathological process.

Involvement of microRNA modifications in anticancer effects of major polyphenols from green tea, coffee, wine, and curry

Epidemiological studies have shown that consumption of green tea, coffee, wine, and curry may contribute to a reduced risk of various cancers. However, there are some cancer site-specific differences in their effects; for example, the consumption of tea or wine may reduce bladder cancer risk, whereas coffee consumption may increase the risk. Animal and cell-based experiments have been used to elucidate the anticancer mechanisms of these compounds, with reactive oxygen species (ROS)-based mechanisms emerging as likely candidates. Chlorogenic acid (CGA), curcumin (CUR), epigallocatechin gallate (EGCG), and resveratrol (RSV) can act as antioxidants that activate AMP-activated protein kinase (AMPK) to downregulate ROS, and as prooxidants to generate ROS, leading to the downregulation of NF-κB. Polyphenols can modulate miRNA (miR) expression, with these dietary polyphenols shown to downregulate tumor-promoting miR-21. CUR, EGCG, and RSV can upregulate tumor-suppressing miR-16, 34a, 145, and 200c, but downregulate tumor-promoting miR-25a. CGA, EGCG, and RSV downregulate tumor-suppressing miR-20a, 93, and 106b. The effects of miRs may combine with ROS-mediated pathways, enhancing the anticancer effects of these polyphenols. More precise analysis is needed to determine how the different modulations of miRs by polyphenols relate to the cancer site-specific differences found in epidemiological studies related to the consumption of foods containing these polyphenols.

The chemistry, processing, and preclinical anti-hyperuricemia potential of tea: a comprehensive review

Hyperuricemia is an abnormal purine metabolic disease that occurs when there is an excess of uric acid in the blood, associated with cardiovascular diseases, hypertension, gout, and renal disease. Dietary intervention is one of the most promising strategies for preventing hyperuricemia and controlling uric acid concentrations. Tea (Camellia sinensis) is known as one of the most common beverages and the source of dietary polyphenols. However, the effect of tea on hyperuricemia is unclear. Recent evidence shows that a lower risk of hyperuricemia is associated with tea intake. To better understand the anti-hyperuricemia effect of tea, this review first briefly describes the pathogenesis of hyperuricemia and the processing techniques of different types of tea. Next, the epidemiological and experimental studies of tea and its bioactive compounds on hyperuricemia in recent years were reviewed. Particular attention was paid to the anti-hyperuricemia mechanisms targeting the hepatic uric acid synthase, renal uric acid transporters, and intestinal microbiota. Additionally, the desirable intake of tea for preventing hyperuricemia is provided. Understanding the anti-hyperuricemia effect and mechanisms of tea can better utilize it as a preventive dietary strategy.HighlightsHigh purine diet, excessive alcohol/fructose consumption, and less exercise/sleep are the induction factors of hyperuricemia.Tea and tea compounds showed alleviated effects for hyperuricemia, especially polyphenols.Tea (containing caffeine or not) is not associated with a higher risk of hyperuricemia.Xanthine oxidase inhibition (reduce uric acid production), Nrf2 activation, and urate transporters regulation (increase uric acid excretion) are the potential molecular targets of anti-hyperuricemic effect of tea.About 5 g tea intake per day may be beneficial for hyperuricemia prevention.

Tea and its phytochemicals: Hidden health benefits & modulation of signaling cascade by phytochemicals

Tea, one of the most widely consumed beverages, is prepared from the leaves of the Camellia sinensis. The promising health recompenses of tea have been linked to its different phenolic components, which have diverse biological characteristics. Tea also contains several flavonoids, alkaloids, phenolic, theanine, etc., which are associated with anti-oxidant characteristics and a variety of health benefits. It can also lower the pervasiveness of neurological disorders as well as prevent different types of cancer, metabolic syndromes, cardiovascular diseases, urinary stone, obesity, type 2 diabetes. Keeping in mind that tea helps to improve health and prevents many diseases, its consumption has been regarded as a "health-promoting habit" and current medical investigators have established the scientific basis for this concept over time. The current review provides new updated information and perspectives on the tea phytochemicals and their overall health benefits based on molecular processes, experimental studies, and clinical trials.

Fermentation with Tea Residues Enhances Antioxidant Activities and Polyphenol Contents in Kombucha Beverages

Kombucha is a popular beverage with various bioactivities (such as antioxidant activity), which can be attributed to its abundant bioactive compounds, especially polyphenols. Kombucha is conventionally prepared by fermentation of a sugared black tea infusion without tea residue. In this study, the effects of black tea residue and green tea residue on kombucha were studied, and its antioxidant activities, total phenolic contents, as well as concentrations of polyphenols at different fermentation stages were evaluated using ferric-reducing antioxidant power, Trolox equivalent antioxidant capacity, Folin-Ciocalteu method and high-performance liquid chromatography with a photodiode array detector. The results showed that fermentation with tea residue could markedly increase antioxidant activities (maximum 3.25 times) as well as polyphenolic concentrations (5.68 times) of kombucha. In addition, green tea residue showed a stronger effect than black tea residue. Overall, it is interesting to find that fermentation with tea residues could be a better strategy to produce polyphenol-rich kombucha beverages.

Anti-inflammatory natural products as potential therapeutic agents of rheumatoid arthritis: A systematic review

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease causing severe locomotor disability and deterioration in the quality of life. Existing treatments for RA mainly focus on the use of immunomodulators and the suppression of synovial inflammation, and many have significant side effects. Medicinal plants are regarded as important alternative sources for treating RA.

PURPOSE

This review summarizes the bioactive compounds of medicinal plants, which have been shown to modulate the immune response by regulating interleukins in vitro and in vivo experimental models, and that may be promising substances for use in the treatment of RA.

METHODS

Articles on natural products used for the management of arthritis were retrieved from PubMed, Embase, Scopus, and Web of Science through electronic and manual search in English. In total, 576 publications were identified, and 34 were included in this systematic review.

RESULTS

Two articles presented findings on the role of natural components in the treatment of arthritis in both in vitro and in vivo studies. Nine reports defined the role of plant-derived natural molecules in the treatment of arthritis using cell lines, and 27 in vivo studies assessed the anti-arthritic efficacy and immunomodulation effects of phytoconstituents on interleukin production and inflammatory responses.

CONCLUSION

This systematic review broadly reports that, in contrast to other classes of phytochemicals, flavonoids have the greatest therapeutic potential against arthritis by modulating the expression of pro-inflammatory TNF-α, IL-1β, IL-6, IL-8, and IL-17, as well as anti-inflammatory IL-2 and IL-10 cytokines, through the suppression of dynamic inflammatory biomarkers.

Alleviation of Malathion Toxicity Effect by Coffea arabica L. Oil and Olea europaea L. Oil on Lipid Profile: Physiological and In Silico Study

The community health plans commonly use malathion (MAL), an organophosphate pesticide (OP), to eliminate pathogenic insects. The objective of the present research is to evaluate the consequences of Coffea arabica L. oil and Olea europaea L. oil on MAL-intoxicated male rats. Six equal groups of animals were used for conducting this study (n = 10). Animals in group one were designated as control, animals belonging to group two were exposed to MAL in the measure of hundred mg per kg BW (body weight) for forty-nine days (seven weeks), rats in the third and fourth groups were administered with 400 mg/kg BW of Coffea arabica L. and Olea europaea L. oils, respectively, and the same amount of MAL as given to the second group. Groups five and six were administered with the same amount of Coffea arabica L. oil and Olea europaea L. oil as given to group three. Exposure of rats to 100 mg/kg body weight of MAL resulted in statistical alteration of the serum lipid profile. A marked decline was noticed in the severe changes of these blood parameters when MAL-intoxicated rats were treated with Coffea arabica L. oil and Olea europaea L. oil. Two compounds from Coffea arabica L. oil (Chlorogenic acid) and Olea europaea L. oil (Oleuropein) demonstrated good interaction with xanthine oxidase (XO) and 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR) enzymes that are associated with cholesterol production. The present study indicated that Coffea arabica L. oil and Olea europaea L. oil could be considered prospective and potential healing agents against metabolic conditions induced by MAL.

Current extraction, purification, and identification techniques of tea polyphenols: An updated review

Tea, as a beverage, has been reputed for its health benefits and gained worldwide popularity. Tea polyphenols, especially catechins, as the main bioactive compounds in tea, exhibit diverse health benefits and have wide applications in the food industry. The development of tea polyphenol-incorporated products is dependent on the extraction, purification, and identification of tea polyphenols. Recent years, many green and novel extraction, purification, and identification techniques have been developed for the preparation of tea polyphenols. This review, therefore, introduces the classification of tea and summarizes the main conventional and novel techniques for the extraction of polyphenols from various tea products. The advantages and disadvantages of these techniques are also intensively discussed and compared. In addition, the purification and identification techniques are summarized. It is hoped that this updated review can provide a research basis for the green and efficient extraction, purification, and identification of tea polyphenols, which can facilitate their utilization in the production of various functional food products and nutraceuticals.

Effects and mechanisms of tea on obesity

Obesity has become a global health concern. It increases the risk of several diseases, such as type 2 diabetes mellitus, nonalcoholic fatty liver disease, and certain cancers, which threatens human health and increases social economic burden. As one of the most consumed beverages, tea contains various phytochemicals with potent bioactive properties and health-promoting effects, such as antioxidant, immune-regulation, cardiovascular protection and anticancer. Tea and its components are also considered as potential candidates for anti-obesity. Epidemiological studies indicate that regular consumption of tea is beneficial for reducing body fat. In addition, the experimental studies demonstrate that the potential anti-obesity mechanisms of tea are mainly involved in increasing energy expenditure and lipid catabolism, decreasing nutrient digestion and absorption as well as lipid synthesis, and regulating adipocytes, neuroendocrine system and gut microbiota. Moreover, most of clinical studies illustrate that the intake of green tea could reduce body weight and alleviate the obesity. In this review, we focus on the effect of tea and its components on obesity from epidemiological, experimental, and clinical studies, and discuss their potential mechanisms.