Anticancer Effects and Molecular Target of Theaflavins from Black Tea Fermentation in Vitro and in Vivo

Theaflavin suppresses necroptosis by attenuating RIPK1-RIPK3-MLKL signaling and mitigates cisplatin-induced kidney injury in mice

Necroptosis is a lytic form of regulated cell death (RCD) that is dependent on receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain like pseudokinase (MLKL). This form of RCD has been implicated in various inflammatory diseases and organ injuries including cisplatin-induced acute kidney injury (AKI), thus representing a therapeutic target for such diseases. Theaflavin is an ingredient of black tea that exhibits beneficial effects on human health and has been shown to regulate pyroptosis, but its effects on necroptosis and cisplatin-induced AKI remain unclear. In this study, we found that theaflavin suppressed necroptosis in murine macrophages, MPC-5 podocytes and human HT-29 cells treated with TNF-α, Smac mimetic and IDN-6556 or LPS plus IDN-6556. The RIPK1/RIPK3/MLKL signaling axis in these cells treated with necroptosis inducers was effectively inhibited by theaflavin. The inhibition of necroptotic signaling was associated with attenuated mitochondrial dysfunction (as evidenced by decreased mitochondrial membrane potential and increased mitochondrial ROS production), reduced ubiquitination of RIPK1 and RIPK3, and blockade of necrosome. Furthermore, oral administration of theaflavin mitigated renal and hepatic injury in a mouse model of cisplatin-induced AKI. In agreement with in vitro cellular data, theaflavin decreased the levels of phosphorylated MLKL, an in vivo biomarker for necroptosis, in macrophages and other cells in the kidney and the liver of mice with cisplatin-induced AKI. Collectively, these results indicate that theaflavin can suppress necroptosis by attenuating RIPK1/RIPK3/MLKL signaling and thereby conferring protection against cisplatin-induced AKI, uncovering a previously unappreciated action of black tea components against necroptosis-related disorders.

Flavonoids from Shiliangcha (Chimonanthus salicifolius) Alleviate Brain Aging in d-Galactose-Induced Senescent Mice through Gut Microbiota

The leaves of Shiliangcha (an alternative tea, Chimonanthus salicifolius), a perennial bush cultivated in Lishui, Zhejiang, have been used for thousands of years by the She ethnic group as an herb and tea. Chimonanthus salicifolius flavonoids (CsFE) have exhibited remarkable antiaging properties. Therefore, we established a d-galactose (d_Gal)-induced aging mouse model to investigate the effect of CsFE on the central nervous system (CNS) of aging hosts. Supplementation with CsFE effectively alleviated symptoms of aging in mice, including weight loss, declining learning and memory capacity, blood-brain barrier (BBB) integrity, release of pro-inflammatory cytokines, oxidative stress, neuroinflammation, and microglia activation. Additionally, CsFE alleviated cognitive deficits by interfering with synaptic plasticity-associated protein levels, altering neuronal excitability, and affecting intracellular neurotransmitters glutamate (Glu) and γ-aminobutyric acid (GABA) release. Furthermore, CsFE supplementation modulated gut microbiota composition by enriching probiotics Akkermansia, Muribaculaceae, Lactobacillus, and Lachnospiraceae, promoting the production of short-chain fatty acids (SCFAs). Therefore, this study suggested that CsFE has the potential to resist brain aging through intervention of the microbiota-gut-brain axis (GBA), which provides a theoretical basis for the development of natural drugs and dietary supplements for antiaging.

Theaflavins Applications to Ameliorate Implant Failure and Eradicate Microbial Infections and Foodborne Pathogens: A Comprehensive Review

Theaflavins, powerful antioxidants found in black tea ( Camellia sinensis ), have garnered increasing interest for their promising therapeutic potential. Experimental studies have contributed to enlightening about the advantages of theaflavins, including their antioxidant, anti-inflammatory, anticancer, antiosteoporosis, and antimicrobial properties. Theaflavin and its derivatives, particularly theaflavin-3,3'-digallate, have been particularly noted for their enhanced action in different areas. These compounds have found an important role as alternatives or adjuvants in the pharmaceutical sector, food industry, and in the improvement of health conditions. This review focuses on the antioxidant and anti-inflammatory aspects of theaflavins, particularly their potential in addressing peri-implant osteolysis. We explore mechanisms and pathways involved in this therapeutic action. Furthermore, we cover some of the relevant studies on the antimicrobial action of theaflavins in both the health and food sectors. Specifically, we explore the use of theaflavins for the treatment of dental infections, where these compounds have shown particular efficacy against several bacterial strains and their antimicrobial application in food matrices. Given the low solubility and stability of theaflavins in physiological conditions, we emphasize the benefits of the development of biocompatible and biodegradable nanoformulations to enhance the stability, bioavailability, and efficacy of these polyphenols, to promote their broader research and application. Given the potential demonstrated so far by in vitro and in vivo studies, the application of theaflavins stands as a promising alternative to enhance the existing strategies and fight prosthetic failure and antimicrobial resistance in the health and food sectors.

Mechanism of red pigment formation in lotus rhizome soup during cooking: The role of polyphenols, iron and organic acids

Lotus rhizome soup, renowned as a unique delicacy made from lotus rhizome, is cherished by many consumers. However, the varying colors of soup are sure to influence individuals' appetites. This research focused on the Miancheng lotus Rhizome (MLR) and Elian No. 6 lotus rhizome (ELR) to investigate the relationship between the variations in polyphenols, organic acids and iron levels in MLR and ELR soups during the cooking process. The findings indicated that cooking MLR for 12 min resulted in a red soup with a* value of 8.65 ± 0.12, whereas the soup made from ELR remained white with a* value of 3.43 ± 0.08. The correlation analysis results indicated that polyphenols, specifically epigallocatechin (0.0169 ± 0.00029 μg/100 mL FW after cooking for 12 min) and epicatechin (0.0211 ± 0.00047 μg/100 mL FW after cooking for 12 min), exhibited a significant positive relationship with a* (p < 0.05). Moreover, lowering the pH, removing polyphenols and incorporating metal-chelating agents can also prevent the development of red pigment. The analysis from HPLC-MS, UV-Vis, FT-IR spectra and ESI-Q-TOF-MS indicated that the development of the red soup color involved i) the generation of epicatechin gallate through the enantiomeric reaction of epigallocatechin, ii) the co-chromic red interaction between anthocyanin cations and catechol structures, and iii) the formation of polyphenol oligomers (i.e., procyanidin A2, (+)-procyanidin B2, procyanidin C1 and prodelphinidin B4) due to heating, while the creation of phenol-iron chelates could inhibit the development of red coloration. In sum, this research introduces a new idea for managing the color of lotus rhizome soup and similar soup products.

Biological potential and mechanisms of Tea's bioactive compounds: An Updated review

BACKGROUND

Tea (Camellia sinensis) has a rich history and is widely consumed across many countries, and is categorized into green tea, white tea, oolong tea, yellow tea, black tea, and dark tea based on the level of fermentation. Based on a review of previous literature, the commonly recognized bioactive substances in tea include tea polyphenols, amino acids, polysaccharides, alkaloids, terpenoids, macro minerals, trace elements, and vitamins, which have been known to have various potential health benefits, such as anticancer, antioxidant, anti-inflammatory, anti-diabetes, and anti-obesity properties, cardiovascular protection, immune regulation, and control of the intestinal microbiota. Most studies have only pointed out the characteristics of tea's bioactivities, so a comprehensive summary of the pharmacological characteristics and mechanisms of tea's bioactivities and their use risks are vital.

AIM OF REVIEW

This paper aims to summarize tea's bioactive substances of tea and their pharmacological characteristics and mechanisms, providing a scientific basis for the application of bioactive substances in tea and outlining future research directions for the study of bioactive substances in tea.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review summarizes the main biologically active substances, pharmacological effects, and mechanisms and discusses the potential risks. It may help researchers grasp more comprehensive progress in the study of tea bioactive substances to further promote the application of tea as a natural bioactive substance in the medical field.

Correlation analysis of secondary metabolites and disease resistance activity of different varieties of Congou black tea based on LC-MS/MS and TCMSP

To investigate the correlation between the difference of secondary metabolites and the disease-resistance activity of different varieties of Congou black tea. Among a total of 657 secondary metabolites identified, 183 metabolites had anti-disease activity, 113 were key active ingredients in traditional Chinese medicine (TCM), 73.22% had multiple anti-disease activities, and all were mainly flavonoids and phenolic acids. The main enriched metabolic pathways were phenylpropanoid biosynthesis, biosynthesis of secondary metabolites, flavonoid biosynthesis, and metabolic pathways. Flavonoid and phenolic acid secondary metabolites were more correlated with anti-disease activity and key active TCM ingredients. Conclusion: The types of JGY and Q601 Congou black tea of the relative contents show large differences in secondary metabolites. Flavonoid and phenolic acid secondary metabolites were identified as the primary factors contributing to the variation in secondary metabolites among different varieties of Congou black tea. These compounds also exhibited a stronger correlation with disease resistance activity.

Novel Pink Pigments Produced by Thermal Interaction of Theaflavins, Theanine, and Glucose: Color Formation, Isolation, and Structural Characterization

A color-deepening effect of theaflavins on the theanine-glucose thermal reaction model was revealed. Generated chromogenic intermediates in the initial stage and an accelerated browning rate through the promoted degradation of theanine-glucose Amadori rearrangement product in the intermediate and final stages are responsible for the color-deepening effect. Four pink-to-red theaflavin-theanine intermediates were verified as theaflavinies referencing the nuclear magnetic resonance and liquid chromatography-mass spectrometry information on theaflavins and l-theanine, including one accurately identified as theaflavinie 4. Theaflavinie 4 showed two maximum absorption peaks at 401 and 506 nm with parallel intensities, which resulted in a significant dichromic color change from pale pink to orange and red. Theaflavinies also could undergo further thermal reactions to yield brown polymers under higher temperatures (130 and 140 °C). This research provided new insight into realizing thermally formed polymers during black tea processing, which may be formed by oxidation products and amino acids or proteins through non-enzymatic thermal reactions.

Possible Combinatorial Utilization of Phytochemicals and Extracellular Vesicles for Wound Healing and Regeneration

Organ and tissue damage can result from injury and disease. How to facilitate regeneration from damage has been a topic for centuries, and still, we are trying to find agents to use for treatments. Two groups of biological substances are known to facilitate wound healing. Phytochemicals with bioactive properties form one group. Many phytochemicals have anti-inflammatory effects and enhance wound healing. Recent studies have described their effects at the gene and protein expression levels, highlighting the receptors and signaling pathways involved. The extremely large number of phytochemicals and the multiple types of receptors they activate suggest a broad range of applicability for their clinical use. The hydrophobic nature of many phytochemicals and the difficulty with chemical stabilization have been a problem. Recent developments in biotechnology and nanotechnology methods are enabling researchers to overcome these problems. The other group of biological substances is extracellular vesicles (EVs), which are now known to have important biological functions, including the improvement of wound healing. The proteins and nanoparticles contained in mammalian EVs as well as the specificity of the targets of microRNAs included in the EVs are becoming clear. Plant-derived EVs have been found to contain phytochemicals. The overlap in the wound-healing capabilities of both phytochemicals and EVs and the differences in their nature suggest the possibility of a combinatorial use of the two groups, which may enhance their effects.

Bioactive nutraceuticals as G4 stabilizers: potential cancer prevention and therapy-a critical review

G-quadruplexes (G4) are non-canonical, four-stranded, nucleic acid secondary structures formed in the guanine-rich sequences, where guanine nucleotides associate with each other via Hoogsteen hydrogen bonding. These structures are widely found near the functional regions of the mammalian genome, such as telomeres, oncogenic promoters, and replication origins, and play crucial regulatory roles in replication and transcription. Destabilization of G4 by various carcinogenic agents allows oncogene overexpression and extension of telomeric ends resulting in dysregulation of cellular growth-promoting oncogenesis. Therefore, targeting and stabilizing these G4 structures with potential ligands could aid cancer prevention and therapy. The field of G-quadruplex targeting is relatively nascent, although many articles have demonstrated the effect of G4 stabilization on oncogenic expressions; however, no previous study has provided a comprehensive analysis about the potency of a wide variety of nutraceuticals and some of their derivatives in targeting G4 and the lattice of oncogenic cell signaling cascade affected by them. In this review, we have discussed bioactive G4-stabilizing nutraceuticals, their sources, mode of action, and their influence on cellular signaling, and we believe our insight would bring new light to the current status of the field and motivate researchers to explore this relatively poorly studied arena.

Is it still worth renewing nucleoside anticancer drugs nowadays?

Nucleoside has situated the convergence point in the discovery of novel drugs for decades, and a large number of nucleoside derivatives have been constructed for screening novel pharmacological properties at various experimental platforms. Notably, nearly 20 nucleosides are approved to be used in the clinic treatment of various cancers. Nevertheless, the blossom of synthetic nucleoside analogs in comparison with the scarcity of nucleoside anticancer drugs leads to a question: Is it still worth insisting on the screening of novel anticancer drugs from nucleoside derivatives? Hence, this review attempts to emphasize the importance of nucleoside analogs in the discovery of novel anticancer drugs. Firstly, we introduce the metabolic procedures of nucleoside anticancer drug (such as 5-fluorouracil) and summarize the designing of novel nucleoside anticancer candidates based on clinically used nucleoside anticancer drugs (such as gemcitabine). Furthermore, we collect anticancer properties of some recently synthesized nucleoside analogs, aiming at emphasizing the availability of nucleoside analogs in the discovery of anticancer drugs. Finally, a variety of synthetic strategies including the linkage of sugar moiety with nucleobase scaffold, modifications on the sugar moiety, and variations on the nucleobase structure are collected to exhibit the abundant protocols in the achievement of nucleoside analogs. Taken the above discussions collectively, nucleoside still advantages for the finding of novel anticancer drugs because of the clearly metabolic procedures, successfully clinic applications, and abundantly synthetic routines.

Dietary flavonoids: a novel strategy for the amelioration of cognitive impairment through intestinal microbiota

The chances of people suffering from cognitive impairments increase gradually with age. Diet and lifestyle are closely related to the occurrence and development of cognitive function. Dietary flavonoid supplementation has been shown to be one of the protective factors against cognitive decline. Flavonoids belong to a class of polyphenols that have been proposed for the treatment of cognitive decline. Recent evidence has shown that intestinal flora in the human body can interact with flavonoids. Intestinal microbiota can modify the chemical structure of flavonoids, producing new metabolites, the pharmacological activities of which may be different from those of the parent; meanwhile, flavonoids and their metabolites can, in turn, regulate the composition and structure of intestinal flora. Notably, intestinal flora affect host nervous system activity through the gut-brain axis, ultimately causing changes in cognitive function. This review therefore summarizes the interaction of dietary flavonoids and intestinal flora, and their protective effect against cognitive decline through the gut-brain axis, indicating that dietary flavonoids may ameliorate cognitive impairment through their interaction with intestinal microbiota. © 2022 Society of Chemical Industry.