Anti-proliferative effect and cell cycle arrest induced by saponins extracted from tea (Camellia sinensis) flower in human ovarian cancer cells

Unraveling the Role of Quinoa in Managing Metabolic Disorders: A Comprehensive Review

PURPOSE OF REVIEW

The review aims to address the knowledge gap and promote the widespread adoption of quinoa as a functional food for improving metabolic health. By presenting a comprehensive overview of its nutritional profile and bioactive components, the review aims to increase consumers' awareness of the potential therapeutic benefits of incorporating quinoa into diets.

RECENT FINDINGS

Recent studies have highlighted the diverse range of bioactive compounds in quinoa, such as phytosterols, saponins, phenolic acids, phytoecdysteroids, and betalains. These compounds exhibit various health-promoting properties, such as anti-inflammatory, antioxidant, antidiabetic, and gut microbiota-modulating effects. Furthermore, research indicates that regular quinoa consumption can improve metabolic parameters, including reduced cholesterol levels, blood sugar, fat accumulation, and blood pressure. These findings highlight the potential of quinoa as a dietary tool for preventing and managing metabolic disorders, such as obesity, cardiovascular diseases, diabetes, and gut dysbiosis. The article concludes that quinoa has emerged as a promising solution to food security challenges due to its adaptability to diverse environments and rich nutritional profile. However, some findings are not consistent in the mentioned studies, therefore, well-designed cohort randomized clinical trials with diverse populations are needed. While in vivo studies are necessary to elucidate the specific mechanisms behind the potential benefits of quinoa.

Plant-Derived Extracellular Vesicles as a Novel Frontier in Cancer Therapeutics

Recent advancements in nanomedicine and biotechnology have unveiled the remarkable potential of plant-derived extracellular vesicles (PDEVs) as a novel and promising approach for cancer treatment. These naturally occurring nanoscale particles exhibit exceptional biocompatibility, targeted delivery capabilities, and the capacity to load therapeutic agents, positioning them at the forefront of innovative cancer therapy strategies. PDEVs are distinguished by their unique properties that facilitate tumor targeting and penetration, thereby enhancing the efficacy of drug delivery systems. Their intrinsic biological composition allows for the evasion of the immune response, enabling the efficient transport of loaded therapeutic molecules directly to tumor sites. Moreover, PDEVs possess inherent anti-cancer properties, including the ability to induce cell cycle arrest and promote apoptotic pathways within tumor cells. These vesicles have also demonstrated antimetastatic effects, inhibiting the spread and growth of cancer cells. The multifunctional nature of PDEVs allows for the simultaneous delivery of multiple therapeutic agents, further enhancing their therapeutic potential. Engineering and modification techniques, such as encapsulation, and the loading of therapeutic agents via electroporation, sonication, and incubation, have enabled the customization of PDEVs to improve their targeting efficiency and therapeutic load capacity. This includes surface modifications to increase affinity for specific tumor markers and the encapsulation of various types of therapeutic agents, such as small molecule drugs, nucleic acids, and proteins. Their plant-derived origin offers an abundant and renewable source to produce therapeutic vesicles, reducing costs and facilitating scalability for clinical applications. This review provides an in-depth analysis of the latest research on PDEVs as emerging anti-cancer agents in cancer therapy.

Metabolite Profiling of External and Internal Petals in Three Different Colors of Tea Flowers (Camellia sinensis) Using Widely Targeted Metabolomics

The flower is the reproductive organ of the tea plant, while it is also processed into different kinds of products and thus of great significance to be utilized. In this study, the non-volatile secondary metabolites in the internal and external petals of white, white and pink, and pink tea flowers were studied using a widely targeted metabolomics method with ultra-high liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). A total of 429 metabolites were identified, including 195 flavonoids, 121 phenolic acids, 40 alkaloids, 29 lignans and coumarins, 19 tannins, 17 terpenoids, and 8 other metabolites. The metabolites in the internal and external petals of different colored flowers showed great changes in flavonoids. Most flavonoids and all tannins in the internal petals were higher compared with the external petals. Some phenolic acids were more accumulated in the external petals, while others showed opposite trends. The pink tea flower contained more flavonoids, alkaloids, lignans, coumarins, terpenoids, and tannins compared with white tea flowers. In addition, cyanidin-3-O-glucoside was more accumulated in the external petals of the pink flower, indicating that anthocyanin may be the main reason for the color difference between the pink and white tea flower. The enriched metabolic pathways of different colored flowers were involved in flavonoid biosynthesis, glycine, serine and threonine metabolism, glycerophospholipid metabolism, and phenylpropanoid biosynthesis. The findings of this study broaden the current understanding of non-volatile compound changes in tea plants. It is also helpful to lay a theoretical foundation for integrated applications of tea flowers.

Solid fuel derived PM2.5 induced oxidative stress and according cytotoxicity in A549 cells: The evidence and potential neutralization by green tea

PM_2.5 (particulate matter with aerodynamic diameter ≤ 2.5 μm) is a well-known cytotoxic pollutant that capable to induce severe intracellular oxidative stress while the underlying mechanisms remain unclear. Herein, 4 types of PM_2.5 derived from solid fuel burning were selected as stimuli in A549 cells exposure model to evaluate their effects on oxidative stress and inflammatory responses. Although resulting in different responses in cell viability, all PM_2.5 exhibited over 50 % higher oxidative stress than control group, expression as intracellular reactive oxygen species, malondialdehyde and superoxide dismutase levels. The Pearson's correlation results indicated that cations (e.g., Ca²⁺), heavy metals (e.g., Cr and Pb), nPAHs (nitro-polycyclic aromatic hydrocarbons, e.g., 6-nitrochrysene) and oPAHs (oxygenated PAHs, e.g., 9-fluorenone) were the main functioning toxics (r > 0.6). A key finding was the dual-directional regulation function of ECG (epicatechin gallate), that is, it could either increase the low A549 cell viabilities in coal combustion PM_2.5 group or reduce them in charcoal PM_2.5 group (P < 0.05). The dual-directional effects were likely because ECG can activate Nrf2 oxidation signaling pathway then inhibit the inflammatory signaling pathway NF-κB accordingly. Therefore, evidences indicated cytotoxicity of solid fuel derived PM_2.5 were mainly caused by oxidative stress, which was proved to be reversed by green tea, providing a potential therapy method to PM_2.5 and other hazards.

Determination of the chemical compounds of Shuchazao tea flowers at different developmental stages and in young shoots using 1H NMR-based metabolomics

The chemical compounds in tea leaves have been extensively explored in recent decades. However, the compounds in tea flowers have not been fully investigated. In present study, the main chemical compounds in tea flowers were identified at four developmental stages using non-targeted metabonomics based on proton nuclear magnetic resonance (1H NMR) and an automatic amino acid analyzer, and compared with those in young tea shoots. The results showed significant differences in catechins, sugars, organic acids and amino acids between tea flowers and young shoots. The concentrations of epigallocatechin gallate, epigallocatechin, epicatechin, and caffeine were significantly lower (p < 0.01) and sugar content significantly higher (p < 0.01) in flowers than in young shoots. Caffeine and β-glucose gradually decreased and sucrose constantly increased during flower development; α-glucose and fructose were most concentrated in the white bud and then decreased with flower development. Tea flowers contained more succinic acid, citric acid, and chlorogenic acid but less quinic acid and malic acid than young shoots. Both tea flowers and young tea shoots contained 20 common amino acids, including 7 essential ones. The concentration of amino acids was highest in the white bud (27.66 mg/g); young tea shoots contained significantly more L-theanine than tea flowers (p < 0.01). Our data indicate that the different stages of tea flowers have a set of characteristic chemical compounds and are potentially useful for functional foods.

Graphical abstract

Tieguanyin Oolong Tea Extracts Alleviate Behavioral Abnormalities by Modulating Neuroinflammation in APP/PS1 Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is a common neurodegenerative disease; tea components have important neuroprotective effects. This article explores the effects and mechanisms of Qingxiang Tiguanyin (Tgy-Q), Nongxiang Tieguanyin (Tgy-N), and Chenxiang Tieguanyin (Tgy-C) extracts on APP/PS1 AD model mice. Morris water maze and new object recognition experiments show that Tieguanyin extracts can effectively enhance the cognitive ability of APP/PS1 mice. H&E staining, Nissl staining, and immunohistochemical staining show that Tieguanyin extracts make nerve cell boundaries and nucleoli become clearer, relieve nucleus pyknosis, and effectively reduce Aβ1-40 and Aβ1-42 in the hippocampus and cortex. They also restore the morphology of microglia and astrocytes. In addition, Tieguanyin extracts can balance the oxidative stress level in the brain of APP/PS1 mice by improving the antioxidant capacity. Western blot results show that Tieguanyin extracts can reduce the expression of NF-κB p65, TNF-α, IL-1β, IL-6, COX-2, and iNOS in mouse brain, which demonstrates that Tieguanyin extracts improves cognitive ability by alleviating inflammation. This article demonstrates for the first time that Tieguanyin extracts can inhibit the excessive activation of the NF-κB p65 signaling pathway and improve the antioxidant capacity in the cerebral cortex and hippocampus, to improve the cognitive ability of APP/PS1 mice. Our results shed light into the beneficial of Tieguanyin tea extracts on preventing and alleviating AD diseases.

Plant-Derived Chinese Medicine Monomers on Ovarian Cancer via the Wnt/β-Catenin Signaling Pathway: Review of Mechanisms and Prospects

Ovarian cancer (OC) is a common malignant tumor of the female reproductive system and has a high morbidity and mortality rate. The progression and metastasis of OC are complex and involve multiple signaling pathways. The Wnt/β-catenin signaling pathway is closely related to OC, and therefore blocking the activation of the Wnt/β-catenin signaling directly or inhibiting related genes, and molecular targets is of great value in treating OC. Toxicities such as myelotoxicity, cardiotoxicity, genotoxicity, and vasospasm are the major side effects for common anticancer drugs and are well documented. There is, therefore, a need to develop new, effective, safer, and more affordable anticancer drugs from alternative sources. In recent years, plant-derived Chinese medicine monomers have drawn increasing attention due to their high safety, low toxicity, minimal side effects, and antitumor effects. Plant-derived Chinese medicine monomers are effective against multiple targets and can regulate the growth, proliferation, apoptosis, invasion, and migration of OC as well as reverse drug resistance by regulating the Wnt/β-catenin signaling pathway. In this review, we summarize and provide mechanisms and prospects for the use of plant-derived Chinese medicines for the prevention and treatment of OC.

Polymeric Hydrogels for Controlled Release of Black Tea and Coffee Extracts for Topical Applications

Tea and coffee are popular beverages. Both are also used in topical applications, such as ultraviolet (UV) protection, anti-aging, and wound healing. However, the impact of tea and coffee extract on skin cells is minimally explored. This study investigated the direct exposure of tea and coffee extract on skin cells using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. It was found that direct exposure of tea and coffee to skin cells can be toxic at a high dose on prolonged exposure (72 h). Therefore, it was hypothesized that a formulation providing a controlled release of tea and coffee could improve their skin compatibility. Thermally cross-linked poly(acrylic acid) hydrogels loaded with tea and coffee extracts (with and without milk) were formulated and optimized. The release profiles of these hydrogels were studied at varying loading efficiency. Milk addition with tea extract retarded the tea extract release from hydrogel while minimally affecting the coffee release. This effect was due to the molecular interaction of tea with milk components, showing changes in size, zeta potential, and polydispersity index. The release study best fitted the Korsmeyer-Peppas release model. Skin cells exposed to tea or coffee-loaded hydrogel showed normal skin cell morphology under fluorescence microscopic analysis. In conclusion, the hydrogels controlled the tea and coffee release and showed biocompatibility with skin cells. It can potentially be used for skin applications.

Saponins in Cancer Treatment: Current Progress and Future Prospects

Saponins are steroidal or triterpenoid glycoside that is distinguished by the soap-forming nature. Different saponins have been characterized and purified and are gaining attention in cancer chemotherapy. Saponins possess high structural diversity, which is linked to the anticancer activities. Several studies have reported the role of saponins in cancer and the mechanism of actions, including cell-cycle arrest, antioxidant activity, cellular invasion inhibition, induction of apoptosis and autophagy. Despite the extensive research and significant anticancer effects of saponins, there are currently no known FDA-approved saponin-based anticancer drugs. This can be attributed to a number of limitations, including toxicities and drug-likeness properties. Recent studies have explored options such as combination therapy and drug delivery systems to ensure increased efficacy and decreased toxicity in saponin. This review discusses the current knowledge on different saponins, their anticancer activity and mechanisms of action, as well as promising research within the last two decades and recommendations for future studies.

Gallic Acid Induces S and G2 Phase Arrest and Apoptosis in Human Ovarian Cancer Cells In Vitro

Ovarian cancer (OC) is among the top gynecologic cancers in the US with a death tally of 13,940 in the past year alone. Gallic acid (GA) is a natural compound with pharmacological benefits. In this research, the role of GA on cell proliferation, cell apoptosis, cell cycle-related protein expression was explored in OC cell lines OVCAR-3 and A2780/CP70. After 24,48 and 72 h of GA treatment, the IC50 values in OVCAR-3 cells were 22.14 ± 0.45, 20.36 ± 0.18, 15.13 ± 0.53 μM, respectively and in A2780/CP70 cells IC50 values were 33.53 ± 2.64, 27.18 ± 0.22, 22.81 ± 0.56, respectively. Hoechst 33,342 DNA staining and flow cytometry results showed 20 μM GA exposure could significantly accelerate apoptosis in both OC cell lines and the total apoptotic rate increased from 5.34%(control) to 21.42% in OVCAR-3 cells and from 8.01%(control) to 17.69% in A2780/CP70 cells. Western blot analysis revealed that GA stimulated programmed OC cell death via a p53-dependent intrinsic signaling. In addition, GA arrested cell cycle at the S or G2 phase via p53-p21-Cdc2-cyclin B pathway in the same cells. In conclusion, we provide some evidence of the efficacy of GA in ovarian cancer prevention and therapy.

Tea bioactive components prevent carcinogenesis via anti-pathogen, anti-inflammation, and cell survival pathways

Cancer seriously impairs human health and survival. Many perturbations, such as increased oxidative stress, pathogen infection, and inflammation, promote the accumulation of DNA mutations, and ultimately lead to carcinogenesis. Tea is one of the most highly consumed beverages worldwide and has been linked to improvements in human health. Tea contains many active components, including tea polyphenols, tea polysaccharides, L-theanine, tea pigments, and caffeine among other common components. Several studies have identified components in tea that can directly or indirectly reduce carcinogenesis with some being used in a clinical setting. Many previous studies, in vitro and in vivo, have focused on the mechanisms that functional components of tea utilized to protect against cancer. One particular mechanism that has been well described is an improvement in antioxidant capacity seen with tea consumption. However, other mechanisms, including anti-pathogen, anti-inflammation and alterations in cell survival pathways, are also involved. The current review focuses on these anti-cancer mechanisms. This will be beneficial for clinical utilization of tea components in preventing and treating cancer in the future.

Saponins Extracted from Tea (Camellia Sinensis) Flowers Induces Autophagy in Ovarian Cancer Cells

Tea flower saponins (TFS) possess effective anticancer properties. The diversity and complexity of TFS increases the difficulty of their extraction and purification from tea flowers. Here, multiple methods including solvent extraction, microporous resin separation and preparative HPLC separation were used to obtain TFS with a yield of 0.34%. Furthermore, we revealed that TFS induced autophagy—as evidenced by an increase in MDC-positive cell populations and mCherry-LC3B-labeled autolysosomes and an upregulation of LC3II protein levels. 3-MA reversed the decrease in cell viability induced by TFS, showing that TFS induced autophagic cell death. TFS-induced autophagy was not dependent on the Akt/mTOR/p70S6K signaling pathway. TFS-induced autophagy in OVCAR-3 cells was accompanied by ERK pathway activation and reactive oxygen species (ROS) generation. This paper is the first report of TFS-mediated autophagy of ovarian cancer cells. These results provide new insights for future studies of the anti-cancer effects of TFS.

Standardized Saponin Extract from Baiye No.1 Tea (Camellia sinensis) Flowers Induced S Phase Cell Cycle Arrest and Apoptosis via AKT-MDM2-p53 Signaling Pathway in Ovarian Cancer Cells

Ovarian cancer is considered to be one of the most serious malignant tumors in women. Natural compounds have been considered as important sources in the search for new anti-cancer agents. Saponins are characteristic components of tea (Camellia sinensis) flower and have various biological activities, including anti-tumor effects. In this study, a high purity standardized saponin extract, namely Baiye No.1 tea flower saponin (BTFS), which contained Floratheasaponin A and Floratheasaponin D, were isolated from tea (Camellia sinensis cv. Baiye 1) flowers by macroporous resin and preparative liquid chromatography. Then, the component and purity were detected by UPLC-Q-TOF/MS/MS. This high purity BTFS inhibited the proliferation of A2780/CP70 cancer cells dose-dependently, which is evidenced by the inhibition of cell viability, reduction of colony formation ability, and suppression of PCNA protein expression. Further research found BTFS induced S phase cell cycle arrest by up-regulating p21 proteins expression and down-regulating Cyclin A2, CDK2, and Cdc25A protein expression. Furthermore, BTFS caused DNA damage and activated the ATM-Chk2 signaling pathway to block cell cycle progression. Moreover, BTFS trigged both extrinsic and intrinsic apoptosis—BTFS up-regulated the expression of death receptor pathway-related proteins DR5, Fas, and FADD and increased the ratio of pro-apoptotic/anti-apoptotic proteins of the Bcl-2 family. BTFS-induced apoptosis seems to be related to the AKT-MDM2-p53 signaling pathway. In summary, our results demonstrate that BTFS has the potential to be used as a nutraceutical for the prevention and treatment of ovarian cancer.

Physiological genetics, chemical composition, health benefits and toxicology of tea (Camellia sinensis L.) flower: A review

The flower of tea (Camellia sinensis L.) plant has been paid an increasing attention in the last twenty years, since it was found that tea flowers contained representative constituents similar to those of tea leaves, such as catechins, caffeine and amino acids. Tea flower is theoretically valuable although it has been considered as an industrial waste over a long period of time. This review summarizes the research findings conducted until now on physiological genetics, chemical composition, health benefits and toxicology of tea flowers, aiming to foresee their future applications. A lot of genes are involved in flower development and the synthesis and transmission of various chemicals in tea flowers. The chemical composition of tea flower consists mainly of catechins, polysaccharides, proteins, amino acids and saponins and thus tea flower possesses various health benefits such as antioxidant, anti-inflammatory, immunostimulating, antitumor, hypoglycemic, anti-obesity and anti-allergic activities. Moreover, tea flower contains a protease that can elevate the free amino acids content in the tea infusion by almost two folds. More importantly, the enzymatic activity of the protease is much higher than that of the commercially available proteases. Additionally, aqueous extracts of tea flower are demonstrated to safe to animals. Thus, the potential uses of tea flowers in food and medical fields are warranted.

Purified Tea (Camellia sinensis (L.) Kuntze) Flower Saponins Induce the p53-Dependent Intrinsic Apoptosis of Cisplatin-Resistant Ovarian Cancer Cells

Ovarian cancer is currently ranked at fifth in cancer deaths among women. Patients who have undergone cisplatin-based chemotherapy can experience adverse effects or become resistant to treatment, which is a major impediment for ovarian cancer treatment. Natural products from plants have drawn great attention in the fight against cancer recently. In this trial, purified tea (Camellia sinensis (L.) Kuntze) flower saponins (PTFSs), whose main components are Chakasaponin I and Chakasaponin IV, inhibited the growth and proliferation of ovarian cancer cell lines A2780/CP70 and OVCAR-3. Flow cytometry, caspase activity and Western blotting analysis suggested that such inhibitory effects of PTFSs on ovarian cancer cells were attributed to the induction of cell apoptosis through the intrinsic pathway rather than extrinsic pathway. The p53 protein was then confirmed to play an important role in PTFS-induced intrinsic apoptosis, and the levels of its downstream proteins such as caspase families, Bcl-2 families, Apaf-1 and PARP were regulated by PTFS treatment. In addition, the upregulation of p53 expression by PTFSs were at least partly induced by DNA damage through the ATM/Chk2 pathway. The results help us to understand the mechanisms underlying the effects of PTFSs on preventing and treating platinum-resistant ovarian cancer.

DNA damage response and repair in ovarian cancer: Potential targets for therapeutic strategies

Ovarian cancer is among the most lethal gynecologic malignancies with a poor survival prognosis. The current therapeutic strategies involve surgery and chemotherapy. Research is now focused on novel agents especially those targeting DNA damage response (DDR) pathways. Understanding the DDR process in ovarian cancer necessitates having a detailed knowledge on a series of signaling mediators at the cellular and molecular levels. The complexity of the DDR process in ovarian cancer and how this process works in metastatic conditions is comprehensively reviewed. For evaluating the efficacy of therapeutic agents targeting DNA damage in ovarian cancer, we will discuss the components of this system including DDR sensors, DDR transducers, DDR mediators, and DDR effectors. The constituent pathways include DNA repair machinery, cell cycle checkpoints, and apoptotic pathways. We also will assess the potential of active mediators involved in the DDR process such as therapeutic and prognostic candidates that may facilitate future studies.

Natural barrigenol-like triterpenoids: A comprehensive review of their contributions to medicinal chemistry

Barrigenol-like triterpenoids (BATs), which contain an unusual oleanane substituted by many hydroxyl groups as the skeleton, are subdivided into five subtypes: barrigenol A₁, barrigenol A₂, barrigenol R₁, barringtogenol C, and 16-deoxybarringtogenol C. The variations in acyl derivatives, hydroxyl groups, and carbohydrate chains in their structures have enhanced the diversity of BATs. Moreover, the stable polyhydroxy-replaced pentacyclic skeleton provides an ideal platform for structural modifications. To date, more than 500 BAT derivatives have been isolated from plants. Synchronously, BATs possess anti-tumour, anti-Alzheimer's disease, anti-inflammatory, anti-microbial, anti-obesity and anti-allergic activities by regulating numerous cellular molecules. Some BAT derivatives, such as escin obtained from Aesculus hippocastanum L. and xanthoceraside isolated from Xanthoceras sorbifolia Bunge, have been used to treat encephaloedema or inflammatory diseases. This review aims to provide comprehensive information about the chemistry, sources, bioavailability, and anti-tumour effects of BATs, with a particular emphasis on the molecular mechanisms of action. The pharmacokinetics and clinical progress are also concerned. More than 300 structures identified over past 25 years are summarized here (249 compounds) and in the supplementary information (114 compounds). Accordingly, the pharmaceutical activity of barrigenol triterpenoids suggests that some compounds should be developed as promising anti-tumour or anti- Alzheimer's disease agents in future.

Anticancer activity and mechanism of total saponins from the residual seed cake of Camellia oleifera Abel. in hepatoma-22 tumor-bearing mice

Total saponins from the residual seed cake of Camellia oleifera Abel. exhibited beneficial properties on anticancer activity in hepatoma-22 tumor-bearing mice and represents a promising species for food applications.

Triterpenoid saponins from the genus Camellia: structures, biological activities, and molecular simulation for structure–activity relationship

This review summarizes the isolation, chemical identification, and biochemical activities of Camellia triterpenoid saponins, updating a previous review and encompassing all new studies through September 2017.