Search Results (1,495)

Quercetin, a natural polyphenolic flavonoid with antioxidant and anti-allergic properties, is extensively found in foods and holds significant importance for human health. In this study, a simple switch-off fluorescent sensor based on copper nanoclusters (Cu NCs) was proposed for the sensitive determination of quercetin. Glutathione acted as the reducing and protective agent in the synthesized process of Cu NCs via a facile, green one-pot method. As anticipated, the glutathione-capped Cu NCs (GSH-Cu NCs) exhibited favorable water solubility and ultrasmall size. The fluorescence property of GSH-Cu NCs was further enhanced with Al³⁺ ion through the aggregation-induced emission effect. When quercetin was present in the sample solution, the system exhibited effective fluorescence quenching, which was attributed to the internal filter effect. The GSH-Cu NCs/Al³⁺-based fluorescent sensor showed a good linear relationship to quercetin in the concentration range from 0.1 to 60 μM. A detection limit of 24 nM was obtained. Moreover, the constructed sensor was employed for the successful determination of quercetin in tea samples. Full article

Waste from zinc−carbon batteries poses a serious environmental protection problem. One of the main problems is also the reliable and rapid determination of some compounds that may be present in food and beverages consumed worldwide. This study addresses these problems and presents a possible solution for the electrochemical detection of xanthine using carbon from spent batteries. Cyclic voltammetry and differential pulse voltammetry are electrochemical methods used for the detection of xanthine. The techniques used demonstrate the mechanism of xanthine oxidation in the tested environment. A linear correlation was found between the oxidation current peaks and the xanthine concentration in the range of 5·10⁻⁷ to 1·10⁻⁴ M, as well as the values for the limit of detection and the limit of quantification, 7.86·10⁻⁸ M and 2.62·10⁻⁷ M, respectively. The interference test shows that the electrode obtained from waste Zn-C batteries has good selectivity, which means that the electrode can be used for xanthine determination in the presence of various ions. The data obtained show that carbon sensors from used zinc−carbon batteries can be used to detect xanthine in real samples. Full article

Metabolic dysfunction-associated fatty liver disease (MASLD) is a chronic, non-communicable spectrum of diseases characterized by lipid accumulation. It is often asymptomatic, and its prevalence varies by region, age, gender, and economic status. It is estimated that 25% of the world’s population currently suffer from MAFLD, and 20 million patients will die from MAFLD-related diseases. In the last 20 years, tea and anti-obesity research have indicated that regularly consuming tea decreases the risk of cardiovascular disease, stroke, obesity, diabetes, and metabolic syndrome (MeS). In this review, we aimed to present studies concerning the influence of matcha extracts and epigallocatechin-3 gallate (EGCG) supplements on metabolic functions in the context of MAFLD in human and animal studies. The published data show promise. In both human and animal studies, the beneficial effects on body weight, cholesterol levels, and liver metabolism and function were noted, even in short-period experiments. The safety levels for EGCG and green tea extract consumption are marked. More experiments are needed to confirm the results observed in animal studies and to show the mechanisms by which green tea exerts its effects. The preliminary data from research concerning microbiota or epigenetic changes observed after polyphenols and green tea consumption need to be expanded. To improve the efficiency and availability of green tea or supplement consumption as a treatment for MAFLD patients, more research with larger groups and longer study durations is needed. Full article

Knowing the superior biochemical defense mechanisms of sessile organisms, it is not hard to believe the cure for any human sickness might be hidden in nature—we “just” have to identify it and make it safely available in the right dose to our organs and cells that are in need. For decades, green tea catechins (GTCs) have been a case in point. Because of their low redox potential and favorable positioning of hydroxyl groups, these flavonoid representatives (namely, catechin—C, epicatechin—EC, epicatechin gallate—ECG, epigallocatechin—EGC, epigallocatechin gallate—EGCG) are among the most potent plant-derived (and not only) antioxidants. The proven anti-inflammatory, neuroprotective, antimicrobial, and anticarcinogenic properties of these phytochemicals further contribute to their favorable pharmacological profile. Doubtlessly, GTCs hold the potential to “cope” with the majority of today‘s socially significant diseases, yet their mass use in clinical practice is still limited. Several factors related to the compounds’ membrane penetrability, chemical stability, and solubility overall determine their low bioavailability. Moreover, the antioxidant-to-pro-oxidant transitioning behavior of GTCs is highly conditional and, to a certain degree, unpredictable. The nanoparticulate delivery systems represent a logical approach to overcoming one or more of these therapeutic challenges. This review particularly focuses on the lipid-based nanotechnologies known to be a leading choice when it comes to drug permeation enhancement and not drug release modification nor drug stabilization solely. It is our goal to present the privileges of encapsulating green tea catechins in either vesicular or particulate lipid carriers with respect to the increasingly popular trends of advanced phytotherapy and functional nutrition. Full article

Although Zn (II)-(−)-Epigallocatechin gallate (EGCg) complex (Zn-EGCg) is known for its promising bioactivities, little attention has been paid to its incorporation into daily green tea consumption. In this study, we aimed to incorporate Zn (II) into green tea extract to promote the formation of Zn-EGCg complex within the tea matrix. We then investigated how the formation of Zn-complexed green tea extract (Zn-GTE) influences the gut microbiota in a Western diet (WD)-fed mouse model. Structural analyses using ultraviolet–visible spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (¹H NMR), and powder X-ray diffraction (PXRD) suggested that Zn (II) interacted with hydroxyl groups of polyphenols within the extract, consistent with Zn-EGCg formation, although the complex could not be unequivocally identified. Under intake levels equivalent to daily consumption, Zn-GTE administration restored WD-induced reductions in alpha-diversity and resulted in a distinct microbial composition compared to treatment with green tea extract (GTE) or Zn alone, as shown by beta-diversity analysis. Linear discriminant analysis Effect Size (LEfSe) analysis revealed increased abundances of bacterial taxa belonging to o_Clostridiales, o_Bacteroidales, and f_Rikenellaceae, and decreased abundances of g_Akkermansia in the Zn-GTE group compared to the GTE group. These findings highlight that Zn-GTE, prepared via Zn (II) supplementation to green tea, may exert distinct microbiota-modulating effects compared to its individual components. This study provides new insights into the role of dietary metal–polyphenol complexes, offering a food-based platform for studying metal–polyphenol interactions under physiologically relevant conditions. Full article

Tetranectin (TN) is a plasminogen-binding protein found in human serum. Although it has been suggested to be closely related to various stem cell differentiation, including myogenesis, the role of TN in muscle development remains unclear. In this study, we identified TN as an anti-myogenic factor during the differentiation of C2C12 satellite cells. The exogenous supplementation of TN inhibited myogenic differentiation, whereas differentiation was significantly enhanced in the TN-depleted medium. Epigallocatechin-3-gallate (EGCG), a catechin abundant in green tea, significantly enhanced myogenic differentiation by reducing TN levels in the medium and downregulating TN gene expression during the differentiation process. These results demonstrate that EGCG promotes myogenesis by inhibiting TN at both the transcriptional and functional levels, highlighting TN as a promising therapeutic target for muscle regeneration disorders. Full article

This study investigates the effect of precursor pH (1.3, 2, 4, 6, 8, and 10) on the synthesis of gold nanoparticles (AuNPs) via a green synthesis approach using an aqueous extract of green tea (Camellia sinensis) leaves. The formation of AuNPs was monitored using UV-vis spectrophotometry and confirmed using transmission electron microscopy (TEM). The results confirmed that the morphology and size of the AuNPs are strongly dependent on the pH of the reaction medium. Based on spectral features, the color of the colloids, and TEM analysis, the synthesized samples were classified into three groups. The first (pH 8 and 10) contained predominantly spherical nanoparticles with an average diameter of ~18 nm, the second (pH 1.3 and 2) contained different shaped nanoparticles (20–250 nm in diameter), and the third (pH 4 and 6) contained flower-like nanostructures with a mean diameter of ~60 nm. UV-vis analysis revealed good stability of all AuNP colloids, except at pH 1.3, where a significant decrease in absorbance intensity over time was observed. These findings confirm that tuning the precursor pH allows for controlled manipulation of nanoparticle morphology and stability in green synthesis systems. Full article

Green tea, derived from the unoxidized leaves of Camellia sinensis (L.) Kuntze, is one of the least processed types of tea and is rich in antioxidants and polyphenols. Among these, catechins—particularly epigallocatechin gallate (EGCG)—play a key role in regulating cell signaling pathways associated with various chronic conditions, including cardiovascular diseases, neurodegenerative disorders, metabolic diseases, and cancer. This review presents a comprehensive analysis of recent clinical studies focused on the therapeutic benefits and potential risks of interventions involving green tea extracts or EGCG. A systematic literature survey identified 17 relevant studies, classified into five key areas related to catechin interventions: toxicity and detoxification, drug pharmacokinetics, cognitive functions, anti-inflammatory and antioxidant properties, and obesity and metabolism. Findings from these clinical studies suggest that the health benefits of green tea catechins outweigh the potential risks. The review highlights the importance of subject genotyping for enzymes involved in catechin metabolism to aid in interpreting liver injury biomarkers, the necessity of assessing drug–catechin interactions in clinical contexts, and the promising effects of topical EGCG in reducing inflammation. This analysis underscores the need for further research to refine therapeutic applications while ensuring the safe and effective use of green tea catechins. Full article

Urinary tract infections (UTIs) are among the most prevalent bacterial infections in women, with high recurrence rates and growing concerns over antimicrobial resistance. The need for alternative or adjunctive therapies has spurred interest in plant-based treatments, which offer antimicrobial, anti-inflammatory, antioxidant, and immune-modulatory benefits. This review summarizes the mechanisms of action, clinical efficacy, and therapeutic potential of various medicinal plants and natural compounds for preventing and treating UTIs in women. Notable candidates include cranberry, bearberry, pomegranate, green tea, and other phytochemicals with proven anti-adhesive and biofilm-disrupting properties. Evidence from clinical trials and meta-analyses supports the role of cranberry natural products and traditional herbal medicines (THMs) in reducing UTI recurrence, especially when combined with antibiotics. Notably, A-type proanthocyanidins in cranberry and arbutin in bearberry are key bioactive compounds that exhibit potent anti-adhesive and biofilm-disrupting properties, offering promising adjunctive strategies for preventing recurrent urinary tract infections. Additionally, emerging therapies, such as platelet-rich plasma (PRP), show promise in restoring bladder function and reducing infection in women with lower urinary tract dysfunction. Overall, plant-based strategies represent a valuable and well-tolerated complement to conventional therapies and warrant further investigation through high-quality clinical trials to validate their efficacy, safety, and role in personalized UTI management. Full article

In this study, the ultrasonic-assisted extraction of deep eutectic solvents (UADES) for tea polysaccharides was optimized, and their physicochemical properties and antioxidant activities were analyzed. The optimal DES comprised choline chloride (CC) and ethylene glycol (EG) in a molar ratio of 1:3, with a water content of 40%. The optimized condition was an extraction temperature of 61 °C, an ultrasonic power of 480 W, and an extraction time of 60 min. The UADES extraction rate of polysaccharides (ERP) was 15.89 ± 0.13%, significantly exceeding that of hot water (HW) extraction. The polysaccharide content in the UADES-extracted tea polysaccharides (UADESTPs) was comparable to that of hot-water-extracted tea polysaccharides (HWTPs) (75.47 ± 1.35% vs. 74.08 ± 2.51%); the UADESTPs contained more uronic acid (8.35 ± 0.26%) and less protein (12.91%) than HWTP. Most of the UADESTPs (88.87%) had molecular weights (Mw) below 1.80 × 10³ Da. The UADESTPs contained trehalose, glucuronic acid, galactose, xylose, and glucose, with molar ratios of 8:16:1:10. The free radical scavenging rate and total reducing power of the UADESTPs were markedly superior to those of the HWTPs. Moreover, the UADESTPs had a better alleviating effect on H₂O₂-induced oxidative injury in HepG2 cells. This study develops an eco-friendly and efficient extraction method for tea polysaccharides, offering new insights for the development of tea polysaccharides. Full article

Tea is one of the most consumed beverages in the world, belonging to the category of compounds known as tannins and flavonoids. One of the polyphenols found in large amounts in green tea leaves (Camellia sinensis) is epigallocatechin-3-O-gallate (EGCG). Though EGCG has shown some pharmacological effects, to date, it has not been utilised as a therapeutic agent. This is attributed to the fact that EGCG lacks adequate stability, and it is known to degrade through epimerization or auto-oxidation processes, especially when it is exposed to light, temperature fluctuations, some pH values, or the presence of oxygen. Consuming green tea with EGCG can alleviate the effects of bone diseases, such as osteoporosis, and support faster bone regeneration in the case of fractures. Therefore, this review focuses on the current state of research, highlighting the effects of EGCG on bone biology, such as enhancing osteoblast differentiation, promoting bone mineralisation, improving bone microarchitecture, and inhibiting osteoclastogenesis through the modulation of the RANK/RANKL/OPG pathway. Additionally, EGCG exerts antioxidant, anti-inflammatory, and dose-dependent effects on bone cells. It also downregulates inflammatory markers (TNF-α, IL-1β, and COX-2) and reduces oxidative stress via the inhibition of reactive oxygen species generation and the activation of protective signalling pathways (e.g., MAPK and NF-κB). Studies in animal models confirm that EGCG supplementation leads to increased bone mass and strength. These findings collectively support the further exploration of EGCG as an adjunct in the treatment and prevention of metabolic bone diseases. The authors aim to present the relationship between EGCG and bone health, highlighting issues for future research and clinical applications. Full article

Background: Early caries management is essential to enable reversal of white spot lesions without the further need for operative interventions, especially in primary dentition. Silver-based compounds can be quite effective in arresting caries lesions; however, a major drawback is teeth staining. This study aimed to evaluate the remineralization potential and aesthetic effects of novel, green-synthesized nano-silver fluoride (NSF) on artificial white spot lesions in primary teeth in comparison to 38% silver diamine fluoride (SDF) and silver diamine fluoride/potassium iodide (SDF/KI). Materials and Methods: NSF was synthesized using green tea extract. Sixty primary teeth specimens with artificial enamel lesions were randomly divided into five groups depending on the applied material: 38% SDF, 38% SDF/KI, single and double application of NSF, and control group. Treatments were followed by pH cycling. Surface microhardness and photographic analysis were conducted to assess remineralization and staining. Statistical analysis was conducted using non-parametric tests including Kruskal–Wallis and Mann–Whitney U tests with Bonferroni correction. Results: The greatest increase in microhardness was observed in the group receiving double NSF application. Its remineralizing potential was comparable to that of 38% SDF/KI, with no statistically significant difference (p = 1.000). Importantly, NSF-treated samples exhibited no teeth discoloration, unlike the black staining observed in SDF and SDF/KI groups. Conclusions: Green-synthesized NSF is a promising alternative to conventional SDF and SDF/KI, offering remineralization benefits without compromising aesthetics. The eco-friendly formulation and non-staining properties support its potential for clinical use in pediatric dentistry. Full article

Organic amendments provide a sustainable strategy to enhance soil quality in degraded environments while also helping to reduce greenhouse gas emissions, for example, by improving soil structure, minimizing the use of synthetic fertilizers, and promoting a green economy. This study assessed the comparative effects of two organic amendments—vermicompost leachate and biochar—on the performance of popcorn maize (Zea mays L. var. everta) cultivated in saline soil conditions. Four treatments were evaluated: T0 (Control), T1 (Vermicompost leachate), T2 (Biochar), and T3 (Vermicompost leachate + Biochar), each with 10 replicates arranged in a Completely Randomized Design (CRD). Although various soil physicochemical, microbiological, and agronomic parameters displayed no significant differences compared to the control, the application of biochar resulted in considerable improvements in soil total organic carbon, the microbial community (mesophilic aerobic bacteria, molds, and yeasts), and increased seed length and diameter. In contrast, vermicompost leachate alone negatively impacted plant growth, leading to decreases in leaf area, stem thickness, and grain yield. Specifically, grain yield declined by 46% with leachate alone and by 31% when combined with biochar, compared to the control. These findings emphasize the superior effectiveness of biochar over vermicompost leachate as a soil amendment under saline conditions and highlight the potential risks of widely applying compost teas in stressed soils. It is recommended to conduct site-specific assessments and screenings for phytotoxins and phytopathogens prior to use. Additionally, the combined application of leachate and biochar may not be advisable given the tested soil characteristics. Full article

Background: Lifestyle modifications are pivotal to preventing the progression of prediabetes and associated cardiometabolic diseases. Recent evidence from cross-sectional analysis of community-dwelling Chinese adults suggests that regular consumption of tea, particularly dark tea, is associated with a reduced risk of both prediabetes and type 2 diabetes. However, the effects of tea consumption on prediabetes progression and regression remain uncertain. This study investigated the associations of tea consumption with prediabetes progression and regression in Chinese adults with prediabetes. Methods: A cohort of 2662 Chinese adults with prediabetes was followed over ~3 years. Baseline tea consumption, including the type (green, black, dark, or other) and frequency (daily, sometimes, or nil), was assessed using standardized questionnaires. Prediabetes was defined according to the American Diabetes Association criteria. Multinomial logistic and linear regression analyses with multivariable adjustment was performed to evaluate associations. Results: Compared to non-tea drinkers, dark tea consumers were less likely to progress to type 2 diabetes (odds ratio [OR]: 0.28, 95% confidence interval [CI]: 0.11, 0.72, p = 0.01), whereas green tea consumption was associated with a reduced probability of regressing to normoglycemia (OR: 0.73, 95 CI%: 0.59, 0.90, p = 0.01). Conclusions: These findings support further exploration of dark tea consumption as a strategy to reduce prediabetes progression, and suggest that effects of green tea consumption should also be examined more closely in this population. Full article

Secondary iron overload exacerbates osteoporosis by elevating reactive oxygen species (ROS), which suppress osteoblast function and enhance osteoclast activity, disrupting bone remodeling. Reducing iron overload and oxidative stress may improve bone health. Epigallocatechin-3-gallate (EGCG), the main bioactive compound in green tea extract (GTE), is recognized for its antioxidant and iron-chelating properties. This study examined the effect of GTE on bone formation and mineralization in iron-overloaded human osteoblast-like MG-63 cells. An iron-overloaded model was established using ferric ammonium citrate (FAC), followed by treatment with GTE, deferiprone (DFP), or their combination. GTE significantly reduced intracellular iron, ROS levels, and lipid peroxidation while upregulating the osteogenic marker BGLAP, the anti-resorptive marker OPG, and osteogenic mineralization, indicating restored bone health. These results suggest that EGCG-containing GTE mitigates iron-induced oxidative stress and promotes osteogenesis, highlighting its potential as a natural therapeutic supplement for managing iron-overload-associated osteoporosis. Full article