Search Results (897)

In this study, the rank of multifaceted activity of catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin-3-gallate (ECG) and epigallocatechin-3-gallate (EGCG) was addressed. Their antioxidant activity was determined by the differential pulse voltammetry (DPV), whereas their ability to inhibit angiotensin-converting enzyme (ACE) activity, acetylcholinesterase activity (AChE), and formation of the advanced glycation end-products (AGEs) was performed in a model system to show their importance against hypertension, Alzheimer-type dementia, and diabetic’s complication, respectively. The order of the antioxidant potential of catechins in comparision to gallic acid (GA) was EGCG > ECG > EC > EGC ≈ C > GA, whereas the order of the ACE inhibitory activity was EGCG > ECG > EGC > EC > C, thus indicating the importance of the structure–activity relationship. The correlation between IC₅₀ for ACE inhibition of catechins and their antioxidant activity had the value r = −0.60. The order of the AChE enzyme inhibitory activity was EGCG ≈ EGC > ECG > EC > C, and the weak positive correlation between IC₅₀ and the first anodic peak potential (E_pa1) values was noted (r = 0.67). The ranking of the anti-AGE activities was EGCG ≈ ECG > EGC > EC > C, and a negative correlation between the inhibitory activity of catechins against AGE formation and their antioxidant activity was r = −0.82, whereas a positive correlation (r = 0.88) was noted between their first anodic peak potential (E_pa1) values. The provided results expand our knowledge on the multifaceted activity of catechins, indicating EGCG and ECG as the most active antioxidants against inhibition of ACE and AChE as well as towards AGE formation. Full article

Background: There is a growing number of studies suggesting the effectiveness of dietary supplements in preventing and treating endometriosis. It has been suggested that deficiencies in vitamins D and E as well as zinc are associated with the increased risk of endometriosis development. Beneficial effects of magnesium, curcumin, resveratrol and epigallocatechin-3-gallate were found in experimental animal studies. A reduction in pain related to endometriosis was shown in women using omega-3 and alpha-lipoic acid. Meanwhile, decreasing endometriotic lesion size after the supplementation of omega-3, N-acetylcysteine, vitamin C and epigallocatechin-3-gallate was observed in animal and human studies. Thus, the aim of this critical review was to summarize the available data describing the effects of dietary supplements used in the treatment of endometriosis. Material and Methods: The PubMed, Embase, Cochrane, and Web of Science databases were searched for related studies until 15 December 2025. Finally, 34 studies were included in the synthesis. Results: Of these 34 studies, only 23 were randomized, placebo-controlled trials. There have been no RCTs evaluating the effectiveness of vitamin E, zinc, alpha-LA, EGCG and DIM in the treatment of endometriosis. Single studies evaluating the effectiveness of vitamin C, magnesium, resveratrol, NAC and PEA with PLD have not confirmed it. Meanwhile single studies evaluating the effectiveness of selenium, propolis and quercetin have confirmed it. Of the four studies assessing the effectiveness of vitamin D, two confirmed it and two did not; of the two studies assessing probiotics, one confirmed its effectiveness and one did not; of the two studies assessing curcumin, one confirmed its effectiveness and one did not; and of the three studies assessing omega-3, two confirmed its effectiveness and one did not. All four RCTs assessing the combination of vitamins C and E confirmed their effectiveness. Conclusions: Despite encouraging observations from experimental studies, the results of RCTs are less encouraging and do not allow for the formulation of recommendations concerning the use of supplements in the treatment of endometriosis symptoms according to EBM. Full article

Polyphenols are plant metabolites with potent physiological activities. Despite their known bitterness and astringency, their specific sensory characteristics remain poorly understood. To clarify the relationship between polyphenol chemical structures and sensory profiles, we developed a sensory evaluation protocol for a young-adult panel. Following four days of intensive monthly training, the panel achieved proficiency in distinguishing bitterness, astringency, and acidity. Four polyphenols with distinct structures—gallic acid, quercetin hydrate, epigallocatechin gallate (EGCG), and a procyanidin-rich fraction (PRF)—were evaluated using flavor profile analysis (FPA) and 3-Alternative Forced Choice (3-AFC) tests for their qualitative properties, and quantitative descriptive analysis (QDA) for their quantitative properties. The results showed that gallic acid was acidic, and EGCG was bitter and astringent, with the intensity being concentration-dependent. In contrast, quercetin hydrate did not show any significant sensory properties. This methodology facilitates the elucidation of the relationship between polyphenol structures, and their organoleptic properties and subsequent findings help to further clarify the role of polyphenol–taste receptor interactions in health benefits. Full article

Fermented Miang (Camellia sinensis var. assamica) serves as a valuable source of bioactive polyphenols and probiotic-associated components. This study characterized the catechin composition of fermented Miang extracts and evaluated their antioxidant capacity and suitability for cosmetic formulations. High-performance liquid chromatography (HPLC) analysis showed that epigallocatechin gallate (EGCG) was the predominant catechin (7.00 ± 0.93 mg/g dry weight), followed by catechin (C), epicatechin (EC), epicatechin gallate (ECG), and epigallocatechin (EGC). The extracts remained physically and chemically stable for at least three months under various storage conditions, with the dried extract form offering advantages for handling and formulation. Fermentation duration significantly influenced phenolic accumulation and antioxidant activity, with four-month fermentation showing the highest activity. Prototype cleansing formulations, including transparent/opaque soap bars, liquid soap, and shampoo containing fermented Miang extract, exhibited acceptable physicochemical characteristics and retained antioxidant function. These findings highlight fermented Miang as a promising natural ingredient for antioxidant and probiotic-inspired cosmetic applications. Full article

This study optimized stabilizer type and concentration, and screened natural antioxidant combinations to enhance the stability of a protein beverage fortified with vitamins A, D₂, and D₃. Three stabilizers—carrageenan, sodium carboxymethyl cellulose (Na-CMC), and microcrystalline cellulose (MCC)—were evaluated at 0.15–0.45% (w/v) during accelerated storage at 45 °C for 21 days. Stability was assessed using Turbiscan analysis, pH, particle size, Zeta potential, and color. MCC at 0.35% demonstrated the best stabilization, with minimal changes in Turbiscan Stability Index, particle size, and Zeta potential. Five natural antioxidants—dl-α-tocopherol, vitamin C, epigallocatechin gallate (EGCG), tea polyphenols (TP), and pyrroloquinoline quinone (PQQ)—were screened for vitamin protection using HPLC. Although vitamin C exhibited the highest in vitro DPPH radical scavenging activity (IC₅₀ = 3.44 μg/mL), TP and EGCG provided superior protection of vitamins in the emulsion system. A synergistic antioxidant blend of EGCG, TP, and dl-α-tocopherol in a 4:4:2 mass ratio was identified as optimal, significantly prolonging vitamin retention over 21 days and yielding the longest predicted shelf-life (>84 days at 25 °C). These findings provide a practical formulation strategy for enhancing the physical and nutritional stability of functional protein beverages. Full article

Background: Squamous cell carcinoma of head and neck (SCCHN) is a devastating disease with high morbidity and mortality and the 6th most common cancer worldwide. The 5-year relative survival for advanced-stage disease is below 50%, stressing the need for chemoprevention. In the current study, we investigated the chemopreventive efficacy of the combination of resveratrol and epigallocatechin gallate (EGCG). Methods: We used the 4-Nitroquinoline 1-oxide (4-NQO)-induced oral carcinogenesis model. C57BL/6 mice were exposed to drinking water containing 4-NQO for 10 weeks. From week 11, mice were treated with vehicle, resveratrol, EGCG and their combination until week 22. RNASeq, qPCR and in silico analysis were performed identifying differentially expressed genes and enriched pathways. Results: Resveratrol alone and in combination with EGCG significantly inhibited the number of visible lesions, whereas the number of microscopic lesions and lesion areas were significantly inhibited only by the combination. The expression of Ki-67 was also significantly inhibited in resveratrol and combination groups. Growth differentiation factor 15 (GDF15), Activation transcription factor 3 (ATF3) and several other genes associated with xenobiotic metabolism as significantly upregulated genes, with GDF15 being the most upregulated one. Furthermore, hallmarks of xenobiotic metabolism and several other anticancer pathways were enriched after treatment with resveratrol and the combination. Conclusions: Our data strongly demonstrate the chemopreventive potential of the combination of resveratrol and EGCG and pave the way for further clinical developments. Full article

The cytotoxic effect of islet amyloid polypeptide (IAPP) misfolding and aggregation has a well-recognized role in the pathogenesis of type 2 diabetes mellitus, mediated by failure of the beta cell’s protein quality control system to rescue the cell from overwhelming proteotoxic stress induced by IAPP aggregates, ultimately leading to apoptosis. A small but growing body of research also links IAPP-mediated proteotoxic stress to the pathogenesis of type 1 diabetes and to the functional decline of transplanted islets. Among the most promising therapeutic approaches under investigation are small organic molecules that may act as direct chemical chaperones to prevent IAPP aggregation, promote the activity of endogenous chaperones, or alter gene networks of the unfolded protein response (UPR) to promote pro-survival rather than pro-apoptotic pathways in response to IAPP-mediated proteotoxic stress. Compounds warranting special attention include 4-phenylbutyrate (PBA), tauroursodeoxycholic acid (TUDCA), and epigallocatechin gallate (EGCG), as each has a growing body of evidence supporting their ability to ameliorate this process, and given that each of these are already known to have good safety profiles in humans, potentially accelerating the timeline to interventional studies. This review explores the evidence for IAPP-mediated proteotoxicity in multiple forms of diabetes, the mechanisms of cytotoxicity at different levels of the cell’s protein quality control systems, how these small organic compounds may act on these processes including new insights on the role of thioredoxin-interacting protein (TXNIP), and the current evidence supporting each of these compounds in mitigating diabetogenesis. Full article

Aquaporins (AQPs) are increasingly recognized as key regulators of tumor progression, influencing key hallmarks of cancer progression and cellular homeostasis. Their frequent overexpression in malignancies highlights their potential as therapeutic targets, yet the development of selective synthetic inhibitors remains challenging due to structural conservation and off-target toxicity. Natural compounds have recently emerged as promising modulators of AQP expression and function, offering greater molecular diversity and generally favorable safety profiles. This review synthesizes current evidence on phytochemicals, including bacopaside II, curcumin, resveratrol, quercetin, EGCG, all-trans retinoic acid, chrysin, and rottlerin, that interact with AQP isoforms relevant to cancer biology. These agents regulate AQPs through transcriptional control, redox modulation, signaling-pathway interference, or direct pore blockade, thereby attenuating oncogenic processes such as migration, angiogenesis, inflammation, and metabolic adaptation. Several compounds, notably bacopaside II and rottlerin, display isoform-selective inhibitory properties that directly impair AQP1- and AQP3-mediated permeability. Collectively, available evidence positions natural AQP modulators as promising lead compounds providing scaffolds for further drug development in oncology. Continued structural, mechanistic, and preclinical research is required to optimize isoform specificity and therapeutic efficacy, paving the way for their integration into future anticancer strategies. Full article

Background: Despite significant improvements in blood safety, the risk of transfusion-transmitted infections persists, particularly from emerging and re-emerging viruses. For red blood cell (RBC) products, this risk is exacerbated by the fact that there is no routine testing for many of these pathogens, and effective, commercially available pathogen inactivation technologies specifically for RBCs are still lacking. This gap in the safety framework means that viruses capable of establishing an asymptomatic viremia—a characteristic of many arboviruses like Zika, dengue, and West Nile virus—present a tangible threat to the blood supply, highlighting the need for broad-spectrum countermeasures. Study Design and Methods: This study aims to investigate the antiviral activity of green tea extract (GTE) and its key catechins, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), against ZIKV in both cellular models and red blood cell (RBC) products. In vitro antiviral activity was assessed using A549 cells treated with GTE (150 μg/mL) or purified EGCG/ECG (20 μM). Mechanistic studies focused on viral attachment inhibition. Additionally, ZIKV-spiked RBC products were co-incubated with GTE (300 μg/mL) for 1 h to evaluate virucidal effects. Erythrocyte integrity was confirmed via hemolysis assays. Results: Co-treatment with GTE or catechins suppressed ZIKV replication by ≥3.64 logs (p < 0.001) in A549 cells. GTE and catechins primarily inhibited viral attachment. In RBCs, GTE reduced viral infectivity by 99.99% (4-log reduction) without compromising erythrocyte membrane integrity or cellular viability. Furthermore, RBCs with added GTE demonstrated a lower hemolysis rate during storage for up to 60 days. Conclusions: GTE exhibits potent virucidal activity against ZIKV in blood matrices, highlighting its potential as a pathogen reduction agent to enhance transfusion safety. Further development of GTE-based additive solutions or technologies is warranted. Full article

(−)-Epigallocatechin 3-gallate (EGCG) is a potent natural antioxidant, but its strong bitterness and poor palatability limit its application in animal production. This study aimed to evaluate the protective effects and underlying mechanisms of chemically synthesized EGCG derivatives against oxidative stress using a diquat-induced mouse model. A total of 36 male ICR mice were randomly assigned into six groups (n = 6): Control (T0), Diquat (T1), EGCG + Diquat (T2), Epigallocatechin octanoate (EGCO) + Diquat (T3), Epigallocatechin p-chloromethylbenzoate (EGCP) + Diquat (T4), and Epigallocatechin ibuprofen ester (EGCI) + Diquat (T5). Oxidative stress was induced by intraperitoneal injection of diquat at day 27 of the experiment, while EGCG or its derivatives were administered via dietary supplementation. At day 28, the mice were weighed, killed, and the tissues were sampled. Diquat challenge significantly impaired growth, increased serum injury markers (ALT, AST, DAO, and D-LA) (p < 0.05), suppressed hepatic and jejunal antioxidant enzymes (GPx, SOD, and TAOC) while elevating MDA (p < 0.05), damaged jejunal morphology (villus atrophy) (p < 0.05), and downregulated tight junction proteins (ZO-1 and Occludin) (p < 0.05). Chemically synthesized EGCG derivatives, especially EGCI, effectively alleviated diquat-induced growth impairment and hepatic and intestinal oxidative damage by improving intestinal barrier function and enhancing systemic antioxidant capacity, possibly in part through activation of the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling pathway. Compared with EGCG, EGCI exhibited reduced bitterness and improved palatability, which favored normal feed intake. These findings provide strong theoretical support for the future application of EGCG derivatives, especially EGCI, as functional antioxidant additives in broiler production. Full article

The α-glucosidase inhibitory activity of Keemun black tea arises from complex interactions among its major polyphenols, which cannot be reliably predicted from the activities of isolated compounds. In this study, eight dominant polyphenols were investigated using a quantitative reconstruction–omission framework designed to reflect typical household tea brewing. The fully reconstructed system recovered approximately 72% of the inhibitory activity of the diluted native infusion, supporting the functional representativeness of the selected compounds. Systematic omission experiments revealed that antagonistic interactions, particularly among theaflavins, dominated the net inhibitory outcome, with removal of the most potent inhibitor, theaflavin-3,3′-digallate (TFDG), paradoxically increasing overall activity. Pairwise Combination Index analysis further demonstrated concentration-dependent biphasic interactions, exemplified by the epigallocatechin-3-gallate (EGCG)–TFDG pair, while molecular docking suggested overlapping binding sites as a potential structural basis for competitive inhibition. Collectively, this work provides a system-level dissection of α-glucosidase inhibition in black tea. Although the reconstructed system does not fully capture all contributions, the proposed framework offers a generalizable strategy for investigating interaction-driven bioactivity in complex dietary matrices and for further mechanistic studies. Full article

The influence of different gas compositions in modified atmospheric packaging (MAP) without and with chitooligosaccharide-EGCG (CE) conjugate on storage stability of Asian hard clam (HC) meat during storage at 4 °C was studied. Microbial load of HC meat was <5 log CFU/g when packaged under MAP, regardless of treatment, up to 18 days of storage, whereas control exceeded viable bacterial count (6 log CFU/g) on day 9. The lowest microbial load, volatile bases, and lipid oxidation were obtained in HC meat pretreated with 600 ppm of CE conjugate and MAP (80% CO₂/20% O₂) (MAP4-CE) (p < 0.05). Correlation heatmap analysis showed that a high-CO₂/low-O₂ atmosphere was the primary determinant of reduced Pseudomonas growth and lipid oxidation in HC meat, whereas the CE conjugate conferred only minor oxidation and nitrogenous spoilage indices. HC packed under MAP exhibited higher cooking and drip loss, along with increased toughness and firmness, irrespective of treatment. PUFA of MAP4-CE was retained during 18 days of storage. High-CO₂, with or without CE, redirected the microbial diversity toward CO₂-tolerant taxa. Overall, MAP4-CE had an extended shelf-life of at least 18 days while better preserving lipid quality and delayed growth of spoilage bacteria. Full article

Background: Alzheimer’s disease (AD) remains a major public health challenge. Observational associations between dietary patterns and reduced dementia risk have prompted investigations of dietary bioactives (DBs) as cognitive nutraceuticals. Methods: This critical narrative review examines interventional trials for nine prominent DBs relevant to AD: docosahexaenoic acid (DHA), curcumin, resveratrol, epigallocatechin gallate (EGCG), nicotinamide riboside (NR), tricaprilin, vitamin E (α-tocopherol), cannabinoids, and NIC5-15 (D-pinitol). Trials were identified through ClinicalTrials.gov (search date: December 2024) and supplemented by PubMed searches for published results. Data were extracted on trial phase, design, cognitive/functional endpoints, biomarker outcomes, and development status. Findings are synthesized qualitatively; no formal meta-analysis or risk of bias assessment was conducted. Results: None of the nine bioactives demonstrated consistent cognitive efficacy in AD. Phase III trials of DHA, curcumin, and tricaprilin did not meet primary cognitive endpoints. Resveratrol reduced CSF Aβ40 without cognitive benefit. Cannabinoids improved behavioral symptoms but showed no measurable cognitive effects. High-dose vitamin E slowed functional decline, while cognition remained unchanged. In contrast, trials in preclinical or at-risk populations reported preliminary cognitive signals for EGCG and biomarker engagement for NR, suggesting potential for early intervention. Conclusions: Current clinical evidence does not support high-dose DBs supplementation as an effective treatment for AD. Predominantly negative late-phase findings highlight limitations, with potential contributors including limited bioavailability, late intervention, insufficient target engagement, and biological heterogeneity. Future research may benefit from early biomarker-defined populations, optimized formulations, multi-nutrient or dietary approaches, and precision nutrition strategies considering genetic risk and baseline nutrient status. DBs may be better positioned for prevention or early-stage intervention rather than late-stage therapy. Full article

Salivary aldehyde dehydrogenases (ALDHs), particularly ALDH3A1 and ALDH1A1, serve as frontline enzymatic defenses in the oral cavity, detoxifying reactive aldehydes generated through metabolic activity, microbial fermentation, and environmental exposures. These enzymes are essential for maintaining redox homeostasis, mucosal integrity, and immune modulation. However, under chronic metabolic stress, such as in diabetes, oral inflammation, and cancer, salivary ALDHs become vulnerable to non-enzymatic glycation by reactive carbonyl species like methylglyoxal. This modification impairs cofactor binding, catalytic activity, and structural stability, thereby compromising detoxification capacity at a time of heightened aldehyde burden. This review provides the first insights into ALDH glycation and particularly that of salivary ALDH, examining its structural mechanisms, disease-specific consequences, and emerging protective strategies. Special focus is given to natural compounds, including curcumin, thymoquinone, resveratrol, carnosine, and EGCG, that prevent glycation or restore ALDH function via carbonyl scavenging, antioxidant activation, and NAD⁺/SIRT1 pathway modulation. We also highlight critical research gaps, such as the absence of site-specific glycation maps, lack of salivary gland-based models, and limited availability of ALDH3A1-specific activators. Importantly, we propose that the glycation status of salivary ALDHs may serve as a non-invasive biomarker of oxidative stress and therapeutic response in metabolic and inflammatory disorders. By bridging biochemical insights with translational potential, this review establishes ALDH glycation as a mechanistic and clinically actionable axis in oral and systemic health. Full article

Tea offers health benefits, but some teas accumulate high fluoride (F), posing fluorosis risks. However, the roles of individual tea components in regulating F bioavailability remain unclear. This study investigated the effects of major tea constituents on F metabolism in male rats (n = 5/group) administered F (40 mg/L) alone or with graded doses of epigallocatechin gallate (EGCG, 150–450 mg/kg); theaflavins, thearubigins, and theabrownin (TFs, TRs, TB, 200–800 mg/kg each); tea polysaccharides (TPSs, 25–250 mg/kg); and calcium and aluminum (Ca, Al, 800–3200 µg/kg each) via gavage. Pharmacokinetic analysis of plasma F (0–480 min) and fecal F excretion were assessed. The result showed that high-dose EGCG (450 mg/kg) reduced C_max by 61.76% and total exposure (AUC_0–t) by 37.48% compared to the control, while significantly increasing fecal F by 26.79% (p < 0.05). TB (800 mg/kg) delayed F absorption by prolonging T_max from 18 to 30 min and reduced C_max by 35.38% (p < 0.05). TPS (250 mg/kg) decreased C_max by 51.72% and AUC_0–t by 24.38% (p < 0.05). Ca and Al (800–3200 µg/kg) reduced C_max by 39.19–69.62%, and low-dose aluminum (800 µg/kg) increased fecal F by 35.58% (p < 0.05). These findings elucidate distinct roles of tea constituents in mitigating F bioavailability, providing a scientific basis for tea safety assessment and dietary interventions against F overexposure. Full article