Epicatechin Gallate Research Articles

Effects of Protein on Green Tea Quality in a Milk-Tea Model during Heat Treatment: Antioxidant Activity, Foaming Properties, and Unbound Small-molecule Metabolome

Tea drinks/beverage has a long history and milk is often added to enhance its taste and nutritional value, whereas the interaction between the tea bioactive compounds with proteins has not been systematically investigated. In this study, a milk-tea model was prepared by mixing green tea solution with milk and then heated at 100°C for 15 min. The milk tea was then measured using biochemical assay, antioxidant detection kit, microscopy as well as HPLC-QTOF-MS/MS after ultrafiltration. The study found that as the concentration of milk protein increased in the milk-tea system, the total phenol-protein binding rate raised from 19.63% to 51.08%, which led to a decrease in free polyphenol content. This decrease of polyphenol was also revealed in the antioxidant capacity, including 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability and ferric ion reducing antioxidant power, in a dose-dependent manner. Untargeted metabolomics results revealed that the majority of small-molecule compounds/polyphenols in tea, such as epigallocatechin gallate, (-)-epicatechin gallate, and Catechin 5,7,-di-O-gallate, bound to milk proteins and were removed by ultrafiltration after addition of milk and heat treatment. The SDS-PAGE and Native-PAGE results further indicated that small molecule compounds in tea formed covalent and non-covalent complexes by binding to milk proteins. All above results partially explained that milk proteins form conjugates with tea small-molecule compounds. Consistently, the particle size of the tea-milk system increased as the tea concentration increased, but the polymer dispersity index decreased, indicating a more uniform molecular weight distribution of the particles in the system. Addition of milk protein enhanced foam ability in the milk-tea system but reduced foam stability. In summary, our findings suggest that the proportion of milk added to tea infusion needs to be considered to maintain the quality of milk-tea from multiple perspectives, including stability, nutritional quality and antioxidant activity.

Polyphenol co-pigments enhanced the antioxidant capacity and color stability of blue honeysuckle juice during storage

The study aimed to assess the impact of incorporating five co-pigments (gallic acid, quercetin, rutin, catechin, and epigallocatechin gallate (EGCG)) on the color stability of blue honeysuckle juice (BHJ). Additionally, it sought to determine the influence of varying proportions of anthocyanins in an accelerated test (light at 40 °C for 24 d). Results indicated that the addition of polyphenol co-pigments effectively mitigated the thermal degradation of anthocyanins, enhancing color saturation and antioxidant capacity of BHJ. Notably, quercetin, rutin, catechin, and EGCG exhibited superior efficacy compared to gallic acid. FTIR analysis revealed non-covalent complex formation between co-pigments and anthocyanins, including hydrogen bonds and van der Waals forces, thereby shielding them from degradation. HPLC-ESI-QTOF-MS2 identified 15 anthocyanins and 39 non-anthocyanin polyphenols. Addition of co-pigments effectively curbed anthocyanin degradation, thus stabilizing juice system. Consequently, judicious incorporation of co-pigments holds promise as a technology for enhancing the color quality and stability of BHJ during processing.

Comparison of Waste from Different Types of Tea to Dried Butterfly Pea Flower

At present, the bioactive compounds of teas are well established and there are more attempts to apply tea as a functional drink or food supplement. In addition, during tea processing, tea waste, including broken tea leaves, buds and stems, is generated and disposed to the environment. The present study aimed to compare the quality of tea waste generated in full fermentation (raw Pu-erh tea, ripen Pu-erh tea and Anhua dark tea) and non-fermentation (green tea) processings in comparison with dried butterfly pea flower (DBPF) (non-Camellia sinensis). The results showed that total flavonoid (TFC) was found to be the highest in raw Pu-erh tea at 474.470 ± 47.173 mg RE/g, followed by ripened Pu-erh tea, green tea, Anhua dark tea, and DBPF, respectively. Similarly, raw Pu-erh tea also had the highest total phenolic (TPC) at 608.090 ± 2.795 mg GAE/g, followed by green tea, Anhua dark tea, ripen Pu-erh tea, and DBPF, respectively. On the other hand, total polysaccharides (TPS) content in DBPF was the highest among samples, whereas that of raw Pu-erh tea was the lowest. According to the HPLC analysis, caffeine (CF) was the major catechin found in all types of tea waste and the total catechin content was in the order of raw Pu-erh > ripen Pu-erh tea > green tea > Anhua dark tea which was in agreement with the TPC results. However, the types of catechin were different in each sample. It is noteworthy that there was no CF in DBPF, and major catechin found in DBPF was catechin gallate. Likewise, antioxidant ability determined by DPPH was the most superior in raw Pu-erh tea, followed by green tea, ripen Pu-erh tea, Anhua dark tea and DBPF, respectively. ORAC antioxidant capacity was highest in the green tea, while that in raw Pu-erh tea, ripen Pu-erh tea and Anhua dark tea was lower but not significantly different, as expected, DBPF possessed the lowest ORAC antioxidant capacity. Finally, it can be said that the potential for tea waste to be a valuable source of antioxidants varies depending on the tea processing, and the plant variety also had an impact on the characteristics of the tea samples.

Hyperspectral guidance for summer tea processing: Enhancing taste and aroma through short‐term cycled heaping

AbstractTo reduce the unpleasant flavor in tea infusion made from summer fresh leaves and lessen tea resource wastage, a short‐term cycled heaping method, addressing the temperature/moisture variations during prolonged heaping, was introduced to produce high‐quality yellow tea with significantly enhanced taste and aroma. Furthermore, a hyperspectral approach was developed to anticipate such improvements. Specifically, short‐term cycled heaping reduced summer tea's astringency and bitterness while increasing sweetness. Using near‐infrared spectroscopy, the multiplicative scatter correction (MSC)–support vector machine (SVM) model predicted tea umami with 66.25% precision and richness with 77.64% accuracy via standard normal variate (SNV)–SVM, based on epigallocatechin (EGC), epicatechin (EC), and gallocatechin gallate (GCG) variations. Aroma enhancement was forecasted by a hyperspectral–electronic nose regression model, achieving over 81.50% prediction accuracy for summer tea aromas in the visible spectrum and surpassing 73.45% in the near‐infrared domain, primarily attributed to pentanal, propanal, toluene, ethyl propionate, and 2,3‐pentanedione variations. Overall, hyperspectral‐guided summer tea processing, particularly for summer‐harvested leaves, shows potential in offering a valuable screening tool, enhancing quality, and efficiency in the tea industry and promoting sustainable development.

An in-silico approach - molecular docking analysis of flavonoids against GSK-3β and TNF-α targets in Alzheimer’s disease

Introduction Drug development for Alzheimer’s disease has one of the greatest failure rates of any therapeutic field and AD is still incurable. Glycogen synthase kinase-3β is a critical enzyme implicated in the pathogenesis of AD, particularly in the hyperphosphorylation of tau protein, which leads to the formation of neurofibrillary tangles. TNF-α also plays a significant role in the pathogenesis of Alzheimer’s disease by promoting neuroinflammation, contributing to the formation of amyloid plaques and neurofibrillary tangles, impairing synaptic function, and disrupting the balance of neurotrophic factors. Phytomedicine has numerous advantages over synthetic medications, acting multiple mode of action, including being less toxic and having fewer adverse effects. Flavonoids act as a promising therapeutic target for treating Alzheimer’s disease. The present work investigates the anti-AD potentials of 35 flavonoids for the inhibition of GSK-3β and TNF-α. Methods The physicochemical, pharmacokinetic parameters, toxicity profile and drug-likeliness of the selected 35 flavonoids were predicted using SwissADME & OSIRIS data Warrier property explorer web tool. All flavonoids were selected for docking studies on GSK-3β and TNF-α protein using Autodock 4.2.1. Results The predictions of this study suggested that among the selected 35 flavonoids, Top 3 flavonoids, such as Epicatechin gallate −10.93 kcal/mol, Fisetin −9.44 kcal/mol and Eriodictyol −8.54 kcal/mol for GSK-3β targets. TNF-α Fisetin −11.52 kcal/mol, Sterubin −10.87 kcal/mol, Biochainin A −10.69 kcal/mol were compared with standard drug donepezil. Conclusion Therefore, these flavonoids could be utilized as possible leads for the structure-based design in the advancement of new, strong Anti-Alzheimer’s agents. However, more invitro and invivo analyses are required to finally confirm the outcomes of this research.

Inhibitory Effect and Mechanism of Epigallocatechin Gallate on the Differentiation of 3T3-L1 Preadipocytes.

Green tea possesses a range of beneficial effects, including anti-obesity, antioxidant, and anti-inflammatory properties, owing to its biologically active components, primarily catechins such as epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin gallate (EGCG). However, few studies have investigated the four catechin monomers simultaneously, and the molecular mechanisms of their anti-obesity effects have not been fully elucidated. In this study, we investigated the effects of four catechin monomers on the differentiation of 3T3-L1 preadipocytes of mice. Our findings demonstrated that four catechin monomers EC/ECG/EGC/EGCG (12, 25, 50 µM) dose-dependently inhibited the differentiation of 3T3-L1 preadipocytes and reduced triglyceride content. EGCG exhibited the most potent inhibitory effect with an optimal concentration of 50 µM. In addition, transcriptome sequencing and lipidomic analysis of EGCG-treated 3T3-L1 preadipocytes revealed that Ptgs2 and Pim1 were the most differentially expressed genes involved in regulating adipocyte differentiation. The results suggested that EGCG up-regulated the expression of the Pla2g2e gene and down-regulated the expression of the Pla2g4a and Pla2g2a genes via the glycerophospholipid metabolic pathway, which subsequently elevated lysophosphatidylcholine (LPC) levels, influencing the differentiation process of 3T3-L1 preadipocytes.

DkDTX1/MATE1 mediates the accumulation of proanthocyanidin and affects astringency in persimmon.

Proanthocyanidins (PAs) is a kind of polyphenols widely distributed in plants, and their astringent properties can protect plants from herbivores and regulate fruit taste. There is a great difference in PA composition between astringent (A)-type and nonastringent (NA)-type persimmon. Here, we studied the potential of DkDTX1/MATE1 in regulating PAs composition through its preferred transport in persimmon fruit. The results of fluorescence microscope showed that the DkDTX1/MATE1 green fluorescence overlapped with the blue light emitted by PA. Overexpression of DkDTX1/MATE1 in persimmon leaves not only significantly increase the concentrations of PA, but also upregulated the expression of PA biosynthesis pathway genes. Further overexpression of DkDTX1/MATE1 in persimmon fruit discs and stable genetic transformation of DkDTX1/MATE1 also led to PA concentrations increased. Molecular docking and transporter assays showed that DkDTX1/MATE1 preferentially transported catechin, epicatechin gallate and epigallocatechin gallate. DkDTX1/MATE1 mainly bound to the PA precursors via serine at position 68. Our findings indicate that DkDTX1/MATE1 play a role in the accumulation of PAs in early stage of fruit development and affects the astringency of persimmon through preferential transport PA precursors, which provided a theoretical basis for the future use of metabolic engineering to regulate the composition of PAs in persimmon.

Evaluation of the effects of storage time and temperature on the beverages

Beverages are an important part of the food sector their storage is also one of the most critical issues. This study investigated the effects of different storage temperatures and times on physicochemical properties, flavonoid and organic acid contents of soda, sherbet and ice tea produced by adding sour grape concentrate. Changes in the flavan-3-ol content of ice tea were also measured during the storage period. The beverages were stored in three different conditions, cold storage (~4°C), room temperature (~24°C) and controlled storage (20±1°C), for six months and analyzed every two months. Storage temperatures and time affected the total soluble solids and acidities of the beverages (p≤0.05). Tartaric acid decreased during storage, especially during the first two months in sherbets. Ice tea and soda drinks were found more stable than sherbets. The malic acid was found the major organic acid in beverages. Flavonoid content in ice tea was higher than others. The flavonoid concentrations of ice tea stored at 20 and 24°C and of sherbet at 4°C were statistically significant as a function of storage time while these values were not significant for ice tea stored at 4°C and of sherbet at 20 and 24°C (p≤0.05). Concentrations of flavan-3-ols varied with storage conditions. The levels of epicatechin, epigallocatechin and epigallocatechin gallate in ice tea samples decreased between an average of 43.72 and 71.15% at the end of six months of storage. Principal component analysis separated two months storage from other storage periods and perfectly discriminated the studied flavan-3-ols except catechin. Soluble solid and brix-acid ratio also dissociated similarly to flavan-3-ols.

Extraction effects of eight deep eutectic solvents on dianhong black tea: From chemical composition analysis to antioxidant and α-glucosidase inhibitory assessments

Deep eutectic solvent (DES) has been widely developed and applied in extracting the functional components of teas, however, few studies devoted to revealing the composition differences of tea extracts obtained with DES. The present study aims to study the chemical composition and bioactive differences of Dianhong congou black tea extracts prepared by eight choline chloride (ChCl)-based DES. In addition, D-101 macroporous resin was used to remove DES for bioactivity analysis. High performance liquid chromatography (HPLC) and LC-mass spectrometry (LC-MS) were applied to quantitatively and qualitatively analyze chemical composition differences of DES extracts before and after DES removal. Quantitative results showed that DES4 (composed of ChCl and ethylene glycol) was suitable for extracting catechins (e.g., the extracted level of epicatechin gallate was 8.75 mg/g), theaflavins (theaflavin-3,3′-digallate, 1.59 mg/g), and monosaccharides (glucose, 4.97 mg/g), meanwhile DES5 (composed of ChCl and glycerol) was proved to be effective for extracting free amino acids (with highest level of theanine, 19.72 mg/g). LC-MS based metabolomics results showed that DES2 (ChCl-citric acid), DES3 (ChCl-proline), and DES4 had considerable remaining amounts of flavonoid glycosides, theasinensins, and hydrolysable tannins after DES removal. Although purified DES5 extract contained a comparable amount of these marker compounds to other purified DES extracts, its antioxidant and α-glucosidase inhibitory activities were the lowest among others. Combining results from above, DES4 was proved to be the optimum solvent for extracting functional components of Dianhong congou black tea. The finding provided basis for the application of DES extraction method in tea science.

Protective effects of catechin (C) and epigallocatechin gallate (EGCG) against high-fat diet (HFD)-exacerbated Salmonella infection in mice

Salmonella is one of the most prevalent foodborne pathogens. This study investigated the impact of HFD on Salmonella infection and the preventive effects of tea-derived polyphenols. Results showed that HFD decreased the survival rate of Salmonella-infected mice, while catechin (C) and epigallocatechin gallate (EGCG) supplementation increased survival rates, with EGCG being more effective. HFD promoted pro-inflammatory cytokines and inhibited intestinal epithelial barrier proteins, but catechins, especially EGCG, restored these levels. 16S rDNA sequencing revealed HFD-induced gut microbiota disruptions. Both catechins altered bacterial composition and diversity, with distinct profiles for C and EGCG. The relative abundance of Desulfovibrio and the Eubacterium coprostanoligenes group was modulated by both catechins, and nine bacteria were identified as biomarkers for EGCG treatment. In summary, Salmonella infection is exacerbated by HFD, but catechins, particularly EGCG, offer protective effects, providing valuable insights for controlling pathogenic infections by tea polyphenols or related functional foods.

Oxidation characteristics of catechins in suspended fermentation of different varieties’ tea leaves

This study focused on the efficiency of enzymatic synthesis for theaflavins (TFs) and SII types of thearubigins (SII-TRs) in suspended fermentation of different varieties of tea leaves. The results showed that the content of catechins in tea variety-Xiaoxianghong 21–3 (XXH21–3) was the highest among the five kinds of fresh tea leaves, and it had the strongest ability of transforming catechins to TFs and SII-TRs. The total amount of catechins for XXH 21–3 decreased rapidly and the conversion ratio of TFs reached the highest level of 13.96 % after 20 min, the residual catechins was the lowest (3.27 %) and the conversion rate of SII-TRs was the highest (13.02 %) after 120 min during the suspended fermentation of five varieties tea leaves. Among six types of catechins, epicatechin gallate (ECG), epigallocatechin gallate (EGCG) and epigallocatechin (EGC) were consumed in large quantities, and the residues were all less than 5 % in the final stage of fermentation, of which ECG consumption was the fastest, followed by EGCG. These results demonstrated that the concentration of catechins and PPO activities were positively correlated with the formation of TFs and SII-TRs, POD activity was positive correlation with synthesis of SII-TRs and negative correlation with TFs.

Enhancing catechins, antioxidant and sirtuin 1 enzyme stimulation activities in green tea extract through pulse electric field-assisted water extraction: Optimization by response surface methodology approach

Green tea is an economic resource in Thailand because it is derived from smallholder agriculture and has expanded into food production. The purpose of this study is to optimize the parameters of pulsed electric field (PEF) assisted green tea extraction to produce a natural health product. A central composite design was involved to determine the effect of independent variables, including the intensity of electric field (I; 3–5 kV/cm), number of pulses (Np; 1000 to 3000 pulses) and green tea-to-water ratio (GT/W; 0.05–0.15 g/mL) on catechin (C), epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC) and epigallocatechin gallate (EGCG), total phenolic compound, antioxidant and sirtuin 1 enzyme stimulating activities. The results indicated that the Np had the most significant impact (p < 0.05) on the content of catechin and its derivatives and sirtuin 1 enzyme stimulating activity. The observations revealed that the I had a greater impact on antioxidant activities compared to the Np. The optimal conditions for PEF using the response surface method were determined to be I of 5 kV/cm, Np of 3000 pulses, GT/W of 0.14 g/mL and specific energy of 27 kJ/kg. Under the optimized conditions, the content of C, EC, ECG, EGC and EGCG were 7.34 ± 0.33, 11.26 ± 0.25, 3.75 ± 0.13, 7.53 ± 0.77 and 37.78 ± 0.58 mg/g extract, respectively. Furthermore, it was observed that green tea extract exhibited the ability to modulate the deacetylation activity of the sirtuin 1 enzyme, with a value of 22.63 ± 0.17 FIR. The results emphasized that the PEF led to achieving better responses compared to without pre-treatment using the PEF. Therefore, innovative technologies as PEF can be utilized for green tea extraction to produce natural ingredients, which can contribute to improved accessibility to healthcare. Additionally, the implementation of innovation techniques, such as PEF, in the extraction industry can enhance productivity growth and economic development.

Exploration of the flavor diversity of oolong teas: A comprehensive analysis using metabolomics, quantification techniques, and sensory evaluation

The taste profile of oolong tea is intricately shaped by origins and roasting. Herein, a comprehensive approach integrating non-targeted metabolomics, quantitative analysis and sensory evaluations was employed to analyze the taste profile of oolong tea. 25 selected representative oolong teas, including Southern Fujian (MN), Northern Fujian (MB), and Taiwan (TW), were meticulously were classified into SX-RG-DD, GS, and TGY based on the chemical taste phenotypes. A total of 314 non-volatile compounds were identified, among which 87 and 77 compounds, including catechin, theaflavins, flavonoids and amino acids were screened as critical taste metabolites responsible for regions and roasting degree, respectively. The reduction of bitter and astringent, coupled with the enhancement of umami, sweet and sweet aftertaste exhibited a correlation with the decrease in (−)-epigallocatechin (EGC), (−)-epicatechin (EC), (−)-epicatechin gallate (ECG) and (−)-epigallocatechin gallate (EGCG), while the increase in catechin (C). These findings provide insights for further research on optimizing tea quality and refining processing techniques.

Structure-dependent capacity of procyanidin dimers to inhibit inflammation-induced barrier dysfunction in a cell model of intestinal epithelium

Diet is of major importance in modulating intestinal inflammation, as the gastrointestinal tract is directly exposed to high concentrations of dietary components. Procyanidins are flavan-3-ol oligomers abundant in fruits and vegetables. Although with limited or no intestinal absorption, they can have GI health benefits which can promote overall health. We previously observed that epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) dimers inhibit in vitro colorectal cancer cell proliferation and invasiveness. Inflammation-mediated intestinal barrier permeabilization can result in a chronic inflammatory condition and promote colorectal cancer onset/progression. Thus, this study investigated the structure-dependent capacity of ECG, EGCG and (−)-epicatechin (EC) dimers to inhibit tumor necrosis factor alpha (TNFα)-induced inflammation, oxidative stress, and loss of barrier integrity in Caco-2 cells differentiated into an intestinal epithelial cell monolayer. Cells were incubated with TNFα (10 ng/ml), in the absence/presence of ECG, EGCG and EC dimers. The three dimers inhibited TNFα-mediated Caco-2 cell monolayer permeabilization, modulating events involved in the loss of barrier function and inflammation, i.e. decreased tight junction protein levels; increased matrix metalloproteinases expression and activity; increased NADPH oxidase expression and oxidant production; activation of the NF-κB and ERK1/2 pathways and downstream events leading to tight junction opening. For some of these mechanisms, the galloylated ECG and EGCG dimers had stronger protective potency than the non-galloylated EC dimer. These differences could be due to differential membrane interactions as pointed out by molecular dynamics simulation of procyanidin dimers-cell membrane interactions and/or by differential interactions with NOX1. Results show that dimeric procyanidins, although poorly absorbed, can promote health by alleviating intestinal inflammation, oxidative stress and barrier permeabilization.

Mechanism of the wine pomace tannin in hyperpigmentation inhibition: Impact on signaling pathways, cell proliferation, and tyrosinase activity

After winemaking, tannins with high polymerization remain in the pomace. Utilizing these tannin fractions is a concern for the wine industry. While tannins show potential in treating hyperpigmentation, their mechanisms in vivo and at the cellular level are unclear. Herein, pomace tannin fractions (PTFs) were isolated post-winemaking. Nuclear magnetic resonance spectroscopy and mass spectrometry analysis showed PTFs were composed of (epi)catechin gallate and (epi)catechin as terminal and extensional units, with polymerization degrees of 10, 16, and 35. In vivo studies demonstrated that PTFs removed ∼76 % of skin melanin, comparable to hydroquinone. The inhibition by PTFs is due to: (1) Inhibition of the Wnt and melanogenesis pathways, downregulating key melanin synthesis proteins (TYR, TYRP1, TYRP2); (2) Inducing cell cycle arrest at the G1/S checkpoint, disrupting DNA, decreasing mitochondrial membrane potential and integrity, and slowing melanocyte proliferation; (3) Superior tyrosinase inhibitory activity by binding to tyrosinase, chelating copper ions, and demonstrating antioxidant properties. These findings suggest that PTFs inhibit melanin synthesis by the combination of the above mentioned ways, supporting the medical use of winemaking tannins.

Seasonal dynamics of phytometabolites content in Assam tea, Camellia sinensis var. assamica by LC-MS/MS: Implications for quality

The study examines the seasonal variation in phytometabolite content in Camellia sinensis var. assamica, a prevalent tea variety in Northeast India. Focusing on both bud and dormant leaf (banjhi) samples harvested during the monsoon, autumn, and winter seasons, the research aims to assist cultivators in selecting optimal harvesting times for tea production. An LC-MS/MS method was developed and validated for phytometabolite quantification. Epigallocatechin gallate (EGCG) emerged as the most abundant catechin, with concentrations ranging from 78.01±13.31–125.21±5.65 µg/mg in buds during the monsoon and decreasing to 17.86±1.22–51.11±1.21 µg/mg in winter. Banjhi leaves exhibited even higher EGCG levels, from 203.86±21.06–312.58±28.23 µg/mg in the monsoon, dropping to 74.43±15.22–97.52±8.47 µg/mg in autumn. Similarly, epicatechin gallate concentrations in buds ranged from 17.04±2.57–24.78±1.15 µg/mg in the monsoon and decreased to 5.36±0.39–11.16±1.74 µg/mg in winter, while banjhi leaves showed a decline from 63.61±1.60–72.72±1.23 µg/mg in the monsoon, dropping to 12.73±2.07–15.35±1.33 µg/mg in autumn. The study also noted seasonal variations in catechin hydrate, caffeine, gallic acid, theanine, and theaflavin. These findings underscore the importance of harvest timing for maintaining tea quality and optimizing cultivation and processing practices for sustainability amid environmental changes.

Optimization of the Search for Neuroprotectors among Bioflavonoids.

For the first time, to optimize the creation of new neuroprotective agents based on bioflavonoids, we applied information technologies; these include docking analysis to calculate the binding of candidate molecules to the pharmacological target protein transthyretin as well as a program of virtual screening of NO scavengers. As a result of this approach, the substance catechin was isolated from candidate molecules-quercetin, catechin, Epicatechin gallate, Epicatechin, Procyanidin B1, Procyanidin B2, Procyanidin B3, and Catechin-3-gallate-according to docking analysis. As a result of virtual screening, catechin was identified as a potential NO scavenger (55.15% prediction). The results of the prediction were confirmed by in vitro experiments. Course administration of catechin to animals with experimental multiple sclerosis (MS) against the background of methylprednisolone administration completely eliminated lethal cases, reduced the number of diseased animals by 20% as well as prevented the development of severe neurological symptoms by 20% (compared to the methylprednisolone group) and by 60% compared to the control group. Course administration of catechin with methylprednisolone leads to a decrease in the neurodegradation markers in the cytosol of rats, with EAE: NSE by 37% and S-100 by 54.8%. The combined administration of methylprednisolone significantly exceeds the combination of methylprednisolone with the reference drug mexidol by the degree of NSE reduction. The obtained results indicate a significant neuroprotective effect of ocular combinations of methylprednisolone and catechin. The above-mentioned confirms the correctness of the bioflavonoid selection with the help of a virtual screening program.

LC-MS and GC–MS based metabolomics analysis revealed the impact of tea trichomes on the chemical and flavor characteristics of white tea

To explore the influence of tea trichomes on the quality of white tea, liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS), and headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC–MS) were used to identify non-volatile and volatile compounds white tea without trichomes (WTwt) and pure trichomes (PT). It was found that the bitter and astringent compounds, caffeine (CAF), epigallocatechin gallate (EGCG), epicatechin gallate (ECG) and flavonol glycosides, were mainly enriched in the WTwt, with 16.3-fold, 47.1-fold and 28.7-fold decrease in CAF and EGCG and ECG, respectively, and the content of these compounds in PT were lower than the taste thresholds. In PT, kaempferol-3-O-(p-coumaroyl)-glucoside and kaempferol-3-O-(di-p-coumaroyl)-glucoside were non-volatile marker compounds, and decanal was significant aroma contributor with rOAV = 250.86. Moreover, the compounds in trichomes mainly contributed to the fruity and floral aroma of white tea, among which benzyl alcohol, (E)-geranylacetone, decanal, dodecanal and 6-methyl-5-hepten-2-one were the crucial aroma components, which were 2.1, 1.7, 1.8, 1.4 and 2.2 times as much as the WTwt in the PT, respectively. In conclusion, trichomes can improve the quality of white tea by reducing the bitterness and astringency, increasing the umami, as well as enhancing the fruity and floral aromas.

Enhancing the flavor profile of strong-flavored green tea from Sichuan: Evaluation and optimization study

This study evaluated seven taste subfactors of 64 green teas from Sichuan province and categorized them into three types: fresh and mellow (FM), strong and thick (ST), and fresh and strong (FS). The FM-type showed excellent freshness and sweetness, while the ST-type exhibited bitterness, astringency, and strength. Component analysis showed higher water extract and tea polyphenols in the ST-type, with the soluble sugar content correlating positively with taste strength but not sweetness, highlighting the complexity of flavor perception. More exhaustively, we used targeted metabolomics to examine the relevant constituent fractions. The levels of epigallocatechin gallate, epicatechin gallate, epigallocatechin, epicatechin, dihydromyricetin and rutin were highest in ST, and positively correlated with bitterness and astringency. Umami amino acids were found mostly in FM, and were positively correlated with freshness. To optimize the taste quality of ST green tea, two methods were investigated: tea bag confinement leaching and aroma enhancement. Both methods effectively reduced bitterness and astringency. Tea bag confinement leaching can be widely applied to enhance the utilization of summer tea raw materials and elevate the sensory quality of middle- and low-grade green teas. While promising for seasoned tea flavor enhancement and bitter suppression, the aroma enhancement technique requires further research.

β-Cyclodextrin and Hyaluronic Acid-Modified Targeted Nanodelivery System for Atherosclerosis Prevention.

Natural products have been widely recognized in clinical treatment because of their low toxicity and high activity. It is worth paying attention to modifying the biopolymer into nanostructures to give natural active ingredients additional targeting effects. In this study, based on the multifunctional modification of β-cyclodextrin (β-CD), a nanoplatform encapsulating the unstable drug (-)-epicatechin gallate (ECG) was designed to deliver to atherosclerotic plaques. Acetalization cyclodextrin (PH-CD), which responds to low-pH environments, and hyaluronic acid cyclodextrin, which targets the CD44 receptor on macrophage membranes, were synthesized from β-CD and hyaluronic acid using acetalization and transesterification, respectively. The resulting dual-carrier nanoparticles (Double-NPs) loaded with ECG were prepared using a solvent evaporation method. The Double-NPs effectively scavenged reactive oxygen species, promoted macrophage migration, inhibited macrophage apoptosis, and suppressed abnormal proliferation and migration of vascular smooth muscle cells. Furthermore, the Double-NPs actively accumulated in atherosclerotic plaques in ApoE-/- mice fed with a high-fat diet, leading to a reduced plaque area, inflammatory infiltration, and plaque instability. Our findings demonstrate that the newly developed ECG nanopreparation represents an effective and safe nanotherapy for diseases such as atherosclerosis.