A novel optimized eco-friendly simple spectrofluorimetric method for the determination of total catechins in green tea extract: Application to commercial tablet.

Green tea extract (GTE) contains antioxidants that are present in green tea. The active constituents of green tea extract are catechins. This study demonstrates a spectrofluorimetric method for measuring GTE's catechin concentration based on its native fluorescence. To design a quick, sensitive, and ecological spectrofluorimetric approach, all features were investigated and adjusted. This method relies on determining the GTE ethanolic solution's native fluorescence at 312 nm after excitation at 227 nm. The calibration graph displayed a linear regression for values between 0.05 and 1.0 µg mL-1. The detection and quantification limits of the proposed technique were 0.008 and 0.026 µg mL-1, respectively. Two pure catechins present in GTE, (-)-epicatechin and (-)-epigallocatechin gallate, were examined by the proposed method. The analytical estimation of GTE in the pharmaceutical tablet was achieved effectively using this approach. An adequate degree of agreement was found when the findings were compared to those obtained by the comparative technique. Therefore, the novel strategy may be used in the GTE quality control study with minimal risks to people or the environment. The quantum yields of catechins were estimated. The validated technique was accepted by the International Council of Harmonization criteria.

Effects of post-fermentation addition of green tea extract for sulfur dioxide replacement on Sauvignon Blanc wine phenolic composition, antioxidant capacity, colour, and mouthfeel attributes.

This study examines the feasibility of replacing SO2 in a New Zealand Sauvignon Blanc wine with a green tea extract. The treatments included the control with no preservatives (C), the addition of green tea extract at 0.1 and 0.2 g/L (T1 and T2), and an SO2 treatment at 50 mg/L (T3). Five monomeric phenolic compounds were detected in the green tea extract used for the experiment, and their concentrations ranged in the order (-)-epigallocatechin gallate > (-)-epigallocatechin > (-)-epicatechin > (-)-epicatechin gallate > gallic acid. At the studied addition rates, these green tea-derived phenolic compounds contributed to ∼70% of the antioxidant capacity (ABTS), ∼71% of the total phenolic index (TPI), and âˆ¼ 84% of tannin concentration (MCPT) of the extract dissolved in a model wine solution. Among wine treatments, T1 and T2 significantly increased the wine's colour absorbance at 420 nm, MCPT, gallic acid and total monomeric phenolic content. TPI and ABTS were significantly higher in wines with preservatives (i.e., T2 > T1 â‰… T3 > C, p < 0.05). These variations were observed both two weeks after the treatments and again after five months of wine aging. Additionally, an accelerated browning test and a quantitative sensory analysis of wine colour and mouthfeel attributes were performed after 5 months of wine aging. When exposed to excessive oxygen and high temperature (50 °C), T1 and T2 exhibited ∼29% and 24% higher browning capacity than the control, whereas T3 reduced the wine's browning capacity by ∼20%. Nonetheless, the results from sensory analysis did not show significant variations between the treatments. Thus, using green tea extract to replace SO2 at wine bottling appears to be a viable option, without inducing a negative impact on the perceptible colour and mouthfeel attributes of Sauvignon Blanc wine.

Effect of marinating with green tea extract on the safety and sensory profiles of oven-baked oyster.

Baked oyster is a popular seafood dish around the world. The present study investigated the effect of various concentrations of a green-tea extract (GTE) marinade on the safety and sensory profiles of oysters baked for different durations. The results showed 10 g/L of GTE and 10-min baking time was the optimal combination, as supported by significantly attenuated lipid oxidation (35.29 %) and Nε-(carboxyethyl)lysine (CEL) content (48.51 %) without appreciable negative impact on the sensory or nutritional quality of the oysters. However, high concentrations of the marinade or prolonged baking promoted protein oxidation and Nε-(carboxymethyl)lysine (CML) formation likely through the pro-oxidative action of the GTE phytochemicals. Correlation analysis further revealed the main factors that affected CML, CEL, and fluorescent AGEs generation, respectively. These findings provide theoretical support for the protective effect and mechanism of GTE against quality deterioration of baked oysters and would help broaden the application of GTE in the food industry.

Amelioration of Functional, Metabolic, and Morphological Deterioration in the Retina following Retinal Detachment by Green Tea Extract.

Retinal detachment (RD) can result in the loss of photoreceptors that cause vision impairment and potential blindness. This study explores the protective effects of the oral administration of green tea extract (GTE) in a rat model of RD. Various doses of GTE or epigallocatechin gallate (EGCG), the most active ingredient in green tea catechins, were administered to Sprague Dawley (SD) rats with experimentally induced retinal detachment. The rats received sub-retinal injections of hyaluronic acid (0.1%) to induce RD and were given different doses of GTE and EGCG twice daily for three days. Notably, a low dose of GTE (142.9 mg/kg) caused significantly higher signal amplitudes in electroretinograms (ERGs) compared to higher GTE doses and any doses of EGCG. After administration of a low dose of GTE, the outer nuclear layer thickness, following normalization, of the detached retina reduced to 82.4 ± 8.2% (Mean ± SEM, p < 0.05) of the thickness by RD treatment. This thickness was similar to non-RD conditions, at 83.5 ± 4.7% (Mean ± SEM) of the thickness following RD treatment. In addition, the number of TUNEL-positive cells decreased from 76.7 ± 7.4 to 4.7 ± 1.02 (Mean ± SEM, p < 0.0001). This reduction was associated with the inhibition of apoptosis through decreased sphingomyelin levels and mitigation of oxidative stress shown by a lowered protein carbonyl level, which may involve suppression of HIF-1α pathways. Furthermore, GTE showed anti-inflammatory effects by reducing inflammatory cytokines and increasing resolving cytokines. In conclusion, low-dose GTE, but not EGCG, significantly alleviated RD-induced apoptosis, oxidative stress, inflammation, and energy insufficiency within a short period and without affecting energy metabolism. These findings suggest the potential of low-dose GTE as a protective agent for the retina in RD.

CdAl4O7/CdO nanocomposites: green tea extract-mediated sol-gel auto-combustion synthesis, characterization, and study as a potential hydrogen storage material.

In this article, we present the synthesis of binary CdAl4O7/CdO nanocomposites using green tea extracts and green chemistry methods for high-performance hydrogen storage. The green tea extract contains bioactive compounds (polyphenols) that act as reducing agents, which facilitate the reaction between metal ions and water. By examining the structural and morphological characteristics of the obtained substrates using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR), it was demonstrated that the nanocomposites were successfully synthesized. We evaluated the electrochemical performance of the synthesized CdAl4O7/CdO nanocomposites using a three-electrode chronopotentiometry system. According to the results, the synthesized nanocomposites are capable of storing 1750 mAh/g of hydrogen at a constant current of 1 Amp. By using green tea extract as a natural structure-directing agent, the CdAl4O7/CdO nanocomposite can be developed more sustainably as high-performance hydrogen storage materials. Ultimately, this work contributes to the advancement of sustainable energy storage through the synthesis of a promising new material.

Effects of adding green tea extract on the oxidative stability and shelf life of sunflower oil during storage.

This study aimed to compare different concentrations effect of green tea extract (GTE) (200, 400, and 800 ppm) with TBHQ (75 ppm) in extend the shelf-life of sunflower oil (SO) and to evaluate the protective effect of GTE on the oxidation of refined SO. The sample's peroxide value (PV), acidity value (AV), anisidine value (pAV), Totox value (TV), oxidative stability, and total phenol content (TPC) were analyzed at specific intervals during 12-month at 25 °C and 60-day at 60 °C. The optimum kinetic model corresponding to the first order for PV, TV, and pAV was obtained at 25, 35, and 45 °C. SO containing GTE (800 ppm) had a similar performance to TBHQ at 25 °C and 60 °C and possessed a longer shelf life than samples treated with TBHQ. Due to synthetic antioxidant's health risk and toxicity, GTE can be a good substitute for TBHQ in the edible oil industry.

Combined treatment of human mesenchymal stem cells and green tea extract on retinal ganglion cell regeneration in rats after optic nerve injury.

Retinal ganglion cell (RGC) death and axonal loss cause irreversible vision loss upon optic nerve (ON) injury. We have independently demonstrated that mesenchymal stem cells (MSCs) and green tea extract (GTE) promote RGC survival and axonal regeneration in rats with ON injury. Here we aimed to evaluate the combined treatment effect of human bone marrow-derived MSCs (hBM-MSCs) and GTE on RGC survival and axonal regeneration after ON injury. Combined treatment of hBM-MSCs and GTE promoted RGC survival and neurite outgrowth/axonal regeneration in ex vivo retinal explant culture and in rats after ON injury. GTE increased Stat3 activation in the retina after combined treatment, and enhanced brain-derived neurotrophic factor secretion from hBM-MSCs. Treatment of 10 µg/mL GTE would not induce hBM-MSC apoptosis, but inhibited their proliferation, migration, and adipogenic and osteogenic differentiation in vitro with reducing matrix metalloproteinase secretions. In summary, this study revealed that GTE can enhance RGC protective effect of hBM-MSCs, suggesting that stem cell priming could be a prospective strategy enhancing the properties of stem cells for ON injury treatment.

Antimicrobial and antioxidant activity of encapsulated tea polyphenols in chitosan/alginate-coated zein nanoparticles: a possible supplement against fish pathogens in aquaculture.

Regulation of antibiotic use in aquaculture calls for the emergence of more sustainable alternative treatments. Tea polyphenols (GTE), particularly epigallocatechin gallate (EGCG), have various biological activities. However, tea polyphenols are susceptible to degradation. In this work, EGCG and GTE were encapsulated in zein nanoparticles (ZNP) stabilized with alginate (ALG) and chitosan (CS) to reduce the degradation effect. ALG-coated ZNP and ALG/CS-coated ZNP encapsulating EGCG or GTE were obtained with a hydrodynamic size of less than 300 nm, an absolute ζ-potential value >30 mV, and an encapsulation efficiency greater than 75%. The antioxidant capacity of the encapsulated substances, although lower than that of the free ones, maintained high levels. On the other hand, the evaluation of antimicrobial activity showed greater efficiency in terms of growth inhibition for ALG/CS-ZNP formulations, with average overall values of around 60%, reaching an inhibition of more than 90% for Photobacterium damselae. These results support encapsulation as a good strategy for tea polyphenols, as it allows maintaining significant levels of antioxidant activity and increasing the potential for antimicrobial activity, in addition to increasing protection against sources of degradation.

The effects of green tea extract supplementation on body composition, obesity-related hormones and oxidative stress markers: a grade-assessed systematic review and dose-response meta-analysis of randomised controlled trials.

Research indicates that green tea extract (GTE) supplementation is beneficial for a range of conditions, including several forms of cancer, CVD and liver diseases; nevertheless, the existing evidence addressing its effects on body composition, oxidative stress and obesity-related hormones is inconclusive. This systematic review and meta-analysis aimed to investigate the effects of GTE supplementation on body composition (body mass (BM), body fat percentage (BFP), fat mass (FM), BMI, waist circumference (WC)), obesity-related hormones (leptin, adiponectin and ghrelin) and oxidative stress (malondialdehyde (MDA) and total antioxidant capacity (TAC)) markers. We searched proper databases, including PubMed/Medline, Scopus and Web of Science, up to July 2022 to recognise published randomised controlled trials (RCT) that investigated the effects of GTE supplementation on the markers mentioned above. A random effects model was used to carry out a meta-analysis. The heterogeneity among the studies was assessed using the I2 index. Among the initial 11 286 studies identified from an electronic database search, fifty-nine studies involving 3802 participants were eligible to be included in this meta-analysis. Pooled effect sizes indicated that BM, BFP, BMI and MDA significantly reduced following GTE supplementation. In addition, GTE supplementation increased adiponectin and TAC, with no effects on FM, leptin and ghrelin. Certainty of evidence across outcomes ranged from low to high. Our results suggest that GTE supplementation can attenuate oxidative stress, BM, BMI and BFP, which are thought to negatively affect human health. Moreover, GTE as a nutraceutical dietary supplement can increase TAC and adiponectin.

Enhancing dentin bonding through new adhesives formulations with natural polyphenols, tricalcium phosphate and chitosan.

OBJECTIVES: The aim of the study was to develop new adhesive formulations that include natural polyphenols extracted from green tea (GTE), tricalcium phosphate (TCP) and chitosan to improve dentin bonding characteristics and cytotoxicity. METHODS: Four experimental adhesives were formulated under laboratory conditions. The groups differed in the integration of either GTE and/or TCP + chitosan. The four experimental and one clinically proven reference adhesive underwent shear bond testing after 24 h and 6 months of aging (n = 200) with subsequent fractographic analysis. Bond morphology was analyzed under a scanning electron microscope. The presence of phenolic compounds was validated by high performance liquid chromatography. Cytotoxicity was assessed by the WST-1 colorimetric assay on eluates up to 6 months. Statistical analysis was performed by one- and three-way ANOVA, Games-Howell and Tukey's post-hoc test as well as multiple students t-tests (α = 0.05). Weibull analysis was further conducted. RESULTS: The addition of GTE into the bonding agent did show immediate (p = 0.023, p = 0.013) and long-term (p < 0.001) effects on bond strength. After 24 h, GTE doped groups performed equal to the reference (p = 0.501, p = 0.270) and TCP and chitosan displayed improvements in reliability (m=4.0, m=4.3). Bond strength is retained after aging by adding GTE (p = 0.983). The additional presence of TCP and chitosan reduces it (p = 0.026). Excluding cohesive and mixed failures, the reference adhesive performed statistically equal to three of the four experimental groups. No long-term cytotoxic effects were shown. SIGNIFICANCE: The integration of GTE can enhance bond strength and a calcium source helps to improve immediate bond reliability.

Antioxidants green tea extract and nordihydroguaiaretic acid confer species and strain-specific lifespan and health effects in Caenorhabditis nematodes.

The Caenorhabditis Intervention Testing Program (CITP) is an NIH-funded research consortium of investigators who conduct analyses at three independent sites to identify chemical interventions that reproducibly promote health and lifespan in a robust manner. The founding principle of the CITP is that compounds with positive effects across a genetically diverse panel of Caenorhabditis species and strains are likely engaging conserved biochemical pathways to exert their effects. As such, interventions that are broadly efficacious might be considered prominent compounds for translation for pre-clinical research and human clinical applications. Here, we report results generated using a recently streamlined pipeline approach for the evaluation of the effects of chemical compounds on lifespan and health. We studied five compounds previously shown to extend C. elegans lifespan or thought to promote mammalian health: 17α-estradiol, acarbose, green tea extract, nordihydroguaiaretic acid, and rapamycin. We found that green tea extract and nordihydroguaiaretic acid extend Caenorhabditis lifespan in a species-specific manner. Additionally, these two antioxidants conferred assay-specific effects in some studies-for example, decreasing survival for certain genetic backgrounds in manual survival assays in contrast with extended lifespan as assayed using automated C. elegans Lifespan Machines. We also observed that GTE and NDGA impact on older adult mobility capacity is dependent on genetic background, and that GTE reduces oxidative stress resistance in some Caenorhabditis strains. Overall, our analysis of the five compounds supports the general idea that genetic background and assay type can influence lifespan and health effects of compounds, and underscores that lifespan and health can be uncoupled by chemical interventions.

Dual action of epigallocatechin-3-gallate in virus-induced cell Injury.

BACKGROUND: Viral infections cause damage and long-term injury to infected human tissues, demanding therapy with antiviral and wound healing medications. Consequently, safe phytochemical molecules that may control viral infections with an ability to provide wound healing to viral-induced tissue injuries, either topically or systemically, are advantageous. Herein, we hypothesized that epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea, might be effective as a wound healing, antiviral, and antifibrotic therapy. RESULTS: The antiviral activities of EGCG against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Herpes simplex virus type 2 (HSV-2) as well as its wound healing activities against different monolayer tissue (continuous and primary) systems were investigated. Consider its possible wound-healing advantages as well. To determine the safe concentrations of EGCG in green monkey kidney (Vero) and Vero-E6 cell lines, MTT assay was performed and showed high CC50 values of 405.1 and 322.9 µM, respectively. The antiviral activities of EGCG against SARS-CoV-2 and HSV-2, measured as half-maximal concentration 50 (IC50) concentrations, were 36.28 and 59.88 µM, respectively. These results confirm that the EGCG has remarkable viral inhibitory activities and could successfully suppress the replication of SARS-CoV-2 and HSV-2 in vitro with acceptable selectivity indices (SI) of 11.16 and 5.39, respectively. In parallel, the EGCG exhibits significant and dose/time-dependent anti-migration effects in human breast cancer cells (MCF-7), its resistant variation (MCF-7adr), and human skin fibroblast (HSF) indicating their potential to heal injuries in different internal and topical mammalian systems. CONCLUSIONS: The EGCG has proven to be an efficient antiviral against SARS-CoV-2 and HSV-2, as well as a wound-healing phytochemical. We assume that EGCG may be a promising option for slowing the course of acute cellular damage induced by systemic (Coronavirus Disease 2019 (COVID-19)) or topical (HSV-2) viral infections.

Green tea extract improves cyclophosphamide-induced immunosuppression in mouse spleen and enhances the immune activity of RAW 264.7 cells.

Cyclophosphamide (CP) is mainly used to treat autoimmune diseases and cancer; however, it damages normal immune cells. Therefore, the effects of chemotherapy on CP are limited. Notably, green tea has been reported to effectively modulate immune function. Here, given the pharmacological properties of green tea, we evaluated the ability of green tea extract (GTE) to restore immunity suppressed by CP in vivo and to activate macrophages in vitro. GTE significantly improved the suppressed immune function, including spleen index and proliferation of spleen T lymphocytes, as revealed by histopathological examination and flow cytometry analysis. Moreover, GTE effectively activated RAW 264.7, as represented by the induction of nitric oxide, reactive oxygen species, and cytokine levels. GTE also increased the phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B in RAW 264.7 cells. In conclusion, GTE ameliorated CP-induced immunosuppression in mice and stimulated immune activity in RAW 264.7 cells, possibly by activating the MAPK signaling pathway. These findings suggest that GTE has the potential to be used as a supplementary agent in chemotherapy for CP.

A comparative study on feeding timing and additive types of broilers in a high-temperature environment.

Antioxidants such as vitamin C (VC) and green tea extract (GTE) have been reported to have various antioxidant functions and are used as one of the nutritional approaches to alleviate heat stress (HS) in chickens. However, studies on the feeding timing that can produce optimal effects have not been reported. In this study, the stress-relieving effect of VC and GTE addition timing was investigated in high-temperature broiler chickens. A total of 880 1-d-old male chickens were used, and the treatments were as follows: no feed additives provided, CON; VC 250 mg/kg added from 1 d, VC1; GTE 600 mg/kg added from 1 d, GTE1; VC 250 mg/kg added from 22 d, VC22; GTE 600 mg/kg added from 22 d, GTE22. The HS environment was provided for 2 wk from the 22 d and was set at 33 ± 1 °C, 55 ± 10% for 24 h. Feed and water were provided ad libitum. Broiler production was similar in all treatments. In chicken meat quality, the addition of VC and GTE had an effect on meat color and pH (P < 0.05). In particular, GTE had a positive effect on the antioxidant capacity and quality preservation of breast meat (P < 0.05). In blood characteristics, GTE1 significantly lowered the level of total cholesterol, and VC1 affected AST and IgM (P < 0.05). Interestingly, the VC1 group had a positive effect on the maintenance and development of intestinal morphology, a lower rectal temperature, and showed to relieve stress. In conclusion, the addition of VC and GTE has been shown to alleviate the high-temperature stress of broilers, and in the case of VC in particular, feeding from 1 d appeared to alleviate stress more effectively. This study suggests that it is important to determine the appropriate timing of addition of functional substances in order to effectively reduce various stresses that occur in livestock rearing.

The increasing frequency of exposure to high-temperature environments has prompted research into nutritional approaches to alleviate heat stress in chickens, but little research has been reported on feeding timing. The aim of this study was to determine the effect of feeding timing on the effectiveness of the natural antioxidants vitamin C (VC) and green tea extract (GTE). Production was similar among all treatments, and GTE fed from 1 d of age increased antioxidant capacity, including DPPH, FRAP, and MDA in carcass quality. VC fed from 1 d of age decreased AST and increased IgM in the blood, and increased villus height (VH), with a positive effect on intestinal development. In conclusion, feeding VC and GTE from 1 d of age has been shown to effectively alleviate stress by increasing antioxidant capacity in breast meat, positively changing total cholesterol, AST, and IgM in the blood, and maintaining intestinal morphology, and it is important to set the timing of feeding to increase the effectiveness of the additives.

The effects of Ascophyllum nodosum, Camellia sinensis-leaf extract, and their joint interventions on glycolipid and energy metabolism in obese mice.

Objectives: Obesity is often associated with glucolipid and/or energy metabolism disorders. Ascophyllum nodosum extract (seaweed extract, SE) and Camellia sinensis-leaf extract (tea extract, TE) have been reported to promote positive metabolic effects through different mechanisms. We investigated the effects of SE and TE on metabolic homeostasis in diet-induced obese mice and discussed their functional characteristics. Methods: Male C57BL/6J mice fed with high-fat diets for 8 weeks were established as obese models and subsequently divided into different intervention groups, followed by SE, TE, and their joint interventions for 10 weeks. Body weight and food intake were monitored. Fasting glucose and oral glucose tolerance tests were interspersed during the experiment. After the intervention, the effects on obesity control were assessed based on body composition, liver pathology section, blood lipids and glucose, respiratory exchange ratio (RER), energy expenditure (EE1, EE2, and EE3), inflammatory factors, lipid anabolism enzymes, and gut flora of the obese mice. Results: After continuous gavage intervention, the mice in the intervention groups exhibited lower body weight (lower ~4.93 g, vs. HFD 38.02 g), peri-testicular fat masses (lower ~0.61 g, vs. HFD 1.92 g), and perirenal fat masses (lower ~0.21 g, vs. HFD mice 0.70 g). All interventions prevented diet-induced increases in plasma levels of glucose, adiponectin, leptin, and the inflammatory factors IL-1ß and TNF-α. The RER was modified by the interventions, while the rhythm of the RER was not. Blood lipids (total cholesterol, triglycerides, and LDL) decreased and were associated with lower lipid anabolism enzymes. In addition, the SE and TE interventions altered the structure and abundance of specific flora. Different interventions inhibited the growth of different genera positively associated with obesity (Escherichia-Shigella, Helicobacter, etc.) and promoted the growth of Akkermansia and Bacteroides, thus affecting the chronic inflammatory state. Conclusion: SE and TE both have synergistic effects on weight control and glucolipid metabolism regulation by improving insulin sensitivity and reducing lipid synthesis-related enzyme expression, whereas the combination of SE and TE (3:1) has a better effect on regulating energy metabolism and inhibiting chronic inflammation.

Synergistic Effects of Heat-Treated Green Tea Extract and Enzymatically-Modified Isoquercitrin in Preventing Obesity.

Previous research has shown that both heat-treated green tea extract (HTGT) and enzymatically modified isoquercitrin (EMIQ) have anti-obesity effects. Given the absence of in vivo evidence demonstrating their synergistic effects, our study aimed to elucidate the combined obesity prevention potential of HTGT and EMIQ in mice. Mice were treated with these compounds for 8 weeks, while being fed a high-fat diet, to investigate their preventive anti-obesity effects. We demonstrated that the co-treatment of HTGT and EMIQ results in a synergistic anti-obesity effect, as determined by a Kruskal-Wallis test. Furthermore, the combined treatment of HTGT and EMIQ was more effective than orlistat in reducing body weight gain and adipocyte hypertrophy induced by high-fat diet. The co-treatment also significantly reduced total body fat mass and abdominal fat volume. Additionally, the group receiving the co-treatment exhibited increased energy expenditure and higher glucose intolerance. We observed a dose-dependent upregulation of genes associated with mitochondrial oxidative metabolism and PKA signaling, which is linked to lipolysis, in response to the co-treatment. The co-treatment group displayed elevated cAMP levels and AMPK activation in adipose tissue and increased excretion of fecal lipids. The results indicate that the co-treatment of HTGT and EMIQ holds the potential to be a promising combination therapy for combating obesity. To further validate the anti-obesity effect of the combined treatment of HTGT and EMIQ in human subjects, additional clinical studies are warranted.

A Preliminary Study on the Release of Bioactive Compounds from Rice Starch Hydrogels Produced by High-Pressure Processing (HPP).

This work aimed to carry out a preliminary study on the release of bioactive compounds loaded into starch-based hydrogels produced by high-pressure processing (HPP). As a study case, the experiments were carried out on rice starch HPP hydrogels. Rice starch (20% w/w) and green tea extract (2% w/w), suspended in distilled water, were treated by HPP at processing conditions enabling starch gelatinisation, namely 600 MPa for 15 min at room temperature. Additional experiments were carried out on samples that were further loaded with glycerol (5% w/w). Gel formation was assessed by analysing the gelatinisation extent, structuring level, and swelling power of the samples. At the processing conditions utilised, stable hydrogels were obtained even in the presence of the extract and/or the glycerol in the starch suspension. As expected, the colour of the hydrogels formed was affected by the addition of green tea extract in the starch solution. HPP starch hydrogels were characterised by Fourier transform infrared spectroscopy (FT-IR) to determine the interactions between the different compounds utilised in the formulation. Moreover, the release kinetics of bioactive compounds from HPP rice starch hydrogels was evaluated using a vertical Franz diffusion cells system, simulating a transdermal pattern. The diffusion of bioactive compounds was measured spectrophotometrically and via HPLC analysis. A controlled release of bioactive compounds from the hydrogel structure was detected, suggesting that small molecules, such as polyphenols, positively interacted with the rice starch HPP hydrogel network that allowed a smooth and constant release of these bioactive compounds over time.

Green tea and tulsi extracts as efficient green corrosion inhibitor for aluminum alloy in alkaline medium.

Corrosion is a major issue in every industrial system. As a result of its widespread application, aluminum suffers enormous annual losses due to corrosion. Scientists are continually on the lookout for effective anti-corrosion strategies. Corrosion may be reduced in a number of ways, but many of them are harmful to the environment, so it's important to find a green alternative. Corrosion inhibitors in aluminum alloys can be found in green tea and tulsi extract. In this research, we found that aluminum alloy 1100 (Al-1100) ina 10% NaOH solution was inhibited by both green tea and Tulsi extract. Samples of AL alloy are submerged in 10% NaOH solutions with and without an inhibitor for a total of 25 days. The weight-loss technique is used to determine the effectiveness of an inhibitor, with tulsi extract far outperforming green tea with the best efficiency of 83.93% compared to the greatest efficiency of 14.29% for green tea. After being submerged in an inhibitory solution, an aluminum alloy surface developed an adsorbed protective layer, which is chemical adsorption, as seen by FTIR (Fourier-Transform Infrared Spectroscopy) spectroscopy. Green inhibitors those are present on the surface of the aluminum alloys are less corrosive confirmed by the SEM (Scanning Electron Microscopy) analysis. The chemical particles were found to be present as a coating over AL alloy surfaces, as determined by EDS (Energy Dispersion Spectroscopy) testing. In a10% NaOH solution, Al-1100 is inhibited more effectively by tulsi extracts than by green tea extracts.

Disinfection of Clostridioides difficile on spinach with epigallocatechin-based antimicrobial solutions and sodium hypochlorite.

The removal of C. difficile inoculated on fresh spinach leaves washed with antimicrobial solutions was investigated. In addition, the effect of washing solutions on the total aerobic mesophilic bacteria (TAMB) and Enterobacteriaceae in the fresh spinach was examined. The fresh spinach was washed through immersion in different concentrations (MIC, 2xMIC, and 4xMIC) of the natural disinfectant solution (NDS) consisting of EDTA, borax, and epigallocatechin gallate (EGCG) content developed in our laboratory and green tea extract-acetic acid (GTE-AA) for varying contact times (5 and 15 min). Different concentrations (50, 100, and 200 ppm) of sodium hypochlorite (NaOCl) and tap water as the control group were used to compare the effectiveness of the NDS. In addition, the effects of washing on the color, texture, and total phenol content of the spinach were determined. No statistical difference was observed in the washing of the spinach leaves with NDS prepared at 2xMIC and 4xMIC concentrations, while inhibition of C. difficile ranged between 2.11 and 2.32 logs. The highest inhibition was observed in the application of 50 ppm NaOCl for 15 min with a decrease of 2.88 logs in C. difficile spores. The GTE-AA and NDS decreased the number of TAMB by 2.27-3.08 log and, 3.21-3.66 log, respectively. Washing spinach leaves with natural disinfectant for 5 min caused a decrease of 2.58 logs in Enterobacteriaceae load, while washing with 50 ppm NaOCl for 15 min reduced Enterobacteriaceae load by 4 logs. Tap water was ineffective in reducing any microbial load. No difference was detected in the color parameters of the spinach through all washes. Although all antimicrobial washes made a difference in the texture of the spinach, the greatest loss in firmness was observed in the spinach washed with NaOCl. Washing spinach with epigallocatechin-based wash solutions can remove C. difficile in possible C. difficile contamination, thereby reducing the environmental load of C. difficile. Epigallocatechin-based disinfectants can be an alternative to chlorine-based disinfectants in improving the microbial quality of vegetables.

Green tea extract supplementation does not modify plasma concentration of F2-isoprostanes in women who are postmenopause: Findings from a randomized controlled trial.

Green tea extract (GTE) is a potential mitigator of oxidative stress, and F2-isoprostanes are a reliable biomarker of oxidative stress. Genetic polymorphisms in the catechol-o-methyltransferase (COMT) gene may modify tea catechin metabolism, prolonging exposure. We hypothesized that GTE supplementation would decrease plasma F2-isoprostanes concentrations compared with placebo and that participants with the COMT genotype polymorphisms would experience a more significant expression of this outcome. This study was a secondary analysis of the Minnesota Green Tea Trial, a randomized placebo-controlled, double-blinded trial investigating the effects of GTE in women who were generally healthy and postmenopausal. The treatment group consumed 843 mg of epigallocatechin gallate daily for 12 months versus placebo. Participants in this study had a mean age of 60 years, were predominantly White, and most had a healthy body mass index. GTE supplementation did not significantly change plasma F2-isoprostanes concentrations compared with placebo after 12 months (P for overall treatment = .07). There were no significant interactions between treatment and age, or body mass index, physical activity, smoking history, and alcohol intake. COMT genotype did not modify the effect of GTE supplementation on F2-isoprostanes concentrations in the treatment group (P = .85). Among participants in the Minnesota Green Tea Trial, consuming GTE supplements daily for 1 year did not result in a significant decrease in plasma F2-isoprostanes concentrations. Likewise, the COMT genotype did not modify the effect of GTE supplementation on F2-isoprostanes concentrations.