Ultraviolet B (UVB) Photosensitivities of Tea Catechins and the Relevant Chemical Conversions

Stabilization of Picea abies Spruce Bark Extracts within Ice-Templated Porous Dextran Hydrogels

Porous hydrogels have brought more advantages than conventional hydrogels when used as chromatographic materials, controlled release vehicles for drugs and proteins, matrices for immobilization or separation of molecules and cells, or as scaffolds in tissue engineering. Polysaccharide-based porous hydrogels, in particular, can address challenges related to bioavailability, solubility, stability, and targeted delivery of natural antioxidant compounds. Their porous structure enables the facile encapsulation and controlled release of these compounds, enhancing their therapeutic effectiveness. In this context, in the present study, the cryogelation technique has been adopted to prepare novel dextran (Dx)-based porous hydrogels embedding polyphenol-rich natural extract from Picea abies spruce bark (SBE). The entrapment of the SBE within the Dx network was proved by FTIR, SEM, and energy-dispersive X-ray spectroscopy (EDX). SEM analysis showed that entrapment of SBE resulted in denser cryogels with smaller and more uniform pores. Swelling kinetics confirmed that higher concentrations of Dx, EGDGE, and SBE reduced water uptake. The release studies demonstrated the effective stabilization of SBE in the Dx-based cryogels, with minimal release irrespective of the approach selected for SBE incorporation, i.e., during synthesis (~3-4%) or post-synthesis (~15-16%). In addition, the encapsulation of SBE within the Dx network endowed the hydrogels with remarkable antioxidant and antimicrobial properties. These porous biomaterials could have broad applications in areas such as biomedical engineering, food preservation, and environmental protection, where stability, efficacy, and safety are paramount.

The multifaceted effects of flavonoids on neuroplasticity

There has been a significant increase in the incidence of multiple neurodegenerative and terminal diseases in the human population with life expectancy increasing in the current times. This highlights the urgent need for a more comprehensive understanding of how different aspects of lifestyle, in particular diet, may affect neural functioning and consequently cognitive performance as well as in enhancing overall health. Flavonoids, found in a variety of fruits, vegetables, and derived beverages, provide a new avenue of research that shows a promising influence on different aspects of brain function. However, despite the promising evidence, most bioactive compounds lack strong clinical research efficacy. In the current scoping review, we highlight the effects of Flavonoids on cognition and neural plasticity across vertebrates and invertebrates with special emphasis on the studies conducted in the pond snail, Lymnaea stagnalis, which has emerged to be a functionally dynamic model for studies on learning and memory. In conclusion, we suggest future research directions and discuss the social, cultural, and ethnic dependencies of bioactive compounds that influence how these compounds are used and accepted globally. Bridging the gap between preclinical and clinical studies about the effects of bioactive natural compounds on brain health will surely lead to lifestyle choices such as dietary Flavonoids being used complementarily rather than as replacements to classical drugs bringing about a healthier future.

Evaluation of the mineral composition, phytochemical and proximate constituents of three culinary spices in Nigeria: a comparative study

Spices are prolific sources of phytochemicals of pharmaceutical and nutritional importance. They have been employed for centuries in the treatment of various maladies, in cuisines, and as inhibitors of oxidative degradation in foods. On this premise, a comparative assessment of the quantitative mineral composition, phytochemical and proximate constituents of Xylopia aethiopica (fruits), Piper guineense (seeds), and Rhaphiostylis beninensis (roots) was done using standard protocols. Subsequently, methanol extracts of the spices were subjected to Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Mineral analysis of the culinary spices revealed significant differences (p < 0.05) in the spices' magnesium, zinc, iron, selenium, copper, calcium, manganese, molybdenum, potassium, and sodium contents. In the phytochemical analysis, flavonoids, phenols, and alkaloids (4.04%, 2.92%, 2.23%) predominate in X. aethiopica. Similarly, proximate analysis shows a preponderance of carbohydrates (81.24%) and proteins (4.83%) in R. beninensis and P. guineense respectively. However, values for the selenium (0.25 mg/L), saponin (0.23%), and moisture (0.71%) contents for R. beninensis were the lowest among the three spices. Results from the GC-MS analysis revealed the presence of thirteen, twelve, and thirteen phytoconstituents of X. aethiopica, P. guineense, and R. beninensis respectively. Prominent among them are hydrocarbons, acids, and esters with renowned biological attributes such as antioxidant, antimicrobial and anti-inflammatory. These findings indicate that the spices are notable wellsprings of bioactive components and justify their plethoric applications in Nigeria. Therefore, they could serve as lead compounds in the search for natural ingredients for drugs and nutraceuticals formulation.

Assessment of Cosmetic and Dermatological Properties and Safety of Use of Model Skin Tonics with Kombucha-Fermented Red Berry Extracts

Kombucha is a health-promoting beverage that is produced by fermenting sweetened tea using symbiotic cultures of bacteria belonging to the genus Acetobacter, Gluconobacter, and yeast of the genus Saccharomyces. This study compared the cosmetic and dermatological properties of the extracts of the following redberries: R. rubrum, F. vesca, and R. idaeus, and their ferments, which were obtained by fermentation for 10 and 20 days using tea fungus. For this purpose, the fermented and non-fermented extracts were compared in terms of their chemical composition using the HPLC/ESI-MS chromatographic method, demonstrating the high content of biologically active compounds that were present in the ferments. The antioxidant activity of the tested samples was evaluated using DPPH and ABTS tests, as well as by evaluating the scavenging of the external and intracellular free radicals. The cytotoxicity of the extracts and the ferments, as well as the cosmetic formulations, were also determined by conducting Alamar Blue and Neutral Red tests assessing the cell viability and metabolism using skin cell lines: fibroblasts and keratinocytes. In addition, application tests were conducted showing the positive effects of the model cosmetic tonics on the TEWL, the skin hydration, and the skin pH. The results indicate that both the extracts and the ferments that were obtained from kombucha can be valuable ingredients in cosmetic products.

Chemical and mechanical accelerated and long-term stability evaluation of sunscreen formulation containing grape seed extract

BACKGROUND

Sunscreens and catechins from grape seed extract (GSE) are sensitive to various environmental factors and undergo certain changes over time that might affect the effectiveness of the final product. To this date, effects of thermal storage conditions have not been sufficiently addressed to guarantee the long-term stability of sunscreen formulations.

AIMS

To study the chemical and mechanical accelerated and long-term stability of sunscreen formulation containing GSE at the Climatic Zone IVb conditions.

METHODS

Stability studies were performed for 6 months for accelerated stability study at 30°C ± 2 and 50°C ± 2, 75 ± 5% relative humidity; and long-term stability study at 5°C ± 5. The quantification of constituents of three formulations: sunscreen with GSE, cream with UV filters only, and cream with GSE only was performed by high-performance liquid chromatography. In vitro spectrophotometry was used to determine changes in sun protection effectiveness through SPF and UVAPF values. Mechanical stability was evaluated by textural and rheological analyzes.

RESULTS

All tested formulations were less stable at high-temperature conditions. The contents of catechin (С) and epicatechin (EC) in sunscreen with GSE were reduced to 37% and 50% at 50°C, respectively, whereas UV filters appeared to be stable. However, despite the significant reduction in catechins over time, polyphenols in GSE remained unchanged at different stored conditions. The SPF values and water resistance of sunscreen with GSE were maintained throughout the study.

CONCLUSIONS

A current in vitro study has shown that sunscreen with GSE is a value-added anti-aging ingredient in sunscreen formulation because its polyphenolic composition as well as SPF values and water resistance were maintained under all temperature conditions over time.

LC-HRMS-Based Profiling: Antibacterial and Lipase Inhibitory Activities of Some Medicinal Plants for the Remedy of Obesity

Globally, obesity is a serious health concern that causes numerous diseases, including type 2 diabetes, hypertension, cardiovascular diseases, etc. Medicinal plants have been used to aid in weight loss since ancient times. Thus, this research is focused on the exploration of pancreatic lipase inhibitory activity and secondary metabolite profiling of Bergenia ciliata, Mimosa pudica, and Phyllanthus emblica, selected based on an ethnobotanical survey. The lipase inhibition was investigated using 4-nitrophenyl butyrate (p-NPB) as a substrate. To uncover further therapeutic potentials of these medicinal plants, antimicrobial activity and minimum inhibitory concentration (MIC) of the extracts were also determined. The ethyl acetate plant extracts showed higher antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Shigella sonnei. The MIC of ethyl acetate extracts of medicinal plants considered in this study ranges from 1.56 to 6.25 mg/mL. The hexane fraction of Mimosa pudica and Phyllanthus emblica showed a higher lipase inhibitory activity as compared to others, with IC50 values of 0.49 ± 0.02 and 2.45 ± 0.003 mg/mL, respectively. In the case of Bergenia ciliata, the methanolic extract inhibited lipase more effectively than others, with an IC50 value of 1.55 ± 0.02 mg/mL (IC50 value of orlistat was 179.70 ± 3.60 µg/mL). A mass spectrometry analysis of various solvent/solvent partition fractions (extracts) revealed 29 major secondary metabolites. The research offers a multitude of evidence for using medicinal plants as antiobesity and antimicrobial agents.

Dual functions of epigallocatechin gallate surface-modified Au nanorods@selenium composites for near-infrared-II light-responsive synergistic antibacterial therapy

Diseases caused by bacterial infections pose ever-increasing threats to human health, making it important to explore alternative antibacterial strategies. Herein, epigallocatechin gallate (EGCG) surface-modified Au nanorods@selenium composites (ASE NPs) were developed for synergistic NIR-II light-responsive antibacterial therapy. In vitro antibacterial experiments demonstrated the improved antibacterial effect of ASE NPs against Staphylococcus aureus (S. aureus) compared with EGCG alone. In addition, in vivo studies demonstrated that ASE NPs cured skin wound infections and sepsis in mice caused by S. aureus. Au nanorods with excellent photothermal conversion realized synergistic photothermal therapy (PTT) in the NIR-II biowindow with an improved penetration depth at a low power density. More importantly, toxicity analysis showed that the composites had no toxic effects on major organs. Thus, the EGCG surface-modified Au nanorods@selenium composites with an NIR-II light-responsive synergistic activity hold great promise for the effective treatment of drug-resistant bacterial infections.

Chemical and Skincare Property Characterization of the Main Cocoa Byproducts: Extraction Optimization by RSM Approach for Development of Sustainable Ingredients

Methylxanthines and polyphenols from cocoa byproducts should be considered for their application in the development of functional ingredients for food, cosmetic and pharmaceutical formulations. Different cocoa byproducts were analyzed for their chemical contents, and skincare properties were measured by antioxidant assays and anti-skin aging activity. Musty cocoa beans (MC) and second-quality cocoa beans (SQ) extracts showed the highest polyphenol contents and antioxidant capacities. In the collagenase and elastase inhibition study, the highest effect was observed for the SQ extract with 86 inhibition and 36% inhibition, respectively. Among cocoa byproducts, the contents of catechin and epicatechin were higher in the SQ extract, with 18.15 mg/100 g of sample and 229.8 mg/100 g of sample, respectively. Cocoa bean shells (BS) constitute the main byproduct due to their methylxanthine content (1085 mg of theobromine and 267 mg of caffeine/100 g of sample). Using BS, various influencing factors in the extraction process were investigated by response surface methodology (RSM), before scaling up separations. The extraction process developed under optimized conditions allows us to obtain almost 2 g/min and 0.2 g/min of total methylxanthines and epicatechin, respectively. In this way, this work contributes to the sustainability and valorization of the cocoa production chain.

LC-HRMS Profiling and Antidiabetic, Antioxidant, and Antibacterial Activities of Acacia catechu (L.f.) Willd

Acacia catechu (L.f.) Willd is a profoundly used traditional medicinal plant in Asia. Previous studies conducted in this plant are more confined to extract level. Even though bioassay-based studies indicated the true therapeutic potential of this plant, compound annotation was not performed extensively. This research is aimed at assessing the bioactivity of different solvent extracts of the plant followed by annotation of its phytoconstituents. Liquid chromatography equipped with high resolution mass spectrometry (LC-HRMS) is deployed for the identification of secondary metabolites in various crude extracts. On activity level, its ethanolic extract showed the highest inhibition towards α-amylase and α-glucosidase with an IC₅₀ of 67.8 ± 1 μg/mL and 10.3 ± 0.1 μg/mL respectively, inspected through the substrate-based method. On the other hand, the plant extract showed an antioxidant activity of 23.76 ± 1.57 μg/mL, measured through radical scavenging activity. Similarly, ethyl acetate and aqueous extracts of A. catechu showed significant inhibition against Staphylococcus aureus with a zone of inhibition (ZoI) of 13 and 14 mm, respectively. With the LC-HRMS-based dereplication strategy, we have identified 28 secondary metabolites belonging to flavonoid and phenolic categories. Identification of these metabolites from A. catechu and its biological implication also support the community-based usage of this plant and its medicinal value.

Bioactive Films from Willow Bark Extract and Nanocellulose Double Network Hydrogels

In nature, the protection of sensitive components from external threats relies on the combination of physical barriers and bioactive secondary metabolites. Polyphenols and phenols are active molecules that protect organisms from physical and chemical threats such as UV irradiation and oxidative stress. The utilization of biopolymers and natural bioactive phenolic components as protective coating layers in packaging solutions would enable easier recyclability of materials and greener production process compared with the current plastic-based products. Herein, we produce a fully wood-based double network material with tunable bioactive and optical properties consisting of nanocellulose and willow bark extract. Willow bark extract, embedded in nanocellulose, was cross-linked into a polymeric nanoparticle network using either UV irradiation or enzymatic means. Based on rheological analysis, atomic force microscopy, antioxidant activity, and transmittance measurements, the cross-linking resulted in a double network gel with enhanced rheological properties that could be casted into optically active films with good antioxidant properties and tunable oxygen barrier properties. The purely biobased, sustainably produced, bioactive material described here broadens the utilization perspectives for wood-based biomass, especially wood-bark extractives. This material has potential in applications where biodegradability, UV shielding, and antioxidant properties of hydrogels or thin films are needed, for example in medical, pharmaceutical, food, and feed applications, but also as a functional barrier coating in packaging materials as the hydrogel properties are transferred to the casted and dried films.

Reactivity of flavanols: Their fate in physical food processing and recent advances in their analysis by depolymerization

Flavanols, a subgroup of polyphenols, are secondary metabolites with antioxidant properties naturally produced in various plants (e.g., green tea, cocoa, grapes, and apples); they are a major polyphenol class in human foods and beverages, and have recognized effect on maintaining human health. Therefore, it is necessary to evaluate their changes (i.e., oxidation, polymerization, degradation, and epimerization) during various physical processing (i.e., heating, drying, mechanical shearing, high-pressure, ultrasound, and radiation) to improve the nutritional value of food products. However, the roles of flavanols, in particular for their polymerized forms, are often underestimated, for a large part because of analytical challenges: they are difficult to extract quantitatively, and their quantification demands chemical reactions. This review examines the existing data on the effects of different physical processing techniques on the content of flavanols and highlights the changes in epimerization and degree of polymerization, as well as some of the latest acidolysis methods for proanthocyanidin characterization and quantification. More and more evidence show that physical processing can affect content but also modify the structure of flavanols by promoting a series of internal reactions. The most important reactivity of flavanols in processing includes oxidative coupling and rearrangements, chain cleavage, structural rearrangements (e.g., polymerization, degradation, and epimerization), and addition to other macromolecules, that is, proteins and polysaccharides. Some acidolysis methods for the analysis of polymeric proanthocyanidins have been updated, which has contributed to complete analysis of proanthocyanidin structures in particular regarding their proportion of A-type proanthocyanidins and their degree of polymerization in various plants. However, future research is also needed to better extract and characterize high-polymer proanthocyanidins, whether in their native or modified forms.

Photolysis kinetics of cartap and nereistoxin in water and tea beverages under irradiation of simulated sunlight and ultraviolet under laboratory conditions

Cartap applied widely in agricultural crops and tea plants is readily degraded into nereistoxin, resulting in a longer residual period and higher exposure risk to humans. The photolysis kinetics of cartap and nereistoxin in water and tea beverages was firstly investigated to explore the effect and mechanism of pesticide residue removal. Cartap and nereistoxin could be effectively photolyzed by ultraviolet and their photolysis rate increased with light intensity increasing. The photolysis percentage of cartap and nereistoxin in different solutions under ultraviolet irradiation of 200 W mercury lamp reached 81.8%-100.0% within 6 h. Relative to water solution, the water-soluble components in tea had an inhibition effect on the photodegradation of cartap and nereistoxin. This research provided a reference for the development of effective methods for the removal of cartap and its metabolite in water and tea beverages.

A Study of Catechin Photostability Using Photolytic Processing

Catechin exhibits numerous physiological characteristics. In this study, we determined the photosensitivity of catechin to various lights under alkaline conditions, and the mechanisms by which catechin generates free radical species and polymerizes via a photoreaction. In addition to this, the application of catechin photolysis was investigated. A solution of catechin is transparent, but turns yellowish under blue light illumination (BLI) in neutral or weak alkaline solutions. When catechin is subjected to BLI, a dimeric catechin (proanthocyanidin) and a superoxide anion radical (O2•−) are generated in a photolytic reaction. When ascorbic acid or gallic acid is added to catechin and the mixture is subjected to BLI at alkaline pH, fewer catechin dimers and less O2•− are produced, because both acids inhibit the photosensitive oxidation of catechin. When AlCl3 is added to catechin and the mixture is subjected to BLI at pH 8, a photolytic reaction is suppressed by AlCl3, and AlCl3 acts as a catalyst for the disconnection of proanthocyanidin during photolysis. Under alkaline conditions, catechin generates O2•− via photosensitive oxidation, which suppresses the growth of Acinetobacter baumannii (A. baumannii) by at least 4 logs, and deactivates its multi-drug-resistant strain. This study shows that catechin photolysis is a process of oxidation, and that it can be safely applied as a tool for environmental applications.

Catechin Photolysis Suppression by Aluminum Chloride under Alkaline Conditions and Assessment with Liquid Chromatography-Mass Spectrometry

Tea is rich in catechins and aluminum. In this study, the process of catechin photolysis was applied as a model for examining the effects of aluminum chloride (AlCl₃) on the structural changes of catechin and the alteration of aluminum complexes under blue light irradiation (BLI) at pH 8 using liquid chromatography and mass spectrometry techniques. Additionally, the effects of anions on catechin upon the addition of AlCl₃ and treatment with BLI were also studied. In this study, when 1 mM catechin was treated with BLI, a superoxide anion radical (O2•-) was generated in an air-saturated aqueous solution, in addition to forming a dimeric catechin (proanthocyanidin) via a photon-induced redox reaction. The relative percentage of catechin was found to be 59.0 and 95.7 for catechin treated with BLI and catechin upon the addition of 1 mM AlCl₃ treated with BLI, respectively. It suggested that catechin treated with BLI could be suppressed by AlCl₃, while AlCl₃ did not form a complex with catechin in the photolytic system. However, under the same conditions, it was also found that the addition of AlCl₃ inhibited the photolytic formation of O2•-, and reduced the generation of proanthocyanidin, suggesting that the disconnection of proanthocyanidin was achieved by AlCl₃ acting as a catalyst under treatment with BLI. The influence of 1 mM fluoride (F-) and 1 mM oxalate (C2O42-) ions on the photolysis of 1 mM catechin upon the addition of 1 mM AlCl₃ and treatment with BLI was found to be insignificant, implying that, during the photolysis of catechin, the Al species were either neutral or negatively charged and the aluminum species did not form a complex with anions in the photolytic system. Therefore, aluminum, which is an amphoteric species, has an inherent potential to stabilize the photolysis of catechin in an alkaline conditions, while suppressing the O2•- and proanthocyanidin generation via aluminum ion catalysis in the catechin/Al system under treatment with BLI.

Bio-Based Packaging Materials Containing Substances Derived from Coffee and Tea Plants

The aim of the research was to obtain intelligent and eco-friendly packaging materials by incorporating innovative additives of plant origin. For this purpose, natural substances, including green tea extract (polyphenon 60) and caffeic acid, were added to two types of biodegradable thermoplastics (Ingeo™ Biopolymer PLA 4043D and Bioplast GS 2189). The main techniques used to assess the impact of phytocompounds on materials’ thermal properties were differential scanning calorimetry (DSC) and thermogravimetry (TGA), which confirmed the improved resistance to thermo-oxidation. Moreover, in order to assess the activity of applied antioxidants, the samples were aged using a UV aging chamber and a weathering device, then retested in terms of dynamic mechanical properties (DMA), colour changing, Vicat softening temperature, and chemical structure, as studied using FT-IR spectra analysis. The results revealed that different types of aging did not cause significant differences in thermo-mechanical properties and chemical structure of the samples with natural antioxidants but induced colour changing. The obtained results indicate that polylactide (PLA) and Bioplast GS 2189, the plasticizer free thermoplastic biomaterial containing polylactide and starch (referred to as sPLA in the present article), both with added caffeic acid and green tea extract, can be applied as smart and eco-friendly packaging materials. The composites reveal better thermo-oxidative stability with reference to pure materials and are able to change colour as a result of the oxidation process, especially after UV exposure, providing information about the degree of material degradation.

Oxidation Stability: The Bottleneck for the Development of a Fully Renewable Biofuel from Wine Industry Waste

Wine industry generates a large amount of biowaste, such as grape marc and wine lees, which is considered in the Directive (EU) 2018/2001 as an adequate feedstock to produce advanced biofuels. Grapeseed oil fatty acid ethyl esters (FAEEs) can be obtained from oil extracted from grape marc and bioethanol distilled from wine lees or wine surplus. Although FAEE still has no specific standard, grapeseed oil FAEE would fulfill all of the properties set by the standard EN 14214, except oxidation stability. This work analyzes the effect of natural antioxidants on the oxidation stability of grapeseed oil FAEE, using grapeseed oil fatty acid methyl esters (FAMEs) as a reference for comparison. On the one hand, the biofuel, produced with conventional transesterification, was mixed with FAME and FAEE produced via in situ transesterification. On the other hand, antioxidants extracted from grapeseed or defatted grapeseed flour were added to the biofuel. The results show that (1) FAEE has worse oxidation stability than FAME, (2) in situ transesterification improves the oxidation stability, and (3) addition of natural antioxidants is hindered by their low solubility in alkyl esters. Finally, the concentration of antioxidants, measured by UV-vis spectroscopy, showed a correlation between the absorbance at 285 nm (characteristic of phenolic compounds) and the induction time (IT) of the samples.

Activity of catechins and their applications

Background

Catechins, which are polyphenol compounds found in many plants and are an important component of tea leaves, are strong anti-oxidants.

Research

Many studies seek to enhance the effects of catechins on the human body and boost their protective power against UV radiation. There are many examples of the positive anti-microbial, anti-viral, anti-inflammatory, anti-allergenic, and anti-cancer effects of catechins. Catechins increase the penetration and absorption of healthy functional foods and bio cosmetics into the body and the skin, thus improving their utility. High value-added anti-oxidant substances have been extracted from food and plant sludge, and experiments have shown that catechins are safe when applied to the human body. The stability of catechins is very important for their absorption into the human body and the effectiveness of their anti-oxidant properties.

Conclusion

Continued research on the strong anti-oxidant effects of catechins is expected to result in many advances in the food, cosmetics, and pharmaceutical industries.

Protective Effect of Selected Antioxidants on Naproxen Photodegradation in Aqueous Media

A photostabilization strategy is an important aspect of quality assurance for photosensitive compounds. This study focused on the photoprotective effects of selected antioxidants including the effect of L-ascorbic acid (AA) on naproxen (NX) photodegradation in aqueous media. NX degradation during ultraviolet light (UV) irradiation and the protective effects of selected antioxidants were monitored by high-performance liquid chromatography (HPLC). The addition of AA induced the suppression of NX photodegradation, although the protective effect disappeared after AA was degraded completely. The results of the evaluations on the photoprotective effects on NX photodegradation and antioxidative activities of AA and other antioxidants showed that the protective effects of antioxidants are dependent on reducing power and photostability under UV irradiation. In this experiment, quercetin (QU) is the most effective antioxidant on account of the residual rate of QU after UV irradiation and the antioxidative activity in the potential antioxidant (PAO) test was significantly higher compared to other antioxidants following the higher protective effect on NX photodegradation.

Lithium biofortification of medicinal tea Apocynum venetum

Lithium (Li) could be much safer and successful approach to supply Li via Li-fortified food products. This study is highlighting the potential scope of Li supply via Li-biofortification of Luobuma tea (made from Apocynum venetum leaves), which is a very popular beverage in Asia with several medical properties. We explored the possibility of A. venetum as Li-enriched tea and investigated plant growth, Li accumulation, total flavonoids (TFs), rutin and hyperoside concentrations, and the antioxidant capacity of A. venetum. With the increase of additional Li, Li concentration in roots, stems and leaves increased gradually. Compared with the control treatment, 10-15 mg kg^-1 Li addition stimulated the growth of A. venetum and 25 mg kg^-1 Li addition significantly increased the Li concentration in leaves by 80 mg kg^-1. Li application did not decrease TFs, rutin, hyperoside and antioxidant capacity of this medicinal herb. A daily consumption of 10 g Li-biofortified A. venetum leaves (cultivated with 25 mg kg^-1 LiCl) can give 592 μg Li intake and would constitute 59% of the provisional recommended dietary daily intake of Li. Our results showed that Li-biofortified A. venetum leaves can be used as Li-fortified tea to enhance Li supply and to improve human health when it was used as daily drink.

Effects of Ultraviolet Radiation (UV-A+UV-B) on the Antioxidant Metabolism of the Red Macroalga Species Acanthophora spicifera (Rhodophyta, Ceramiales) From Different Salinity and Nutrient Conditions

Acanthophora spicifera (M.Vahl) Børgesen is a macroalga of great economic importance. This study evaluated the antioxidant responses of two algal populations of A. spicifera adapted to different abiotic conditions when exposed to ultraviolet-A+ultraviolet-B radiation (UV-A+UV-B). Experiments were performed using the water at two collection points for 7 days of acclimatization and 7 days of exposure to UVR (3 h per day), followed by metabolic analyses. At point 1, water of 30 ± 1 practical salinity unit (psu) had concentrations of 1.06 ± 0.27 mm NH 4 + , 8.47 ± 0.01 mm NO 3 - , 0.17 ± 0.01 mm PO 4 - 3 and pH 7.88. At point 2, water of 35 ± 1 psu had concentrations of 1.13 ± 0.05 mm NH 4 + , 3.73 ± 0.01 mm NO 3 - , 0.52 ± 0.01 mm PO 4 - 3 and pH 8.55. Chlorophyll a, phycobiliproteins, carotenoids, mycosporins, polyphenolics and antioxidant enzymes (catalase, superoxide dismutase and guaiacol peroxidase) were evaluated. The present study demonstrates that ultraviolet radiation triggers antioxidant activity in the A. spicifera. However, such activation resulted in greater responses in samples of the point 1, with lower salinity and highest concentration of nutrients.

Effects of Epigallocatechin Gallate on the Stability of Epicatechin in a Photolytic Process

Catechins belonging to polyhydroxylated polyphenols are the primary compounds found in green tea. They are associated with many physiological properties. Epicatechin (EC) is a non-gallate-type catechin with four phenolic hydroxyl groups attached. The changes in EC treated with color light illumination in an alkaline condition were investigated by chromatographic and mass analyses in this study. In particular, the superoxide anion radical (O₂•^-) was investigated during the EC photolytic process. EC is unstable under blue light illumination in an alkaline solution. When EC was treated with blue light illumination in an alkaline solution, O₂•^- was found to occur via a photosensitive redox reaction. In addition, the generation of monomeric, dimeric, and trimeric compounds is investigated. On the other hand, epigallocatechin gallate (EGCG), which is a gallate-type catechin, is stable under blue light illumination in an alkaline solution. Adding EGCG, during the blue light illumination treatment of EC decreased photolytic formation, suggesting that gallate-type catechins can suppress the photosensitive oxidation of EC. Gallate-type catechins are formed via the esterification of non-gallate-type catechins and gallic acid (GA). The carbonyl group on the gallate moiety of gallate-type catechins appears to exhibit its effect on the stability against the photosensitive oxidation caused by blue light illumination.

Effects of Blue-Light-Induced Free Radical Formation from Catechin Hydrate on the Inactivation of Acinetobacter baumannii, Including a Carbapenem-Resistant Strain

Catechin is a flavan-3-ol, a derivative of flavans, with four phenolic hydroxyl groups, which exhibits a wide range of physiological properties. Chromatographic analyses were employed to examine the effects of blue light irradiation on the changes of catechin hydrate in an alkaline condition. In particular, the detection of a superoxide anion radical (O₂•⁻), a reactive oxygen species (ROS), and the inactivation of Acinetobacter baumannii (A. baumannii)—including a carbapenem-resistant A. baumannii (CRAB)—was investigated during the photoreaction of catechin hydrate. Following basification with blue light irradiation, the transparent solution of catechin hydrate turned yellowish, and a chromogenic catechin dimer was separated and identified as a proanthocyanidin. Adding ascorbic acid during the photolytic treatment of catechin hydrate decreased the dimer formation, suggesting that ascorbic acid can suppress the photosensitive oxidation of catechin. When catechin hydrate was irradiated by blue light in an alkaline solution, O₂•⁻ was produced via photosensitized oxidation, enhancing the inactivation of A. baumannii and CRAB. The present findings on the photon-induced oxidation of catechin hydrate provides a safe practice for the inactivation of environmental microorganisms.

Food-grade Encapsulation Systems for (-)-Epigallocatechin Gallate

(-)-Epigallocatechin gallate (EGCG) has attracted significant research interest due to its health-promoting effects such as antioxidation, anti-inflammation and anti-cancer activities. However, its instability and poor bioavailability have largely limited its efficacy and application. Food-grade materials such as proteins, carbohydrates and lipids show biodegradability, biocompatibility and biofunctionality properties. Food-grade encapsulation systems are usually used to improve the bioavailability of EGCG. In the present paper, we provide an overview of materials and techniques used in encapsulating EGCG, in which the adsorption mechanisms of food-grade systems during in vitro digestion are reviewed. Moreover, the potential challenges and future work using food-grade encapsulates for delivering EGCG are also discussed.

Green tea and cocoa enhance cognition in Lymnaea

A flavonoid, (-)-epicatechi (Epi), enhances long-term memory (LTM) formation in Lymnaea and reverses memory obstruction caused by stress. Many foods contain substantial amounts of Epi, (e.g. green tea and cocoa). In humans eating such foods may directly or indirectly enhance cognition. We directly test whether operant conditioning training Lymnaea in these natural foods result in the same effects as training snails in pure Epi. We found that exposure to products containing high concentrations of Epi (e.g. green tea and cocoa) during training enhanced memory formation and could even reverse a learning and memory deficit brought about by stress. Epi can be photo-inactivated by exposure to ultraviolet light. We found that following photo-inactivation of Epi, memory enhancement did not occur. Photo-inactivation of foods containing Epi (e,g. green tea) blocked their ability to enhance LTM. Our data are thus consistent with the hypothesis that dietary sources of Epi can have positive benefits on cognitive ability and be able to reverse memory aversive states.