Animal efficacy study of a plant extract complex (BEN815) as a potential treatment for COVID-19

In a short time, several types of injectable and oral therapeutics have been developed and used to effectively manage patients with coronavirus disease 2019 (COVID-19). BEN815 is an improved mixture of three extracts (Psidium guajava, Camellia sinensis, and Rosa hybrida) recognized by the Ministry of Food and Drug Safety of Korea as a health food ingredient that alleviates allergic rhinitis. The current animal efficacy study was performed to assess its probability of improving COVID-19 symptoms. BEN815 treatment significantly increased the survival of K18-hACE2 transgenic mice and reduced viral titers in the lungs at 5 days post infection (DPI). Furthermore, the lungs of the treated mice showed mild tissue damage at 5 DPI and nearly complete recovery from COVID-19 at 14 DPI. BEN815 appears to be an effective and minimally toxic anti-SARS-CoV-2 agent in mice and has potential for clinical applications.

Could Natural Products Help in the Control of Obesity? Current Insights and Future Perspectives

Obesity is a global issue faced by many individuals worldwide. However, no drug has a pronounced effect with few side effects. Green tea, a well-known natural product, shows preventive effects against obesity by decreasing lipogenesis and increasing fat oxidation and antioxidant capacity. In contrast, other natural products are known to contribute to obesity. Relevant articles published on the therapeutic effect of natural products on obesity were retrieved from PubMed, Web of Science, and Scopus. The search was conducted by entering keywords such as "obesity", "natural product", and "clinical trial". The natural products were classified as single compounds, foods, teas, fruits, herbal medicines-single extract, herbal medicines-decoction, and herbal medicines-external preparation. Then, the mechanisms of these medicines were organized into lipid metabolism, anti-inflammation, antioxidation, appetite loss, and thermogenesis. This review aimed to assess the efficacy and mechanisms of effective natural products in managing obesity. Several clinical studies reported that natural products showed antiobesity effects, including Coffea arabica (coffee), Camellia sinensis (green tea), Caulerpa racemosa (green algae), Allium sativum (garlic), combined Ephedra intermedia Schrenk, Thea sinensis L., and Atractylodes lancea DC extract (known as Gambisan), Ephedra sinica Stapf, Angelica Gigantis Radix, Atractylodis Rhizoma Alba, Coicis semen, Cinnamomi cortex, Paeoniae radix alba, and Glycyrrhiza uralensis (known as Euiiyin-tang formula). Further studies are expected to refine the pharmacological effects of natural products for clinical use.

Fluoride and Aluminium in Tea (Camellia sinensis L.)-Tea Quality Indicators and Risk Factors for Consumers

In recent years, the quality and sourcing of tea have gained importance in Europe, but information remains scarce. The aim of this study was to determine the concentrations of fluoride (F-) and total aluminium (Al) species in infusions of commercially available teas in Slovenia, and thus in Europe, and to relate them to tea quality and their impact on consumer safety. F- concentrations were determined using a fluoride-ion-selective electrode and Al concentrations using inductively coupled plasma optical emission spectroscopy. A comparison of the results obtained for four selected tea samples using the calibration curve and a standard addition technique showed good agreement, with no interferences caused by the sample matrix. The concentrations of 35 commercial teas ranged from 0.34 to 4.79 and 0.51 to 8.90 mg/L for F- and Al, respectively. The average concentrations of the two elements followed the same descending order: black filter > green filter > black leaves ≈ green leaves. Single and multivariate statistical methods supported the categorisation of teas by packaging but not by type, with tea in filter bags being more expensive than loose tea. The linear relationship between F- and Al concentrations in infusions (C(Al) = 1.2134 · C(F-)) allows for the determination of one element and estimation of the other, leading to a significant reduction in laboratory effort and cost. This research advances tea assessment by proposing Al concentration alongside F- as a quality indicator and provides the basis for tea-monitoring protocols. Finally, the daily consumption of larger quantities of tea (≈1 L) with elevated F- and Al concentrations could potentially pose a health risk.

Dissecting the role of microorganisms in tea production of different fermentation levels: a multifaceted review of their action mechanisms, quality attributes and future perspectives

Tea is one of the most popular beverages worldwide, with several health benefits attributed for its rich chemical composition and further associated with fermentation process to improve its quality attributes. Most tea types originate from the leaves of Camellia sinensis with differences in fermentation levels yielding black tea, green tea, pouchong tea, oolong tea. Teas like pu-erh or kombucha to encompass both green and red types are further post-fermented. Tea fermentation is a traditional process involving physical, biochemical, and microbial changes which are associated with improved organoleptic characters, nutritive value, and health outcomes. The production of fermented tea relies on naturally occurring enzymes and microbial metabolic activities. This review focuses on presenting a holistic overview on the effect of different microorganisms including bacteria, yeast, and fungi on the biochemical changes and sensory attributes of fermented tea products reported in research articles along the last 15 years. Moreover, production conditions and major biochemical changes are dissected to present the best factors influencing fermented tea quality. This review presents an evidence-based reference for specialists in tea industry to optimize tea fermentation process for targeted attributes.

Composite films of sodium alginate and konjac glucomannan incorporated with tea polyphenols for food preservation

At present, food waste has become a serious issue and the use of petroleum-based food packaging films has resulted in a series of potential hazards. Therefore, more attention has been focused on the development of new food packaging materials. The polysaccharide-based composite film loaded with active substances considered to be an excellent preservative material. A novel packaging film based on sodium alginate and konjac glucomannan (SA-KGM) blended with tea polyphenols (TP) was prepared in the present study. The excellent microstructure of films was shown by atomic force microscopy (AFM). It was indicated by FTIR spectra that the components could interact with each other through hydrogen bonds, which was also confirmed by molecular docking simulation. Meanwhile, the mechanical properties, barrier property, oxidation property, antibacterial activity, and stability of the structure of the TP-SA-KGM film were significantly improved. The AFM images and results of molecular docking simulation indicated that TP could affect the cell wall of bacteria by acting with peptidoglycan. Finally, the film showed excellent preservation effects in both beef and apples, which suggested that TP-SA-KGM film could be a novel bioactive packaging material with wide application potential in food preservation.

The potential antidiabetic properties of green and purple tea [Camellia sinensis (L.) O Kuntze], purple tea ellagitannins, and urolithins

ETHNOPHARMACOLOGICAL RELEVANCE

Tea (Camellia sinensis) has been consumed for centuries as traditional medicine for various diseases, including diabetes. The mechanism of action of many traditional medicines, including tea, often requires elucidation. Purple tea is a natural mutant of Camellia sinensis, grown in China and Kenya, and is rich in anthocyanins and ellagitannins.

AIM OF THE STUDY

Here we aimed to determine whether commercial green and purple teas are a source of ellagitannins and whether green and purple teas, purple tea ellagitannins and their metabolites urolithins have antidiabetic activity.

MATERIALS AND METHODS

Targeted UPLC-MS/MS was employed to quantify the ellagitannins corilagin, strictinin and tellimagrandin I, in commercial teas. The inhibitory effect of commercial green and purple teas and purple tea ellagitannins was evaluated on α-glucosidase and α-amylase. The bioavailable urolithins were then investigated for additional antidiabetic effects, by evaluating their effect on cellular glucose uptake and lipid accumulation.

RESULTS

Corilagin, strictinin and tellimagrandin I (ellagitannins) were identified as potent inhibitors of α-amylase and α-glucosidase, with K_i values significantly lower (p < 0.05) than acarbose. Commercial green-purple teas were identified as ellagitannin sources, with especially high concentrations of corilagin. These commercial purple teas, containing ellagitannins, were identified as potent α-glucosidase inhibitors with IC₅₀ values significantly lower (p < 0.05) than green teas and acarbose. Urolithin A and urolithin B were as effective (p> 0.05) as metformin in increasing glucose uptake in adipocytes, muscle cells and hepatocytes. In addition, similar (p > 0.05) to metformin, both urolithin A and urolithin B reduced lipid accumulation in adipocytes and hepatocytes.

CONCLUSIONS

This study identified green-purple teas as an affordable widely available natural source with antidiabetic properties. Furthermore, additional antidiabetic effects of purple tea ellagitannins (corilagin, strictinin and tellimagrandin I) and urolithins were identified.

Exogenous methyl jasmonate and cytokinin antagonistically regulate lignin biosynthesis by mediating CsHCT expression in Camellia sinensis

Tea plant, an important beverage crop, is cultivated worldwide. Lignification can improve the hardness of tea plant, which is of great significance for tea quality. Jasmonates (JAs) and cytokinin are plant hormones that control processes of plant development and secondary metabolite accumulation. Hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase (HCT) is primarily involved in lignin biosynthesis. The effects of exogenous application of JAs and cytokinin on lignin biosynthesis and related HCT gene expression profiles in tea plants are still unclear. In order to investigate the effects of exogenous JAs and cytokinin on lignin accumulation, anatomical structures, and CsHCT gene profiles in tea plants, we treated tea plants with methyl jasmonate (MeJA) and cytokinin (6-BA). MeJA and 6-BA treatments triggered the lignification at 6 and 12 d in tea leaves. The combined treatment resulted in an increase in lignin content at 6 d, which was 1.32 times of that at 0 d for 'Mengshan 9.' The CsHCTs in clade 2 (CsHCT5, CsHCT6, CsHCT7, and CsHCT8) were mainly expressed in leaves. We found that exogenous MeJA and cytokinin might be able to antagonistically regulate tea plant lignin accumulation through the mediation of CsHCT expression. This study revealed that HCTs play potential important roles involved in lignin biosynthesis of tea plant development and hormonal stimuli.

Synthesis of iron oxide nanoparticles mediated by Camellia sinensis var. Assamica for Cr(VI) adsorption and detoxification

Environment-benign synthesis of nanoparticles (NPs) are of great importance. Plant-based polyphenols (PPs) are electron donor analytes for the synthesis of metal and metal oxide NPs. This work produced and investigated iron oxide nanoparticles (IONPs) from PPs of tea leaves of Camellia sinensis var. assamica for Cr(VI) removal. The conditions for IONPs synthesis were using RSM CCD and found to be optimum at a time of 48 min, temperature of 26 °C, and iron precursors/leaves extract ratio (v/v) of 0.36. Further, these synthesized IONPs at a dosage of 0.75 g/L, temperature of 25 °C, and pH 2 achieved a maximum of 96% Cr(VI) removal from 40 mg/L of Cr(VI) concentration. The exothermic adsorption process followed the pseudo-second-order model, and Langmuir isotherm estimated a remarkable maximum adsorption capacity (Q_m) of 1272 mg g^-1 of IONPs. The proposed mechanistic for Cr(VI) removal and detoxification involved adsorption and its reduction to Cr(III), followed by Cr(III)/Fe(III) co-precipitation.

Monitoring and evaluating the dietary risk of trace elements content in bottled and hand-shaken tea in Taiwan

Tea is the most frequently consumed beverage worldwide and is obtained from the leaves Camellia sinensis. The traditional way of tea consumption through brewing is gradually being replaced by the consumption of bottled and hand-shaken tea. Despite the different ways of tea consumption, trace elements accumulation and contamination of tea leaves have caused concerns. However, limited studies have reported trace element concentrations in different types of tea in bottled or hand-shaken tea and their health risks. This study aimed to determine the level of trace elements (V, Cr, Co, As, Cd, Pb, Mn, and Zn) in green tea, black tea, and Oolong tea in two varieties of products (bottled and hand-shaken tea). The health risks associated with tea consumption in various age subgroups among Taiwan's general population were also estimated. A Monte Carlo simulation was applied to estimate the distribution of daily trace elements intake through bottled and hand-shaken tea consumption. As to the non-carcinogenic risks, the Monte Carlo simulation showed that hand-shaken green tea had a higher percentage of hazard index (HI) >1 (1.08%~6.05%) among all age groups. As to carcinogenic risks, the Monte Carlo simulation showed that the risks of As exposure from bottled Oolong tea and hand-shaken black, green, and Oolong teas in the 90th percentile in >18 to ≤65 and >65-year-old groups were higher than 10^-6. The current study findings provided some information about trace elements of both bottled and hand-shaken tea and human health risks in the general population of Taiwan.

Hot Water Extraction of Antioxidants from Tea Leaves—Optimization of Brewing Conditions for Preparing Antioxidant-Rich Tea Drinks

There are billions of tea drinkers around the world. However, the optimized tea-brewing temperature and time conditions for achieving a higher concentration of antioxidants in tea drinks have not been thoroughly studied. Finding out the optimized brewing conditions can benefit tea drinkers significantly. In this work, we have studied ten antioxidants from seven different popular green, Oolong, black, and scented teas using hot water extraction followed by HPLC analysis. The antioxidant yield was evaluated at 25–100 °C with 5 to 720 min of brewing time. Our results show that the extraction efficiency was enhanced by increasing the water temperature and the highest yield of antioxidants was achieved at 100 °C. The antioxidant yield increased with prolonged brewing time. However, the degradation of antioxidants occurred when tea leaves were extracted for 120 to 720 min. Caffeine was found in all seven tea samples. At 100 °C, the caffein concentration in the tea extract ranged from 7.04 to 20.4 mg/g in Rizhao green tea. Longjing green tea contained the highest concentration of antioxidants (88 mg/g) in the 100 °C extract. Epigallocatechin and caffeine were the most abundant compounds found in all tea samples studied, ranging from 4.77 to 26.88 mg/g. The antioxidant yield was enhanced by increasing the extraction time to up to 60–120 min for all ten compounds studied.

Green Tea and Benign Gynecologic Disorders: A New Trick for An Old Beverage?

Green tea is harvested from the tea plant Camellia sinensis and is one of the most widely consumed beverages worldwide. It is richer in antioxidants than other forms of tea and has a uniquely high content of polyphenolic compounds known as catechins. Epigallocatechin-3-gallate (EGCG), the major green tea catechin, has been studied for its potential therapeutic role in many disease contexts, including pathologies of the female reproductive system. As both a prooxidant and antioxidant, EGCG can modulate many cellular pathways important to disease pathogenesis and thus has clinical benefits. This review provides a synopsis of the current knowledge on the beneficial effects of green tea in benign gynecological disorders. Green tea alleviates symptom severity in uterine fibroids and improves endometriosis through anti-fibrotic, anti-angiogenic, and pro-apoptotic mechanisms. Additionally, it can reduce uterine contractility and improve the generalized hyperalgesia associated with dysmenorrhea and adenomyosis. Although its role in infertility is controversial, EGCG can be used as a symptomatic treatment for menopause, where it decreases weight gain and osteoporosis, as well as for polycystic ovary syndrome (PCOS).

Characteristics of Leaf Spot Disease Caused by Didymella Species and the Influence of Infection on Tea Quality

Leaf spots are the most damaging and common foliar diseases of tea and are caused by several species of fungi. During 2018 to 2020, leaf spot diseases showing different symptoms (large and small spots) were observed in commercial tea plantations in Guizhou and Sichuan provinces of China. The pathogen causing the two different sized leaf spots was identified as the same species (Didymella segeticola) based on morphological characteristics, pathogenicity, and multilocus phylogenetic analysis using the combined ITS, TUB, LSU, and RPB2 gene regions. Microbial diversity analysis of lesion tissues from small spots on naturally infected tea leaves further confirmed Didymella to be present as the main pathogen. Results of sensory evaluation and quality-related metabolite analysis of tea shoots infected with the small leaf spot symptom indicated that D. segeticola negatively affected the quality and flavor of tea by changing the composition and content of caffeine, catechins, and amino acids. In addition, the significantly reduced amino acid derivatives in tea are confirmed to be positively associated with the enhanced bitter taste. The results improve our understanding of the pathogenicity of Didymella species and the influence of Didymella on the host plant, Camellia sinensis.

The effect of natural antioxidants, pH, and green solvents upon catechins stability during ultrasonic extraction from green tea leaves (Camellia sinensis)

BACKGROUND

This is a first-time report to evaluate the effect of natural antioxidants, pH, and green solvents upon catechins yield and stability during the active process of extraction from green tea leaves.

METHODOLOGY

Green solvents (model-A) augmented with piperine (PPN) and quercetin (QT) as natural antioxidants (model-B) at different pH 2-6 (model-C) were used to extract catechins from green tea leaves using an ultrasonic extraction process (USE). For quantification of catechins (EC; epicatechins, ECG; epicatechin gallate, and EGCG; epigallocatechin gallate), a green and sensitive UHPLC-MS/MS method was developed and validated.

RESULTS

The UHPLC-MS/MS method showed an accuracy of 98.3-102.6 % within the linearity range of 1-500 ppb for EC (m/z) 289 → 245 → 109, ECG (m/z) 441.2 → 169 → 289, and EGCG (m/z) 457.1 → 169 → 125.1. The general yield (ppb) for EC, ECG, and EGCG was observed with the ranges and sum of (N = 180) 0.06-157.80 and 6696.83, 0.04-316.93 and 12632.60 and, 0.12-584.11 and 26144.83, respectively. Model-C revealed the highest yield for catechins at the lowest pH-2 with an individual catechin yield of EGCG (584.11) > ECG (316.93) > EC (157.80) in CW2. In terms of stability, EGCG was the most unstable catechin whereas, catechins extracted in model-B exhibited more stability (%recovery of 14.70 for EC, 10.55 for ECG, and 5.36 for EGCG in BEP). Moreover, model-B showed the minimal degradation for catechins within the range of 11.81-94.64 (BEP); even the most degradable EGCG was seen with the smallest %loss of 11.81-94.64 at time 24-70 h, as compared to the loss of > 95 % in model-A and C. The ANOVA score for catechins yield was; F_11,168 = 61.06 (EC), F_11,168 = 66.53 (ECG), and F_11,168 = 48.92 (EGCG) (P = 0.00) with mean scores of (M = 94.63, SD = 25.46) for EC, (M = 194.87, SD = 51.41) ECG, and (M = 357.57, SD = 96.80) EGCG in CE2.

CONCLUSION

A significant effect on catechins yield and stability was observed with the use of natural antioxidants and lowest pH-2.

Influence of chicken feather waste derived protein hydrolysate on the growth of tea plants under different application methods and fertilizer rates

Modern agriculture prioritizes eco-friendly and sustainable strategies to enhance crop growth and productivity. The utilization of protein hydrolysate extracted from chicken feather waste as a plant biostimulant paves the path to waste recycling. A greenhouse experiment was performed to evaluate the implications of different doses (0, 1, 2, and 3 g L-1) of chicken feather protein hydrolysate (CFPH), application method (soil and foliar), and fertilizer rate (50% and 100%) on the growth performance of tea nursery plants. The highest dose of CFPH (3 g L-1) increased the shoot and root dry weights by 43% and 70%, respectively over control. However, no significant differences were observed between 2 and 3 g L-1 doses in plant dry weight, biometric, and root morphological parameters. Foliar application of CFPH significantly increased all the growth parameters compared to soil drenching except N, P, and K concentrations in leaves and roots. Plants grown under 100% fertilizer rate showed better growth performance than 50% fertilizer rate. Tea nursery plants treated with foliar 2 g L-1 dose and grown under full fertilizer rate recorded the highest plant dry weight, root length, and root surface area. However, tea plants under 50% fertilizer rate and treated with foliar 2 and 3 g L-1 doses sustained the growth similar to untreated plants under 100% fertilizer rate. The significantly higher N, P, and K concentrations in leaves were observed in plants treated with soil drenching of 2 and 3 g L-1 CFPH doses under 100% fertilizer rate. Our results indicate that the application of CFPH as a foliar spray is highly effective in producing vigorous tea nursery plants suitable for field planting, eventually capable of withstanding stress and higher yield.

Comparison of machine learning and deep learning models for evaluating suitable areas for premium teas in Yunnan, China

BACKGROUND

Tea is an important economic crop in Yunnan, and the market price of premium teas such as Lao Banzhang is significantly higher than ordinary teas. For planting lands to promote, the tea industry to develop and minority lands' economies to prosper, it is vital to evaluate and analyze suitable areas for premium tea cultivation.

METHODS

Climate, terrain, soil, and green cropping system in the premium tea planting areas were used as evaluation variables. The suitability of six machine learning models for predicting suitable areas of premium teas were evaluated.

RESULT

FA+ResNet demonstrated the best performance with an accuracy score of 0.94 and a macro-F1 score of 0.93. The suitable areas of premium teas were mainly located in the southern catchment of LancangJiang River, south-central part of Dehong, a few areas in the mid-west of Lincang, central scattered areas of Pu'er, most of the southern western part of Xishuangbanna and the southern edge of Honghe. Annual mean temperature, annual mean precipitation, mist belt, annual mean relative humidity, soil type and elevation were the key components in evaluating the suitable areas of premium teas in Yunnan.

In silico molecular modeling and simulations of black tea theaflavins revealed theaflavin-3'-gallate as putative liver X receptor-beta agonist

The low constitutive activation of Liver X receptor, an endogenous nuclear receptor with two subtypes (α and β), is a condition lying at the crossroad of cancer and cardiovascular disease. Both natural and synthetic Liver X receptor agonists have reportedly shown remarkable antiproliferative and atheroprotective effects but the repeated doses of its synthetic ones are also paradoxically associated with hyperlipidaemic effects and neurotoxicity, though attributed to the alpha subtype. This highlights the need for novel, safe, and potent LXR-beta-selective agonists. Hypocholesterolaemic effects of black theaflavins have been widely reported, but data on the exact theaflavin compound (s) responsible for these effects is currently lacking. Neither is information on the possible modulatory effects of the compound (s) on LXR-beta nor its possible implications in the context of drug development for cardiovascular diseases and cancers is explored. On this account, we investigated the potential interaction of four main theaflavin monomers (TF1, TF2A, TF2B & TF3) with human LXR-beta through robust computational modelling that entails molecular docking, free energy calculations and molecular dynamics simulations. The ligands were further profiled (in silico) for absorption, distribution, metabolism, excretion, and toxicological properties. Our result revealed theaflavin TF2B as a putative LXR-beta agonist, possibly responsible for the widely observed hypocholesterolaemic effect in black tea. This finding, while encouraging, needs to be experimentally verified in wet studies.Communicated by Ramaswamy H. Sarma.

Insights into the effects of tea pruning litter biochar on major micronutrients (Cu, Mn, and Zn) pathway from soil to tea plant: An environmental armour

A field study was conducted from 0 to 360 days to investigate the effect of tea pruning litter biochar (TPLBC) on the accumulation of major micronutrients (copper: Cu, manganese: Mn, and zinc: Zn) in soil, their uptake by tea plant (clone: S.3 A/3) and level of contamination in soil due to TPLBC. To evaluate the level of contamination due to TPLBC, a soil pollution assessment was carried out using the geo-accumulation index (I_geo), enrichment factor (EF), contamination factor (CF), potential ecological risk factor (PERF), individual contamination factor (ICF), and risk assessment code (RAC). The total content of Cu, Mn, and Zn gradually increased with increasing doses of TPLBC at 0D, and then decreased with time. The fractionation of the three micronutrients in soil changed after the application of TPLBC. The contamination risk assessment of soil for Cu, Mn, and Zn based on the I_geo, EF, CF, PERF,ICF, and RAC suggested that the application of TPLBC does not have any adverse effect on soil. Except for Mn, the bioconcentration and translocation factors were less than one for Cu and Zn. Results from this study revealed that the application of 400 kg TPLBC ha^-1 is significantly better than the other treatments for Cu, Mn, and Zn at a 5% level of significance.

Insights into the Key Odorants in Large-Leaf Yellow Tea (Camellia sinensis) by Application of the Sensomics Approach

Large-leaf yellow tea (LYT) is a yellow tea product with a specific aroma characteristic and is enjoyed with increasing enthusiasm in China. However, its key odorants are still unknown. In this study, 46 odorants in the headspace and vacuum-distillate of the tea infusion were identified via aroma extract dilution analysis. Sixteen compounds were newly found in LYT infusion. They were present in the highest flavor dilution factors together with 2-ethyl-3,5-dimethylpyrazine. All odorants were quantitated to evaluate their own odor activity values (OAVs). High OAVs were found for 2-methylbutanal (malty, 210), (E,E)-2,4-heptandienal (fatty/flowery, 170), 2-methylpropanal (malty, 120) and 2,3-diethyl-5-methylpyrazine (earthy/roasty, 110). An aroma recombinate consisting of 17 odorants (all OAVs ≥ 1) in an odorless nonvolatile LYT matrix mimicked the overall aroma of the original infusion, verifying the successful characterization of key aroma components in a LYT beverage. The knowledge of key odorants obtained showed potential for simplifying industrial flavor optimization of the LYT product.

The Effects of Black Tea Consumption on Intestinal Microflora-A Randomized Single-Blind Parallel-Group, Placebo-Controlled Study

We previously reported that black tea consumption for 12 wk reduced the risk of acute upper respiratory tract inflammation, and improved secretory capacity in individuals with low salivary SIgA levels (Tanaka Y et al. 2021. Jpn Pharmacol Ther 49: 273-288). These results suggested that habitual black tea consumption improves mucosal immunity. Therefore, in this study we evaluated the effect of black tea intake on gut microbiota, which is known to be involved in mucosal immunity, by analyzing the bacterial flora and the short-chain fatty acids (SCFAs) concentration of feces collected during the above clinical study. The clinical design was a randomized, single-blind, parallel-group, placebo-controlled study with 72 healthy Japanese adult males and females, who consumed three cups of black tea (Black Tea Polymerized Polyphenols 76.2 mg per day) or placebo per day for 12 wk. In all subjects intake of black tea significantly increased abundance of Prevotella and decreased fecal acetic acid concentration. Particularly in the subjects with low salivary SIgA levels, the change over time of total bacteria, Prevotella, and butyrate-producing bacteria, which are involved in normalizing immune function, were higher in the black tea group than in the placebo group. In subjects with low abundance of Flavonifractor plautii a butyrate-producing bacteria, black tea consumption significantly increased salivary SIgA concentration and the absolute number of Flavonifractor plautii. In conclusion, our results suggest that improvement of mucosal immunity via an increase in butyrate-producing bacteria in the gut may partly contribute to the suppressive effect of black tea consumption on acute upper respiratory tract inflammation observed in our previous report.

Impact of Camellia sinensis Iron Oxide Nanoparticle on Growth, Hemato-biochemical and Antioxidant Capacity of Blue Gourami (Trichogaster trichopterus) Fingerlings

The effect of green tea (Camellia sinensis) iron oxide nanoparticles (nano-Fe) on the effectiveness, growth, antioxidant capacity, and immunological response of Trichogaster trichopterus (Blue gourami) fingerlings was investigated. UV-Visible, Fourier Transform Infrared, Scanning Electron Microscopy, Energy Dispersive X-ray, X-ray diffraction, Dynamic Light Scattering, and Zeta Potential spectroscopy were used to evaluate the biologically synthesized nano-Fe. Characterization revealed the hexagonal and spherical morphology with an average diameter of 114 nm. Six different experimental diets were supplied to the fish in duplicate for 60 days. The first diet served as a control (no nano-Fe supplementation), whereas the remaining five diets contained nano-Fe at concentrations of 10, 20, 30, 40, and 50 mg/kg (D1 to D5). The results indicated that fish fed a nano-Fe diet at a concentration of 40 mg/kg had improved growth performance, biochemical constituents, hematological parameters, and antioxidant activity in T. trichopterus, implying that it might be used as a vital feed supplement in ornamental fish culture.

Accumulation of potentially toxic elements in Chinese tea (Camellia sinensis): Towards source apportionment and health risk assessment

Tea (Camellia sinensis) is a popular beverage that is consumed globally. However, a better understanding of potentially toxic elements (PTEs) content in tea leaves and infusion is necessary to minimize risk on human health. Therefore, 249 tea samples (grown in different areas) covering six types of tea were collected in China to investigate the PTEs contents, identify their potential source and assess the health risk associated with drinking tea. PTE contents in tea leaves across six tea types were ND-0.900 (Cd), 0.005-2.133 (As), ND-5.679 (Pb), ND-13.86 (Cr), 1.601-22.93 (Ni), ND-2.048 (Se), 0.109-622.4 (F), 13.02-269.9 (Rb), 1.845-50.88 (Sr), and 2.796-53.23 (Ba) mg/kg. The result of tea infusion showed that 14.3 %-44.1 % (green tea), 14.5 %-46.7 % (black tea), 10.5 %-25.3 % (dark tea), 13.6 %-34.2 % (oolong tea), 16.9 %-40.7 % (yellow tea), and 19.9 %-35.1 % (white tea) of F were released. All tea types, except green tea, exhibited comparatively low leachability of Cd, As, Pb and Cr in tea infusion. The source apportionment revealed that PTEs in tea leaves mainly originated from soil parental materials, while industrial activities, fertilizer application, and manufacturing processes may contribute to exogenous Se, Cd, As, and Cr accumulation. Health risk assessment indicated that F in tea infusion dominated the health risk. Humans may be exposed to a higher health risk by drinking green tea compared to that of other tea types. Nevertheless, the long-term tea consumption is less likely to contribute to pronounced non-carcinogenic and carcinogenic risks. This study confirmed that tea consumption is an important and direct pathway of PTEs uptake in humans. The health risk associated with drinking tea should be of concern.

Kombuchas from Green and Black Tea Modulate the Gut Microbiota and Improve the Intestinal Health of Wistar Rats Fed a High-Fat High-Fructose Diet

The Western diet can negatively affect the gut microbiota and is associated with metabolic disorders. Kombucha, a tea fermented by a symbiotic culture of bacteria and yeast (SCOBY), is known for its bioactive properties and has become popular in the last years. In this study, we evaluated the effects of regular kombucha consumption on the gut microbiota and on outcomes related to the intestinal health of Wistar rats fed a high-fat high-fructose diet. After eight weeks receiving a standard diet (AIN-93M) (n = 10) or a high-fat and high-fructose diet (HFHF) (n = 30) to induce metabolic disorders, the animals were subdivided into four groups: AIN-93M (n = 10); HFHF (n = 10); GTK (HFHF + green tea kombucha (n = 10); and BTK (HFHF + black tea kombucha; n = 10) for 10 weeks. Although body composition did not differ among the groups, the HFHF diet was associated with metabolic alterations, and stimulated the growth of gram-negative bacteria such as Proteobacteria and Bacteroides. Kombucha ingestion could somewhat modulate the gut microbiota, attenuating the effects of a Western diet by increasing propionate production and favoring the growth of beneficial bacteria, such as Adlercreutzia in the GTK group. Our results suggest that regular kombucha consumption may be beneficial to intestinal health, which can be mostly attributed to its high content and diversity of phenolic compounds.

N-doped carbon fibers in situ prepared by hydrothermal carbonization of Camellia sinensis branches waste for efficient removal of heavy metal ions

N-doped carbon fibers (NCFs) were in situ prepared by Camellia sinensis branches waste through hydrothermal carbonization with urea/ZnCl2 at 160-280 °C under 0.8-8.9 MPa. The structural characteristics of NCFs were investigated by elemental analysis, SEM, TEM, XRD, XPS, Raman spectra, and BET surface area. The highest N content of NCFs obtained at 280 °C was 8.96%, and the main forms of doped N were pyridinic N, pyrrolic N, and graphitic N. Moreover, NCFs were applied to remove metal ions successfully. The results showed that NCF-240 had the maximum adsorption amounts of 106.52, 125.23, and 153.49 mg/g for Cu2+, Pb2+, and Zn2+, respectively, while NCF-280 had the best removal ability on Cr6+ (145.67 mg/g). Finally, it demonstrated that the adsorption behavior of NCFs was well fitted by the pseudo-second-order kinetic and the Langmuir adsorption isotherm models.

Changes in immune responses, gene expression, and life table parameters of Helicoverpa armigera Hübner fed on a diet containing the saponin of tea plant, Camellia sinensis

Saponins cause mortality in insects by reducing food absorption and movement in the gut, which may be used to exploit the control of insect pests. In the current study, tea seed saponin (TSS) was extracted and then added to the artificial diets of Helicoverpa armigera. Pre-ovipositional period of the TSS-treated individuals increased while longevity and fecundity decreased compared to control. There was a significant reduction of the treated individuals in the life table parameters of TSS-treated Individuals including net reproduction rate (R₀ ), intrinsic rate of population increase (r), finite rate of increase (λ), and gross reproduction rate (GRR). Also, we found that saponin suppressed the immune system by reducing the total hemocyte count, immune-related gene expression, and phenoloxidase activity. Our results demonstrated a lower expression of cecropin gene in the treated larvae with TSS while no significant differences were observed in attacin gene. Our results clearly showed that feeding of H. armigera larvae in the diet containing TSS significantly reduced demographic parameters, forced insects to obtain more time to complete one generation, and caused vulnerabilities against pathogens. These discrepancies alleviated nutrient uptake of the larvae and disrupted their feeding and growth. Hence, a proper formulation with a desirable concentration would be prepared and applied in the fields suffering H. armigera damage to monitor insecticidal efficiency of TSS.

Green Tea Catechins Attenuate Neurodegenerative Diseases and Cognitive Deficits

Neurodegenerative diseases exert an overwhelming socioeconomic burden all around the globe. They are mainly characterized by modified protein accumulation that might trigger various biological responses, including oxidative stress, inflammation, regulation of signaling pathways, and excitotoxicity. These disorders have been widely studied during the last decade in the hopes of developing symptom-oriented therapeutics. However, no definitive cure has yet been discovered. Tea is one of the world's most popular beverages. The same plant, Camellia Sinensis (L.).O. Kuntze, is used to make green, black, and oolong teas. Green tea has been most thoroughly studied because of its anti-cancer, anti-obesity, antidiabetic, anti-inflammatory, and neuroprotective properties. The beneficial effect of consumption of tea on neurodegenerative disorders has been reported in several human interventional and observational studies. The polyphenolic compounds found in green tea, known as catechins, have been demonstrated to have many therapeutic effects. They can help in preventing and, somehow, treating neurodegenerative diseases. Catechins show anti-inflammatory as well as antioxidant effects via blocking cytokines' excessive production and inflammatory pathways, as well as chelating metal ions and free radical scavenging. They may inhibit tau protein phosphorylation, amyloid beta aggregation, and release of apoptotic proteins. They can also lower alpha-synuclein levels and boost dopamine levels. All these factors have the potential to affect neurodegenerative disorders. This review will examine catechins' neuroprotective effects by highlighting their biological, pharmacological, antioxidant, and metal chelation abilities, with a focus on their ability to activate diverse cellular pathways in the brain. This review also points out the mechanisms of catechins in various neurodegenerative and cognitive diseases, including Alzheimer's, Parkinson's, multiple sclerosis, and cognitive deficit.