Chemical composition, plant secondary metabolites, and minerals of green and black teas and the effect of different tea-to-water ratios during their extraction on the composition of their spent leaves as potential additives for ruminants

Dried tea residue can alter the blood metabolism and the composition and functionality of the intestinal microbiota in Hu sheep

Ruminant animals face multiple challenges during the rearing process, including immune disorders and oxidative stress. Green tea by-products have gained widespread attention for their significant immunomodulatory and antioxidant effects, leading to their application in livestock production. In this study, we investigated the effects of Dried Tea Residue (DTR) as a feed additive on the growth performance, blood biochemical indicators, and hindgut microbial structure and function of Hu sheep. Sixteen Hu sheep were randomly divided into two groups and fed with 0 and 100 g/d of DTR, respectively. Data were recorded over a 56-day feeding period. Compared to the control group, there were no significant changes in the production performance of Hu sheep fed with DTR. However, the sheep fed with DTR showed a significant increase in IgA (p < 0.001), IgG (p = 0.005), IgM (p = 0.003), T-SOD (p = 0.013), GSH-Px (p = 0.005), and CAT (p < 0.001) in the blood, along with a significant decrease in albumin (p = 0.019), high density lipoprotein (p = 0.050), and triglyceride (p = 0.021). DTR supplementation enhanced the fiber digestion ability of hindgut microbiota, optimized the microbial community structure, and increased the abundance of carbohydrate-digesting enzymes. Therefore, DTR can be used as a natural feed additive in ruminant animal production to enhance their immune and antioxidant capabilities, thereby improving the health status of ruminant animals.

Effect of dietary inclusion of tea residue and tea leaves on ruminal fermentation characteristics and methane production

The aim of this study was to compare the differences of dietary tea leaves (TL) and tea residue (TR) inclusion on rumen fermentation characteristics and to explore whether TR could be an alternative feedstuff of ruminants. For these purposes, seven treatments consisted of two inclusion types (TL vs. TR) and three inclusion levels (g/g of dry matter basis) of 10% (TL10/TR10), 20% (TL20/TR20), and 30% (TL30/TR30) in each inclusion type, plus control group with inclusion of 0% (CON) were designed, with four replicates in each group, to conduct an in vitro ruminal fermentation test. Results showed that the contents of crude protein, neutral detergent fiber, and acid detergent fiber were higher in TR than TL, while TL contained more ether extract and crude ash than TR. Interaction effects between inclusion type and inclusion level were observed in concentrations of isobutyrate and microbial crude protein (MCP), as well as in gas production and digestibility of organic matter. Fermentation characteristics were significantly influenced by TL and TR depending on the inclusion level, except for the concentration of total branched-chain volatile fatty acid. These significant differences of fermentation characteristics due to inclusion level mainly focused on CON and tea inclusion, with higher values in CON than TR or TL groups. The total gas production during the 48-h incubation showed no differences among CON, TL10, and TR10. The inclusion of TR and TL decreased the production of methane. The concentration of MCP in CON, TR10 and TR30 was lower than TR20 and all TL groups. In conclusion, dietary inclusion of TR and TL possessed equivalent effect on rumen fermentation characteristics and methane production, substituting diet with TR or TL for over 10% would inhibit rumen fermentation despite positive effects in TR20 and all TL groups regarding more MCP and less methane production. This study indicates that special attention should be paid to the inclusion level of TR and TL when considering them as alternative feedstuffs of ruminants. Further in vivo study is needed to evaluate the applicability of tea residue as a feedstuff for production of ruminants.

Extraction methods, physiological activities and high value applications of tea residue and its active components: a review

Tea is a traditional plant beverage originating from China as one of the most popular beverages worldwide, which has been an important companion in modern society. Nevertheless, as the waste after tea processing, tea residues from agriculture, industry and kitchen waste are discarded in large quantities, resulting in waste of resources and environmental pollution. In recent years, the comprehensive utilization of tea residue resources has attracted people's attention. The bioactive components remaining in tea residues demonstrate a variety of health benefits and can be recycled using advanced extraction processes. Furthermore, researchers have been devoted to converting tea residues into derivatives such as biosorbents, agricultural compost, and animal feeds through thermochemical techniques and biotechnology. This review summarized the chemical composition and physiological activities of bioactive components from tea residue. The extraction methods of bioactive components in tea residue were elucidated and the main high-value applications of tea residues were proposed. On this basis, the utilization of tea residues can be developed from a single way to a multi-channel or cascade way to improve its economic efficiency. Novel applications of tea residues in different fields, including food development, environmental remediation, energy production and composite materials, are of far-reaching significance. This review aims to provide new insights into developing the utilization of tea residue using a comprehensive strategy and exploring the mechanism of active components from tea residue on human health and their potential applications in different areas.HighlightsThe composition and function of tea residue active components were introduced.The extraction methods of active components from tea residue were proposed.The main high-value applications of tea residues were summarized.The current limitations and future directions of tea residue utilization were concluded.

Characterization, dose dependent assessment of hepatorenal oxidative stress, hematological parameters and histopathological divulging of the hepatic damages induced by Zinc oxide nanoparticles (ZnO-NPs) in adult male Sprague Dawley rats

Nanoparticles are beneficial in many aspects to human life but their excessive use can cause various abnormalities. They dispose in the environment through transport, industrial and agricultural usage and enter in living body through dermal, respiratory route or ingested with the lipsticks and there higher concentration produces toxicity. Therefore, current study characterized ZnO-NPs to evaluate toxic ability by X-rays diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques and showed 29.83 and 35 nm size, respectively with hexagonal crystalline structure. LC50 value of ZnO-NPs was also evaluated as 72.48 ± 10.33 mg/kg BW. Male Sprague Dawley (Post weaning) rats were divided into five groups with five rats in each group. Control (C) group received no treatment, placebo (S) group received normal saline (0.9% sodium chloride) intraperitoneally and three treated groups received different levels of ZnO- NPs intraperitoneally at the dose of either 10 or 20 or 30 mg/kg for 21 days on alternate days and named as 1G1, 1G2 and 1G3, respectively for the assessment of toxicity for better understanding of precautionary measures in future. Oxidative stress enzymes of liver and kidney, hepatorenal function enzymes and hematological parameters along with hepatic histology were measured at the end of the experiment. Results showed highly significant variations in all parameters in a dose dependent manner as compared to control group while groups receiving 10 or 20 mg/kg of ZnO-NPs showed low to moderate pathological changes in both organs. Liver histological analysis showed congestion, necrosis, hemorrhage, RBC's accumulations; inflammatory cells infiltration and severe abnormalities in high dose group while medium, low dose group showed moderate and least effects, respectively. It is concluded that ZnO-NPs are highly toxic at more concentration so their careful usage is needed in daily routine.

Tea film formation in artificial tap water

On the surface of tea infusions, the formation of a transparent, shiny film which cracks upon disturbance can often be observed. This study aims to determine how water composition, tea varieties, and tea additives impact the formation and properties of tea film, often also called tea scum. The strength of the surface film, composed of polyphenols complexed with various ions from tap water, was investigated by interfacial rheology. Microscopy and ellipsometry were used to investigate structure and thickness of the adsorption layer, respectively. We find that green tea forms more visible layers than black tea in soft and moderate artificial tap water, but in these same waters, black tea demonstrated greater surface strength. In hard artificial tap water, green tea demonstrated greater surface strength than black. No visible layer nor surface strengthening was observed on rooibos tea. Brews in hard artificial tap water formed brittle films for green tea, fracturing at strains one order of magnitude lower than in soft or moderate. Despite large variations in film strength, black tea at all water hardness levels tested formed a film with 20 nm thickness. In black tea an increased resilience to deformation was found when adding β-casein, a protein found in milk.

Valorization of cocoa, tea and coffee processing by-products-wastes

The growing threat of food insecurity together with some challenges in demography, health, malnutrition, and income instability around the globe has led researchers to take sustainable solutions to ensure secure production and distribution of food. The last decades have been remarkable in the agri-food supply chain for many food industries. However, vast quantities of food by-products and wastes are generated each year. These products are generally disposed in the environment, which could have remarkable adverse effects on the environment and biodiversity. However, they contain significant quantities of bioactive, nutritional, antioxidative, and aroma compounds. Their sustainable use could meet the increased demand for value-added pharmaceutical, nutraceutical, and food products. The amount of agri-food wastes and their disposal in the environment are predicted to double in the next decade. The valorization of these by-products could effectively contribute to the manufacture of cheaper functional food ingredients and supplements while improving regional economy and food security and mitigating environmental pollution. The main aim of this chapter is to present an understanding of the valorization of the wastes and by-products from cacao, coffee and tea processing with a focus on their bioactive, nutritional, and antioxidant capacity.

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.

NPASS database update 2023: quantitative natural product activity and species source database for biomedical research

Quantitative activity and species source data of natural products (NPs) are important for drug discovery, medicinal plant research, and microbial investigations. Activity values of NPs against specific targets are useful for discovering targeted therapeutic agents and investigating the mechanism of medicinal plants. Composition/concentration values of NPs in individual species facilitate the assessments and investigations of the therapeutic quality of herbs and phenotypes of microbes. Here, we describe an update of the NPASS natural product activity and species source database previously featured in NAR. This update includes: (i) new data of ∼95 000 records of the composition/concentration values of ∼1 490 NPs/NP clusters in ∼390 species, (ii) extended data of activity values of ∼43 200 NPs against ∼7 700 targets (∼40% and ∼32% increase, respectively), (iii) extended data of ∼31 600 species sources of ∼94 400 NPs (∼26% and ∼32% increase, respectively), (iv) new species types of ∼440 co-cultured microbes and ∼420 engineered microbes, (v) new data of ∼66 600 NPs without experimental activity values but with estimated activity profiles from the established chemical similarity tool Chemical Checker, (vi) new data of the computed drug-likeness properties and the absorption, distribution, metabolism, excretion and toxicity (ADMET) properties for all NPs. NPASS update version is freely accessible at http://bidd.group/NPASS.

Effect of Yerba Mate Extract as Feed Additive on Ruminal Fermentation and Methane Emissions in Beef Cattle

The inclusion of plant extracts that contain secondary compounds with the potential to modulate rumen fermentation and improve animal performance has gained attention in recent years. The aim of this study was to evaluate the effect of the inclusion of yerba mate extract (Ilex paraguariensis ST. Hilaire) (YME) on the ruminal parameters. Eight castrated cattle were divided into four groups, a control without YME (0%) and three treatment groups with 0.5, 1 and 2% inclusion of YME in the dry matter. The inclusion of YME did not show differences in ruminal methane emissions (CH4), and total apparent digestibility (p = 0.54). Likewise, YME did not modify ruminal pH, but positively affected NH3-N, which decreased linearly as the extract level in the diet increased (p = 0.01). No short chain fatty acids (SCFA) were influenced by YME, except isovaleric acid (p = 0.01), which showed a lower concentration in the inclusion of 2% YME. Our results show that up to 2% YME does not affect digestibility, ruminal fermentation parameters, or the concentration of short-chain fatty acids in the rumen.

Identification and Quantification of Anthocyanin and Catechin Compounds in Purple Tea Leaves and Flakes

Tea is the first most popular beverage worldwide and is available in several selections such as black (fully oxidized), Oolong (partially oxidized) and green (non-oxidized), in addition to purple tea, an emerging variety derived from the same tea plant (Camellia sinensis). This study investigated purple tea leaves (non-oxidized) and flakes (water extractable) to thoroughly identify their composition of anthocyanins and catechins and to study the effect of a water extraction process on their compositional properties in comparison with green tea. Anthocyanin and catechin compounds were separated and quantified using UPLC, and their identity was confirmed using LC-MS/MS in positive and negative ionization modes. Delphinidin was the principal anthocyaninidin in purple tea, while cyanidin came in second. The major anthocyanin pigments in purple tea were delphinidin-coumaroyl-hexoside followed by delphinidin-3-galactoside and cyanidin-coumaroyl-hexoside. The water extraction process resulted in substantial reductions in anthocyanins in purple tea flakes. There were no anthocyanin compounds detected in green tea samples. Both purple and green tea types were rich in catechins, with green tea containing higher concentrations than purple tea. The main catechin in purple or green tea was epigallocatechin gallate (EGCG) followed by either epicatechin gallate (ECG) or epigallocatechin (EGC), subject to tea type. The extraction process increased the concentration of catechins in both purple and green tea flakes. The results suggest that purple tea holds promise in making healthy brews, natural colorants and antioxidants and/or functional ingredients for beverages, cosmetics and healthcare industries due to its high content of anthocyanins and catechins.

A comparative review on the anti-nutritional factors of herbal tea concoctions and their reduction strategies

Tea is an important beverage consumed worldwide. Of the different types of tea available, herbal tea is an important beverage consumed owing to its popularity as a drink and stress relieving factors, several different herbal concoctions made from seeds, leaves, or roots are currently consumed and sold as herbal teas. The herbal teas are not the usual tea but "tisanes." They are caffeine free and popular for their medicinal property or immune boosters. Herbal tea formulations are popularly sold and consumed by millions owing to their health benefits as they are rich in antioxidants and minerals. However, plants are also known to contain toxic and anti-nutritional factors. Anti-nutritional factors are known to interfere with the metabolic process and hamper the absorption of important nutrients in the body. These anti-nutritional factors include saponins, tannins, alkaloids, oxalates, lectins, goitrogens, cyanogens, and lethogens. These chemicals are known to have deleterious effects on human health. Therefore, it is important to understand and assess the merits and demerits before consumption. Also, several techniques are currently used to process and reduce the anti-nutrients in foods. This review is focused on comparing the contents of various anti-nutritional factors in some underutilized plants of North-East India used as herbal tea along with processing methods that can be used to reduce the level of these anti-nutrients.

Effect of tea polyphenols on the fermentation quality, protein preservation, antioxidant capacity and bacterial community of stylo silage

The present study was aimed to evaluate the improvement potential of tea polyphenols (TPP) on silage characteristics and bacterial community. Stylo ensiled with TPP (0, 0.2 or 0.4%, on a fresh basis) were analyzed for fermentation parameter, protein fraction, antioxidant activity and bacterial community after 7, 14, 30 and 60 days fermentation. The addition of TPP resulted in the decrease (P < 0.05) of pH values (5.09 vs. 4.91), dry matter loss (11.77 vs. 8.02% DM), butyric acid concentration (1.64 vs. 1.02% DM) and ammonia-N proportion (13.69 vs. 8.98% CP, on Day 30) of stylo silage as well as the increase (P < 0.01) of lactic acid bacteria population (6.17 vs. 7.54 cfu/g FM) and true protein content (6.03 vs. 7.44% DM), particularly at the first 30 days of ensiling. It somewhat enhanced the antioxidant capacity of style silage at the early stage, and altered the bacterial community of stylo silage, with Clostridium_sensu_stricto_1 and Lachnoclostridium_5 much decreased but Enterobacter and Clostridium still being the dominant genera. It is suggested that TPP could help improve fermentation quality and nutrient preservation of stylo silage, and delay proteolysis process and antioxidant decay.

Mixed Fermentation of Lactiplantibacillus plantarum and Bacillus licheniformis Changed the Chemical Composition, Bacterial Community, and Rumen Degradation Rate of Tea Residue

Tea residue, as a byproduct in tea processing, is highly nutritious and can be used as a good raw material for ruminant feed. This study aimed to investigate the effects of Lactiplantibacillus plantarum (L. plantarum) and Bacillus licheniformis (B. licheniformis) mixed fermentation of tea residue mixture (tea residue:wheat bran, 7:3) on chemical composition, bacterial community, and rumen degradation rate. Changes in chemical composition and bacterial community were evaluated after 0 (F0), 1 (F1), 3 (F3), and 5 (F5) days of fermentation. The rumen degradation rate was studied by the in situ nylon bag method. Compared with group F0, acid soluble protein in other groups increased while pH and neutral detergent fiber decreased (p < 0.05). The group F5 was the best. The diversity of bacterial communities in group F0 was significantly lower than those in the other groups (p < 0.05). The relative abundance of phylum Firmicutes and the genus Lactobacillus increased with increasing fermentation time. The rumen degradation rates of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber were increased after fermentation. In conclusion, mixed fermentation of tea residue by L. plantarum and B. licheniformis can ameliorate chemical composition, reduce bacterial community diversity, and improve the rumen degradation rate.

Green Tea (Camellia sinensis) Products as Alternatives to Antibiotics in Poultry Nutrition: A Review

The overuse and misuse of antibiotics in poultry feeds increase the total cost of production and compromise the quality of poultry products, which poses a serious threat to human health. Globally, health-conscious poultry consumers have long called for the alternate use of natural additives to mitigate the development and spread of multidrug resistant pathogens. Phytogenic plants, such as green tea (Camellia sinensis) products, contain putative nutraceuticals with antibiotic properties that can be used as alternatives to therapeutic, metaphylactic, prophylactic, and growth-promoting antibiotics. However, there are limited studies in the literature that have evaluated the potential of green tea (GT) products when used as replacements to in-feed antibiotics, with most studies focusing on their potential as sources of dietary nutrients in poultry feeds. Thus, this review paper discusses the potential of GT products to replace various antibiotics in poultry diets while presenting GT bioactive substances that can improve the growth performance, carcass and meat quality traits, and health status of the birds. We postulate that the utilisation of GT products in place of antibiotics could deliver sustainable, organic poultry production systems that would contribute significantly to global food and nutrition security.

Effect of heat-treated green tea waste feeding on fermentation kinetics, in vitro degradability, in vivo apparent digestibility, nitrogen balance, and blood metabolites in Black Bengal goat

The study was conducted to examine the effect of heat treatment of green tea waste (GTW) on rumen degradability, apparent digestibility, and plasma metabolites in Black Bengal goat based on in vitro and in vivo studies. The in vitro incubation was performed with autoclaved, oven, and freeze-dried GTW, whereas animal study was conducted using 12 Black-Bengal goats in a 3 × 3 Latin-square design. Goats were fed a total-mixed-ration without (control) or with the partial replacement of soybean meal and barley with 50 g/kg dry matter (DM) of either oven-dried or autoclaved GTW. Heat treatments reduced ether extract and tannins concentration but increased the effective DM and crude protein (CP) degradability of GTW. The highest values of in vitro volatile fatty acid concentration, molar proportion of propionate, ammonia-nitrogen concentration, and cumulative gas production were observed for oven-dried GTW among the tested GTW. Dietary treatment did not alter the DM intake, but apparent CP digestibility and retained nitrogen (N) were increased in goats fed control or oven-dried GTW incorporated diets. Feeding autoclaved GTW diet increased the urinary and fecal N excretion in goats. In contrast, plasma glucose concentration was highest in goats fed control or oven-dried GTW diet. In conclusion, oven drying could be a practical approach to increase protein digestibility and retained N in goats.

Advances in bioconversion of spent tea leaves to value-added products

Spent tea leaves (STL) are generated after the extraction of liquor from processed tea leaves and are regarded as an underutilized waste. STL are rich in essential amino acids, ω-6 and ω-3 fatty acids, alkaloids (theobromine and caffeine), polyphenols (catechin, theaflavins and rutin) and minerals (Ca, P, K, Mg, Mn) that could be utilized for the production of industrially important products. Vermicomposting, anaerobic digestion, silage preparation and fermentation are currently used as low cost methods for the bioconversion of STL to a usable form. Structural, morphological and chemical modification of STL after suitable bioconversion enables its application in the development of biopolymers, biofuels, catechin derivatives, biochar, absorbents for dye, and for removal of Cd, Hg, Cr(IV), As(V) and aspirin. This review discusses the composition, characterization, bioconversion and value added product generation from STL while highlighting prospective applications of STL in developing battery electrodes, nanocatalysts, insulation materials and edible bioactive peptides.

Biochemical Properties of Black and Green Teas and Their Insoluble Residues as Natural Dietary Additives to Optimize In Vitro Rumen Degradability and Fermentation but Reduce Methane in Sheep

Black (BTL) or green (GTL) tea and their spent tea (STL) leaves can be used as natural dietary additives for ruminants. Experiment 1 used a 3 × 2 × 2 factorial arrangement, with four replicates (n = 4) to test the effects of three different inclusions of tea leaves at 0 (control), 50, and 100 g/kg DM of two different tea types (BTL and GTL) in two different total mixed diets containing either ryegrass hay (RH) or rice straw (RS) on in vitro rumen organic matter degradability (IVOMD), volatile fatty acids (VFA), pH, ammonia (NH3), and methane (CH4) outputs over a 24 h incubation time. Experiment 2 followed a 3 × 2 × 2 factorial arrangement, with eight replicates (n = 8) to study the impacts of three different STL inclusions at 0, 100, and 200 g/kg DM of two different STL types (black and green) into two different total mixed diets containing either RH or RS on the same in vitro measurements. Both types of tea leaves decreased NH3 (p < 0.001) and CH4 (p < 0.01) without affecting (p > 0.05) rumen degradability, but the effect of their STL was less remarkable. Tea leaves and their STL inclusions improved (p < 0.01 and p < 0.001, respectively) the acetate to propionate (A:P) ratio. Compared with BTL, GTL containing diets had higher IVOMD (p < 0.05) and A:P ratio (p < 0.05) but lower NH3 (p < 0.001). Reduced rumen NH3 and CH4 outputs can be useful for protein and energy use efficiency while an increased A:P ratio might lead to increased milk fat synthesis and reduced low-fat milk syndrome. The surplus or wasted tea leaf products could be used as sustainable sources of nutrients to optimize rumen function and minimize environmental impacts of feeding ruminant animals.

Recent Developments in Metabolomics Studies of Endophytic Fungi

Endophytic fungi are microorganisms that colonize living plants' tissues without causing any harm. They are known as a natural source of bioactive metabolites with diverse pharmacological functions. Many structurally different chemical metabolites were isolated from endophytic fungi. Recently, the increasing trends in human health problems and diseases have escalated the search for bioactive metabolites from endophytic fungi. The conventional bioassay-guided study is known as laborious due to chemical complexity. Thus, metabolomics studies have attracted extensive research interest owing to their potential in dealing with a vast number of metabolites. Metabolomics coupled with advanced analytical tools provides a comprehensive insight into systems biology. Despite its wide scientific attention, endophytic fungi metabolomics are relatively unexploited. This review highlights the recent developments in metabolomics studies of endophytic fungi in obtaining the global metabolites picture.

Current understanding in conversion and application of tea waste biomass: A review

Along with the increasing consumption of tea and its extracts, the amount of tea waste grows rapidly, which not only results in huge biomass loss, but also increases environmental stress. In past years, interest has been attracted on utilization of tea waste biomass, and a lot of work has been carried out. This review summarized the progress in conversion of tea waste by thermo-chemical and biological technologies and analyzed the property of the derived products and their performance in applications. It was found that biochar derived from tea waste had relatively large surface area, porous structures, and abundant functional groups, and could be used as bio-adsorbents and catalysts and electrochemical energy storage, while the cost of its largescale production should be evaluated. Profoundly, biological conversion, including ensiling and composting, was suggested to be an effective way to develop the tea waste biomass in practice due to its low-cost and specific functions.

Catechins: Therapeutic Perspectives in COVID-19-Associated Acute Kidney Injury

Data obtained from several intensive care units around the world have provided substantial evidence of the strong association between impairment of the renal function and in-hospital deaths of critically ill COVID-19 patients, especially those with comorbidities and requiring renal replacement therapy (RRT). Acute kidney injury (AKI) is a common renal disorder of various etiologies characterized by a sudden and sustained decrease of renal function. Studies have shown that 5-46% of COVID-19 patients develop AKI during hospital stay, and the mortality of those patients may reach up to 100% depending on various factors, such as organ failures and RRT requirement. Catechins are natural products that have multiple pharmacological activities, including anti-coronavirus and reno-protective activities against kidney injury induced by nephrotoxic agents, obstructive nephropathies and AKI accompanying metabolic and cardiovascular disorders. Therefore, in this review, we discuss the anti-SARS-CoV-2 and reno-protective effects of catechins from a mechanistic perspective. We believe that catechins may serve as promising therapeutics in COVID-19-associated AKI due to their well-recognized anti-SARS-CoV-2, and antioxidant and anti-inflammatory properties that mediate their reno-protective activities.

The chemical diversity, the attractant, anti-acetylcholinesterase, and antifungal activities of metabolites from biocontrol Trichoderma harzianum uncovered by OSMAC strategy

Eight new compounds (1-8) were discovered from Trichoderma harzianum associated with edible mushroom by the one strain many compounds (OSMAC) strategy. Triharzianin A (1) is the first naturally scaffold characterized by a C₁₃-prostaglandin skeleton. The configurations of 1-3, and 5 were determined by the Mosher's method, experimental and calculated ECD spectra, and plausible biosynthesis of stereospecific epoxidation. Most compounds indicated obvious feeding attractant activities to silkworm with attraction rates at 30-90%. Compound 7 showed anti-acetylcholinesterase (anti-AChE) activity with a ratio of 29% at a concentration of 50 μM for insecticidal potential. So 2,​3-​dialkylchromone (7) had potential of chemical entrapment and killing of insects. Compounds 2, 3 and 7-11 showed antifungal activities against Aspergillus fumigates, and Trichoderma sp. from mushroom with MICs ≤ 300 μM. The four fermentation extracts also indicated obvious feeding attractant activities to silkworm for the activities brought by active metabolites from T. harzianum. The material base of biocontrol induced by the interaction of host-fungal symbiont can be investigated by the antifungal metabolites against pathogen fungi.

Simplified Method of Multi-Elemental Analysis of Dialyzable Fraction of Tea Infusions by FAAS and ICP OES

A fast and straightforward sample preparation procedure of the dialyzable fraction of infusions of teas prior to their analysis on Al, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr, and Zn contents by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) was developed and validated. The proposed methodology was based on acidification with HNO3 only and demonstrated good analytical performance, i.e., precision (0.80-5.0%), accuracy (< 5%), recoveries of elements (97.4-105%), and their detection limits (0.075-1.1 μg L-1) along with linearity of calibration curves in the whole studied concentration ranges. Applicability of the evaluated procedure, being a useful alternative to time-consuming wet digestions, was tested by determining bioaccessibility of elements in 20 infusions of black (BT) and green (GT) teas as assessed with the aid of in vitro gastrointestinal digestion. Average contributions of bioaccessible fractions (%) of studied metals were as follows: 1.18 (Al)-40.7% (Ca) and 4.65% (Al)-46.3% (Ca) for BTs and GTs, respectively. Drinking daily four cups (1 L) of tea, recommended dietary intakes (RDIs) of Ca, Cu, Fe, Mg, and Zn were covered to a small degree (< 1.5%). Only bioaccessibility of Mn highly contributed to RDI for this metal. According to provisional tolerable weekly intakes (PTWIs) for toxic elements such as Al and Ni, consumption of both types of teas should not represent any health risk. Additionally, analysis of variance of results clearly indicated that BTs and GTs were mostly differentiated due to concentrations of the bioaccessible fraction of Al, Ba, Cu, and Ni.

Effect of using banana by-products and other agricultural residues for beef cattle in southern China

Banana (Musa acuminata) by-products and other agricultural residues such as rice straw and sugarcane top are abundant in the southern part of China, but most of them are wasted and discarded. Under this experiment, several silages containing banana by-products with other crop residues were investigated for their fermentation characteristics and feeding values to beef cattle. There were three treatments (T) as follows: T₁ = fresh banana by-products (FBBP) + 4% corn meal (CM), T₂ = FBBP + rice straw (RS) at 70:30 (fresh weight), T₃ = FBBP + sugarcane top (SCT) at 70:30 (fresh weight). Twenty-one beef cattle bulls (220 ± 15 kg body weight) were randomly assigned to 3 groups and assigned to one of three silage treatments in a total feeding period of 237 days. Results revealed that all of the three silage mixtures had a good fermentative profile with lower pH and higher organic acids. The FBBP + CM group significantly increased DM, CP, EE, and Ca content (P < 0.05), while decreased ash, NDF, ADF, ADL, and condensed tannins (CT) content (P < 0.01). Significant effects on weight gain, feed intake, and feed efficiency were observed at the end of the experiment (P < 0.05). The FBBP + CM group also had the greatest total weight gain at 109 kg/head, twice of the FBBP + RS group (P = 0.001), as well as the greatest average daily weight gain at 0.48 kg/head/day, followed by the FBBP + SCT group at 0.30 kg/head/day and the FBBP + RS group at 0.27 kg/head/day, respectively. Cattle fed FBBP + CM silage mixture diet had better feed efficiency than the cattle fed with the other mixtures (P < 0.001). Results of body measurements showed that cattle consumed FBBP + CM silage mixture tended to have a greater body diagonal length, height at the hip, hip width, and rump length than those either consumed FBBP + RS or FBBP + SCT (P < 0.05). The findings showed promising results of banana by-products silage with other agricultural crop residues to be used for increasing beef cattle production in southern China.

Validation of reference genes for gene expression studies in post-harvest leaves of tea plant (Camellia sinensis)

Tea is one of three major non-alcoholic beverages that are popular all around the world. The economic value of tea product largely depends on the post-harvest physiology of tea leaves. The utilization of quantitative reverse transcription polymerase chain reaction is a widely accepted and precise approach to determine the target gene expression of tea plants, and the reliability of results hinges on the selection of suitable reference genes. A few reliable reference genes have been documented using various treatments and different tissues of tea plants, but none has been done on post-harvest leaves during the tea manufacturing process. The present study selected and analyzed 15 candidate reference genes: Cs18SrRNA, CsGADPH, CsACT, CsEF-1α, CsUbi, CsTUA, Cs26SrRNA, CsRuBP, CsCYP, CselF-4α, CsMON1, CsPCS1, CsSAND, CsPPA2, CsTBP. This study made an assessment on the expression stability under two kinds of post-harvest treatment, turn over and withering, using three algorithms-GeNorm, Normfinder, and Bestkeeper. The results indicated that the three commonly used reference genes, CsTUA, Cs18SrRNA, CsRuBP, together with Cs26SrRNA, were the most unstable genes in both the turn over and withering treatments. CsACT, CsEF-1α, CsPPA2, and CsTBP were the top four reference genes in the turn over treatment, while CsTBP, CsPCS1, CsPPA2, CselF-4α, and CsACT were the five best reference genes in the withering group. The expression level of lipoxygenase genes, which were involved in a number of diverse aspects of plant physiology, including wounding, was evaluated to validate the findings. To conclude, we found a basis for the selection of reference genes for accurate transcription normalization in post-harvest leaves of tea plants.

Nutritive evaluation of spent green and black tea leaf silages by in vitro gas production characteristics, ruminal degradability and post-ruminal digestibility assessed with inhibitory activity of their tannins

Spent tea leaf contains high levels of crude protein, suggesting that it may be used as an alternative source for ruminant feeding. We assessed the nutritive characteristics of spent green tea leaf silage (GTS) and black tea leaf silages (BTS) in comparison with soybean meal (SBM) and alfalfa hay cube (AHC) using in vitro assay. The effects of tannin on the nutritive characteristics were also evaluated by adding polyethylene glycol (PEG) as a tannin-binding agent. The amount of gas production was greater for SBM, followed by AHC, GTS, and BTS. A significant improvement in gas production upon addition of PEG was observed only for BTS. Ruminal protein degradability and post-ruminal digestibility was higher for SBM, followed by AHC, GTS, and BTS. The presence of PEG significantly increased ruminal degradability and post-ruminal protein digestibility for GTS and BTS, but not for AHC. The increment of protein digestibility by PEG was much greater for BTS than for GTS, indicating that GTS tannins suppress protein digestibility slightly, whereas BTS tannins do so strongly. According to these results, GTS but not BTS has a potential as an alternative to AHC as a ruminant feedstuff.

Diabetes and Alzheimer's Disease: Can Tea Phytochemicals Play a Role in Prevention?

Dementia and diabetes mellitus are prevalent disorders in the elderly population. While recognized as two distinct diseases, diabetes has more recently recognized as a significant contributor to risk for developing dementia, and some studies make reference to type 3 diabetes, a condition resulting from insulin resistance in the brain. Alzheimer's disease, the most common form of dementia, and diabetes, interestingly, share underlying pathological processes, commonality in risk factors, and, importantly, pathways for intervention. Tea has been suggested to possess potent antioxidant properties. It is rich in phytochemicals including, flavonoids, tannins, caffeine, polyphenols, boheic acid, theophylline, theobromine, anthocyanins, gallic acid, and finally epigallocatechin-3-gallate, which is considered to be the most potent active ingredient. Flavonoid phytochemicals, known as catechins, within tea offer potential benefits for reducing the risk of diabetes and Alzheimer's disease by targeting common risk factors, including obesity, hyperlipidemia, hypertension, cardiovascular disease, and stroke. Studies also show that catechins may prevent the formation of amyloid-β plaques and enhance cognitive functions, and thus may be useful in treating patients who have Alzheimer's disease or dementia. Furthermore, other phytochemicals found within tea offer important antioxidant properties along with innate properties capable of modulating intracellular neuronal signal transduction pathways and mitochondrial function.

Multiligand Metal-Phenolic Assembly from Green Tea Infusions

The synthesis of hybrid functional materials using the coordination-driven assembly of metal-phenolic networks (MPNs) is of interest in diverse areas of materials science. To date, MPN assembly has been explored as monoligand systems (i.e., containing a single type of phenolic ligand) where the phenolic components are primarily obtained from natural sources via extraction, isolation, and purification processes. Herein, we demonstrate the fabrication of MPNs from a readily available, crude phenolic source-green tea (GT) infusions. We employ our recently introduced rust-mediated continuous assembly strategy to prepare these GT MPN systems. The resulting hollow MPN capsules contain multiple phenolic ligands and have a shell thickness that can be controlled through the reaction time. These multiligand MPN systems have different properties compared to the analogous MPN systems reported previously. For example, the Young's modulus (as determined using colloidal-probe atomic force microscopy) of the GT MPN system presented herein is less than half that of MPN systems prepared using tannic acid and iron salt solutions, and the disassembly kinetics are faster (∼50%) than other, comparable MPN systems under identical disassembly conditions. Additionally, the use of rust-mediated assembly enables the formation of stable capsules under conditions where the conventional approach (i.e., using iron salt solutions) results in colloidally unstable dispersions. These differences highlight how the choice of phenolic ligand and its source, as well as the assembly protocol (e.g., using solution-based or solid-state iron sources), can be used to tune the properties of MPNs. The strategy presented herein expands the toolbox of MPN assembly while also providing new insights into the nature and robustness of metal-phenolic interfacial assembly when using solution-based or solid-state metal sources.

Optimized aqueous extraction of saponins from bitter melon for production of a saponin-enriched bitter melon powder

Bitter melon, Momordica charantia L. (Cucurbitaceae), aqueous extracts are proposed to have health-promoting properties due to their content of saponins and their antioxidant activity. However, the optimal conditions for the aqueous extraction of saponins from bitter melon and the effects of spray drying have not been established. Therefore, this study aimed to optimize the aqueous extraction of the saponins from bitter melon, using response surface methodology, prepare a powder using spray drying, and compare the powder's physical properties, components, and antioxidant capacity with aqueous and ethanol freeze-dried bitter melon powders and a commercial powder. The optimal aqueous extraction conditions were determined to be 40 °C for 15 min and the water-to-sample ratio was chosen to be 20:1 mL/g. For many of its physical properties, components, and antioxidant capacity, the aqueous spray-dried powder was comparable to the aqueous and ethanol freeze-dried bitter melon powders and the commercial powder. The optimal conditions for the aqueous extraction of saponins from bitter melon followed by spray drying gave a high quality powder in terms of saponins and antioxidant activity.

PRACTICAL APPLICATION

This study highlights that bitter melon is a rich source of saponin compounds and their associated antioxidant activities, which may provide health benefits. The findings of the current study will help with the development of extraction and drying technologies for the preparation of a saponin-enriched powdered extract from bitter melon. The powdered extract may have potential as a nutraceutical supplement or as a value-added ingredient for incorporation into functional foods.

Fermentation Characteristics, Tannin Contents and In vitro Ruminal Degradation of Green Tea and Black Tea By-products Ensiled at Different Temperatures

Green and black tea by-products, obtained from ready-made tea industry, were ensiled at 10°C, 20°C, and 30°C. Green tea by-product silage (GTS) and black tea by-product silage (BTS) were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG) as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at 10°C. The GTS stored at 20°C and 30°C showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on NH₃-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and NH₃-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and NH₃-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin’s activity in the rumen.

Differential activities of fungi-derived tannases on biotransformation and substrate inhibition in green tea extract

Tannases are important enzymes in the antioxidant potential of tea leaves. In this study, we evaluated the effect of two tannases (T1 and T2) on biotransformation of tea polyphenols and antioxidative activities from catechins in green tea extract (GTE). The T1 tannase-catalyzed reaction was inhibited by the addition of >2.0% GTE substrate, whereas the T2-catalyzed reaction was not inhibited, even by addition of 5.0% GTE. Furthermore, the T1 tannase-catalyzed reaction was inhibited by addition of 10 mg mL(-1) EGCG, whereas the T2 tannase-catalyzed reaction did not display any inhibitory effect. These results indicate that T2 tannase was more tolerant than T1 tannase to substrate inhibition in degallation reactions. Specifically, the substrate EGCG (90,687.1 μg mL(-1)) was transformed into gallic acid (50,242.9 μg mL(-1)) and EGC (92,598.3 μg mL(-1)) after 1-h treatment with T2 tannase (500 U g(-1)). The tannase-mediated product displayed higher in vitro radical-scavenging activity than the control. IC50 value of GTE on ABTS and DPPH radicals (46.1 μg mL(-1) and 18.4 μg mL(-1), respectively) decreased markedly after T2 tannase treatment (to 35.8 μg mL(-1) and 15.1 μg mL(-1), respectively). These results indicate that T2 tannase treatment of GTE enhanced its radical-scavenging activity, an increase that was also observed in the reaction using EGCG substrate. Taken together, our results revealed that T2 tannase is more suitable for biotransformation of catechins in GTE than T1 tannase, and T2 treatment provides an enhanced radical-scavenging effect.