The considerable hazard posed by periprosthetic joint infections underlines the urgent need for the rapid advancement of in-situ drug delivery systems within joint materials.However,the pursuit of sustained antibacter...The considerable hazard posed by periprosthetic joint infections underlines the urgent need for the rapid advancement of in-situ drug delivery systems within joint materials.However,the pursuit of sustained antibacterial efficacy remains a formidable challenge.In this context,we proposed a novel strategy that leverages swelling and erosion mechanisms to facilitate drug release of drug-loaded ultrahigh molecular weight polyethylene(UHMWPE),thereby ensuring its long-lasting antibacterial performance.Polyethylene oxide(PEO),a hydrophilic polymer with fast hydrating ability and high swelling capacity,was incorporated in UHMWPE alongside the antibacterial tea polyphenol(epigallocatechin gallate,EGCG as representative).The swelling of PEO enhanced water infiltration into the matrix,while the erosion of PEO balanced the release of the encapsulated EGCG,resulting in a steady release.The behavior was supported by the EGCG release profiles and the corresponding fitted release kinetic models.As demonstrated by segmented antibacterial assessments,the antibacterial efficiency was enhanced 2to 3 times in the PEO/EGCG/UHMWPE composite compared to that of EGCG/UHMWPE.Additionally,the PEO/EGCG/UHMWPE composite exhibited favorable biocompatibility and mechanical performance,making it a potential candidate for the development of drug-releasing joint implants to combat prosthetic bacterial infections.展开更多
Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity ag...Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.展开更多
The interaction between host circadian rhythm and gut microbes through the gut-brain axis provides new clues for tea polyphenols to improve host health.Our present research showed that oolong tea polyphenols(OTP)impro...The interaction between host circadian rhythm and gut microbes through the gut-brain axis provides new clues for tea polyphenols to improve host health.Our present research showed that oolong tea polyphenols(OTP)improved the structural disorder of the intestinal flora caused by continuous darkness,thereby modulating the production of metabolites related to pyruvate metabolism,glycolysis/gluconeogenesis,and tryptophan metabolism to alleviate the steady-state imbalance.After fecal microbiota transplantation from the OTP group,the single-cell transcriptomic analysis revealed that OTP significantly increased the number of hypothalamus cell clusters,up-regulated the number of astrocytes and fibroblasts,and enhanced the expression of circadian rhythm genes Cry2,Per3,Bhlhe41,Nr1d1,Nr1d2,Dbp and Rorb in hypothalamic cells.Our results confirmed that OTP can actively improve the intestinal environmental state as well as internal/peripheral circadian rhythm disorders and cognitive impairment,with potential prebiotic functional characteristics to notably contribute to host health.展开更多
[Objective]This paper was to investigate the action targets and pathways of tea polyphenols in alleviating heat stress-induced injury by using network pharmacological analysis and an H9C2 cell model.[Method]First,the ...[Objective]This paper was to investigate the action targets and pathways of tea polyphenols in alleviating heat stress-induced injury by using network pharmacological analysis and an H9C2 cell model.[Method]First,the corresponding targets of tea polyphenols were obtained from the PubChem database.Then,the core targets were screened based on topological parameters.The relevant metabolism pathways of tea polyphenols related to diseases were identified through GO functional annotation and KECG signaling pathway enrichment.Moreover,common targets for thermal injury and targets of tea polyphenols were obtained.Then,GO functional annotation was performed to explore the pathway of tea polyphenols in alleviating heat stress damage.H9C2 cells were cultured at 42℃ to construct the heat stress model,and the cells were treated with 10μg/mL tea polyphenols.The key genes were confirmed using RT-PCR technology.[Result]The study yielded 364 targets corresponding to tea polyphenols,including 68 core targets.These targets are related to various biological processes such as involve oxidative stress,cancer,lipopolysaccharide-mediated signaling pathways,antiviral responses,regulation of cellular response to heat,apoptosis,and cellular lipid metabolic metabolism.Tea polyphe nols alleviate thermal damage by targeting BCL2,HSP90AA1,HSPA1A,JUN,MAPK1,NFKB1,NFKBIA,NOS3,and TP53.Moreover,10 mg/L tea polyphenols were found to upregulate the transcription levels of Hsp70,HO-1,NQ-O1,Nrf2,and MAPKI,and the transcription levels of Bax/Bcl2,p38,and JNK were downregulated to alleviate the heat stress-induced injury.[Conclusion]Tea polyphenols may enhance the antioxidant ability of H9C2 cells and inhibit cell apoptosis,thereby reducing heat stress injury.展开更多
Harmful algal blooms(HABs)resulting from eutrophication pose a major threat to ecosystems and human health,necessitating effective control measures.Allelochemicals have shown their importance in slowing down algal pro...Harmful algal blooms(HABs)resulting from eutrophication pose a major threat to ecosystems and human health,necessitating effective control measures.Allelochemicals have shown their importance in slowing down algal proliferation due to their proven efficacy and low ecological impacts.In this study,allelopathy tea polyphenols(TPs)andβ-cyclodextrin were combined to prepare slow-release algicidal microcapsules,and the diversity of microbial community in the algal inhibition process was analyzed.Results showed that TP slow-release microcapsules had strong algicidal activity.When against Microcystis aeruginosa within 20 d,their constant inhibitory rate was up to 99%compared to the control group.Microbial diversity decreased with an increase in algae density,and the species richness and diversity of algae increased under the stress of TP slow-release microcapsules.The redundancy analysis showed that the environmental factors with impacts on the abundance and diversity of bacterial communities in descending order were dissolved oxygen,pH,and temperature.This study provides a theoretical basis for the application of TP slow-release microcapsules to actual water.展开更多
Mice were administered a selenium-rich Agaricus blazei Murill(Se-AbM)polysaccharides and tea polyphenol compound solution for prevention and treatment.Following exposure to 2 Gy of infrared radiation,peripheral blood ...Mice were administered a selenium-rich Agaricus blazei Murill(Se-AbM)polysaccharides and tea polyphenol compound solution for prevention and treatment.Following exposure to 2 Gy of infrared radiation,peripheral blood counts of white blood cells,red blood cells,and platelets were assessed,along with serum levels of apoptosis-related factors Fas and Fas ligand,inflammatory factors interferon-gamma and tumor necrosis factor-alpha,immune-related factors interleukin-3 and interleukin-6,and indicators of oxidative stress,including malondialdehyde,superoxide dismutase,and glutathione.The results showed significant differences in these indicators between the Se-AbM-treated group and the model group,suggesting that Se-AbM may inhibit apoptosis,enhance the clearance of free radicals in the body,improve antioxidant capacity,and provide a significant protective effect against radiation-induced immune damage.展开更多
AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cer...AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cerebral ischemia reperfusion injury was produced by bilateral ligation of the common carotid arteries with vagus nerves and reperfusion for 45 min. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. Superoxide anion (O 2) from xanthine xanthine oxidase system and hydroxyl radical (·OH) from Fe 2+ -H 2O 2 system were determined with spectrophotometry. RESULTS During Cerebral ischemia reperfusion,TP improved the activities of superoxide dismutase ( P 【0 05), GSH peroxidase( P 【0 01) and catalase( P 【0 01), while decreasing the maiondialdchyde content in the brain( P 【0 05) and brain water content ( P 【0 01). Tea polyphenol possessed significantly scavenging effects on ·OH produced by Fenton reaction and O 2 produced by xanthine xanthine oxidase system (the IC 50 were 2 2 mmol·L -1 and 1 9 mmol·L -1 respectively). Tea polyphenol could significant inhibit the lipid peroxidation of cerbral mitochondrial membrane induced by ·OH in a concentration dependent manner. CONCLUSION The results indicate that tea polyphenol could protect the injury on cerebral ischemia reperfusion in rats for OFR, these effects may be related to its scavenging effects on oxygen free radicals and antilipid peroxidant.展开更多
Lipophilic tea polyphenols (LTP) were prepared by catalytic esterification of green tea polyphenols (GTP) with hexadecanoyl chloride. A novel long chain acyl derivative of epigallocatechin 3 o gallate (EGCG) ...Lipophilic tea polyphenols (LTP) were prepared by catalytic esterification of green tea polyphenols (GTP) with hexadecanoyl chloride. A novel long chain acyl derivative of epigallocatechin 3 o gallate (EGCG) was first isolated from purification of LTP by high speed countercurrent chromatography (HSCCC) using a solvent system composed of n hexane ethyl acetate methanol water (1:1:1:1, v/v). The molecular structure of the acyl derivative, Epigallocatechin 3 O gallate 4′ O hexadecanate , was elucidated by means of elemental analysis, IR, 1H NMR and MS spectra.展开更多
Teapolyphenols are the generic term of polyphenols in tea.Tea polyphenols are non-toxic and odorless with high oxidation resistance.Heat stress causes oxidative stress,which impairs the capacity of antioxidant defense...Teapolyphenols are the generic term of polyphenols in tea.Tea polyphenols are non-toxic and odorless with high oxidation resistance.Heat stress causes oxidative stress,which impairs the capacity of antioxidant defense system and immunity,thereby seriously affecting the production performance of animals.Teapolyphenols could reduce heatstress response in animals by scavenging harmful free radicals and increasing the activities of antioxidant enzymes.展开更多
AIM To investigate protective effects and molecular mechanisms of green tea polyphenols(GTP) on nonalcoholic fatty liver disease(NAFLD) in Zucker fatty(ZF) rats.METHODS Male ZF rats were fed a high-fat diet(HFD) for 2...AIM To investigate protective effects and molecular mechanisms of green tea polyphenols(GTP) on nonalcoholic fatty liver disease(NAFLD) in Zucker fatty(ZF) rats.METHODS Male ZF rats were fed a high-fat diet(HFD) for 2 wk then treated with GTP(200 mg/kg) or saline(5 m L/kg) for 8 wk, with Zucker lean rat as their control. At the end of experiment, serum and liver tissue were collected for measurement of metabolic parameters, alanine aminotransferase(ALT) and aspartate aminotransferase(AST), inflammatory cytokines and hepatic triglyceride and liver histology. Immunoblotting was used to detect phosphorylation of AMP-activated protein kinase(AMPK) acetyl-Co A carboxylase(ACC), and sterol regulatory element-binding protein 1c(SREBP1c). RESULTS Genetically obese ZF rats on a HFD presented with metabolic features of hepatic pathological changes comparable to human with NAFLD. GTP intervention decreased weight gain(10.1%, P = 0.052) and significantly lowered visceral fat(31.0%, P < 0.01). Compared with ZF-controls, GTP treatment significantly reduced fasting serum insulin, glucose and lipids levels. Reduction in serum ALT and AST levels(both P < 0.01) were observed in GTP-treated ZF rats. GTP treatment also attenuated the elevated TNFα and IL-6 in the circulation. The increased hepatic TG accumulation and cytoplasmic lipid droplet were attenuated by GTP treatment, associated with significantly increased expression of AMPK-Thr172(P < 0.05) and phosphorylated ACC and SREBP1c(both P < 0.05), indicating diminished hepatic lipogenesis and triglycerides out flux from liver in GTP treated rats. CONCLUSION The protective effects of GTP against HFD-induced NAFLD in genetically obese ZF rats are positively correlated to reduction in hepatic lipogenesis through upregulating the AMPK pathway.展开更多
Objective： To investigate the effect of tea polyphenols on cardiac function in rats with diabetic cardiomyo- pathy, and the mechanism by which tea polyphenols regulate autophagy in diabetic cardiomyopathy. Methods： ...Objective： To investigate the effect of tea polyphenols on cardiac function in rats with diabetic cardiomyo- pathy, and the mechanism by which tea polyphenols regulate autophagy in diabetic cardiomyopathy. Methods： Sixty Sprague-Dawley （SD） rats were randomly divided into six groups： a normal control group （NC）, an obesity group （OB）, a diabetic cardiomyopathy group （DCM）, a tea polyphenol group （TP）, an obesity tea polyphenol treatment group （OB-TP）, and a diabetic cardiomyopathy tea polyphenol treatment group （DCM-TP）. After successful modeling, serum glucose, cholesterol, and triglyceride levels were determined; cardiac structure and function were inspected by ul- trasonic cardiography; myocardial pathology was examined by staining with hematoxylin-eosin; transmission electron microscopy was used to observe the morphology and quantity of autophagosomes; and expression levels of autophagy-related proteins LC3-11, SQSTM1/p62, and Beclin-1 were determined by Western blotting. Results： Com- pared to the NC group, the OB group had normal blood glucose and a high level of blood lipids; both blood glucose and lipids were increased in the DCM group; ultrasonic cardiograms showed that the fraction shortening was reduced in the DCM group. However, these were improved significantly in the DCM-TP group. Hematoxylin-eosin staining showed disordered cardiomyocytes and hypertrophy in the DCM group; however, no differences were found among the remaining groups. Transmission electron microscopy revealed that the numbers of autophagosomes in the DCM and OB-TP groups were obviously increased compared to the NC and OB groups; the number of autophagosomes in the DCM-TP group was reduced. Western blotting showed that the expression of LC3-11/I and Beclin-1 increased obviously whereas the expression of SQSTM1/p62 was decreased in the DCM and OB-TP groups （P〈0.05）. Conclusions： Tea polyphenols had an effect on diabetic cardiomyopathy in rat cardiac function and may alter the levels of autophagy to improve glucose and lipid metabolism in diabetes.展开更多
Objective Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseas...Objective Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseases, we observed the expressions of ROS-related enzymes in endothelial cells. Methods Tea polyphenols were co-incubated with bovine carotid artery endothelial cells (BCAECs) in vitro and intracellular NADPH oxidase subunits p22phox and p67phox, SOD-1, and catalase protein were detected using Western blot method. Results Tea polyphenols of 0.4 ug/mL and 4.0 ug/mL (from either green tea or black tea) down-regulated NADPH oxidase p22phox and p67phox expressions in a dose-negative manner (P<0.05), and up-regulated the expressions of catalase (P<0.05). Conclusions Tea polyphenols regulate the enzymes involved in ROS production and elimination in endothelial cells, and may be beneficial to the prevention of endothelial cell dysfunction and the development of cardiovascular diseases.展开更多
Polyphenols,including phenolic acids,flavonoids,and procyanidins,are abundant in food and beverage derived from plants.Tea(Camellia sinensis)is particularly rich in polyphenols(e.g.,catechins,theaflavins,thearubigins,...Polyphenols,including phenolic acids,flavonoids,and procyanidins,are abundant in food and beverage derived from plants.Tea(Camellia sinensis)is particularly rich in polyphenols(e.g.,catechins,theaflavins,thearubigins,gallic acid,and flavonols),which are thought to contribute to the health benefits of tea.High intake of tea polyphenols has been described to prevent and/or attenuate a variety of chronic pathological conditions like cardiovascular diseases,neurodegenerative diseases,diabetes,and cancer.This review focuses on established antioxidant and anti-inflammatory properties of tea polyphenols and underlying mechanisms of their involvement in inflammatory bowel diseases(IBD).Tea polyphenols act as efficient antioxidants by inducing an endogenous antioxidant defense system and maintaining intracellular redox homeostasis.Tea polyphenols also regulate signaling pathways such as nuclear factor-κB,activator protein 1,signal transducer and activator of transcriptions,and nuclear factor E2-related factor 2,which are associated with IBD development.Accumulating pieces of evidence have indicated that tea polyphenols enhance epithelial barrier function and improve gut microbial dysbiosis,contributing to the management of inflammatory colitis.Therefore,this study suggests that supplementation of tea polyphenols could prevent inflammatory conditions and improve the outcome of patients with IBD.展开更多
In order to study the molecular mechanisms of green tea polyphenols（GTPs） in treatment or prevention of breast cancer, the cytotoxic effects of GTPs on five human cell lines（MCF-7, A549, Hela, PC3, and HepG2 cells...In order to study the molecular mechanisms of green tea polyphenols（GTPs） in treatment or prevention of breast cancer, the cytotoxic effects of GTPs on five human cell lines（MCF-7, A549, Hela, PC3, and HepG2 cells） were determined and the antitumor mechanisms of GTPs in MCF-7 cells were analyzed. The results showed that GTPs exhibited a broad spectrum of inhibition against the detected cancer cell lines, particularly the MCF-7 cells. Studies on the mechanisms revealed that the main modes of cell death induced by GTPs were cell cycle arrest and mitochondrialmediated apoptosis. Flow cytometric analysis showed that GTPs mediated cell cycle arrest at both G1/M and G2/M transitions. GTP dose dependently led to apoptosis of MCF-7 cells via the mitochondrial pathways, as evidenced by induction of chromatin condensation, reduction of mitochondrial membrane potential（ΔΨ_m）, improvement in the generation of reactive oxygen species（ROS）, induction of DNA fragmentation, and activations of caspase-3 and caspase-9 in the present paper.展开更多
Colorectal cancer(CRC),a multifactorial disease,is usually induced and developed through complex mechanisms,including impact of diet and lifestyle,genomic abnormalities,change of signaling pathways,inflammatory respon...Colorectal cancer(CRC),a multifactorial disease,is usually induced and developed through complex mechanisms,including impact of diet and lifestyle,genomic abnormalities,change of signaling pathways,inflammatory response,oxidation stress,dysbiosis,and so on.As natural polyphenolic phytochemicals that exist primarily in tea,tea polyphenols(TPs)have been shown to have many clinical applications,especially as anticancer agents.Most animal studies and epidemiological studies have demonstrated that TPs can prevent and treat CRC.TPs can inhibit the growth and metastasis of CRC by exerting the antiinflammatory,anti-oxidative or pro-oxidative,and pro-apoptotic effects,which are achieved by modulations at multiple levels.Many experiments have demonstrated that TPs can modulate several signaling pathways in cancer cells,including the mitogen-activated protein kinase pathway,phosphatidylinositol-3 kinase/Akt pathway,Wnt/β-catenin pathway,and 67 kDa laminin receptor pathway,to inhibit proliferation and promote cell apoptosis.In addition,novel studies have also suggested that TPs can prevent the growth and metastasis of CRC by modulating the composition of gut microbiota to improve immune system and decrease inflammatory responses.Molecular pathological epidemiology,a novel multidisciplinary investigation,has made great progress on CRC,and the further molecular pathological epidemiology research should be developed in the field of TPs and CRC.This review summarizes the existing in vitro and in vivo animal and human studies and potential mechanisms to examine the effects of tea polyphenols on CRC.展开更多
AIM： To investigate the hepatoprotective activity of tea polyphenols （TP） and its relation with cytochrome P450 （CYP450） expression in mice. METHODS： Hepatic CYP450 and CYPbs levels were measured by UV-spectroph...AIM： To investigate the hepatoprotective activity of tea polyphenols （TP） and its relation with cytochrome P450 （CYP450） expression in mice. METHODS： Hepatic CYP450 and CYPbs levels were measured by UV-spectrophotometry in mice 2 d after intraperitoneal TP （25, 50 and 100 mg/kg per day）. Then the mice were intragastricly pre-treated with TP （100, 200 and 400 mg/kg per day） for six days before paracetamol （1000 mg/kg） was given. Their acute mortality was compared with that of control mice. The mice were pre-treated with TP （100, 200, and 400 mg/kg per day） for five days before paracetamol （500 mg/kg） was given. Hepatic CYP2E1 and CYPIA2 protein and mRNA expression levels were evaluated by Western blotting, immunohistochemical staining and transcriptase-polymerase chain reaction. RESULTS： The hepatic CYP450 and CYPb5 levels in mice of TP-treated groups （100, 200 and 400 mg/kg per day） were decreased in a dose-dependent manner compared with those in the negative control mice.TP significantly attenuated the paracetamol-induced hepatic injury and dramatically reduced the mortality of paracetamol-treated mice. Furthermore, TP reduced CYP2E1 and CYPIA2 expression at both protein and mRNA levels in a dose-dependent manner. CONCLUSION： TP possess potential hepatoprotective properties and can suppress CYP450 expression.展开更多
Abstract： Vanadium compounds are promising therapeutic agents for the treatment of diabetes and cancer. However, vanadium toxicity has been a great concern. Many works suggested that vanadium-induced oxidative stress...Abstract： Vanadium compounds are promising therapeutic agents for the treatment of diabetes and cancer. However, vanadium toxicity has been a great concern. Many works suggested that vanadium-induced oxidative stress is a major reason of vanadium toxicity. Quercetin and green tea polyphenols （GTP） are well-known antioxidants that play important roles in the prevention of many oxidative stress-related diseases. In this study, we investigated the protective effects of quercetin and GTP against damages caused by VO（acac）2 on isolated mitochondria and whole cells. The experimental results demonstrated that quercetin and GTP could significantly inhibit mitochondrial dysfimctions induced by VO（acac）2, such as mitochondrial swelling, depolarization of the inner mitochondrial membrane potential （△ψm）, and increased release of reactive oxygen species （ROS）. Moreover, they also reduce cytotoxicity in Hep G2 cells. These results indicated that use of natural antioxidants to control the metal toxicity of vanadium compounds may be a promising strategy for developing metal-based therapeutic agents.展开更多
Myriad evidence attests to the health-promoting benefits of tea drinking.While there are multiple factors of tea influencing the effective biological properties,tea polyphenols are the most significant and valuable co...Myriad evidence attests to the health-promoting benefits of tea drinking.While there are multiple factors of tea influencing the effective biological properties,tea polyphenols are the most significant and valuable components.The chemical characterization and physical characteristics of tea polyphenols have been comprehensively studied over the previous years.Still the emergence of new chemistry in tea,particularly the property of scavenging reactive carbonyl species(RCS)and the newly discovered flavoalkaloid compounds,has drawn increasing attention.In this review,we summarize recent findings of a new class of compounds in tea-flavonoid alkaloids(flavoalkaloids),which exist in fresh tea leaves and can be generated during the process of post-harvesting,and also postulate the formation mechanism of flavoalkaloids between catechins and theanine-derived Strecker aldehyde.Additionally,we detail the up-to-date research results of tea polyphenols regarding their ability to trap RCS and their in vivo aminated metabolites to suppress advanced glycation ends products(AGEs).We further raise questions to be addressed in the near future,including the synthetic pathways for the generation of flavoalkaloids and AGEs in fresh tea leaves before processing and the concentrations of tea polyphenols that affect their RCS scavenging capability due to their pro-oxidant nature.More intensive research is warranted to elucidate the mechanisms of action underlying the biological activity of flavoalkaloids and the pharmacological application of tea polyphenols in scavenging RCS and impeding detrimental AGEs.展开更多
This study investigates the long-term effects of oral tea polyphenols （TPs） and Lactobacillus brevis M8 （LB） on biochemical parameters, digestive enzymes, and cytokines expression in broilers. In experiment 1,240 ...This study investigates the long-term effects of oral tea polyphenols （TPs） and Lactobacillus brevis M8 （LB） on biochemical parameters, digestive enzymes, and cytokines expression in broilers. In experiment 1,240 broiler chickens were selected to investigate the effects of 0.06 g/kg body weight （BW） TP and 1.0 ml/kg BW LB on broilers; in experiment 2, 180 broiler chickens were assigned randomly to three groups to investigate the effects of different dosages of TP （0.03, 0.06, and 0.09 g/kg BW） combined with 1.0 ml/kg BW LB on broilers; in experiment 3, 180 broiler chickens were assigned randomly to three groups to investigate the effects of different dosages of LB （0.5, 1.0, and 1.5 ml/kg BW） combined with 0.06 g/kg BW TP on broilers. The results showed that TP and LB affected serum biochemical parameters, and TP reduced serum cholesterol （CHO） and low-density lipoprotein cholesterol （LDL-C） abundances in a dosage-dependent manner （P〈0.05） on Day 84. Meanwhile, broilers fed a diet supplemented with TP or LB had a lower intestinal lipase activity on Day 84 compared with the control group （P〈0.05）. Middle and high dosages of TP increased pancreatic lipase and proventriculus pepsin activities （P〈0.05）. Also middle and high dosages of LB significantly enhanced pancreatic lipase activity （P〈0.05）, while high LB supplementation inhibited intestinal trypsase （P〈0.05） on Day 84. Furthermore, both TP and LB reduced intestinal cytokine expression and nuclear factor-K B （NF-KB） mRNA level on Days 56 and 84. In conclusion, long-term treatment of TP and LB improved lipid metabolism and digestive enzymes activities, and affected intestinal inflammatory status, which may be associated with the NF-KB signal.展开更多
Extraction of theanine from waste liquid of tea polyphenol production was studied in aqueous surfactanttwo-phase system （ASTP） with cationic surfactant （CTAB） and anionic surfactant （SDS）. Results indicate that ...Extraction of theanine from waste liquid of tea polyphenol production was studied in aqueous surfactanttwo-phase system （ASTP） with cationic surfactant （CTAB） and anionic surfactant （SDS）. Results indicate that the region of ASTP is narrow and there is only a two-phase region of cationic surfactant. The increase in concentrations of NaBr and Na2SO4 are beneficial to the formation of ASTP. Theanine concentration in the bottom phase increases with increasing concentration of theanine, whereas the Partition coefficient and extraction rate only change a littlewhen the concentration of theanine is above 0.2 g.L-＇. With the increase of SDS concentration, the phase ratio and the partition coefficient decrease, while the extraction efficiency of theanine increases and the concentration of theanine changes a little in the range from 2.4/7.5 to 2.8/7.2 for SDS/CTAB ratio. The temperature has a notable ef- fect on the concentration of theanine in the bottom phase, partition coefficient and extraction rate of theanine. The increase of waste liquid decreases the phase ratio, increases the concentration and extraction rate of theanine in the bottom ohase, since the orotein and the saccharide enter the bottom nhase with theanine.展开更多
基金the National Natural Science Foundation of China(No.5220031085)the Postdoctoral Research Project in Henan Province(No.HN2022054)+2 种基金the Key Scientific Research Projects of Colleges and Universities in Henan Province(No.23A430009)the State Key Laboratory of Polymer Materials Engineering(No.sklpme2022-4-03)the Key Technologies R&D Program of Henan Province(No.242102230131)。
文摘The considerable hazard posed by periprosthetic joint infections underlines the urgent need for the rapid advancement of in-situ drug delivery systems within joint materials.However,the pursuit of sustained antibacterial efficacy remains a formidable challenge.In this context,we proposed a novel strategy that leverages swelling and erosion mechanisms to facilitate drug release of drug-loaded ultrahigh molecular weight polyethylene(UHMWPE),thereby ensuring its long-lasting antibacterial performance.Polyethylene oxide(PEO),a hydrophilic polymer with fast hydrating ability and high swelling capacity,was incorporated in UHMWPE alongside the antibacterial tea polyphenol(epigallocatechin gallate,EGCG as representative).The swelling of PEO enhanced water infiltration into the matrix,while the erosion of PEO balanced the release of the encapsulated EGCG,resulting in a steady release.The behavior was supported by the EGCG release profiles and the corresponding fitted release kinetic models.As demonstrated by segmented antibacterial assessments,the antibacterial efficiency was enhanced 2to 3 times in the PEO/EGCG/UHMWPE composite compared to that of EGCG/UHMWPE.Additionally,the PEO/EGCG/UHMWPE composite exhibited favorable biocompatibility and mechanical performance,making it a potential candidate for the development of drug-releasing joint implants to combat prosthetic bacterial infections.
基金supported by National Natural Science Foundation of China(31972021)R&D Projects in Key Areas of Guangdong Province(2019B020212003)+4 种基金the Science and Technology Program of Guangzhou,China(202206010177)Guangdong key research and development program(2021B0202060001)Foshan and agricultural academy cooperation projectGuangdong Modern Agriculture project(2022KJ117)Aquatic Products Center Project of GAAS。
文摘Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.
基金sponsored by the Ningbo Natural Science Foundation(2021J107)。
文摘The interaction between host circadian rhythm and gut microbes through the gut-brain axis provides new clues for tea polyphenols to improve host health.Our present research showed that oolong tea polyphenols(OTP)improved the structural disorder of the intestinal flora caused by continuous darkness,thereby modulating the production of metabolites related to pyruvate metabolism,glycolysis/gluconeogenesis,and tryptophan metabolism to alleviate the steady-state imbalance.After fecal microbiota transplantation from the OTP group,the single-cell transcriptomic analysis revealed that OTP significantly increased the number of hypothalamus cell clusters,up-regulated the number of astrocytes and fibroblasts,and enhanced the expression of circadian rhythm genes Cry2,Per3,Bhlhe41,Nr1d1,Nr1d2,Dbp and Rorb in hypothalamic cells.Our results confirmed that OTP can actively improve the intestinal environmental state as well as internal/peripheral circadian rhythm disorders and cognitive impairment,with potential prebiotic functional characteristics to notably contribute to host health.
基金Supported by National Natural Science Foundation of China(32302919,32302918)Taishan Industrial Experts Program(tscx202306046)+1 种基金Key R&D Program Rural Revitalization Project of Shandong Province(2023TZXD083)Science and Technology Cooperation Project of Shandong and Chongqing(2022LYXZ030)。
文摘[Objective]This paper was to investigate the action targets and pathways of tea polyphenols in alleviating heat stress-induced injury by using network pharmacological analysis and an H9C2 cell model.[Method]First,the corresponding targets of tea polyphenols were obtained from the PubChem database.Then,the core targets were screened based on topological parameters.The relevant metabolism pathways of tea polyphenols related to diseases were identified through GO functional annotation and KECG signaling pathway enrichment.Moreover,common targets for thermal injury and targets of tea polyphenols were obtained.Then,GO functional annotation was performed to explore the pathway of tea polyphenols in alleviating heat stress damage.H9C2 cells were cultured at 42℃ to construct the heat stress model,and the cells were treated with 10μg/mL tea polyphenols.The key genes were confirmed using RT-PCR technology.[Result]The study yielded 364 targets corresponding to tea polyphenols,including 68 core targets.These targets are related to various biological processes such as involve oxidative stress,cancer,lipopolysaccharide-mediated signaling pathways,antiviral responses,regulation of cellular response to heat,apoptosis,and cellular lipid metabolic metabolism.Tea polyphe nols alleviate thermal damage by targeting BCL2,HSP90AA1,HSPA1A,JUN,MAPK1,NFKB1,NFKBIA,NOS3,and TP53.Moreover,10 mg/L tea polyphenols were found to upregulate the transcription levels of Hsp70,HO-1,NQ-O1,Nrf2,and MAPKI,and the transcription levels of Bax/Bcl2,p38,and JNK were downregulated to alleviate the heat stress-induced injury.[Conclusion]Tea polyphenols may enhance the antioxidant ability of H9C2 cells and inhibit cell apoptosis,thereby reducing heat stress injury.
基金supported by the National Key Research and Development Program(Grants No.2023YFC3208900 and 2023YFC3208904)the Jiangsu Water Resources Conservancy Science and Technology Project(Grant No.2022063).
文摘Harmful algal blooms(HABs)resulting from eutrophication pose a major threat to ecosystems and human health,necessitating effective control measures.Allelochemicals have shown their importance in slowing down algal proliferation due to their proven efficacy and low ecological impacts.In this study,allelopathy tea polyphenols(TPs)andβ-cyclodextrin were combined to prepare slow-release algicidal microcapsules,and the diversity of microbial community in the algal inhibition process was analyzed.Results showed that TP slow-release microcapsules had strong algicidal activity.When against Microcystis aeruginosa within 20 d,their constant inhibitory rate was up to 99%compared to the control group.Microbial diversity decreased with an increase in algae density,and the species richness and diversity of algae increased under the stress of TP slow-release microcapsules.The redundancy analysis showed that the environmental factors with impacts on the abundance and diversity of bacterial communities in descending order were dissolved oxygen,pH,and temperature.This study provides a theoretical basis for the application of TP slow-release microcapsules to actual water.
文摘Mice were administered a selenium-rich Agaricus blazei Murill(Se-AbM)polysaccharides and tea polyphenol compound solution for prevention and treatment.Following exposure to 2 Gy of infrared radiation,peripheral blood counts of white blood cells,red blood cells,and platelets were assessed,along with serum levels of apoptosis-related factors Fas and Fas ligand,inflammatory factors interferon-gamma and tumor necrosis factor-alpha,immune-related factors interleukin-3 and interleukin-6,and indicators of oxidative stress,including malondialdehyde,superoxide dismutase,and glutathione.The results showed significant differences in these indicators between the Se-AbM-treated group and the model group,suggesting that Se-AbM may inhibit apoptosis,enhance the clearance of free radicals in the body,improve antioxidant capacity,and provide a significant protective effect against radiation-induced immune damage.
文摘AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cerebral ischemia reperfusion injury was produced by bilateral ligation of the common carotid arteries with vagus nerves and reperfusion for 45 min. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. Superoxide anion (O 2) from xanthine xanthine oxidase system and hydroxyl radical (·OH) from Fe 2+ -H 2O 2 system were determined with spectrophotometry. RESULTS During Cerebral ischemia reperfusion,TP improved the activities of superoxide dismutase ( P 【0 05), GSH peroxidase( P 【0 01) and catalase( P 【0 01), while decreasing the maiondialdchyde content in the brain( P 【0 05) and brain water content ( P 【0 01). Tea polyphenol possessed significantly scavenging effects on ·OH produced by Fenton reaction and O 2 produced by xanthine xanthine oxidase system (the IC 50 were 2 2 mmol·L -1 and 1 9 mmol·L -1 respectively). Tea polyphenol could significant inhibit the lipid peroxidation of cerbral mitochondrial membrane induced by ·OH in a concentration dependent manner. CONCLUSION The results indicate that tea polyphenol could protect the injury on cerebral ischemia reperfusion in rats for OFR, these effects may be related to its scavenging effects on oxygen free radicals and antilipid peroxidant.
文摘Lipophilic tea polyphenols (LTP) were prepared by catalytic esterification of green tea polyphenols (GTP) with hexadecanoyl chloride. A novel long chain acyl derivative of epigallocatechin 3 o gallate (EGCG) was first isolated from purification of LTP by high speed countercurrent chromatography (HSCCC) using a solvent system composed of n hexane ethyl acetate methanol water (1:1:1:1, v/v). The molecular structure of the acyl derivative, Epigallocatechin 3 O gallate 4′ O hexadecanate , was elucidated by means of elemental analysis, IR, 1H NMR and MS spectra.
文摘Teapolyphenols are the generic term of polyphenols in tea.Tea polyphenols are non-toxic and odorless with high oxidation resistance.Heat stress causes oxidative stress,which impairs the capacity of antioxidant defense system and immunity,thereby seriously affecting the production performance of animals.Teapolyphenols could reduce heatstress response in animals by scavenging harmful free radicals and increasing the activities of antioxidant enzymes.
文摘AIM To investigate protective effects and molecular mechanisms of green tea polyphenols(GTP) on nonalcoholic fatty liver disease(NAFLD) in Zucker fatty(ZF) rats.METHODS Male ZF rats were fed a high-fat diet(HFD) for 2 wk then treated with GTP(200 mg/kg) or saline(5 m L/kg) for 8 wk, with Zucker lean rat as their control. At the end of experiment, serum and liver tissue were collected for measurement of metabolic parameters, alanine aminotransferase(ALT) and aspartate aminotransferase(AST), inflammatory cytokines and hepatic triglyceride and liver histology. Immunoblotting was used to detect phosphorylation of AMP-activated protein kinase(AMPK) acetyl-Co A carboxylase(ACC), and sterol regulatory element-binding protein 1c(SREBP1c). RESULTS Genetically obese ZF rats on a HFD presented with metabolic features of hepatic pathological changes comparable to human with NAFLD. GTP intervention decreased weight gain(10.1%, P = 0.052) and significantly lowered visceral fat(31.0%, P < 0.01). Compared with ZF-controls, GTP treatment significantly reduced fasting serum insulin, glucose and lipids levels. Reduction in serum ALT and AST levels(both P < 0.01) were observed in GTP-treated ZF rats. GTP treatment also attenuated the elevated TNFα and IL-6 in the circulation. The increased hepatic TG accumulation and cytoplasmic lipid droplet were attenuated by GTP treatment, associated with significantly increased expression of AMPK-Thr172(P < 0.05) and phosphorylated ACC and SREBP1c(both P < 0.05), indicating diminished hepatic lipogenesis and triglycerides out flux from liver in GTP treated rats. CONCLUSION The protective effects of GTP against HFD-induced NAFLD in genetically obese ZF rats are positively correlated to reduction in hepatic lipogenesis through upregulating the AMPK pathway.
基金Project supported by the Scientific and Technological Projects for Medicine and Health of Zhejiang Province(No.2015128660)the Major Research and Development Projects for the Zhejiang Science and Technology Agency(No.2017C03034),China
文摘Objective： To investigate the effect of tea polyphenols on cardiac function in rats with diabetic cardiomyo- pathy, and the mechanism by which tea polyphenols regulate autophagy in diabetic cardiomyopathy. Methods： Sixty Sprague-Dawley （SD） rats were randomly divided into six groups： a normal control group （NC）, an obesity group （OB）, a diabetic cardiomyopathy group （DCM）, a tea polyphenol group （TP）, an obesity tea polyphenol treatment group （OB-TP）, and a diabetic cardiomyopathy tea polyphenol treatment group （DCM-TP）. After successful modeling, serum glucose, cholesterol, and triglyceride levels were determined; cardiac structure and function were inspected by ul- trasonic cardiography; myocardial pathology was examined by staining with hematoxylin-eosin; transmission electron microscopy was used to observe the morphology and quantity of autophagosomes; and expression levels of autophagy-related proteins LC3-11, SQSTM1/p62, and Beclin-1 were determined by Western blotting. Results： Com- pared to the NC group, the OB group had normal blood glucose and a high level of blood lipids; both blood glucose and lipids were increased in the DCM group; ultrasonic cardiograms showed that the fraction shortening was reduced in the DCM group. However, these were improved significantly in the DCM-TP group. Hematoxylin-eosin staining showed disordered cardiomyocytes and hypertrophy in the DCM group; however, no differences were found among the remaining groups. Transmission electron microscopy revealed that the numbers of autophagosomes in the DCM and OB-TP groups were obviously increased compared to the NC and OB groups; the number of autophagosomes in the DCM-TP group was reduced. Western blotting showed that the expression of LC3-11/I and Beclin-1 increased obviously whereas the expression of SQSTM1/p62 was decreased in the DCM and OB-TP groups （P〈0.05）. Conclusions： Tea polyphenols had an effect on diabetic cardiomyopathy in rat cardiac function and may alter the levels of autophagy to improve glucose and lipid metabolism in diabetes.
基金This study was supported in part by the Japan-China Sasakawa Medical Fellowship.
文摘Objective Elevation of reactive oxygen species (ROS), especially the level of superoxide is a key event in many forms of cardiovascular diseases. To study the mechanism of tea polyphenols against cardiovascular diseases, we observed the expressions of ROS-related enzymes in endothelial cells. Methods Tea polyphenols were co-incubated with bovine carotid artery endothelial cells (BCAECs) in vitro and intracellular NADPH oxidase subunits p22phox and p67phox, SOD-1, and catalase protein were detected using Western blot method. Results Tea polyphenols of 0.4 ug/mL and 4.0 ug/mL (from either green tea or black tea) down-regulated NADPH oxidase p22phox and p67phox expressions in a dose-negative manner (P<0.05), and up-regulated the expressions of catalase (P<0.05). Conclusions Tea polyphenols regulate the enzymes involved in ROS production and elimination in endothelial cells, and may be beneficial to the prevention of endothelial cell dysfunction and the development of cardiovascular diseases.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF-2020R1F1A1073595 and 2021R1A2C2006745)。
文摘Polyphenols,including phenolic acids,flavonoids,and procyanidins,are abundant in food and beverage derived from plants.Tea(Camellia sinensis)is particularly rich in polyphenols(e.g.,catechins,theaflavins,thearubigins,gallic acid,and flavonols),which are thought to contribute to the health benefits of tea.High intake of tea polyphenols has been described to prevent and/or attenuate a variety of chronic pathological conditions like cardiovascular diseases,neurodegenerative diseases,diabetes,and cancer.This review focuses on established antioxidant and anti-inflammatory properties of tea polyphenols and underlying mechanisms of their involvement in inflammatory bowel diseases(IBD).Tea polyphenols act as efficient antioxidants by inducing an endogenous antioxidant defense system and maintaining intracellular redox homeostasis.Tea polyphenols also regulate signaling pathways such as nuclear factor-κB,activator protein 1,signal transducer and activator of transcriptions,and nuclear factor E2-related factor 2,which are associated with IBD development.Accumulating pieces of evidence have indicated that tea polyphenols enhance epithelial barrier function and improve gut microbial dysbiosis,contributing to the management of inflammatory colitis.Therefore,this study suggests that supplementation of tea polyphenols could prevent inflammatory conditions and improve the outcome of patients with IBD.
基金Project supported by the Research Fund for the Doctoral Program of Higher Education of China(No.20120172110017)the National Natural Science Foundation of China(Nos.31471673 and 31271978)
文摘In order to study the molecular mechanisms of green tea polyphenols（GTPs） in treatment or prevention of breast cancer, the cytotoxic effects of GTPs on five human cell lines（MCF-7, A549, Hela, PC3, and HepG2 cells） were determined and the antitumor mechanisms of GTPs in MCF-7 cells were analyzed. The results showed that GTPs exhibited a broad spectrum of inhibition against the detected cancer cell lines, particularly the MCF-7 cells. Studies on the mechanisms revealed that the main modes of cell death induced by GTPs were cell cycle arrest and mitochondrialmediated apoptosis. Flow cytometric analysis showed that GTPs mediated cell cycle arrest at both G1/M and G2/M transitions. GTP dose dependently led to apoptosis of MCF-7 cells via the mitochondrial pathways, as evidenced by induction of chromatin condensation, reduction of mitochondrial membrane potential（ΔΨ_m）, improvement in the generation of reactive oxygen species（ROS）, induction of DNA fragmentation, and activations of caspase-3 and caspase-9 in the present paper.
基金Supported by the Innovative Talents Support Program of Institution of Higher Learning of Liaoning Province,No.2018-478Innovative Talents of Science and Technology Support Program of Young and Middle Aged People of Shenyang,No.RC170446
文摘Colorectal cancer(CRC),a multifactorial disease,is usually induced and developed through complex mechanisms,including impact of diet and lifestyle,genomic abnormalities,change of signaling pathways,inflammatory response,oxidation stress,dysbiosis,and so on.As natural polyphenolic phytochemicals that exist primarily in tea,tea polyphenols(TPs)have been shown to have many clinical applications,especially as anticancer agents.Most animal studies and epidemiological studies have demonstrated that TPs can prevent and treat CRC.TPs can inhibit the growth and metastasis of CRC by exerting the antiinflammatory,anti-oxidative or pro-oxidative,and pro-apoptotic effects,which are achieved by modulations at multiple levels.Many experiments have demonstrated that TPs can modulate several signaling pathways in cancer cells,including the mitogen-activated protein kinase pathway,phosphatidylinositol-3 kinase/Akt pathway,Wnt/β-catenin pathway,and 67 kDa laminin receptor pathway,to inhibit proliferation and promote cell apoptosis.In addition,novel studies have also suggested that TPs can prevent the growth and metastasis of CRC by modulating the composition of gut microbiota to improve immune system and decrease inflammatory responses.Molecular pathological epidemiology,a novel multidisciplinary investigation,has made great progress on CRC,and the further molecular pathological epidemiology research should be developed in the field of TPs and CRC.This review summarizes the existing in vitro and in vivo animal and human studies and potential mechanisms to examine the effects of tea polyphenols on CRC.
基金Grant from the Science Foundation of Educational Department of Liaoning Province,05L117Dalian Science&Technology Bureau,2007J22JH012
文摘AIM： To investigate the hepatoprotective activity of tea polyphenols （TP） and its relation with cytochrome P450 （CYP450） expression in mice. METHODS： Hepatic CYP450 and CYPbs levels were measured by UV-spectrophotometry in mice 2 d after intraperitoneal TP （25, 50 and 100 mg/kg per day）. Then the mice were intragastricly pre-treated with TP （100, 200 and 400 mg/kg per day） for six days before paracetamol （1000 mg/kg） was given. Their acute mortality was compared with that of control mice. The mice were pre-treated with TP （100, 200, and 400 mg/kg per day） for five days before paracetamol （500 mg/kg） was given. Hepatic CYP2E1 and CYPIA2 protein and mRNA expression levels were evaluated by Western blotting, immunohistochemical staining and transcriptase-polymerase chain reaction. RESULTS： The hepatic CYP450 and CYPb5 levels in mice of TP-treated groups （100, 200 and 400 mg/kg per day） were decreased in a dose-dependent manner compared with those in the negative control mice.TP significantly attenuated the paracetamol-induced hepatic injury and dramatically reduced the mortality of paracetamol-treated mice. Furthermore, TP reduced CYP2E1 and CYPIA2 expression at both protein and mRNA levels in a dose-dependent manner. CONCLUSION： TP possess potential hepatoprotective properties and can suppress CYP450 expression.
基金National Natural Science Foundation of China (Grant No.20671008).
文摘Abstract： Vanadium compounds are promising therapeutic agents for the treatment of diabetes and cancer. However, vanadium toxicity has been a great concern. Many works suggested that vanadium-induced oxidative stress is a major reason of vanadium toxicity. Quercetin and green tea polyphenols （GTP） are well-known antioxidants that play important roles in the prevention of many oxidative stress-related diseases. In this study, we investigated the protective effects of quercetin and GTP against damages caused by VO（acac）2 on isolated mitochondria and whole cells. The experimental results demonstrated that quercetin and GTP could significantly inhibit mitochondrial dysfimctions induced by VO（acac）2, such as mitochondrial swelling, depolarization of the inner mitochondrial membrane potential （△ψm）, and increased release of reactive oxygen species （ROS）. Moreover, they also reduce cytotoxicity in Hep G2 cells. These results indicated that use of natural antioxidants to control the metal toxicity of vanadium compounds may be a promising strategy for developing metal-based therapeutic agents.
基金supported by Hubei Science and Technology Plan Key Project(G2019ABA100)。
文摘Myriad evidence attests to the health-promoting benefits of tea drinking.While there are multiple factors of tea influencing the effective biological properties,tea polyphenols are the most significant and valuable components.The chemical characterization and physical characteristics of tea polyphenols have been comprehensively studied over the previous years.Still the emergence of new chemistry in tea,particularly the property of scavenging reactive carbonyl species(RCS)and the newly discovered flavoalkaloid compounds,has drawn increasing attention.In this review,we summarize recent findings of a new class of compounds in tea-flavonoid alkaloids(flavoalkaloids),which exist in fresh tea leaves and can be generated during the process of post-harvesting,and also postulate the formation mechanism of flavoalkaloids between catechins and theanine-derived Strecker aldehyde.Additionally,we detail the up-to-date research results of tea polyphenols regarding their ability to trap RCS and their in vivo aminated metabolites to suppress advanced glycation ends products(AGEs).We further raise questions to be addressed in the near future,including the synthetic pathways for the generation of flavoalkaloids and AGEs in fresh tea leaves before processing and the concentrations of tea polyphenols that affect their RCS scavenging capability due to their pro-oxidant nature.More intensive research is warranted to elucidate the mechanisms of action underlying the biological activity of flavoalkaloids and the pharmacological application of tea polyphenols in scavenging RCS and impeding detrimental AGEs.
文摘This study investigates the long-term effects of oral tea polyphenols （TPs） and Lactobacillus brevis M8 （LB） on biochemical parameters, digestive enzymes, and cytokines expression in broilers. In experiment 1,240 broiler chickens were selected to investigate the effects of 0.06 g/kg body weight （BW） TP and 1.0 ml/kg BW LB on broilers; in experiment 2, 180 broiler chickens were assigned randomly to three groups to investigate the effects of different dosages of TP （0.03, 0.06, and 0.09 g/kg BW） combined with 1.0 ml/kg BW LB on broilers; in experiment 3, 180 broiler chickens were assigned randomly to three groups to investigate the effects of different dosages of LB （0.5, 1.0, and 1.5 ml/kg BW） combined with 0.06 g/kg BW TP on broilers. The results showed that TP and LB affected serum biochemical parameters, and TP reduced serum cholesterol （CHO） and low-density lipoprotein cholesterol （LDL-C） abundances in a dosage-dependent manner （P〈0.05） on Day 84. Meanwhile, broilers fed a diet supplemented with TP or LB had a lower intestinal lipase activity on Day 84 compared with the control group （P〈0.05）. Middle and high dosages of TP increased pancreatic lipase and proventriculus pepsin activities （P〈0.05）. Also middle and high dosages of LB significantly enhanced pancreatic lipase activity （P〈0.05）, while high LB supplementation inhibited intestinal trypsase （P〈0.05） on Day 84. Furthermore, both TP and LB reduced intestinal cytokine expression and nuclear factor-K B （NF-KB） mRNA level on Days 56 and 84. In conclusion, long-term treatment of TP and LB improved lipid metabolism and digestive enzymes activities, and affected intestinal inflammatory status, which may be associated with the NF-KB signal.
基金Supported by the Fundamental Research Funds for the Central Universities(JUSRP11205)
文摘Extraction of theanine from waste liquid of tea polyphenol production was studied in aqueous surfactanttwo-phase system （ASTP） with cationic surfactant （CTAB） and anionic surfactant （SDS）. Results indicate that the region of ASTP is narrow and there is only a two-phase region of cationic surfactant. The increase in concentrations of NaBr and Na2SO4 are beneficial to the formation of ASTP. Theanine concentration in the bottom phase increases with increasing concentration of theanine, whereas the Partition coefficient and extraction rate only change a littlewhen the concentration of theanine is above 0.2 g.L-＇. With the increase of SDS concentration, the phase ratio and the partition coefficient decrease, while the extraction efficiency of theanine increases and the concentration of theanine changes a little in the range from 2.4/7.5 to 2.8/7.2 for SDS/CTAB ratio. The temperature has a notable ef- fect on the concentration of theanine in the bottom phase, partition coefficient and extraction rate of theanine. The increase of waste liquid decreases the phase ratio, increases the concentration and extraction rate of theanine in the bottom ohase, since the orotein and the saccharide enter the bottom nhase with theanine.
