A comprehensive review of polyphenol oxidase in tea (Camellia sinensis): Physiological characteristics, oxidation manufacturing, and biosynthesis of functional constituents.

Polyphenol oxidase (PPO) is a metalloenzyme with a type III copper core that is abundant in nature. As one of the most essential enzymes in the tea plant (Camellia sinensis), the further regulation of PPO is critical for enhancing defensive responses, cultivating high-quality germplasm resources of tea plants, and producing tea products that are both functional and sensory qualities. Due to their physiological and pharmacological values, the constituents from the oxidative polymerization of PPO in tea manufacturing may serve as functional foods to prevent and treat chronic non-communicable diseases. However, current knowledge of the utilization of PPO in the tea industry is only available from scattered sources, and a more comprehensive study is required to reveal the relationship between PPO and tea obviously. A more comprehensive review of the role of PPO in tea was reported for the first time, as its classification, catalytic mechanism, and utilization in modulating tea flavors, compositions, and nutrition, along with the relationships between PPO-mediated enzymatic reactions and the formation of functional constituents in tea, and the techniques for the modification and application of PPO based on modern enzymology and synthetic biology are summarized and suggested in this article.

Research progress on the lipid-lowering and weight loss effects of tea and the mechanism of its functional components.

Obesity caused by poor eating habits has become a great challenge faced by public health organizations worldwide. Optimizing dietary intake and ingesting special foods containing biologically active substances (such as polyphenols, alkaloids, and terpenes) is a safe and effective dietary intervention to prevent the occurrence and development of obesity. Tea contains several active dietary factors, and daily tea consumption has been shown to have various health benefits, especially in regulating human metabolic diseases. Here, we reviewed recent advances in research on tea and its functional components in improving obesity-related metabolic dysfunction, and gut microbiota homeostasis and related clinical research. Furthermore, the potential mechanisms by which the functional components of tea could promote lipid-lowering and weight-loss effects by regulating fat synthesis/metabolism, glucose metabolism, gut microbial homeostasis, and liver function were summarized. The research results showing a "positive effect" or "no effect" objectively evaluates the lipid-lowering and weight-loss effects of the functional components of tea. This review provides a new scientific basis for further research on the functional ingredients of tea for lipid lowering and weight loss and the development of lipid-lowering and weight-loss functional foods and beverages derived from tea.

Role and Mechanism of Theaflavins in Regulating Skeletal Muscle Inflammation.

Persistent inflammatory infiltration of skeletal muscle is a principal trigger for the loss of muscle mass and strength. Theaflavins, the main functional components of black tea, have effects on muscle health, but their biological effects on skeletal muscle inflammation are unclear. We constructed in vitro and in vivo models of muscle inflammation and found that theaflavins reduced the expression of inflammatory factors (IL-1ß, IL-6, and TNF-α) by regulating the TLR4/MyD88/NF-κB signaling pathway to alleviate muscle inflammation. In addition, TF1 can regulate the metabolic function of skeletal muscle under inflammatory conditions, reduce the content of proinflammatory substances, improve the mechanical properties (stiffness and roughness) of the surface of inflammatory myotubes, and promote the recovery of muscle after an inflammatory injury. In conclusion, theaflavins may serve as a diet-derived anti-inflammatory factor with potential modulatory effects on skeletal muscle metabolism and mechanical properties in an inflammatory environment.

Theaflavin Promotes Myogenic Differentiation by Regulating the Cell Cycle and Surface Mechanical Properties of C2C12 Cells.

Aging and muscle diseases often lead to a decline in the differentiation capacity of myoblasts, which in turn results in the deterioration of skeletal muscle (SkM) function and impairment of regeneration ability after injury. Theaflavins, the "gold molecules" found in black tea, have been reported to possess various biological activities and have a positive effect on maintaining human health. In this study, we found that among the four theaflavins (theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B), and theaflavin-3,3'-digallate (TF3) monomers), TF1 (20 µM) significantly promoted the fusion index of myoblasts, number of mature myotubes, and degree of myotube development. By combining transcriptomics, bioinformatics, and molecular biology experiments, we showed that TF1 may promote myoblast differentiation by (1) regulating the withdrawal of myoblasts from the cell cycle, inducing the release of myogenic factors (MyoD, MyoG, and MyHC) and accelerating myogenic differentiation and (2) regulating the adhesion force of myoblasts and mechanical properties of mature myotubes and promoting the migration, fusion, and development of myoblasts. In conclusion, our study outcomes show that TF1 can promote myoblast differentiation and regulate myotube mechanical properties. It is a potential dietary supplement for the elderly. Our findings provide a new scientific basis for the relationship between tea drinking and aging.

Advances in the Antagonism of Epigallocatechin-3-gallate in the Treatment of Digestive Tract Tumors.

Due to changes in the dietary structure of individuals, the incidence of digestive tract tumors has increased significantly in recent years, causing a serious threat to the life and health of patients. This has in turn led to an increase in cancer prevention research. Many studies have shown that epigallocatechin-3-gallate (EGCG), an active ingredient in green tea, is in direct contact with the digestive tract upon ingestion, which allows it to elicit a significant antagonizing effect on digestive tract tumors. The main results of EGCG treatment include the prevention of tumor development in the digestive tract and the induction of cell cycle arrest and apoptosis. EGCG can be orally administered, is safe, and combats other resistances. The synergistic use of cancer drugs can promote the efficacy and reduce the anti-allergic properties of drugs, and is thus, favored in medical research. EGCG, however, currently possesses several shortcomings such as poor stability and low bioavailability, and its clinical application prospects need further development. In this paper, we have systematically summarized the research progress on the ability of EGCG to antagonize the activity and mechanism of action of digestive tract tumors, to achieve prevention, alleviation, delay, and even treat human gastrointestinal tract tumors via exogenous dietary EGCG supplementation or the development of new drugs containing EGCG.

Nutrient Supplement Use among the Chinese Population: A Cross-Sectional Study of the 2010⁻2012 China Nutrition and Health Surveillance.

Nutrient supplements play a key role in managing malnutrition/chronic diseases and are commonly used in the world, but few studies described the prevalence of nutrient supplement use at the national level in China. To our knowledge, this study provides the first detailed investigation of nutrient supplement use in a nationally representative sample of the Chinese population. This study aimed to describe the prevalence of the nutrient supplement use among the Chinese population aged 6 years or older in 2010⁻2012. A stratified multistage cluster sampling method was conducted to recruit participants from 150 surveillance sites. The demographic characteristics and information about nutrient supplement use were collected through an interview-administrative questionnaire. A total of 74,501 children and adults (excluding the pregnant women) were included in the study (mean age, 35.7 years; male, 47.0%, female, 53.5%). Only 0.71% of the participants reported using nutrient supplements in the previous month. Participants aged 6⁻11 years and 60 years and above, female, living in large urban, with higher education level and higher family incomes were more likely to use nutrient supplements than their counterparts (p < 0.05). The prevalence of nutrient supplement use increased with age in Chinese adults. The highest usage among the nutrient supplements was multi-vitamins and minerals with 0.37%. More females used single vitamin, multi-mineral, multi-vitamins and minerals than males (p < 0.05). The nutrient supplement use proportion was highest amongst the participants with a health problem, and the participants who had no idea about their health conditions were the least likely to use the nutrient supplements (p < 0.05). The prevalence of nutrient supplement use was low among the Chinese population in 2010⁻2012. Further research is required to understand the social cognition, usage reasons, dosage and consumption motivation of NS, and the relationships with health effects, to ensure that the nutrient supplements can be appropriately promoted in China.

The Chinese Children and Families Cohort Study: The Nutrition, Physical Activity, and Ultraviolet Radiation Data Collection.

This article reports the study design, methodological issues and early results of a pilot study testing methods for collecting nutrition, physical activity, and ultraviolet (UV) radiation exposure data in a groundbreaking study in China. Epidemiological studies suggest that exposures across the entire life course, including in utero, early childhood, and adolescence, may be important in the etiology of adult cancers and other chronic diseases. The Chinese Children and Families Cohort Study intends to follow-up subjects from the 1993 to 1995 Community Intervention Program of folic acid supplementation for the prevention of neural tube defects. This cohort is unique in that only folic acid exposure during pregnancy varies between groups as other supplements were not available, and there were nutrient deficiencies in the populations. Prior to launching a large-scale follow-up effort, a pilot study was conducted to assess the feasibility of recontacting original study participants to collect extensive diet, physical activity, and UV radiation exposure data in this population. The pilot study included 92 mothers and 184 adolescent children aged 14 to 17 years from 1 urban and 1 rural Community Intervention Program site. Subjects completed a Food Frequency Questionnaire, a 3-day food record, a physical activity questionnaire, a 3-day sun exposure diary together with 3 days of personal UV dosimetry, and 7 days of pedometry measurements and provided blood, saliva, and toenail samples. Grip strength and body composition measurements were taken, and ambient solar UV radiation was monitored in both study sites. While most of the assessments were successful, future studies would likely require different dietary intake instruments. The purpose of this report is to describe the study design and methodological issues emerging from this pilot work relevant for the follow-up of this large birth cohort.

The inhibitory mechanism of Cordyceps sinensis on cigarette smoke extract-induced senescence in human bronchial epithelial cells.

OBJECTIVES: Cellular senescence is a state of irreversible growth arrest induced either by telomere shortening (replicative senescence) or stress. The bronchial epithelial cell is often injured by inhaled toxic substances, such as cigarette smoke. In the present study, we investigated whether exposure to cigarette smoke extract (CSE) induces senescence of bronchial epithelial cells; and Cordyceps sinensis mechanism of inhibition of CSE-induced cellular senescence. METHODS: Human bronchial epithelial cells (16HBE cells) cultured in vitro were treated with CSE and/or C. sinensis. p16, p21, and senescence-associated-galactosidase activity were used to detect cellular senescence with immunofluorescence, quantitative polymerase chain reaction, and Western blotting. Reactive oxygen species (ROS), PI3K/AKT/mTOR and their phosphorylated proteins were examined to testify the activation of signaling pathway by ROS fluorescent staining and Western blotting. Then, inhibitors of ROS and PI3K were used to further confirm the function of this pathway. RESULTS: Cellular senescence was upregulated by CSE treatment, and C. sinensis can decrease CSE-induced cellular senescence. Activation of ROS/PI3K/AKT/mTOR signaling pathway was enhanced by CSE treatment, and decreased when C. sinensis was added. Blocking ROS/PI3K/AKT/mTOR signaling pathway can attenuate CSE-induced cellular senescence. CONCLUSION: CSE can induce cellular senescence in human bronchial epithelial cells, and ROS/PI3K/AKT/mTOR signaling pathway may play an important role in this process. C. sinensis can inhibit the CSE-induced senescence.

A label-free assay for T4 polynucleotide kinase/phosphatase activity and its inhibitors based on poly(thymine)-templated copper nanoparticles.

DNA 3'-phosphatase takes an important role in DNA damage repair, replication and recombination. Here, we present a novel label-free fluorescent assay for T4 polynucleotide kinase/phosphatase (T4 PNKP) activity and its inhibitor screening by using poly(thymine)-templated fluorescent copper nanoparticles (CuNPs) as a fluorescent indicator. In this assay, we designed a simple T-rich hairpin primer with a 3'-phosphoryl end, which can serve as both the substrate for T4 PNKP and DNA template for the formation of fluorescent CuNPs. Once the phosphorylated hairpin primer was hydrolyzed by T4 PNKP, the resulting hairpin primer with a 3'-hydroxyl end was immediately elongated to form a long double-strand product by DNA polymerase, which prohibited the formation of fluorescent CuNPs due to the lack of poly T single-stranded DNA template. This new strategy provides a sensitive, selective, and cost-effective manner for T4 PNKP analysis, which holds a great potential in the study of DNA damage repair mechanisms.

[Effect of moxibustion of "dachangshu" (BL 25) area on pain reaction and TRPV 1 mRNA expression of bone marrow cells in visceral hyperalgesia rats].

OBJECTIVE: To observe the effect of moxibustion of "Dachangshu" (BL 25) on pain reaction and expression of transient receptor potential vanilloid 1 (TRPV 1) of bone marrow cells in visceral hyperalgesia (VHA) rats so as to explore its mechanism underlying visceral pain-relief. METHODS: Twenty-eight male SD rats were divided into control group, control+moxibustion group, VHA model and VHA+moxibustion group (n = 7/group). The VHA model was made by giving colorectal distension (CRD, 60 mmHg) to the newborn rats for 1 min (repeated once again in 30 min) from postnatal day 8 on, once daily for a week. Moxibustion was applied to ipsilateral "Dachangshu"(BL 25) area for 40 min from the 8th week on after birth. Abdominal withdrawal reflex (AWR) and pain threshold during CRD were measured before and after moxibustion. The TRPV 1 mRNA expressio of bone marrow cells was detected by real time-POR. RESULTS: (1) The AWR score of the model group was significantly higher than that of the control group, but the pain threshold of the model group was significantly lower than that of the control group (P < 0.01), suggesting a VHA in model rats. (2) After moxibustion, the AWR scores were significantly lower in the VHA+moxibustion group than in the model group (P < 0.05, P < 0.01), and the pain threshold was remarkably higher in the former group than in the latter group (P < 0.01). Similar results were found in the control+moxibustion group compared to the control group: the decreased AWR scores (CRD 40 mmHg, 60 mmHg and 80 mmHg, P < 0.01) and the increased pain threshold (P < 0.05). (3) The TRPV 1 mRNA expression level of bone marrow cells was significantly lower in the VHA + moxibustion group than in the model group (P < 0.01). No significant difference was found between the control and moxibustion+control groups in TRPV 1 mRNA expression level (P > 0.05). CONCLUSION: Moxibustion of "Dachangshu" (BL 25) can reduce visceral hyperalgesia and down-regulate TRPV 1 mRNA expression of bone marrow cells in VHA rats, suggesting an involvement of TRPV 1 mRNA of bone marrow cells in CRD-induced visceral pain development.

Fluid intake of adults in four Chinese cities.

To investigate the fluid intake and knowledge on water and health in Chinese adults, and to provide a scientific basis for the development of adequate water intake values for people in China. A total of 1,483 adults aged 18-60 years were selected from four provincial capital cities using a multiple-stage random sampling method. The information on the amounts and types of daily fluid intake was collected using a 24-h fluid intake record for 7 consecutive days. Trained interviewers used a questionnaire to assess knowledge on water. The median of daily total fluid intake was 1,488 mL, with a wide range from 86 mL to 7,036 mL. Significant differences were found for fluid intake among the four cities. The medians of daily intakes of plain water, tea, and beverages were 786 mL, 109 mL, and 186 mL, respectively. Approximately 32% of the subjects drank less water than the amount recommended by the Chinese Nutrition Society (1,200 mL/day) and 71.6% of participants lacked knowledge of these recommendations. Moreover, 48.3% of them drank water only when they felt thirsty.

Calcium supplementation for 2 years improves bone mineral accretion and lean body mass in Chinese adolescents.

OBJECTIVE: to study the effects of different doses of calcium intake on bone health and body composition in Chinese adolescents. METHODS: a double-blind randomized controlled trial of calcium carbonate supplementation in 257 healthy adolescents aged 12-15 years old for 24 months. Subjects were randomly assigned to four groups receiving chewable calcium carbonate tablets providing elemental calcium at 63 mg/d, 354 mg/d, 660 mg/d, 966 mg/d, respectively. At the end of intervention, we reclassified 197 adolescents into 3 groups who had received actual doses of elemental calcium of 85 mg/d (Low dose), 230 mg/d (Medium dose) and 500 mg/d (High dose). We measured bone mineral content (BMC), bone mineral density (BMD) and body composition by dual-energy X-ray absorptiometry. RESULTS: BMC and BMD of total body and lumbar spine were increased significantly in both males and females after intervention at all doses (p<0.05). In males, after supplementation, total body BMC in the medium and high dose groups (2464 g and 2437 g, respectively) was significantly higher than that in the low dose group (2321 g) after adjusting for age, pubertal development, BMI, physical activity and energy intake; in addition, lean body mass in the medium and high dose groups (49.1 kg and 48.8 kg, respectively) was significantly higher than that in the low dose group (46.7 kg) (p<0.05). There was no significant effect of calcium supplementation on bone mass or body composition in females. CONCLUSIONS: calcium supplementation more than 230 mg/d for two years can improve bone mineral accretion and lean body mass in Chinese male adolescents.

Factors affecting calcium balance in Chinese adolescents.

Chinese dietary reference intakes (DRIs) for calcium were developed mainly from studies conducted amongst Caucasians, yet a recent review showed that reference calcium intakes for Asians are likely to be different from those of Caucasians (Lee and Jiang, 2008). In order to develop calcium DRIs for Chinese adolescents, it is necessary to explore the characteristics and potential influencing factors of calcium metabolic balance in Chinese adolescents. A total of 80 students (15.1+/-0.8 years) were recruited stratified by gender from a 1-year calcium supplementation study. Subjects were randomly designed to four groups and supplemented with calcium carbonate tablets providing elemental calcium at 63, 354, 660, and 966 mg/day, respectively. Subjects consumed food from a 3-day cycle menu prepared by staff for 10 days. Elemental calcium in samples of foods, feces, and urine was determined in duplicates by inductively coupled plasma atomic emission spectrometry. The total calcium intake ranged from 352 to 1323 mg/day. The calcium apparent absorption efficiency and retention in boys were significantly higher than that in girls (68.7% vs. 46.4%, 480 mg/day vs. 204 mg/day, P<0.05). Calcium retention increased with calcium intakes, but did not reach a plateau. Calcium absorption efficiency in boys increased with calcium intake up to 665 mg/day, and decreased after that. In girls, calcium absorption efficiency decreased with calcium intake. Calcium absorption efficiency increased within 1 year after first spermatorrhea in boys, but decreased with pubertal development in girls. Sex, calcium intake, age, and pubertal development were the most important determinants of calcium absorption (R(2)=0.508, P<0.01) and retention (R(2)=0.745, P<0.05). This study indicates that sex, calcium intake, age, and pubertal development are important factors for calcium retention and absorption during growth, which should be considered for the development of calcium DRIs for Chinese adolescents.

Expression analysis of nine rice heat shock protein genes under abiotic stresses and ABA treatment.

Expression profiles of nine rice heat shock protein genes (OsHSPs) were analyzed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The nine genes exhibited distinctive expression in different organs. Expression of nine OsHSP genes was affected differentially by abiotic stresses and abscisic acid (ABA). All nine OsHSP genes were induced strongly by heat shock treatment, whereas none of them were induced by cold. The transcripts of OsHSP80.2, OsHSP71.1 and OsHSP23.7 were increased during salt tress treatment. Expression of OsHSP80.2 and OsHSP24.1 genes were enhanced while treated with 10% PEG. Only OsHSP71.1 was induced by ABA while OsHSP24.1 was suppressed by ABA. These observations imply that the nine OsHSP genes may play different roles in plant development and abiotic stress responses.

Panax ginseng ginsenoside-Rg2 protects memory impairment via anti-apoptosis in a rat model with vascular dementia.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginsenosides, the major active ingredients of Panax ginseng, produce a variety of pharmacological or physiological responses with effects on the central and peripheral nervous systems. AIM OF THE STUDY: In this report, we investigated the effects of ginsenoside Rg2 on cerebral ischemia-reperfusion induced impairment of neurological responses, memory and caudate-putamen neuronal apoptosis in a vascular dementia (VD) rat model. MATERIALS AND METHODS: Neurological evaluation was performed 24h after reperfusion and Y-maze memory performance was assessed at 48 h after reperfusion. Immunocytochemical techniques were employed to check the protein expression of BCL-2, BAX, heat shock protein 70 and P53, which are related with cell apoptosis. RESULTS: Neurological responses and memory ability of the ginsenoside Rg2 or nimodipine groups improved significantly compared with the VD group. The expression of BCL-2 and HSP70 were decreased, while BAX and P53 were increased in the VD model. The expression of BCL-2 and HSP70 proteins were increased, while BAX and P53 decreased after ginsenoside Rg2 (2.5, 5 and 10mg/kg) and nimodipine (50 microg/kg) treatment compared with the VD group. The study suggests that ginsenoside Rg2 improved neurological performance and memory ability of VD rats through mechanisms related to anti-apoptosis. CONCLUSIONS: The capacity for ginsenoside Rg2 to modulate the expression of apoptotic related proteins suggests that ginsenoside Rg2 may represent a potential treatment strategy for vascular dementia or other ischemic insults.