Tea Polyphenols Supplementation Research Articles

Dietary tea polyphenol supplementation improved egg production performance, albumen quality, and magnum morphology of Hy-Line Brown hens during the late laying period.

The aim of this study was to investigate how dietary supplementation of tea polyphenols (TP) and tea catechins (TC) affect laying performance, albumen quality, ovomucin composition, and magnum morphology of laying hens in the late phase of production. Two hundred seventy Hy-Line Brown laying hens (64 wk old) were assigned to a basal diet (the control), the basal diet supplemented with 200 mg/kg tea polyphenols (TP200) or 200 mg/kg tea catechins (TC200). Each treatment had 6 replicates with 15 hens each. The feeding trial lasted 10 wks. Over the course of the trial, dietary supplementation with TP200 significantly increased the egg production (EP) and improved the feed conversion ratio (FCR) in wk 6 to 10 and wk 1 to 10 (P < 0.05). The albumen height and the Haugh unit (HU) of hens fed TP200 were higher than those of hens fed the control diet at wks 8 and 10 (P < 0.05). However, there were no significant differences in the albumen height and the HU between the TP200 and TC200 groups (P > 0.05). The SDS-PAGE analysis indicated that bands of the ovomucin fractions in the TP200 group had the highest intensity compared with those of the control and TC200 groups. Compared with the control, there was a significant increase in protein sulfhydryl (SH) content of the albumen in the TP200 group at the end of experiment, while a significant decrease in protein carbonyl content and protein surface hydrophobicity (P < 0.05). There were also obvious increase in the height and width of the primary folds, epithelial cell height, and cilia height of the simple columnar epithelium in the TP200 group compared with the control and TC200 groups (P < 0.05). In conclusion, dietary supplementation with 200 mg/kg TP can improve performance, albumen quality, and magnum morphology of aged hens. In addition, TP rather than TC could improve the health status of the magnum for aged layers.

Effect of Dietary Supplementation of Glycyrrhetinic Acid and Tea Polyphenols on Depuration of 2-methylisoborneol from Blunt Snout Bream, Megalobrama amblycephala

Abstract_Off-flavor is a serious issue in cultured fish. It affects marketability and texture of fish and causes great economic losses in the aquaculture industry. Holding fish in a clean-water environment for some time is an effective method to depurate them although it involves weight loss. This study investigates the potential effects of dietary supplementation of glycyrrhetinic acid (GA) and tea polyphenols (TP) on the depuration of the strong odors of 2- methylisoborneol (MIB) from blunt snout bream, Megalobrama amblycephala. 560 fish, initial average weight of 48.75±0.48 g were distributed into 28 tanks at a rate of 20 fish per tank. Three diets, namely the control diet, a GA supplemented diet (0.3 g/kg), and a (TP) supplemented diet (0.3 g/kg) were used in this study. The control diet was randomly assigned to 20 tanks, 4 tanks with clean water (control), or with water containing 1μg/L MIB. During the first 28-day the fish in each treatment were hand-fed to apparent satiation three times daily. In the second phase (29-42 day), the control, GA, and TP treatments were divided into four groups: MIB, low density (LD), high density (HD), and dynamic sampling (DS) with twenty fish in DS, and fifteen fish in the others. Fish in LD, HD, and DS in all treatments were starved in clean water. Fish in the DS treatment were sampled at 0, 24, 48, 72 hours, at 7 and 14 days. No differences were observed in body weights between groups within the 28-day feeding trial (P&gt;0.05). Fish in GA, LD, and HD groups had significantly lower hepatosomatic index (HSI) and intraperitoneal fat ratios (IPF) than the control, MIB, and TP groups (P&lt;0.05). After 28 and 42 days, fish in the MIB group had higher MIB concentrations than the other groups (P&lt;0.05). Scores of sensory characteristics were similar, with no statistical differences between the control, GA, and TP groups (P&gt;0.05). MIB content decreased significantly in relation to longer depuration times (P&lt;0.05). Fish weight in LD and HD treatments declined by 10% and 12% respectively after 14-day fasting. In conclusion, clean water depuration for fourteen days is an effective method to purge off-flavored flesh although it involves weight loss and dietary supplementation of GA and TP which also depurate MIB from flesh of Megalobrama amblycephala.

Effects of dietary tea polyphenols on growth, biochemical and antioxidant responses, fatty acid composition and expression of lipid metabolism related genes of large yellow croaker(Larimichthys crocea)

The study was conducted to investigate the effects of dietary tea polyphenols (TP) on growth performance, biochemical and antioxidants responses, fatty acid composition, and lipid metabolism-related gene expressions of large yellow croaker (Larimichthys crocea). Four diets were formulated with different levels of TP (0.00%, 0.01%, 0.02% and 0.05%). Results showed that growth performance of L. crocea were not different among dietary treatments. Compared with the control group, fish in 0.02% TP group had lower body and hepatic lipid content and lower total cholesterol content. The minimum content of triglycerides and low-density lipoprotein-cholesterol were found in 0.05% TP group. Hepatic n-6 PUFA and n-3 PUFA were significantly higher in TP supplementation groups. Malondialdehyde content was lower in TP supplementation groups, and superoxide dismutase activity was higher in 0.01% TP group than the control group. The mRNA expressions of carnitine palmitoyltransferase1, acyl-CoA oxidase and peroxisome proliferators-activated receptor α were up-regulated in 0.01% and 0.02% TP groups, while lipoprotein lipase expression was down-regulated in TP supplementation groups than the control group. Results suggested that 0.01%–0.02% TP supplementation could reduce the deposition of liver lipid of L. crocea caused by high-lipid diet, which might be due to the increase in lipid oxidation related gene expressions.

Effects of dietary green tea polyphenol supplementation on the health of workers exposed to high-voltage power lines.

Although it has been several decades since the focus on the effect of extremely low frequency electromagnetic fields (ELF-EMF) of high-voltage power lines on human health, no consistent conclusion has been drawn. The present study aimed to investigate the change in oxidative stress after exposure to ELF-EMFs, and potential protective effects of green tea polyphenol supplementation (GTPS) on ELF-EMFs induced oxidative stress. A total of 867 subjects, including workers with or without exposure to ELF-EMFs of 110-420kV power lines, participated and were randomized into GTPS and placebo treatment groups. Oxidative stress and oxidative damage to DNA were assessed by urinary tests of 8-isoprostane and 8-OHdG. Significant increased urinary 8-isoprostane and 8-OHdG were observed in workers with ELF-EMFs exposure, which were diminished after 12 months of GTPS. No protective effects of GTPS on oxidative stress and oxidative damage to DNA were observed after three months of GTPS withdraw. We found a negative impact of high-voltage power lines on the health of workers. Long-term GTPS could be an efficient protection against the health issues induced by high-voltage power lines.

Effect of tea polyphenols on production performance, egg quality, and hepatic antioxidant status of laying hens in vanadium-containing diets

This study was conducted to determine the effect of tea polyphenols (TP) on production performance, egg quality, and hepatic-antioxidant status of laying hens in vanadium-containing diets. A total of 300 Lohman laying hens (67 wk old) were used in a 1 plus 3 × 3 experiment design in which hens were given either a diet without vanadium and TP supplementation (control) or diets supplemented with 5, 10, or 15 mg V/kg and TP (0, 600, 1,000 mg/kg) diets for 8 wk, which included 2 phases: a 5-wk accumulation phase and a 3-wk depletion phase. During the accumulation phase, dietary vanadium addition decreased (linear, P < 0.01) albumen height and Haugh unit (HU), and TP supplementation mitigated (linear effect, P < 0.01) this reduction effect induced by vanadium. Eggshell thickness (linear, P < 0.01), redness (linear and quadratic, P < 0.05), and yellowness (linear and quadratic, P < 0.05) were decreased by vanadium and increased by the effect of TP when a vanadium-containing diet was fed. In the depletion phase, the bleaching effect on eggshells induced by vanadium disappeared one wk after vanadium withdrawal. Eggshell thickness, eggshell strength, albumen height, and HU were lower (P < 0.05) in the 15 mg/kg vanadium group compared with the control diet until 2 wk post vanadium challenge, but hens fed 15 mg/kg vanadium and 600 mg/kg TP showed no difference from the control diet only after 1 wk withdrawal. In the liver, the activity of glutathione S-transferases and glutathione peroxidase was increased (linear, P < 0.01) with the TP addition at 5 wk in the accumulation phase in the vanadium-containing diet; the malondialdehyde content increased (linear effect, P = 0.02) with the addition of vanadium. The results indicate that supplementation of 10 and 15 mg/kg vanadium resulted in reduced albumen quality, bleaching effect on eggshell color, and antioxidant stress in the liver. The effect of TP addition can prevent laying hens from the adverse effect of vanadium on egg quality, liver antioxidant stress and shorten the recovery time.

Effect of Vanadium and Tea Polyphenols on Intestinal Morphology, Microflora and Short-Chain Fatty Acid Profile of Laying Hens.

Vanadium (V) is a trace element which can induce dysfunction of gastro-intestine and egg quality deterioration of laying hens. This study was conducted to determine the effect of tea polyphenols (TP) on intestinal morphology, microflora, and short-chain fatty acid (SCFA) profile of laying hens fed vanadium containing diets. A total of 120 Lohman laying hens (67-week-old) were randomly divided into 4 groups with 6 replicates and 5 birds each for a 35-day feeding trial. The dietary treatments were as follows: (1) control (CON), fed a basal diet; (2) vanadium treatment (V10), CON +10mgV/kg; (3) TP treatment 1 (TP1): V10+600mg TP/kg; (4) TP treatment 2 (TP2): V10+1000mg TP/kg. Fed 10mgV/kg diets to laying hens did not affect the cecum flora diversity index (H), degree of homogeneity (EH), and richness (S), but hens fed TP2 diet decreased the H, EH, and S (P<0.05). The cecum butyrate acid concentration was lower in V10 treatment and higher in TP2 treatment (P<0.05). Addition of 10mg/kgV resulted in an increased (P<0.01) duodenal cell apoptosis rate, and 1000mg/kg TP supplementation overcame (P<0.01) this reduction effect induced by vanadium. The results indicated that supplementation of 10mg/kg vanadium increased duodenal cell apoptosis and reduced cecum butyrate acid content. Addition of 1000mg/kg TP increased the SCFA production to affect cecum flora ecology and protected the duodenal cell from excess apoptosis caused by vanadium.

Quantitative optimization and assessments of supplemented tea polyphenols in dry dog food considering palatability, levels of serum oxidative stress biomarkers and fecal pathogenic bacteria

The objective of this study was to investigate the effects of supplementation of tea polyphenols (TP) in dry dog food on the palatability of dry dog food, serum oxidative stress biomarkers, and fecal pathogenic bacteria in adult dogs.

Green tea polyphenols benefits body composition and improves bone quality in long-term high-fat diet–induced obese rats

This study investigates the effects of green tea polyphenols (GTPs) on body composition and bone properties along with mechanisms in obese female rats. Thirty-six 3-month-old Sprague Dawley female rats were fed either a low-fat (LF) or a high-fat (HF) diet for 4 months. Animals in the LF diet group continued on an LF diet for additional 4 months, whereas those in the HF diet group were divided into 2 groups: with GTP (0.5%) or without in drinking water, in addition to an HF diet for another 4 months. Body composition, femur bone mass and strength, serum endocrine and proinflammatory cytokines, and liver glutathione peroxidase (GPX) protein expression were determined. We hypothesized that supplementation of GTP in drinking water would benefit body composition, enhance bone quality, and suppress obesity-related endocrines in HF diet-induced obese female rats and that such changes are related to an elevation of antioxidant capacity and a reduction of proinflammatory cytokine production. After 8 months, compared with the LF diet, the HF diet increased percentage of fat mass and serum insulin-like growth factor I and leptin levels; reduced percentage of fat-free mass, bone strength, and GPX protein expression; but had no effect on bone mineral density and serum adiponectin levels in the rats. Green tea polyphenol supplementation increased percentage of fat-free mass, bone mineral density and strength, and GPX protein expression and decreased percentage of fat mass, serum insulin-like growth factor I, leptin, adiponectin, and proinflammatory cytokines in the obese rats. This study shows that GTP supplementation benefited body composition and bone properties in obese rats possibly through enhancing antioxidant capacity and suppressing inflammation.

Green tea polyphenols supplementation and Tai Chi exercise for postmenopausal osteopenic women: safety and quality of life report

BackgroundEvidence suggests that both green tea polyphenols (GTP) and Tai Chi (TC) exercise may benefit bone health in osteopenic women. However, their safety in this population has never been systematically investigated. In particular, there have been hepatotoxicity concerns related to green tea extract. This study was to evaluate the safety of 24 weeks of GTP supplementation combined with TC exercise in postmenopausal osteopenic women, along with effects on quality of life in this population.Methods171 postmenopausal women with osteopenia were randomly assigned to 4 treatment arms for 24 weeks: (1) Placebo (500 mg starch/day), (2) GTP (500 mg GTP/day), (3) Placebo + TC (placebo plus TC training at 60 min/session, 3 sessions/week), and (4) GTP + TC (GTP plus TC training). Safety was examined by assessing liver enzymes (aspartate aminotransferase, alanine aminotransferase), alkaline phosphatase, and total bilirubin at baseline and every 4 weeks. Kidney function (urea nitrogen and creatinine), calcium, and inorganic phosphorus were also assessed at the same times. Qualify of life using SF-36 questionnaire was evaluated at baseline, 12, and 24 weeks. A mixed model of repeated measures ANOVA was applied for analysis.Results150 subjects completed the study (12% attrition rate). The compliance rates for study agents and TC exercise were 89% and 83%, respectively. Neither GTP supplementation nor TC exercise affected liver or kidney function parameters throughout the study. No adverse event due to study treatment was reported by the participants. TC exercise significantly improved the scores for role-emotional and mental health of subjects, while no effect on quality of life was observed due to GTP supplementation.ConclusionsGTP at a dose of 500 mg/day and/or TC exercise at 3 hr/week for 24 weeks appear to be safe in postmenopausal osteopenic women, particularly in terms of liver and kidney functions. TC exercise for 24 weeks (3 hr/wk) significantly improved quality of life in terms of role-emotional and mental health in these subjects. ClinicalTrials.gov identifier: NCT00625391.

Green tea polyphenols and Tai Chi exercise for postmenopausal osteopenic women: safety report from a 24‐week placebo‐controlled randomized trial

Osteoporosis is a major health problem in postmenopausal women. This study was to evaluate the effects of 24‐week green tea polyphenols supplementation (GTP) along with Tai Chi exercise (TC) on safety. 171 postmenopausal women with osteopenia (57.4±6.8 yr, BMI 28.4±5.3 kg/m2) were assigned to 4 treatment: placebo (500 mg starch/d), GTP (500 mg GTP/d), placebo+TC (60 min TC/session, 3×/wk), and GTP+TC for 24 weeks. Laboratory blood chemistry parameters including liver function (aspartate aminotransferase, AST and alanine aminotransferase, ALT), alkaline phosphates, total bilirubin, urea nitrogen, calcium, inorganic phosphorus, and creatinine were assessed in overnight fasting blood samples taken at baseline and every 4 weeks throughout the study period. Data was analyzed by two‐way ANOVA. After 24 weeks intervention, 21 participants dropped out (12% attrition rate) due to loss of interest or any other condition unrelated to the current study intervention. The compliance rates for study agent and TC exercise were 89% and 83%, respectively. Neither GTP supplementation nor TC exercise affected liver function, as determined by AST and ALT laboratory results. Similarly, other blood chemistry parameters were not affected by any treatment throughout the study. No adverse event due to study treatment was reported by the participants, regardless of group assignment. These data demonstrated that GTP supplementation at 500 mg daily and TC exercise for 24 weeks was considered a safe approach to postmenopausal women with low bone mass. Study was supported by NCCAM/NIH R21AT003735 (CLS).

Induction of apoptosis by tea polyphenols mediated through mitochondrial cell death pathway in mouse skin tumors

Many naturally occurring phytochemicals have shown cancer chemopreventive potential in a variety of bioassay systems. One such naturally occurring biologically active compound is tea (Camellia sinensis), which is the most consumed beverage in the world after water. The most abundant and active constituents of tea are polyphenols (epigallocatechin gallate and theaflavins). In the present study, cancer chemopreventive properties of both black tea polyphenols (BTP) and green tea polyphenols (GTP) on 7,12- dimethylbenz[a]anthracene (DMBA) induced mouse skin carcinogenesis were studied. BTP and GTP treatment showed delay in onset of tumorigenesis, reduction in cumulative number of tumors and increased tumor free survival. Both BTP and GTP were found to modulate the expression of proteins involved in apoptotic pathway. Tea polyphenols treatment along with DMBA exposure resulted in up-regulation of p53, and proapoptotic protein Bax, whereas enhanced expression of antiapoptotic proteins, Bcl-2 and survivin by DMBA were down-regulated. Further, we showed that tea polyphenols supplementation resulted in release of cytochrome c, caspases activation, and increase in apoptotic protease activating factor and poly (ADP-ribose) polymerase cleavage as mechanism of apoptosis induction. The results also provide strong evidence that BTP is a better chemopreventive agent against skin tumorigenesis as compared to GTP at the tested dose levels. Thus, we can conclude that the polyphenolic constituents present in black tea and green tea induce mitochondrial pathway of apoptosis and hence can be used as a potential chemopreventive agents against skin cancer.

Inhibitory effect of tea polyphenols on hepatic preneoplastic foci in Wistar rats

Tea (Camellia sinensis) is one of the most widely used beverages worldwide and tea consumption has been shown to have an inverse correlation to the incidence of human cancers in epidemiological and experimental studies. In the present study, the protective effects of green tea polyphenols (GTP) and black tea polyphenols (BTP) in Wistar rats were assessed by medium-term bioassay, using altered hepatic foci (AHF) as end point. Animals were exposed to a single dose of diethylnitrosamine (DEN; 200 mg/kg body weight intraperitoneally), and GTP (1%) and BTP (1%) were then administered orally together with 0.05% 2-acetyl aminofluorene (2-AAF) crushed and mixed in the diet for 8 weeks. Numbers of AHF were scored and analyzed by quantitative stereology using the Image analysis system from frozen liver tissue sections. Tea polyphenol supplementation resulted in a significant protection against AHF induction in Wistar rats. In addition, levels of the positive biomarkers: gamma-glutamyl transpeptidase and glutathione-S-transferase (placental form) were reduced with GTP and BTP supplementation. Levels of the negative biomarkers adenosine triphosphatase and glucose-6-phosphatase were also restored by GTP and BTP administration. Thus, these results show the hepatoprotective effects of GTP and BTP against DEN- and 2-AAF-induced AHF development.

Effects of long-term dietary supplement of tea polyphenols on lipid peroxide levels in rats

We examined the effects of tea polyphenols (TP) on the body weight gain and contents of lipids and lipid peroxides in rat plasma, kidney and liver. The supplementation of TP (0.5% and 1.0%) in the diet was performed from weanling (3 weeks of age) to 19 months old. A significant suppression of body weight gain was observed only at 7–11 weeks of age, but there were no significant changes in liver and kidney weight between control group and TP-feeding group (TP group). Daily food intake of animals in two TP groups was almost the same as the control group.