Use Of Tea Polyphenols Research Articles

Effects and mechanism of tea polyphenols on the quality of oil during frying process.

The effects and action mechanism of tea polyphenols (TP) on the quality of rapeseed oil during frying process were investigated. Results showed that compared with control, TP (0.04%, w/w) exhibited the remarkable ability to inhibit the deterioration of acid value, peroxide value, anisidine value, viscosity, and color of frying oil. By using gas chromatography-mass spectrometry, frying oil with TP showed the higher content of unsaturated fatty acids (72.79%) and lower content of trans fatty acids (3.36%) than those of control. Meanwhile, frying oil with TP had a higher total phenolic content than control at the same frying time. In addition, the thermo gravimetric-differential scanning calorimetry results showed that TP could increase the oxidation stability of rapeseed oil. Furthermore, according to the Fourier transform infrared and molecular dynamic simulation results, TP could reduce the breaking degree of = C-H bond, C-O-C bond, and C = C bond in oil molecules, and inhibit the oxidation of oil components by inhibiting the generation of free radicals and eliminating free radicals. All present results suggested that TP showed the potential value to be used for protecting the quality of oil during the frying process in food and chemical industries. PRACTICAL APPLICATIONS: The inhibitory effect of tea polyphenols on the deterioration of quality of rapeseed oil during frying was found and the mechanism had also preliminarily interpretation. This work provided a method for monitoring the quality of fry oil and provided the theoretical basis for the use of tea polyphenols in frying.

Tea polyphenols as multi-target therapeutics for Alzheimer’s disease: An in silico study

Alzheimer’s disease (AD) is the most common progressive neurodegenerative disease characterized by cognitive decline, dementia, and in later stages complete loss of feelings, sensation and death. The global prevalence of the disease is on the rise, and it affects 35–40% of the population above 80 years. The pathological hallmarks of the disease include extra-neuronal deposition of amyloid-β (Aβ) as plaques and intra-neuronal hyperphosphorylated tau protein as neurofibrillary tangles, which cause neurodegeneration and cerebral atrophy. Aβ deposition is catalyzed by β-secretase and γ-secretase, while tau hyperphosphorylation is catalyzed by glycogen synthase kinase – 3β (GSK-3β). With neurodegeneration, the level of the neurotransmitter acetylcholine (ACh), as well as acetylcholinesterase (AChE), decreases in the synaptic cleft, called cholinergic deficiency. This leads to the cardinal behavioural abnormalities of AD, which is referred to as cholinergic hypothesis of AD. The other enzyme which degrades ACh is the butyrylcholinesterase (BuChE). Thus, current treatment options of AD include symptomatic treatment to elevate the levels of ACh by inhibiting AChE. However, the currently used drugs cause several side effects, and the quest for novel drugs remains an interesting and essential venture. Since the disease has multiple pathophysiologies, there is an unrelenting need to develop novel drugs and lead molecules capable of inhibiting multiple pathways. The present study hypothesizes use of tea polyphenols against the key drug targets of AD, viz. β–Secretase, γ-Secretase, GSK-3β, AChE and BuChE. The hypothesis has been validated using molecular docking tools. The result indicates that the polyphenols may potentially inhibit these enzymes, similar to their known inhibitors. Thus, the findings are of immense significance in the therapeutic interventions of AD, using tea polyphenols as exciting multi-target drugs.

The Combined Use of Tea Polyphenols and Lactobacillus Plantarum ST8SH Bacteriocin in a Rabbit Model of Infection Following Femoral Fracture with Internal Fixation.

BackgroundWorldwide, the increasing use of antibiotics has resulted in antimicrobial resistance, leading to studies to find alternative antimicrobial treatments. Tea polyphenols have antibacterial properties. Bacteriocins produced by probiotic lactobacilli can inhibit Gram-positive bacteria. This study used a rabbit model of infection, following femoral fracture with internal fixation, to evaluate the efficacy of the combined use of tea polyphenols and Lactobacillus plantarum ST8SH bacteriocin.Material/MethodsTwenty-four New Zealand White rabbits underwent femoral fracture, internal fixation, and insertion of a mini-titanium implant, and were inoculated intravenously with suspensions of Staphylococcal bacteria. Four treatment groups included group A, injected with tea polyphenols and bacteriocins (N=6); group B, injected with cefradine and bacteriocins (N=6); group C, injected with tea polyphenols and cefradine (N=6); and group D (controls), injected with saline (N=6). Blood samples were collected at 1, 6, 12, 24, and 48 hours after the injection of bacteriocins. Biofilms that formed on the mini-titanium implant were studied by fluorescence microscopy. Serum levels of level of interleukin (IL)-8, IL-6, and tumor necrosis factor-α (TNF-α) were measured using an enzyme-linked immunosorbent assay (ELISA).ResultsThe combination of tea polyphenols and bacteriocins (group A) had a significant inhibitory effect on Staphylococcus aureus (P<0.05) and significant differences in serum levels of IL-8, TNF-α, and IL-6 levels in serum (P<0.05) when compared with groups, B, C, and D.ConclusionsIn a rabbit model of femoral fracture with internal fixation, the combined use of tea polyphenols and Lactobacillus plantarum ST8SH bacteriocin effectively controlled Staphylococcus aureus infection.

Tea polyphenols suppress growth and virulence-related factors of Haemophilus parasuis.

The bacterium Haemophilus parasuis (H. parasuis) is the primary cause of Glässer’s disease. Currently, there are no effective vaccines that can confer protection against all H. parasuis serovars. Therefore, the present study aimed to investigate the effect of tea polyphenols on growth, expression of virulence-related factors, and biofilm formation of H. parasuis, as well as to evaluate their protective effects against H. parasuis challenge. Our findings demonstrated that tea polyphenols can inhibit H. parasuis growth in a dose-dependent manner and attenuate the biofilm formation of H. parasuis. In addition, tea polyphenols exerted inhibitory effects on the expression of H. parasuis virulence-related factors. Moreover, tea polyphenols could confer protection against a lethal dose of H. parasuis and can reduce pathological tissue damage induced by H. parasuis. In summary, our findings demonstrated the promising use of tea polyphenols as a novel treatment for H. parasuis infection in pigs.

Application of tea polyphenols in combination with 6-gingerol on shrimp paste of during storage: biogenic amines formation and quality determination.

Tea polyphenols (TP) have shown antioxidant activity and antimicrobial properties in the food industry. Assessment of anti-oxidation potential of 6-gingerol (GR) has also been verified. As little is known about the use of tea polyphenols either individually or in combination with 6-gingerol in shrimp paste, we aimed to investigate the effect of tea polyphenols combined with 6-gingerol on the biogenic amines inhibition and quality of shrimp paste stored at 25°C for 160 days. The shrimp paste samples were assigned into four groups: (1) control; (2) tea polyphenols treatment (0.3%); (3) 6-gingerol treatment (0.3%); (4) tea polyphenols (0.15%) + 6-gingerol (0.15%). Samples with no addition were used as control. The results indicate that treatment with tea polyphenols + 6-gingerol (TPGR) maintained paste appearance, inhibited oxidation of protein and lipids, and reduced microorganism counts compared to control treatment. The efficiency was superior to that of tea polyphenols or 6-gingerol treatment. Furthermore, shrimp paste treated with TPGR also exhibited significantly higher inhibition of biogenic amines. Total amino acids determination proved the efficacy of TPGR by maintaining the more amino acids of shrimp paste during ambient temperature storage. Our study suggests that TPGR might be a promising candidate for fermented foods due to its synergistic effect to maintain products quality and extending their shelf-life.

Tea Polyphenols for Skin Care

Dietary polyphenols of tea show antioxidant, anti-ageing, anti-wrinkle, anti-acne, anti-microbial, antiinflammatory and skin lightening properties which are beneficial for dermal tissue. This article explores the potential of topical application of polyphenols from tea in skin care. The use of tea polyphenols as a topically applied plant extract which can penetrate in the dermis has been well documented. The findings of these studies indicate that tea polyphenols when used in an appropriate way and amount can be used to prevent skin related problems.

Chemopreventive and Therapeutic Potential of Tea Polyphenols in Hepatocellular Cancer

The prophylactic and therapeutic properties of tea have been attributed to green tea catechins and black tea theaflavins besides several other polyphenolic compounds. Tea polyphenols possess potent antioxidant and antiinflammatory properties and modulate several signaling pathways. These biochemical facets of tea polyphenols are responsible for its anticancer properties. Several lethal cancers, such as liver cancer, develop within a background of oxidative stress and inflammation. Liver cancer, also known as hepatocellular carcinoma (HCC), has been shown to occur throughout the world including Asia, Africa, Western Europe, and the United States. Phytochemicals, such as tea polyphenols, provide an effective and promising alternative for the chemoprevention and treatment of HCC. In this article, we systematically review, for the first time, the effects of tea polyphenols in the preclinical in vitro and in vivo HCC models. The review also examines, in critical detail, the biochemical mechanisms involved in the chemopreventive and antineoplastic effects of tea polyphenols in hepatic cancer. Finally, we highlight the role of synergy, bioavailability and pharmacokinetics of tea polyphenols, current status of clinical trials, discuss future directions, and comment on the future challenges involved in the effective use of tea polyphenols for the prevention and management of liver cancer.

Molecular targets of tea polyphenols in the cardiovascular system

Tea-derived polyphenols have attracted considerable attention in the prevention of cancer and cardiovascular diseases. In comparison to tumour cells, the elucidation of their molecular targets in cardiovascular relevant cells is still at the beginning. Although promising experimental and clinical data demonstrate protective effects for the cardiovascular system, little information is actually available on how these beneficial effects of tea polyphenols are mediated at the cellular level. By affecting the activity of receptor and signal transduction kinases, both catechins and theaflavins--the major ingredients of green and black tea, respectively--exert a variety of cardiovascular beneficial effects. In general, the number and positions of galloyl groups have major influence on the potency of polyphenols. Compared to their broad impact on cellular signal transduction, tea polyphenols reveal little transcriptional effects. However, more detailed and profound analysis of molecular actions in different cells of the cardiovascular system is necessary before safe clinical use of tea polyphenols for treatment of cardiovascular diseases will become possible.

Green tea polyphenol epigallocatechin-3-gallate differentially modulates oxidative stress in PC12 cell compartments

Tea polyphenols have been reported to be potent antioxidants and beneficial in oxidative stress related diseases. Prooxidant effects of tea polyphenols have also been reported in cell culture systems. In the present study, we have studied oxidative stress in the subcellular compartments of PC12 cells after treatment with different concentrations of the green tea polyphenol, epigallocatechin-3-gallate (EGCG). We have demonstrated that EGCG has differentially affected the production of reactive oxygen species (ROS), glutathione (GSH) metabolism and cytochrome P450 2E1 activity in the different subcellular compartments in PC12 cells. Our results have shown that although the cell survival was not inhibited by EGCG, there was, however, an increased DNA breakdown and activation of apoptotic markers, caspase 3 and poly- (ADP-ribose) polymerase (PARP) at higher concentrations of EGCG treatment. Our results suggest that the differential effects of EGCG might be related to the alterations in oxidative stress, GSH pools and CYP2E1 activity in different cellular compartments. These results may have implications in determining the chemopreventive therapeutic use of tea polyphenols in vivo.

Induction of poly(ADP-ribosyl)ation and DNA damage in human peripheral lymphocytes after treatment with (−)-epigallocatechin-gallate

With regard to a future use of tea polyphenols in intervention trials with individuals at high cancer risk, the effects of the tea ingredient (−)-epigallocatechin gallate (EGCG) on poly(ADP-ribose) (PAR) levels and on DNA damage were investigated in human lymphocytes. A dose- and time-dependent elevation of both PAR formation as assessed by quantitative immunofluorescence analysis and DNA damage as assessed by the comet assay were observed after treatment with EGCG at 20, 40 and 80 μM for 10–240 min. Maximum levels of PAR formation and of DNA damage were observed after 10 min at all concentrations tested. Increased PAR levels were still detectable by 240 min in the 40 and 80 μM groups. At the lowest concentration, which is near the physiological peak values found after tea ingestion, PAR formation was not correlated with DNA damage. Here, EGCG led to pronounced PAR levels, whereas the comet assay was almost negative. In contrast, such marked differences in time course and extent of both genotoxicity and PAR formation following EGCG treatment were not detected after γ-irradiation. Our results suggest that the known chemopreventive effects of EGCG, the main constituent of tea, may be partly attributed to an induction of PAR formation.

Modification of milk using immobilized enzymes

The preparation and use of immobilized enzyme systems for the modification of the principle components of milk—casein, lactose, and butterfat—are discussed. Design of a pilot-scale bioreactor is described. Also the use of tea polyphenols as a crosslinking agent is reported. A review of methods for hydrolyzing lactose and characteristics of a concentrated liquid sweetener derived from dairy byproducts is presented. Further, the application of immobilized esterases to modify milk, cream, and butterfat is reported.