
Research Database
The only comprehensive database for clinical and medical research papers on the healthy benefits of matcha/green tea
Recent Research Papers on
cancer-prevention
Author: Xinshan Lu and Yan Zhao and Yanfei Sun and Su Yang and Xingbin Yang
This study was to examine the hepatoprotective effects of polysaccharides from green tea of Huangshan Maofeng (HMTP) against CCl4-induced oxidative damage in mice. HMTP is an acidic heteropolysaccharide with galactose (35.0%, mol.%), arabinose (28.9%) and galacturonic acid (11.3%) being the main monosaccharide components. HMTP (400 and 800 mg/kg·bw) administered orally daily for 14 days before CCl4 administration significantly reduced the impact of CCl4 toxicity on the serum markers of liver damage, alanine aminotransferase, aspartate aminotransferase, total-cholesterol and triglycerides. This method of HMTP administration also markedly restrained hepatic lipid peroxidation formation of malondialdehyde and 15-F2t isoprostanes, and elevated the antioxidant levels of hepatic glutathione and superoxide dismutase. These results together with liver histopathology indicated that HMTP exhibited hepatoprotection against CCl4-induced injury, which was found to be comparable to that of biphenyldicarboxylate. The hepatoprotective effects of HMTP may be due to both the inhibition of lipid peroxidation and the increase of antioxidant activity.
Author: Martina Bancirova
The combination of light, photosensitizer and molecular oxygen is involved in the photodynamic effect. The life-time of ROS is extremely short and ROS can damage biological systems. The reactive oxygen species (ROS) are also produced upon excitation of the photosensitizer by visible light only. Some drinks and foods have the potential or definite antioxidant capacity to inhibit or terminate the ROS action. Usually, Paramecium caudatum is used to determine the toxic effect; well known is especially the toxicity determination of the photodynamic effect. The aim of this work was to explore if the protective effect of tea against ROS produced by the different types of photosensitizer (methylene blue, eosin, fluorescein, phthalocyanines) upon the excitation by visible light only is also possible to determine on the unicellular organism P. caudatum, and compare the protective effect of the black and green teas against ROS with the protective effect of ascorbic acid and Trolox (a standard for the total antioxidant capacity determination). The teas were able to prolong the P. caudatum life-time; the highest observed protection against the photodynamic ROS production (triggered by methylene blue) was caused by the black and green teas and was identical for both of them. The stronger protective antioxidant properties of the green tea were not observed. The pro-oxidant influence of the used antioxidants was not observed.
Author: Melina Bucco Soares and Aryele Pinto Izaguirry and Laura Musacchio Vargas and Andreas Sebastian Loureiro Mendez and Cristiano Chiapinotto Spiazzi and Francielli Weber Santos
Cadmium has been associated with a wide spectrum of deleterious effects on the reproductive tissues, including ovary. This investigation evaluated the protective role of Camellia sinensis (green, white and red teas) in the cadmium-induced inhibition of ovarian δ-aminolevulinate dehydratase (δ-ALA-D) activity in vitro and ex vivo. This study demonstrated that green and white teas restored the cow ovary δ-ALA-D activity inhibited by cadmium whereas red tea had no effect in vitro. In addition, green tea was able to restore enzyme activity inhibited after acute cadmium exposure in mice ovary. Teas infusions composition was assessed by HPLC in a quantitative assay for catechins, purine alkaloids and gallic acid as well as total polyphenol content. The greatest effect of green tea observed in vitro as well as the protective role presented in the ex vivo study could be attributed to the major content of phenols, but not catechins. In fact, catechins were not able to restore enzyme activity inhibited by cadmium, demonstrating that these compounds are not major components responsible for the beneficial effect of green tea observed in this study. This study demonstrated the helpful effect of green tea infusion in ameliorating a marker protein of cadmium intoxication in ovarian tissue.
Author: Aditi Jain and Chanchal Manghani and Shrey Kohli and Darshika Nigam and Vibha Rani
Tea is one of the most popularly consumed beverage. Depending on the manufacturing process, different varieties of tea can be produced. The antioxidative and antimutagenic potential of tea in cardiovascular diseases, cancer and obesity have long been studied. These therapeutic and nutritional benefits of tea can be attributed to the presence of flavanoids. However, these flavanoids also have certain detrimental effects on human health when their consumption exceeds certain limits. The toxicity of these flavanoids can be attributed to the formation of reactive oxygen species in the body which causes damage to the DNA, lipid membranes etc. The aim of this review is to summarize briefly, the less studied evidences of various forms of toxicity associated with tea and its harmful effects on human health.
Author: Jungmin Oh and Heonjoo Jo and Ah Reum Cho and Sung-Jin Kim and Jaejoon Han
We evaluated the antioxidant and antimicrobial activities of various leafy herbal tea (LHT) extracts, including rooibos, green tea, black tea, rosemary, lemongrass, mulberry leaf, bamboo leaf, lotus leaf, peppermint, persimmon leaf, and mate tea. To compare the antioxidant activities of various LHTs, samples of each were extracted with 80 °C water or 20 °C ethanol, and their total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis-3 ethyl benxothiazoline-6-sulphonic acid (ABTS) radical cation decolorization activity, ferric reducing power, and ferrous ion chelating effect were measured. Green tea ethanol extract showed the highest antioxidant activity in all assays except the ferrous ion-chelating assay. Water extracts of green tea and black tea and ethanol extracts of rosemary, mate, and persimmon leaf teas also exhibited considerable antioxidant potential, followed by the green tea ethanol extract. Minimum inhibitory concentrations (MIC) and minimum lethal concentrations (MLC) were determined to verify the antimicrobial activities of the LHT extracts against two oral pathogens (Streptococcus mutans and Streptococcus sobrinus) and three food-borne pathogens (Listeria monocytogenes, Shigella flexneri, and Salmonella enterica). Among the tested LHTs, green tea ethanol extract had potent antimicrobial activity against all five pathogens, and the mate tea water extract was the most effective against Gram-positive bacteria. Consequently, green tea ethanol extracts had the most powerful antioxidant and antimicrobial properties, suggesting their potential application as a health-promoting functional ingredient or natural preservative in foods.
Author: Cornelia Braicu and Michael R. Ladomery and Veronica S. Chedea and Alexandru Irimie and Ioana Berindan-Neagoe
Catechins and their gallate esters are a class of polyphenolic compounds. The catechin subclass known as flavan-3-ols have recently attracted much attention with regards to their beneficial effect on human health. Their biological actions are dependent on the structure of the compounds and vary according to cell type. They are best known as powerful antioxidants; however depending on the doses they also exhibit prooxidant effects. The anti- or prooxidant effects of green tea catechins have been implicated in the modulation of several cellular functions often associated with strong chemoprotective properties. This review summarises the benefit catechins to human health, the main molecular pathways modulated by catechins. The relationship between the structure and activity of the catechins needs to be studied further. In the future, the structure of catechins could be modified so as to synthesise novel compounds with more specific beneficial properties and higher bioavailability.
Author: Ayelet Zlotogorski and Aliza Dayan and Dan Dayan and Gavriel Chaushu and Tuula Salo and Marilena Vered
Summary Nutraceuticals with anti-neoplastic potential are suitable candidates for extending the range of therapeutic options for several types of cancers. One of these malignancies is oral cancer of the squamous cell carcinoma type, for which current treatment approaches have not succeeded in improving long-term clinical outcome. We recently reviewed the beneficial effects of curcumin for the treatment of oral cancer. In the current review, we focused on the beneficial effects of other two nutraceuticals, green tea extracts [especially (−)-epigallocatechin-3-gallate (EGCG)] and resveratrol, in the treatment of oral cancer. In vivo and in vitro studies as well as clinical trials were reviewed, focusing on the beneficial effect of each of these plant-derived dietary agents, either alone or in combination with various pharmacological agents. We also presented the anti-cancer effects against cancer cells and against components of the tumor microenvironment. It emerged that the poor bioavailability of these nutraceuticals poses an obstacle to their exerting adequate anti-cancer potential. Ground-breaking studies employing new nanotechnology-based therapeutic approaches were presented.
Author: Shahab Nootash and Najmeh Sheikhzadeh and Behzad Baradaran and Ali Khani Oushani and Mohammad Reza Maleki Moghadam and Katayoon Nofouzi and Amir Monfaredan and Leili Aghebati and Fatemeh Zare and Sadigheh Shabanzadeh
Present study elucidates the efficacy of green tea (Camellia sinensis) on growth performance, immune and antioxidant systems and cytokine gene expression in rainbow trout tissues. Green tea was supplemented at 20, 100, and 500 mg kg−1 diet and fed to fish (average weight: 23.5 g) for 35 days. No remarkable changes in growth performance were observed among all test groups. Lower lipid peroxidation product and higher superoxide dismutase activity were noted in fish received the medium dose of green tea. Significant increase in serum bactericidal activity and total protein were recorded in all treatment groups. All doses of green tea up-regulated Interleukin-1β transcription in the spleen, while Interleukin-1β mRNA level decreased significantly in the kidney of low dose of green tea. Interleukin-6 mRNA level was up-regulated in the spleen of high dose of green tea and liver of middle and high doses of green tea. High dose and medium dose of green tea up-regulated the interleukin-8 transcription in the kidney and liver, respectively. Meanwhile, green tea inhibited the production of interleukin-10 in all treatment groups compared with control group. Medium dose of green tea up-regulated tumor necrosis factor-α transcription in all fish tissues, while high dose and low dose of green tea enhanced tumor necrosis factor-α mRNA levels in the kidney and spleen, respectively. Present study suggests that green tea especially at 100 mg kg−1 feed may effectively enhance the antioxidant system and immune system in rainbow trout.
Author: Ugo Vertolli and Paul A. Davis and Lucia Dal Maso and Giuseppe Maiolino and Agostino Naso and Mario Plebani and Lorenzo A. Calò
Cardiovascular disease (CVD) remains the most common cause for excess morbidity and mortality in patients with chronic kidney disease (CKD) and end stage renal disease (ESRD) under chronic dialysis. ESRD patients have increased oxidative stress and endothelial dysfunction alongside increased levels of inflammation related proteins, which has prompted the exploration of anti-inflammatory and antioxidant treatments to improve outcomes. As green tea is increasingly well recognized for its antioxidant properties, we probed the effect of consumption of 1 capsule daily of green tea as a commercially available, decaffeinated green tea capsule (1 g, catechin content 68 mg) for 6 months on fibrinogen and inflammation in dialysis patients. Chronic hemodialysis patients (N = 25) were recruited and fibrinogen, FDP-D-dimer, high sensitivity (hs) CRP and the mononuclear cell protein expression of p22phox, were assessed before, i.e. baseline and after 6 months of ingestion of 1 green tea capsule per day. After 6 months of daily green tea capsule ingestion, dialysis patients showed reduced protein expression of p22phox (p < 0.0001), reduced hsCPR (p = 0.032) and fibrinogen (p = 0.022) levels and increased FDP-D-dimer (p = 0.0019) compared to their values at baseline. These results document lower oxidative stress and inflammation with green tea capsule ingestion and suggest a likely positive impact of green tea treatment on the atherosclerotic process of ESRD patients under dialysis.
Author: B. Giménez and A. López de Lacey and E. Pérez-Santín and M.E. López-Caballero and P. Montero
Active biodegradable films based on agar and agar–fish gelatin were developed by the incorporation of green tea aqueous extract to the film forming solution. The effect of the partial replacement of agar by fish skin gelatin as well as the addition of the green tea extract on the physical properties of the resultant films was evaluated. Special attention was given to the release of antioxidant and antimicrobial compounds from the agar film matrices with and without gelatin. Agar–gelatin films were less resistant and more deformable than agar films. The inclusion of green tea extract decreased tensile strength and elongation at break in both agar and agar–gelatin films. Water vapour permeability and water resistance was not affected either by the replacement of agar by gelatin or the addition of green tea extract, but the water solubility noticeably increased in the films containing green tea extract. The presence of gelatin in the agar–green tea matrix film hindered the release of total phenolic compounds, catechins and flavonols in water. As a consequence, the antioxidant power released by the films was lower in the case of films containing gelatin. However, the antimicrobial activity of the films was not affected by the presence of gelatin.