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Effects of Pu-erh Tea on Oxidative Damage and Nitric Oxide Scavenging

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Abstract

The effects of pu-erh tea, which is prepared by fermentation of tea, on oxidative damage and nitric oxide scavenging, compared with various other brands of tea were investigated. The total antioxidant activity was determined using the Trolox equivalent antioxidant capacity (TEAC) assay. The results showed that TEAC values of the 200 microg/mL water extracts of pu-erh tea (WEPT), green tea, oolong tea, and black tea were 86.3, 85.3, 87.4, and 80.3 (microg/mL), respectively, indicating that WEPT showed a significant antioxidant activity. WEPT, like green tea extract, oolong tea extract, and black tea extract, exhibited a remarkable protective effect in lipid (liposome) and nonlipid (protein and deoxyribose) model systems, implying that it is an inhibitor of lipid and nonlipid oxidative damage. It also exhibited metal-binding ability, reducing power, and scavenging effect for free radicals. Moreover, WEPT showed a decreasing effect on nitric oxide production of lipopolysaccharide-induced RAW 264.7 macrophages. In addition, the results revealed that epicatechin (EC), flavonoid, ascorbic acid, and polyphenolic compounds are present in WEPT, which may partially account for the protective effect on oxidative damage. Thus, WEPT may have potential as an antioxidant and as a nitric oxide scavenging agent.

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... Duh et al. [16] stated that the content of total catechins in tea is related to the degree of fermentation of tea, which implies that the higher the degree of the fermentation, the more intense is the decrease in total catechins. ...
... Observations described by Duh et al. [16] could not detect EGCG, ECG or EGC in water extracts of pu'er tea. Hereby, 50 g of tea was extracted with 500 mL boiling water for 5 min. ...
... HCA shows primarily a grouping into two clusters according to processing and year of harvest: APT (No. [13][14][15][16][17] and YPT (No. [1][2][3][4][5][6][7][8][9][10][11][12], whereby the second cluster also contains sheng 1980 and sheng 1992 (No. 18 and 19). This latter alliance results from a similar polyphenol profile and a lower content of chemical compounds than for APT. ...
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Pu'er tea produced from Camellia sinensis var. assamica is a widely appreciated and consumed beverage that can be divided into two kinds of tea depending on the different fermentation processed used, the special sensory characteristics, and their chemical composition. However, authentication seems to be very important for such teas, as they are traded to comparatively high prices, especially in Europe. The results for selected biochemical markers showed that aged raw pu'er tea contained 210.2 mg GAE/g polyphenols, of which 2.2 mg/g were gallic acid, 16.1 mg/g theogallin, 35.1 mg/g (−)-epigallocatechin gallate, and 40.1 mg/g (−)-epicatechin gallate, on average. Young ripened pu'er tea contained about 104.6 mg GAE/g polyphenols, of which 5.5 mg/g gallic acid, 0.9 mg/g theogallin, 0.7 mg/g (−)-epigallocatechin gallate, and 1.8 mg/g (−)-epicatechin gallate, on average. An additional objective of the present study was to unravel the best brewing conditions for optimal extraction of the bioactive compounds. Infusions of nineteen commercial teas (from pu'er cakes) were obtained at different time-temperature ratios for studying the content of bioactive compounds (flavan-3-ols, flavonols, caffeoylquinic acids, methylxanthines). Brewing at 90 • C for 5 min was the best condition to obtain a high content of total polyphenols in ripened pu'er tea. Principal component analysis and hierarchical cluster analysis showed, that young ripened and aged raw pu'er tea can be successfully differentiated by the analyzed chemical compounds. Principal component analysis results indicated that young ripened pu'er tea has higher contents of gallic acid, quercetin, and kaempferol than aged raw pu'er tea.
... Pu-erh manufacturers in Yunnan are increasingly experimenting with inoculating pu-erh leaves with selected microorganisms such as Aspergillus sp., Blastobotrys adeninivorans, Actinoplanes sp., Saccharomyces sp. and Streptomyces sp. for controlled fermentation (Ku et al., 2010;Duh et al., 2004;Chen et al., 2010). Manufacturers may experiment by selecting species and strains that do not produce mycotoxins that can be harmful to human health or inhibit the growth of beneficial microorganisms that enhance the taste of tea. ...
... CHAPTER 5 Pu-erh Tea: Botany, Production, and Chemistry hypo-cholesterolemic effects, anti-obesity, anti-viral, anti-mutagenic, anti-microbial, anticarcinogenic, anti-diabetic, and neuro-protective effects (Jie et al., 2006;Duh et al., 2004;Qian et al., 2005;Sano et al., 1986;Kuo et al., 2005;Wang et al., 2008;Wang et al., 2010;Syu et al., 2008;Way et al., 2009;Cao et al., 2010;Chen et al., 2009;Gong et al., 2010;Zhang 2010). Pu-erh teas have also been found to prevent tooth decay and ulcers, control halitosis, cure stomach disorders, improve bacterial flora in the intestine, increase bone density, and protect against UV rays . ...
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Pu-erh (pu’er) tea refers to processed leaves and buds of the broad-leaf variety of the tea plant ( Camellia sinensis var. assamica (L.) O. Kuntze; Theaceae) primarily sourced from China’s Yunnan province, as well as from neighboring areas of southwestern China, Laos, Vietnam, Myanmar, Cambodia, and northeastern India. This region is the center of origin of the tea plant. The diverse habitats from where pu-erh tea is sourced result in a botanical product that is highly heterogeneous in terms of sensory profiles and morphological, phytochemical, and genetic variation. Pu-erh may be processed as a loose or pressed green tea or a post-fermented black. Unlike other green teas, the heat-processing step is less complete for green pu-erh, and consequently it has a distinct oxidation profile with age. Fresh green pu-erh has similar health claims to other green teas while aged green pu-erh and post-fermented black pu-erh have additional health claims unique to fermented foods and beverages. Black post-fermented pu-erh is distinct from other black teas in that it undergoes fermentation by microbial enzymes. This results in the formation of new chemical constituents and fermentation-derived compounds with pro-biotic health claims.
... Green tea (GT) extract, rich in catechins, has a protective function against antioxidant stress (Perumalla and Hettiarachchy 2011). Fully fermented pu-erh (PE) exhibits antioxidant and antimicrobial properties (Der Duh et al. 2004). Green tea and pu-erh extracts are cheap, safe, and acceptable to consumers. ...
... The presence of catechins, in particular epigallocatechin gallate and epigallocatechin, contribute to the antioxidant activity of green tea extract (Rusak et al. 2008). Moreover, the polyphenolic compounds present in the pu-erh infusion contribute to the protective effect on oxidative damage (Der Duh et al. 2004). Similar results were observed after adding PE and GT extracts to the furcellaran-gelatin film (Jamróz et al. 2019b) and after adding YM and WT extracts to FUR/WPI films (Pluta-Kubica et al. 2020). ...
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In recent years, there has been a serious need to develop and test new biodegradable packaging. Therefore, furcellaran (FUR) and whey protein isolate (WPI) films containing pu-erh (PE) or green tea (GT) extracts were prepared in this study. The effect of the extracts on the structure, rheological and mechanical properties, and antioxidant and antimicrobial activity of FUR/WPI films was tested. The films were applied as packaging of an acid-curd cheese (quark). Water content, pH, water activity, and microbiological and organoleptic quality of cheese were examined. The storage loss modulus increased with the PE addition as well as tensile strength (by 1.37 MPa) and antioxidant activity (by 42.5 percentage points). The GT addition caused no changes in rheological properties but did affect tensile strength (an increase by 1.33 MPa), elongation at break values (a decrease by 7.08 percentage points), and antioxidant activity (an increase by 39.33 percentage points). The FUR/WPI with GT revealed bacteriostatic effect against Staphylococcus aureus. The number of Lactococcus and total bacteria count decreased in almost all cheeses during storage (approximately by 1–2 log cfu g⁻¹), except FUR/WPI + PE. The yeast count increased during storage in all samples (approximately by 4.3–5.5 log cfu g⁻¹), regardless of packaging used. Most of the examined films had a negative influence on organoleptic quality of cheese, especially after storage. Therefore, they were found not to be appropriate as packaging of an acid-curd cheese. However, this research did enable the obtaining of a new edible film with good mechanical properties—the FUR/WPI + PE film.
... Administration of lemon balm extract increases GSH level in the liver and blood of rats with hyperlipidemia (Bolkent et al., 2005) and may prevent damages caused by oxygen free radicals. Lemon balm contains high level of flavonoids (Bayat et al., 2012) with a variety of biochemical and pharmacological activities such as lipid lowering effects, antioxidant and cardioprotective properties (Lin et al., 2012;Wattanapitayakul and Bauer, 2001;Duh et al., 2004). Oxidative stress is a reflection of the concentration of intercellular oxidants such as H 2 O 2 and O 2 -, and glutathione (GSH) serves as an endogenous antioxidant molecule. ...
... Oxidative stress is a reflection of the concentration of intercellular oxidants such as H 2 O 2 and O 2 -, and glutathione (GSH) serves as an endogenous antioxidant molecule. Low level of GSH is known to be associated with a number of diseases in which reactive oxygen species are produced in large quantities, including arthrosclerosis, heart failure, diabetes and neurological disorders (Wattanapitayakul and Bauer, 2001;Duh et al., 2004). Lipid lowering effect of lemon balm extract is related to its flavonoids content (Chung et al., 2010). ...
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Introduction: Diabetes mellitus is a metabolic disorder of the endocrine system leading to increased blood glucose concentration in the patients. As a basic treatment for managing the blood glucose level, insulin or hypoglycemic medications are used but herbal medicines are more favored. The design of this research project was to study the therapeutic effect of hydroalcoholic extract of Melissa officinalis (HEMO) in diabetic rats. Methods: Twenty-five Wistar male rats weighing 220±25 grams were distributed semi-randomly into five groups of five each. Group 1 and 2 was respectively the control and diabetic animals. Group 3, 4 and 5 were the diabetic animals treated with HEMO either at 20, 100 or 500 mg/Kg of body weight. To induce diabetic rat models, each animals received a single intraperitoneal injection of alloxan at the dose of 120 mg/Kg. All treatments with HEMO performed daily via gavage for a period of 4 weeks. Then, blood samples were collected from all animals to measure the blood glucose level, cholesterol, triglycerides, LDL and HDL. Results: The results of this study indicated significant (P<0.05) decreases in blood sugar level, cholesterol, triglycerides and LDL in diabetic rats treated with HEMO. In addition, significant (P<0.05) increase in HDL level was observed in HEMO treated diabetic rats compared with the non-treated ones. Conclusion: HEMO has significant effects on attenuating the blood sugar level, serum lipids and lipoproteins levels, whereas it improves the HDL level. These effect might be attributed to the antioxidant benefits of flavonoids which are present in HEMO.
... The effect of the fermentation process on tea bioactive components changes and their antioxidative activity, as a consequence, have not been well documented. Quantification of bioactive compounds in Pu-erh, green, oolong, and black teas were reported in which green tea had the highest amount of both total phenolics and catechins, whereas black tea and Pu-erh tea had the lowest levels of total phenolics and catechins, respectively [10]. With respect to the antioxidative activity of teas, catechin (C) and its derivatives; (+)-C, (?)-EC, (?)-EGC, (?)-ECG, (?)-EGCG, and (?)-gallocatechin gallate (GCG) play crucial roles for antioxidative activity [9]. ...
... Furthermore, polysaccharides in teas were also responsible for antioxidative activity in green, white, oolong, black, and dark green teas [11]. The total antioxidative activities of teas were reported in which green tea had the highest activity level, followed by oolong, black, and Pu-erh tea, in sequence [10]. Moreover, a comparison of antioxidants in tea was previously documented. ...
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Teas can be classified according to their degree of fermentation, which has been reported to affect both the bioactive components in the teas and their antioxidative activity. In this study, four kinds of commercial Taiwanese tea at different degrees of fermentation, which include green (non-fermented), oolong (semi-fermented), black (fully fermented), and Pu-erh (post-fermented) tea, were profiled for catechin levels by using high performance liquid chromatography (HPLC). The result indicated that the gallic acid content in tea was directly proportional to the degree of fermentation in which the lowest and highest gallic acid content were 1.67 and 21.98 mg/g from green and Pu-erh tea, respectively. The antioxidative mechanism of the gallic acid was further determined by in vitro and in silico analyses. In vitro assays included the use of phorbol ester-induced macrophage RAW264.7 cell model for determining the inhibition of reactive oxygen species (ROS) production, and PKCδ and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit (p47) activations. The results showed that only at a concentration of 5.00 μM could gallic acid significantly (p < 0.05) reduce ROS levels in phorbol ester-Activated macrophages. Moreover, protein immunoblotting expressed similar results in which activations of PKCδ and p47 were only significantly (p < 0.05) attenuated by 5.00 μM treatment. Lastly, in silico experiments further revealed that gallic acid could block PKCδactivation by occupying the phorbol ester binding sites of the protein.
... Puer tea is believed to have an anti-obesity effect (Abe, 2008). Besides that, its hypolipidemic and antioxidative properties have also been documented by a few authors (Duh et al., 2004;Jie et al., 2006;Kuo et al., 2005;Sano et al., 1986). ...
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... For example, long-term tea drinking prevents coronary atherosclerosis [21]. In previous studies, each single component was extracted from the tea to assess the efficacy [22][23][24]. For example, the total polyphenols, main content of pu-erh tea, have the cardiovascular protection by various mechanisms, including anti-inflammatory properties, antioxidant capacities, improvement in endothelial function, inhibition of platelet aggregation, and antithrombotic properties [25]. ...
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We explored whether pu-erh tea consumption ameliorates atherosclerosis and the possible mechanism for its effects in apolipoprotein E-deficient (ApoE −/− ) mice. Our data showed that pu-erh tea consumption markedly reduced early fatty streak formation and the advanced fibrofatty plaque sizes. Additionally, the mean proportion of inflammatory macrophages in the plaque decreased, and the number of apoptotic macrophages increased significantly. NF- κ B activity in peritoneal macrophages decreased by 75.6% compared to the controls, similar with the levels of IL-6, IL-12, and TNF- α expression. The tea extract increased the apoptosis of RAW264.7 cells by decreasing NF- κ B activation and reducing the inflammatory cytokine expression. In conclusion, pu-erh tea ameliorates atherosclerosis progress by alleviating the chronic inflammatory state by reducing NF- κ B activation and promoting macrophage apoptosis in atherosclerotic plaques.
... Puer tea is believed to have an anti-obesity effect (Abe, 2008). Besides that, its hypolipidemic and antioxidative properties have also been documented by a few authors (Duh et al., 2004;Jie et al., 2006;Kuo et al., 2005;Sano et al., 1986). ...
... assamica (Masters) Kitamura) in Yunnan Province of China [1]. It has been proven to possess multiple health-promoting effects, including antioxidation, anti-aging, and hypolipidemic efficacies [2,3]. As a well-known tea, Pu-erh tea is increasingly popular among consumers in Southeast Asia and has many derivative products. ...
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Ganpu tea is an emerging tea drink produced from Pu-erh tea and the pericarp of Citrus reticulate Chachi (GCP). Recently, it has been increasingly favored by consumers due to the potential health effects and special taste. However, information concerning its chemical profile and biological activities is scarce. In this work, a total of 92 constituents were identified in hot-water extracts of Ganpu tea with ultra-high performance liquid chromatography/quadrupole-time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS). Moreover, the antioxidative and gut microbiota modulatory properties of Ganpu tea were investigated in rats after long-term dietary consumption. Ganpu tea and GCP could significantly enhance the activities of superoxide dismutase (SOD) by 13.4% (p < 0.05) and 15.1% (p < 0.01), as well as the activities of glutathione peroxidase (GSH-Px) by 16.3% (p < 0.01) and 20.5% (p < 0.01), respectively. Both showed better antioxidant capacities than Pu-erh tea. Ganpu tea increased the abundance of Bifidobacterium, Lactobacillus, and Lactococcus, suggesting the potential of Ganpu tea in modulating the gut microbiota to benefit human health. The obtained results provide essential information for further investigation of Ganpu tea.
... Results of Jeng et al. [26] showed that superoxide scavenging activity did not differ greatly due to either strains or fermentation period, however the DPPH radicals reducing capacity increased 4-fold with the duration of fermentation. Other research showed excellent DPPH radical reducing activity of Pu Erh tea ethanolic infusions [10]. ...
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http://www.ejpau.media.pl/volume20/issue2/art-02.html In recent years an increased interest in healthy lifestyle caused that other types of tea, e.g. Pu Erh, are also increasingly selected by the consumers. Currently, Pu Erh tea is considered to promote weight loss, as well as support the treatment of numerous diseases, by neutralizing free radicals activity in the human body. Present research aimed at the evaluation of antiradical capacity of Pu Erh tea leaves available on the Polish market. The research was conducted on seven Pu Erh teas produced according to the accelerated ripening method (wo dui), supplied by Polish dealers. Pu Erh tea was subjected to traditional brewing methods, followed by DPPH and ABTS radical reducing activity assays. Tea leaves and its brews were also characterized according to the commodity value. The antiradical capacity of Pu Erh tea leaves showed that examined teas exhibited antiradical properties, however in a varied degree, not conditioned by the type of tea and brewing time. The quality of tea had no significant effect on the ability to reduce the DPPH and ABTS radicals, whereas it affected the extraction process efficiency. Pu Erh tea may be a dietary source of antioxidants, helping with the treatment of diseases caused by free radicals activity, such as diabetes or coronary heart disease.
... Tea is a popular beverage globally, and has been used as a medicine for more than 4000 years. Among a variety of teas, the fermented Pu-erh tea has been considered to have numerous health benefits, such as suppressing hyperlipidemia and hyperglycemia [14,15], lowering the atherogenic index [16], as well as anti-oxidation [17], anti-cancer [18], and anti-obesity in particular [19][20][21]. Pu-erh tea is produced from the leaves of tea trees (Camellia sinensis (L.) var. ...
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Due to misbalanced energy surplus and expenditure, obesity has become a common chronic disorder that is highly associated with many metabolic diseases. Pu-erh tea, a traditional Chinese beverage, has been believed to have numerous health benefits, such as anti-obesity. However, the underlying mechanisms of its anti-obesity effect are yet to be understood. Here, we take the advantages of transcriptional profile by RNA sequencing (RNA-Seq) to view the global gene expression of Pu-erh tea. The model organism Caenorhabditis elegans was treated with different concentrations of Pu-erh tea water extract (PTE, 0 g/mL, 0.025 g/mL, and 0.05 g/mL). Compared with the control, PTE indeed decreases lipid droplets size and fat accumulation. The high-Throughput RNA-Sequence technique detected 18073 and 18105 genes expressed in 0.025 g/mL and 0.05 g/mL PTE treated groups, respectively. Interestingly, the expression of the vitellogenin family (vit-1, vit-2, vit-3, vit-4 and vit-5) was significantly decreased by PTE, which was validated by qPCR analysis. Furthermore, vit-1(ok2616), vit-3(ok2348) and vit-5(ok3239) mutants are insensitive to PTE triggered fat reduction. In conclusion, our transcriptional profile by RNA-Sequence suggests that Pu-erh tea lowers the fat accumulation primarily through repression of the expression of vit(vitellogenin) family, in addition to our previously reported (sterol regulatory element binding protein) SREBP-SCD(stearoyl-CoA desaturase) axis.
... Pu-erh tea is a dark, aged tea that is produced in Yunnan province, China, from a large-leaved variety of tea plant, Camellia sinensis assamica, following a two-step process of microbial fermentation by organisms such as the mould Aspergillus sp. and oxidation 65,66 . Several beneficial activities of Pu-erh tea are documented, including prevention and treatment of cancer, heart diseases, rheumatoid arthritis and immune disease such as AIDS [67][68][69] . Due to its inhibitory effect on HIV replication Pu-erh tea extracts may be used as a dietary supplement or a natural product administered to HIV patients 65 . ...
Article
Belonging to the Lentivirus genus of animal retroviruses, human immunodeficiency virus (HIV) is the etiological agent of acquired immunodeficiency syndrome (AIDS) which attacks cells of the immune system including CD4⁺ T lymphocytes, monocytes, macrophages and dendritic cells. A rapid progression to immunodeficiency and the higher transmissibility of HIV-1 compared to HIV-2 are hallmarks of the worldwide spread of AIDS. Conventional HIV treatments are limited by drug toxicity and by multi-drug resistance, caused by the high genetic variability of HIV. This has led researchers into new areas of drug discovery in search of novel therapeutic molecules. Accumulating evidence indicates that tea polyphenols possess a range of beneficial properties including anti-cancer, anti-inflammatory, anti-oxidative, neuro-protective, anti-bacterial, anti-fungal and anti-viral effects. The anti-HIV infection potential of tea polyphenols has been confirmed by several preclinical studies. This suggests that polyphenol-rich extracts of tea could be used as dietary supplements as part of a combined therapeutic regimen with conventional anti-HIV drugs. Phenolic structures may also be considered as backbones for the discovery of a new generation of anti-HIV remedies. This review provides a perspective on the anti-HIV activity of tea polyphenols and their development as a possible source of future drugs for the therapy of HIV/AIDS.
... Pu-erh tea is a unique fermented tea, which is originally produced in Yunnan Province, southwest of China using the leaves of the cultivated variety large-leaf tea of Camellia sinensis. It has been confirmed that Pu-erh tea exhibits multiple beneficial health effects, such as antioxidant, [1,2] anticancer, [3] antimutagenic, [4] antimicrobial, [4] anti-atherogenic, antiobesity, [5,6] as well as hepatoprotective [7] activities. The health benefits attributed to Pu-erh tea has increased its popularity. ...
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Pu-erh tea has gained more and more popularity and attracted much attention for its various biological effects. The objective of this study was to determine the active phenolic compounds and the biological effects of 15 differently aged Pu-erh teas. The results showed that 43 active phenolics, containing 7 flavan-3-ols, 11 organic acids, and esters, 3 proanthocyanidin dimers, 2 benzotropolones, and 20 flavonoid glycosides were identified based on high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-QTOF-MS/MS). In particular, 2’-O-galloylhyperin and quercetin-3-O-p-coumaroyl-rhamnosyl-arabinosyl-hexoside were identified from constituents of tea for the first time. The 15 Pu-erh teas exhibited strong DPPH and ABTS scavenging activity in a concentration-dependent manner with IC50 0.99–2.12 and 0.97–2.67 mmol Trolox equivalent antioxidant capacity/g, respectively. All of the Pu-erh teas tested significantly inhibited the proliferation of SMMC-7721 cells, in a dosage-dependent manner. Of the 15 Pu-erh teas examined, the cake tea P6 had the strongest effect on SMMC-7721 cells with IC50 = 65.88 ± 3.53 µg/mL. The others Pu-erh teas had an IC50 = 96 – 509 µg/mL. Our results also indicated that not all the older Pu-erh teas display stronger anti-activities and anti-cancer than the younger ones and the youngest Pu-erh tea did not possess the highest level of active components. This study provides useful information for consumers to deeply understand the chemical constituents and bioactivity of Pu-erh tea preserved for a long time.
... There has been a speculation about the content of total catechins in Pu-erh tea, as some studies suggest that the content of total catechins in Pu-erh tea is one tenth of that in green tea. [7] The main objectives of the present study are to evaluate the potential anticancerogenic effect of the catechins derived from Pu-erh tea leaves on non-carcinomas and carcinomas cell lines, as well as evaluation of combination effects with oxaliplatin. ...
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In this study we investigated the effects of catechin fraction extracted from the Pu-erh tea leaves against human colon carcinoma cell line HT-29, human breast carcinoma cell line MDA-MB-231 and healthy cell lines – BALB/3T3 and BJ. We added different concentrations of the catechin fraction (2 – 1000 μg/ml) to the cultured cells and incubated them for 24 and 72 h. To detect cytotoxic and antiproliferative effects, we used MTT assay. The catechin fraction extracted from Pu-erh tea slightly exerted a direct cytotoxic effect; while the anti-proliferative action was concentration-dependent on forth used cell lines. Combination of Pu-erh catechins with oxaliplatin did not result in synergistic effects.
... Pu-erh tea is a Chinese tea made from green tea leaves that have been oxidized and fermented using micro-organisms such as Aspergillus species. Several studies have reported that Pu-erh tea has the ability to reduce body weight, fatty acid synthesis, hyperlipidaemia, NAFLD and oxidative stress [6][7][8][9][10][11][12][13]. However, the mechanisms underlying Pu-erh tea's alleviation of these metabolic processes and symptoms are not clear. ...
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Background Tea polyphenols are the prominent component in tea. After the fermentation process, tea polyphenols are oxidized by polyphenol oxidase to form oxidized tea polyphenols (OTPs). OTPs contain a significant amount of hydrophobic phenyl groups that can bind with non-aqueous materials. Here, we determined whether OTPs can bind with lipids and reduce fat uptake and assessed the effect of OTPs on decreasing obesity and alleviating hyperlipidaemia and other metabolic syndromes. Methods Rats were divided into three groups: control, high-fat diet (HFD) and OTP groups. The control and HFD groups were fed a chow diet and a high-fat diet, respectively, for 12 weeks; the OTP group was fed a high-fat diet for 6 weeks and then a high-fat diet containing 2 % OTP for 6 weeks. The serum and excrement triglyceride (TAG) and total cholesterol (CHOL) concentrations were determined, and liver tissue and white adipose tissue were collected to detect the expression levels of genes involved in lipid metabolism. Results Our results revealed that OTPs failed to decrease the serum concentrations of TAG and CHOL. OTPs alleviated the accumulation of lipids in the liver tissue and changed the expression levels of the regulators of lipid metabolism, i.e., peroxisome proliferation-activated receptors (ppars), compared with the rats fed a high-fat diet alone. We also observed a significantly decreased reduction of weight in the visceral white adipose, enhanced regulation of fatty acid β-oxidation by PPARα and enhanced biosynthesis of mitochondria in the visceral white adipose of the OTP rats compared with the HFD rats. Additionally, OTPs promoted the excretion of lipids. Conclusion Our results suggest that OTPs alleviate the accumulation of lipids in liver and visceral white adipose tissue and promote lipid excretion in rats in vivo.
... Various types of tea are categorized based on the degree of fermentation during manufacturing, each of the four types with different chemical composition and health benefits: nonfermented (green) tea, partially fermented (oolong) tea, fully fermented (black) tea, and postfermented tea (Puer). [12][13][14][15] Puer tea originated in Yunnan Province in imperial China, and has long been consumed as one of the most popular beverages in Asia. 16 Historically, Puer tea was used as a medicinal drink in the treatment of a variety of illnesses, such as common colds, flatulence, poor digestion, and onset of dysentery. ...
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Objective The goal for this study was to evaluate the effects of daily consumption of Puer tea extract (PTE) on body weight, body-fat composition, and lipid profile in a non-Asian population in the absence of dietary restrictions. Materials and methods A randomized, double-blind, placebo-controlled study design was used. A total of 59 overweight or mildly obese subjects were enrolled upon screening to confirm fasting cholesterol level at or above 220 mg/dL (5.7 mmol/dL). After giving informed consent, subjects were randomized to consume PTE (3 g/day) or placebo for 20 weeks. At baseline and at 4-week intervals, blood lipids, C-reactive protein, and fasting blood glucose were evaluated. A dual-energy X-ray absorptiometry scan was performed at baseline and at study exit to evaluate changes to body composition. Appetite and physical and mental energy were scored at each visit using visual analog scales (0–100). Results Consumption of PTE was associated with statistically significant weight loss when compared to placebo (P<0.05). Fat loss was seen for arms, legs, and the gynoid region (hip/belly), as well as for total fat mass. The fat reduction reached significance on within-group analysis, but did not reach between-group significance. Consumption of PTE was associated with improvements to lipid profile, including a mild reduction in cholesterol and the cholesterol:high-density lipoprotein ratio after only 4 weeks, as well as a reduction in triglycerides and very small-density lipoproteins, where average blood levels reached normal range at 8 weeks and remained within normal range for the duration of the study (P<0.08). No significant changes between the PTE group and the placebo group were seen for fasting glucose or C-reactive protein. A transient reduction in appetite was seen in the PTE group when compared to placebo (P<0.1). Conclusion The results from this clinical study showed that the daily consumption of PTE was associated with significant weight loss, reduced body mass index, and an improved lipid profile.
... During the recent past, studies have shown that tea can lower the risk of cardiovascular disease and cancers, 2,3 reduce body weight and plasma levels of free triglycerides (TG), cholesterol, and low-density lipoprotein cholesterol, 4 as well as showing extraordinary antioxidant and antiaging effects 5,6 and anticancer properties. 7 Yerba maté and guarana have been shown to be potentially useful for weight loss and weight maintenance in overweight patients. ...
Article
Tea from the leaves of guayusa (Ilex guayusa) has a long history of consumption by Ecuadorian natives in regions where the plant is indigenous. The tea contains the methylxanthines caffeine and theobromine as well as chlorogenic acids, flavonoids, and sugars. Various studies were performed to evaluate the general and genetic toxicology of a standardized liquid concentrate of guayusa (GC). Guayusa concentrate was found to be negative in in vitro genotoxicity tests including the Ames test and a chromosome aberration study in human lymphocytes. The oral median lethal dose (LD50) of GC was >5,000 mg/kg for female rats. Guayusa concentrate was administered to male and female rats in a 90-day subchronic study at 1,200, 2,500, and 5,000 mg/kg/d of GC and a caffeine-positive control at 150 mg/kg/d corresponding to the amount of caffeine in the high-dose GC group. Effects observed in the GC-treated groups were comparable to those in the caffeine control group and included reductions in body weights, food efficiency, triglycerides values, and fat pad weights and increases in blood chemistry values for serum aspartate aminotransferase, serum alanine aminotransferase, and cholesterol and adaptive salivary gland hypertrophy. No signs of incremental toxicity due to any other components of guayusa were observed. The studies indicate no harmful effects of GC in these test systems.
... During the last decade, the effects of tea and tea polyphenols have been extensively investigated and studies have shown that tea is capable of exerting an antioxidant and antiaging effect (Cooper et al., 2005;Duh et al., 2004). However, the fermentation process lowers the polyphenol levels in Zijuan Pu-erh tea; conversely, levels of LMPP greatly increase after the fermentation process (Wang et al., 2012). ...
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The antioxidative effect of large molecular polymeric pigments (LMPP) extracted from Zijuan Pu-erh tea was investigated in vitro and in vivo. The results showed that LMPP had significant scavenging activities on the hydroxyl radical and the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical in vitro and showed strong reducing power. Moreover, the 50% inhibitory concentrations of LMPP for scavenging DPPH radical and hydroxyl radical were 0.217 mg.mL-1 and 0.461 mg.mL-1, respectively. In vivo, the LMPP-treated rat groups showed significantly increased serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities, reduced malondialdehyde (MDA) formation, increased nitric oxide (NO) production and significantly decreased rat endothelin-1(ET-1) concentrations compared with those in the hyperlipidemia model group (P < 0.05). The serum SOD and GSH-PX activities and NO concentration were 66.88, 29.09 and 55.11% higher, respectively, whereas, the serum ET-1 and MDA concentrations were 34.62 and 59.11% lower in the high-dose LMPP treatment group (1.215 g.kg-1 body weight) than in the hyperlipidemia model group (P < 0.05). These results showed that LMPP has a good antioxidative function and can be considered as a natural antioxidant source.
... Similar results were obtained by Yashin, Yashin and Nemzer [52] who examined the antioxidant activity of different types of teas (green, oolong, black and pu-erh). Polyphenolic compounds are present in water extracts of pu-erh tea, which could contribute to the protective effect on oxidative damage and nitric oxide scavenging [53]. Similar to our study, Yang, Lee, Won and Song [50] reported that the DDGS films containing GTE had the greatest antioxidant activity (ABTS and DPPH assay). ...
Article
Biodegradable films from furcellaran and gelatin (FUR/GEL) with pu-erh (RTE) and green tea (GTE) water extracts (TEs)were obtained by a casting method. The films were examined in terms of physical properties (thickness, density, water solubility, water content, degree of swelling, color), antioxidant properties (DPPH, ABTS, TPC), antimicrobial properties (Escherichia coli, Staphylococcus aureus, Candida albicans and Henseniaspora uvarum) and mechanical properties (tensile strength, elongation at break). The values of tensile strength (TS) increased from 9.62 to 24.14 or 13.59MPa after GTE or RTE incorporation, respectively. Parameters of elongation at break were not changed. Higher color parameters: a*, b* and ΔE were observed in biocomposite films with RTE. The FUR/GEL films with GTE and RTE can be used for intelligent food packaging, due to their sensibility of pH changes. Possible interaction between the film matrix and TEs was confirmed using FTIR. The antioxidant properties were significantly enhanced with increasing GTE and RTE concentration reaching 43.92 and 48.94% of DPPH and 15.76 and 14.98% of ABTS radical inhibition, respectively. The microbiological analysis confirmed the antimicrobial properties of FUR/GEL with GTE against E.coli and S. aureus (inhibition zones of 16 and 22.5 mm, respectively).
... One potential such therapy may lie in a long used traditional beverage produced in southwestern China known as Pu-erh tea. Pu-erh tea, a tea post-fermented by microorganisms [2] has long been consumed for its supposed benefits to health that are only recently being scientific explored, marked effects against oxidation [3][4][5], cancer [6], atherosclerosis [7], obesity [8,9], hypercholesterolemia, [10][11][12], among others. ...
... Increasingly, Puerh tea is being consumed beyond its region of origin. Pu-erh tea has various health benefits, including hypolipidemic (Hou et al., 2009), antiobesity (Oi et al., 2012), antioxidative and free radical scavenging (Duh et al., 2004), antimutagenic and antitumor (Hayakawa et al., 2001), and toxicity suppressing activities (Zhang et al., 2011). These benefits are mostly associated with theabrownins (TB), the water soluble polymeric phenolic compounds derived from various polyphenols (Wang et al., 2018). ...
Article
Theabrownins (TB) are polymeric phenolic compounds associated with the multiple bioactivities of Pu‐erh tea, a post‐fermented Chinese dark tea. High‐TB instant Pu‐erh tea was produced via a novel submerged fermentation (SF) using Aspergillus tubingensis and compared with samples produced commercially via the conventional solid‐state fermentation (SSF). Viable microorganisms and microbial toxins, especially aflatoxins B1, G1, B2, G2, cyclopiazonic acid, fumonisins B1, B2, B3 and ochratoxin A, were below the detection limit in all samples. Fewer microbial metabolites were found in SF instant tea compared with the SSF teas. Based on an adult consuming 1 g of instant Pu‐erh tea daily, the dietary intake of investigated elements was below the safe limits recommended by various authorities. Tasters viewed the instant tea infusions as very mild, smooth, mellow and full. This suggested that submerged fermentation using A. tubingensis offers a speedy and safe alternative to commercial production of instant Pu‐erh tea.
... [42] tarafından yapılan çalışmada meyve ekstraktlarında en yüksek oranda bulunan fenolik asidin şiringik asit, yaprak ekstraktlarında ise bu asidin yanı sıra, p-kumarik, gallik ve vanillik asitler olduğu tespit edilmiştir. Şiringik asit gibi p-kumarik asit, trans ferulik asit, gallik asit, klorojenik asit ve naringin'in özellikle Gr (-) ve (+) patojenlere karşı (Tablo 3) demir bağlama kapasitelerinin yüksek olmasından dolayı S. aureus ve E. coli üzerinde güçlü antibakteriyel etki göstermesi ve biyofilm oluşumunu engelleme yeteneklerinin bulunması da dikkate değerdir [3,22,[30][31][53][54][55][56][57][58][59][60]. [61], barsak kökenli bakteriler ve toksinlerinin barsak epitellerinden geçişini azaltan fenolik bileşiklerce zengin meyvelerin tüketimi ve bu meyvelerin probiyotik katkılı gıda üretimlerinde prebiyotik amaçlı kullanımı önem arz etmektedir. ...
Article
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Blueberry (Vaccinium myrtillus) has a significant place among berry fruits, and is a rich source of phenolic compounds with antioxidant, antimicrobial, anti-diabetic and anti-inflammatory properties. Recently, studies on plant-derived antimicrobial agents against pathogens have increased. In this study, the antibacterial activity of fresh and dried blueberry fruit and leaf extracts grown in three different locations of Erdek and Kapıdağ, Turkey and phenolic standards were determined. The extracts and phenolic standards were tested against Salmonella Enteritidis (ATCC 13076), Escherichia coli (ATCC 25922), Staphylococcus aureus spp. aureus (ATCC 29213), Enterobacter aerogenes (ATCC 13048), Listeria monocytogenes serotype 1/2b, Salmonella Typhimurium, Lactobacillus delbrueckii NRRL B 548, Lactobacillus casei NRRL B 1922, and Lactobacillus acidophilus NRRL B 4495 by the disc diffusion method. Fresh and dried blueberry fruit and leaf extracts exhibited phenolic composition with a dose-dependent inhibitory effect against the growth of pathogens and probiotics. The dried leaf extracts were the most effective (20-25 mm) against all bacteria (except L. acidophilus NRRL B 4495) in comparison to positive control (24-26 mm) while syringic acid (16-26 mm), trans ferulic acid (14-26 mm), and naringin (14-26 mm) were the most effective and caffeic acid (16-18 mm), resveratrol (16-19 mm) and (+)-catechin (16-18 mm) were the least effective phenolics on all pathogens. S. Enteritidis (ATCC 13076) was the most resistant to phenolics, followed by L. monocytogenes serotype 1/2b and S. Typhimurium. Syringic acid, hesperidin, 3-hydroxyl-4-methoxy-cinnamic acid, and rutin hydrate were the effective phenolics on LAB. Results indicated that blueberry extracts are effective against pathogens and LABs (except L.acidophilus), and they may have an important potential as a natural preservative while phenolic standards may exhibit variations in their effects. Keywords: Antibacterial activity, Disc diffusion, Blueberry, Extract, Phenolics
... DPPH and ABTS method influenced the most significant scavenging activity. Pu-erh tea contains phenolic compounds in its water extracts that are responsible for the prevention against oxidative damage and nitric oxide scavenging (Duh et al., 2004). ...
Article
Background The growing environmental concern of plastic packaging disposal has led to the innovation of biodegradable biopolymers. Consumer demand and health concern further necessitate the emergence of active and intelligent packaging system to monitor the quality of packed food. Whereas, the use of chemical dyes as an indicator in smart packaging is not suitable for food packaging because of their high toxicity and harmful effects on human health and the environment. Hence, the researchers are focused on natural pigments derived from plants and food waste as indicating substance in biodegradable packaging and also for the valorization of food waste. Scope and approach This paper summarizes the research on the utilization of naturally derived food- and food waste-based pigments (anthocyanins, curcumin, betalains, carotenoids, chlorophyll, brazilin, quercetin, etc.) with biopolymeric matrices (starch, cellulose, chitin, gums, agar, etc.) to fabricate “smart biodegradable films”, for effective monitoring of spoilage and quality of meat products, seafood, milk, and others. Key Findings and Conclusions: The results show that the smart packaging material developed by the biopolymers with plant-based pigment has the potential to replace the traditional plastic packaging materials. The extracted from food and food waste act as an indicator in smart packaging and promotes the valorization of food waste. The biodegradable packaging is economical, safe, non-toxic, sensitive, and natural pigments act as a quality indicator in packaging systems. Further, these packaging films can be optimized and commercialized and to be employed as active and intelligent packaging for visual quality evaluation of fresh food products.
... Green, black and oolong tea are produced differently. Green tea keeps the highest level of total phenolics, of which about 94% of flavonoids is catechins (Duh et al. 2004). Oolong tea contains about 18% of total phenolics and 4.4% of flavonoids. ...
Chapter
The quality of food in terms of taste and nutritional value is primarily based on the composition. Plant-based foods contain phenols that may determine consumer’s acceptance of such foods. Besides their role in preventing the emergence of some diseases and in protecting our gut’s health, phenols play a cardinal role in shaping our perception of foods. In this specific ambit and during the last decade, many scientific researches have been revealing the health and nutritional benefits of polyphenols and have thus stimulated the creation and the development of a market niche linked to polyphenols. These molecules are mainly extracted from 12 vegetable matrices, including grape seeds, green tea, cocoa, olives (including fruit and oil) and coffee predominate. For these reasons, many of these food products are considered as ‘functional foods’. Interestingly, the Mediterranean Diet includes mainly foods of vegetable origin, many of which contain remarkable amounts and a wide variety of polyphenols. This chapter examines the consumers’ reaction to polyphenol-rich foods in terms of sensorial features, mainly flavours and colours. In addition, chemical properties and natural sources of phenolics have to be investigated.
... Green, black and oolong tea are produced differently. Green tea keeps the highest level of total phenolics, of which about 94% of flavonoids is catechins (Duh et al. 2004). Oolong tea contains about 18% of total phenolics and 4.4% of flavonoids. ...
Chapter
Foods are the vehicle and the support of a wide variety of macronutrients, micronutrients and minor compounds that are responsible for the nutritional and sensorial properties. Mediterranean Diet is abundant in plant-based (nutrient-dense, seasonal and low-energy) foods, and despite including industrial products, it does not have place to ultraprocessed foods, which are energetically dense and low in nutrients; the first type of foods (including fresh produce as well as foodstuffs) is grounded on agro-biodiversity and respectful of the environment, while the second class of foods (sodas, fast-food) is responsible for the rise in obesity and other non-communicable diseases. Products of the second food category generally have a high carbon footprint, contribute to deforestation, to the reduction of biodiversity, and generally do not bring any social benefit. This chapter emphasizes the important involvement of polyphenols of natural origin specifically in connection with organoleptic features, on the one side; on the other side, the use of polyphenols as food supplements and additives is also detailed. Polyphenols can configure the sensorial proprieties of foods by their colours, their taste (e.g. astringency and bitterness) in addition to various nutritional functions and health benefits, which make them popular bioactive compounds. It is important to raise awareness on the need of official regulations of health claims (particularly in food supplements) and standardization of recommended daily intakes for these phytonutrients. It is also important to claim that phenols are just one piece of the whole puzzle of dietary components that must be present in our dishes.
... Green, black and oolong tea are produced differently. Green tea keeps the highest level of total phenolics, of which about 94% of flavonoids is catechins (Duh et al. 2004). Oolong tea contains about 18% of total phenolics and 4.4% of flavonoids. ...
Book
This book focuses on polyphenols in the Mediterranean diet, providing a detailed overview of their chemical structure, extraction and analysis methods, and their role in the diet and in flavor. Phenols are important not only in terms of preventing a number of diseases due to their antimicrobial and antioxidant effects, but also in shaping our perception of foods. The first chapter discusses consumers’ sensory assessment of foods containing polyphenols in terms of flavor and color, as well as the chemical properties and natural sources of phenolic compounds. The second chapter examines hygiene and safety claims with respect to naturally occurring polyphenols, especially in connection with organoleptic features. The third and final chapter examines the dietary sources of these molecules from various fruits, including processed products such as infusions, wines, oils and olives. Given its scope, this book is a valuable resource for researchers in academia and industry interested in food safety, hygiene and production issues related to the Mediterranean diet.
... assamica (Masters) Kitamura) in Yunnan Province of China [1]. It has been proven to possess multiple health-promoting effects, including antioxidation, anti-aging, and hypolipidemic efficacies [2,3]. As a well-known tea, Pu-erh tea is increasingly popular among consumers in Southeast Asia and has many derivative products. ...
Article
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Ganpu tea is an emerging tea drink produced from Pu-erh tea and the pericarp of Citrus reticulate Chachi (GCP). Recently, it has been increasingly favored by consumers due to the potential health effects and special taste. However, information concerning its chemical profile and biological activities is scarce. In this work, a total of 92 constituents were identified in hot-water extracts of Ganpu tea with ultra-high performance liquid chromatography/quadrupole-time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS). Moreover, the antioxidative and gut microbiota modulatory properties of Ganpu tea were investigated in rats after long-term dietary consumption. Ganpu tea and GCP could significantly enhance the activities of superoxide dismutase (SOD) by 13.4% (p < 0.05) and 15.1% (p < 0.01), as well as the activities of glutathione peroxidase (GSH-Px) by 16.3% (p < 0.01) and 20.5% (p < 0.01), respectively. Both showed better antioxidant capacities than Pu-erh tea. Ganpu tea increased the abundance of Bifidobacterium, Lactobacillus, and Lactococcus, suggesting the potential of Ganpu tea in modulating the gut microbiota to benefit human health. The obtained results provide essential information for further investigation of Ganpu tea.
... The ingredients in fermented Pu-erh tea include caffeine, polyphenols, γ-aminobutyric acid, theanine, statin, polysaccharides (3,(20)(21)(22), theaflavins, thearubigins and theabrownins (23)(24)(25)(26). ...
Article
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Pu-erh tea has become a focus of research due to its reported biological activities, including anti-oxidation, anti-inflammation and anti-immunosenescence. The present study was performed to evaluate the potential gastroprotective function of Pu-erh tea extracts against ethanol-induced gastric mucosal damage in rats. Sprague Dawley rats were randomly divided into seven groups: A normal control, a model control, a cimetidine (0.08 g/kg) group, three Pu-erh tea extracts groups (low, moderate and high-dose; 0.50, 1.00 and 1.50 g/kg, respectively, and a green tea powder (1.00 g/kg) group. The normal and model groups were pre-treated with distilled water while the other groups were respectively administered cimetidine, Pu-erh tea extracts and green tea powder for 14 days. Then, absolute ethanol was orally administered to the rats of all groups excluding the normal controls. The effects of the pretreatments on gastric mucosal injury were evaluated by gross assessment of gastric lesions, examination of histopathology and determination of myeloperoxidase (MPO) activity and asymmetric arginine (ADMA) concentration in gastric mucosal homogenate. Pre-treatment with cimetidine or Pu-erh tea extracts markedly suppressed the formation of ethanol-induced gastric lesions. Furthermore, clear decreases in MPO activity and ADMA concentration in the gastric mucosal homogenate were observed following pretreatment with cimetidine or Pu-erh tea extracts. The anti-gastric ulcer activity of green tea was less than that of Pu-erh tea. Overall, these effects of Pu-erh tea extracts may be due to potential functions in protecting the gastric mucus layer and suppressing inflammation.
... Dark tea extract has been found to inhibit lipogenic metabolism by repressing gene expression of sterol regulatory element binding protein-1c and fatty acid synthase and CCAAT/enhancer binding protein α, while promote energy expenditure and lipodieresis through upregulation of gene expressions of hepatic peroxisome proliferator-activated receptor α, carnitine palmitoyltransferase 1a and LDL receptor [9]. Dark tea also has been shown to potentially act as the antioxidant and nitric oxide scavenging agent, as exemplified by the finding that dark tea extract exhibits the negative effect on nitric oxide production in lipopolysaccharide-induced RAW 264.7 macrophages [10]. Referring to cancer research, a newly identified acylated flavonol glycoside named as Camellikaempferoside A (kaempferol3-O-[E-pcoumaroyl-(→2)][α-l-arabinopyranosyl-(1→3)][α-l-rh amnopyranosyl(1→6)]-β-dglucopyranoside) is isolated from dark tea, which has been shown to exhibit anti-proliferative activity against breast cancer MCF-7 and MDA-MB-231 cells [11]. ...
Article
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Background: Dark tea is one of the most popular types of Chinese tea, which has been reported to exhibit anti-obesity, anti-oxidation and antitumor activities in according human cell lines. In terms of tumorigenesis, the systemic study of the physiological effect of specific fraction of dark tea and the relevant molecular mechanism warrant more attention. Methods: Dark tea was firstly isolated through solvent extraction method. Dissolved ethyl acetate extract was further fractioned by elution with various concentration of ethyl alcohol. The cytotoxicity effect of dark tea on cell proliferation was evaluated by CCK8 assay in HPDE human normal pancreatic duct epithelial cells, SW1990 and PANC-1 human pancreatic cancer cells, and SW1116 human colorectal cancer cells. Immunoblotting and flow cytometry analysis were utilized to examine the status of protein and reactive oxygen species respectively. Gene expression profile was analyzed by cDNA microarray and real-time PCR. The plasmid for ID1 expression was stably transfected into SW1990 cells for relevant functional analysis. The effect of dark tea extract on tumorigenesis in vivo was studied in xenograft tumor model. Results: Water eluate fraction of the ethyl acetate extract from dark tea inhibited the growth of SW1990, PANC-1 and SW1116 cells more efficiently compared with that in HPDE cells. Meanwhile, p38 activity was increased and AKT activity was dropped in cancer cells with dark tea extract treatment. Further functional analyses indicated that water eluate fraction and p38 inhibitor treatment exerted a synergic inhibitory effect on cancer cells growth, which was related to their suppressive effect on expression level of ID1 (inhibitor of differentiation protein 1), which was highly expressed in cancer cells. The analysis utilizing xenograft tumor model further indicated water eluate fraction exhibited a significantly inhibitory effect on tumorigenesis. Conclusion: Based on the sequential extraction procedure, our results reveal the inhibitory effect of water eluate fraction of the ethyl acetate extract from dark tea and its synergistic effect with p38 inhibition on the growth of pancreatic cancer cells, in which ID1 is identified as a downstream effector. This sheds insights into the physiological relevance of specific fraction of dark tea to tumorigenesis in pancreatic cancer.
... Phenolic compounds are one of the main contributors in antioxidant activity in fruit juices. Previous study shows that there is a positive relation between TA B L E 3 Effect of ultrasound processing on organic acids of functional peach beverage total phenolic contents and antioxidant activity in many plant species (Duh, Yen, Yen, Wang, & Chang, 2004;Jayaprakasha, Girennavar, & Patil, 2008). Therefore, increase or decrease in antioxidant activity is directly proportional to loss or gain of phenolic compounds in the juices. ...
Article
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Abstract The influence of thermal treatment (at 90°C for 10 min) and sonication (at 20 kHz and 130 W for 30, 60, and 90 min on room temperature) on the physicochemical properties, bioactive compounds, antioxidant activity, and organic acids of fresh formulated functional peach beverage was investigated. The results indicated that conventional pasteurization and sonication treatment did not show any significant changes in pH value and Brix amount of juice, and however, a rise in cloud value was observed under all processing conditions. The thermal treatment caused the decrement in total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity (assessed by diphenyl dipicryl hydrazyl (DPPH), ferric ion reducing antioxidant power (FRAP) and 2,2'‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS)), and organic acids of juice, whereas sonication treatment for 90 min increased maximum the activity of bioactive compounds (TPC: 600.61 µg/100 ml; TFC: 177 µg CE/100 ml), antioxidants (DPPH: 51.87%; FRAP: 506.13 µmol Trolox/L; ABTS: 1,507.375 µmol Trolox/L), and organic acids (malic acid: 998; citric acid: 128; oxalic acid: 145; shikimic acid: 63 µg/100 ml) as compared to other treatment conditions and control. Multivariate data analysis was done by principal component analysis as it identifies patterns in data by comparing data sets which is further expressed based on their similarities and discriminations, respectively.
... Fermente siyah çayda, çay yapraklarında bulunan fenolik bileşiklerin oksidasyonu polifenoloksidaz enzimiyle biyokimyasal süreç kapsamında gerçekleşirken, pu-erh çay yapraklarındaki fenoliklerin oksidasyonunda mikroorganizmalar etkili olmaktadır [70]. Yapılan çalışmalarda, önemli miktarda suda çözünür nitelikte flavonoid içeren pu-erh çay ekstraktlarının hem Gram (+) hem de Gram (-) mikroorganizmalar üzerine, ATP, DNA ve RNA gibi protein yapısındaki intraselülar moleküllerin kaybına sebep olan mikrobiyal hücre geçirgenliğini değiştirerek yüksek düzeyde antimikrobiyal aktivite gösterdiği ifade edilmektedir [63,71] [39], Mani-Lopez ve ark. [82], Ayed ve ark. ...
Article
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Kombucha is a symbiotic system including synergistic effects of yeasts and acetic acid bacteria, produced by the fermentation of tea leaves and the incorporation of kombucha cultures under aerobic conditions. In this study, kombucha samples were produced using different tea leaves (white, green, oolong, black and pu-erh), and the number of lactic acid bacteria (LAB), total yeast (TM), total acetic acid (TAA) and total gluconobacter (TGB) were determined in these samples during the fermentation of 21 days (30°C, dark conditions). Moreover, the survival rates of the present microbiota were investigated by using the in vitro artificial gastrointestinal model depending on the various fermentation periods. On the 12th day of fermentation, the highest vitality rates were obtained for acetic acid bacteria (91.16-99.61%) and gluconobacteria (90.84-99.37%) in artificial gastrointestinal model. At the end of the fermentation period, TAA and TGB counts were 7.77-10.66 and 7.68-9.68 log cfu/mL, respectively. LAB counts increased first, followed by a reduction of 60% due to high acidity (11.17 g/L, as acetic acid) and a decrease in pH (2.82). In terms of antibacterial activity; E. coli was the most sensitive microorganism and Lactobacillus acidophilus was the most resistant microorganism to the elevated acidity. The Kombucha tea produced by Pu-erh tea leaves had the highest antibacterial effect on the microorganisms investigated (p<0.05). In terms of the industrial production of Kombucha tea and the viability of the probiotics, it was concluded that the ideal fermentation period should be 2 weeks, and the fermentation conditions should be standardized in order to maintain its functional properties.
... There are some features that may influence the antioxidant activity of foods such as genetics, harvest season, and geographic and environmental conditions (Prior et al., 2005). The high content of flavonoids in lemon balm, which can have an antioxidant effect, is reported by Duh et al. 2004;Bolkent et al., 2005. Other phytochemicals in lemon balm that may provide antioxidant activity include phenolic acids, terpenes, rosmarinic acid, and caffeic acids (Ribiero et al., 2001. ...
Article
Full-text available
Medicinal plants includes several plants used in herbal medicine. These days, it states any portion of the plant like seed, flower, fruit, stem, bark, leaf, stigma, root, etc used for their medicinal values. These plants are also used as food, flavonoid, medicine , or perfume. Before the creation of chemical drugs, people were dependent on the curative matter of medicinal plants. Yield, physiological, and biochemical data were collected such as plant height, number of active branches, plant diameter, SPAD value, fresh weight of leaves, and phenolic and an-tioxidant capacity. The harvested samples were freeze-dried, and the freeze-dried samples were kept at-81 °C. Stevia had the highest percentage (10.2%) of total soluble solutes followed by chocolate mint (7.76%), while the least amount was obtained from lemon balm (6.46 %). The lemon balm (13026 µg/gm) contained a significantly higher amount total phenols as compared to other varieties studied. The lowest total phenol content was found in stevia (6962 µg/gm). Out of four herb varieties studied, lemon balm showed the highest content of antioxi-dant activities (6018.04 µg/gm), followed by sweet basil (5978.64 µg/gm) and stevia (5972.42 µg/gm). Chocolate mint (5933.02 µg/gm) featured the least amount of antioxidant activity. Some influences, such as genetics, harvest season and conservational conditions, may affect the antioxidant activity of foods. There was a substantial positive correlation among total phenol and antioxidant activity. Medicinal plants play a large role in the pharmaceutical businesses for the manufacture of new drugs to remedy many diseases. It is likely that the important phytochemical properties recognized by our study in medicinal plants will aid in the cure of a number of conditions.
... Flavanoid have been shown to possess a variety of biochemical and pharmacological activities, including hypolipidemic effects 9 cardioprotective and antioxidant properties . Lagenaria siceraria contain Flavanoid and these Flavanoid may prevent oxidative 10 damage . ...
Article
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Hyperlipidemia is acknowledged to be a major risk factor for atherosclerosis and cardiovascular diseases. The purpose of the study is to compare between the hypolipidemic effect of Lagenaria siceraria and Lovastatin in hypercholesterolemic rats. Hyperlipidemic rats were randomized into two groups (5 in each). Oral administration of the aqueous extract of Lagenaria siceraria (200 mg/kg b.wt/day) to Group I and Lovastatin (7.2 mg/kg b.wt/day) to Group II, once in a day for two weeks was done. Both the group has shown significant reduction in total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL) and very low density lipoprotein (VLDL), but Group II has shown higher reduction. Thus, the study concludes that besides the standard drug lovastatin, Lagenaria siceraria can also serve as a drug for treating hyperlipidemia.
Chapter
This paper deals with the following aspects of tea authentication: (I) the differentiation of green and black tea can be achieved using ratios of different polypenolic compounds, e.g. catechins vs. total phenolics or catechins vs theaflavins. The concept of the ratio of total phenolics to total catechins is currently established by accumulation of more data. (II) To detect the geographic origin the flavonol glycosides ratios seem to be promising, but there is still a lack of data. (Ill) White teas are increasingly sold but there are not many data available on the constituents. It is currently impossible to asure the authenticity of white teas, especially of instant products. The ratio total polyphenols vs catechins is similar to green teas. (IV) The use and the amount of (instant) tea in RTD beverages such as ice tea is not always easy to detect depending on the process used to produce a cold water soluble tea. The authenticity can be checked using the flavonol pattern, in case of a harsh treatment by flavone C glycosides. Theanine could possibly be used as a marker in tea products. Methods are available for the determination and for the separation of D- and L-theanine. However, not much is known about the fate of theanine during the extraction and drying process.
Article
To study the spectroscopic and physicochemical properties of theabrownins in ripened Pu-erh tea "7572" produced by solid-state fermentation and the Pu-erh powder produced by natural liquid-state fermentation, two types of theabrownins were extracted with an organic solvent. The UV-visible results showed that liquid theabrownin had an additional absorption peak at~380 nm compared to solid theabrownin. The IR results indicated that the two theabrownins had similar functional groups. Both of them were composed of phenolic and carboxylic compounds, along with proteins and polysaccharides. The quantitative analysis of the acidic functional groups in theabrownins showed that both types of theabrownins contained carboxyl and phenolic hydroxyl groups, and the number of the two functional groups in liquid theabrownin was more than that in solid theabrownin. Theabrownins were isolated and graded based on membranes. The results showed that the contents of the oligomer fraction (M<10 ku) in solid and liquid theabrownins were 26.74% and 18.84%, respectively. The contents of the high-polymer fraction (M〉100 ku) in solid and liquid theabrownins were 56.98% and 70.72%, respectively. The reducing powers of two theabrownins were dose-dependent and had similar activities. The measurement of the reducing power of each fraction after the grading by membranes indicated that the reducing powers of the middle-(10 ku〈M〈100 ku) and high-(M〉100 ku) polymer fractions in both the theabrownins were significantly higher than that of the oligomeric fraction. ©, 2014, South China University of Technology. All right reserved.
Article
Antioxidant activity of different solvent extracts of sun-dried green tea was studied in this paper. The scavenging ability of DPPH free radical, OH- free radical, superoxide anion free radical and nitrite of different solvent extracts of sun-dried green tea as well as reducing power were investigated by using rutin and ascorbic acid (vitamin C) as control. Results suggested that the different solvent extracts of sun-dried green tea had significant scavenging effects on the DPPH free radical, OH- free radical, superoxide anion free radical and nitrite, all kinds of extracts had significant reducing power. Antioxidant activity of different solvent extracts of sun-dried green tea had positive correlation with their concentrations. The scavenging effects of ethanol sedimentation segment (IC50 93.80 μg/mL), n-butanol extract (IC50 153.90 μg/mL), ethanol extract (IC50 161.20 μg/mL) on the DPPH free radical were stronger than that of rutin control at the same concentration. All kinds of extracts had significant scavenging effects on ·OH- free radical, IC50 value of different solvent extracts of sun-dried green tea was very small except chloroform extract (IC50 57.67 μg/mL) and ethanol sedimentation segment (IC50 13.10 μg/mL). The scavenging effects of ethanol sedimentation segment and water extract on superoxide anion free radical were stronger than that of VC control at the 20 μg/mL concentration and stronger other extracts at the same concentration. Acetal extract and ethanol extract had stronger ability of scavenging nitrite, but lower than that of VC control. Reducing power of water extract, ethanol sedimentation segment and acetal extract had stronger than that of rutin control at the same concentration. These results suggest that the antioxidant activity of different solvent extracts of sun-dried green tea had significant differences.
Article
Forty two normal male albino rats of Sprague Dawley strain, weighing (170 ± 5 g) strain were fed on high fat diet for six week to induce obesity. The obesity rats were randomly classified into six groups (7 rats each) and treated with orlistat, coffee, green tea, cinnamon and mixture of them for six week. The results revealed that, obese rat groups which treated with orlistate, green tea, coffee,cinnamon and mixture of them showed lowered values of final weight, weight gain, gain percent, FER, leptin, glucose,cholesterol, total lipids, phospholipids,triglyceride, LDL-C,VDL-C and cholesterol/HDL-c but a significant increase in the value of serum HDL-C in comparing with control (+ve). The rat group which treated with orlistat showed non significant difference in the values of serum AST, ALT &ALP but all rat groups treated with green tea, coffee, cinnamon and mixture of them showed a significant decrease in serum AST, ALT &ALP, serum creatinine and urea compared with control (+ve). The rat groups which treated with green tea, coffee, cinnamon and mixture of them showed a significant decrease in the values of serum creatinine and urea but the rat groups which treated with cinnamon and mixture of green tea, coffee and cinnamon showed a significant decrease in the value of serum uric acid compared with control (+ve).
Article
In this study, the effects of Melissa officinalis L. on hyperlipidemic rats were investigated biochemically. The animals were fed a lipogenic diet consisting of 2% cholesterol, 20 % sunflower oil and 0.5 % cholic acid added to normal chow and were given 3 % ethanol for 42 d. The extract was given gavage technique to rats a dose of 2 g/kg everyday for 28 d, after 14 d, experimental animals done hyperlipidemia. In hyperlipidemic groups, a reduction of the skin glutathione level (GSH), skin Superoxide dismutase (SOD) activity and serum catalase (CAT), paraoxonase (PON) activity and an increase in serum cholesterol, total lipid, triglycerides and uric acid, γ-glutamyl transferase activity (CAT) and skin cholesterol, total lipid, lipid peroxidation (LPO), nonenzymatic glycosylation (NEG) and skin CAT, lactate dehydrogenase (LDH), glutathione peroxidase (GPx) and myeloperoxidase (MPO) activity were observed. Treatment with Melissa officinalis L. extract reversed these effects. Present results show that Melissa officinalis L. extract has a protective effect against skin tissue damage as result of hyperlipidemia, in addition to hypolipidemic effect.
Chapter
Tea (Camellia sinensis) is a refreshing, popular, socially accepted, economical, and benefi cial beverage (Cheng and Chen, 1994). Globally, the production and consumption of tea has increased over the last decade, and this increase is expected to remain sustained (Ho et al., 2008). Tea contains signifi cant amount of phenolic compounds (Gramza and Korczak, 2005). During the last decade, epidemiological studies have shown that intake of tea catechins is associated with a lower risk of cardiovascular disease (Yang et al., 2001). Thus, tea polyphenols have exhibited health benefi cial effects and potential uses. A growing body of evidence suggests that moderate consumption of tea may protect against several forms of cancer, cardiovascular diseases, bacterial infections, the formation of kidney stones, and dental cavities (Ho et al., 2008; Khan and Mukhtar, 2007). Furthermore, tea is considered as a functional food based on the reported benefi cial effects on human health (An et al., 2004; Farhoosh et al., 2007; Halder et al., 2005; Han, 1997; Mello et al., 2004; Navas et al., 2005; Zhu et al., 2006), and, thus, it can be used as a readily accessible source of natural antioxidants and a possible supplement in the food or pharmaceutical industry. Tea is usually classifi ed into green, Oolong, black, and Puer in terms of the manufacturing process. This chapter focuses mainly on polyphenols and antioxidants of the black, Oolong, and Puer teas, with an emphasis on their benefi cial effects on health. For more information on green tea, readers may refer to other chapters of this book.
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To evaluate effects of Pu-erh ripened tea in hyperuricemic mice, a mouse hyperuricemia model was developed by oral administration of potassium oxonate for 7 d. Serum metabolomics, based on gas chromatography–mass spectrometry, was used to generate metabolic profiles from normal control, hyperuricemic and allopurinol-treated hyperuricemic mice, as well as hyperuricemic mice given Pu-erh ripened tea at three doses. Pu-erh ripened tea significantly lowered serum uric acid levels. Twelve potential biomarkers associated with hyperuricemia were identified. Pu-erh ripened tea and allopurinol differed in their metabolic effects in the hyperuricemic mice. Levels of glutamic acid, indolelactate, L-allothreonine, nicotinoylglycine, isoleucine, L-cysteine and glycocyamine, all involved in amino acid metabolism, were significantly changed in hyperuricemic mice treated Pu-erh ripened tea. Thus, modulating amino acid metabolism might be the primary mechanism of anti-hyperuricemia by Pu-erh ripened tea.
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Antioxidant properties of 21 non-phenolic terpenoids containing in essential oil extracted from the buds of Cleistocalyx operculatus have been investigated using density functional theory (DFT)-based computational methods. The C–H bond dissociation enthalpy (BDE), proton dissociation enthalpy (PDE), proton affinity (PA), electron transfer enthalpy (ETE) and ionization energy (IE) were calculated in the gas phase and in two different solvents (water and ethanol) at the ROB3LYP/6-311++G(2df,2p)//B3LYP/6-311G(d,p) model chemistry and the PM6 method for the latter. Quantum chemical descriptors like chemical potential (µ), chemical hardness (η), global electrophilicity (ω) were calculated in order to evaluate the reactivity and stability of all studied compounds. The interaction of HOO● radical with α-terpinene, an example molecule, was also studied in detail by establishing potential energy surface (PES). As a result, a kinetic concurrence between H-abstraction reaction at the weakest C-H bond and addition reactions at C=C double bonds was clarified. On the basis of this mechanism, the antioxidant capacity may happen via the termination-enhancing process. Among the studied compounds, α-terpinene, γ-terpinene, cembrene and abieta-7,13-diene represent as potential antioxidants.
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Pu-erh tea is a unique post-fermented tea with special quality and unique aroma characteristics, which are achieved by aging as part of the tea-making processing in China. In this work, we developed a new method, based on the combination of the mid-infrared (MIR) spectroscopy of graphene oxide-5,10,15,20-mesotetra (4-aminophenyl) porphyrin hybrid (GO-TAP), with chemometrics, for the variety identification and age prediction of twelve Pu-erh teas. Partial least squares discriminant analysis (PLSDA) and partial least squares regression (PLSR) models were respectively employed to classify the variety of and predict the age of Pu-erh teas based on the collected MIR spectra. Compared with traditional MIR spectroscopy, MIR spectroscopy based on GO-TAP gave better accuracy and specificity in variety classification and age prediction. The GO-TAP complex-based MIR spectroscopy sensor coupled with chemometrics could achieve 100% accuracy for variety classification and predicts storage time of Pu-erh tea. This method can be applied for the accurate identification and prediction of Pu-erh tea storage time, and it might have enormous potential for the application in storage time identification of other food stuff.
Chapter
In order to investigate the effect of the enzyme on the liquid-fermentation of sun dried green tea of Yunnan large leaf, three enzymes were used, including cellulase, pectinase, and flavourzyme. On the base of single factor experiments, the optimal design with the content of the theabrownines was carried out using response surface methodology (RSM). It is feasible to optimize the enzyme in the process of the liquid-state fermentation of Pu’er tea by RSM. Pretreated the raw material under the optimal concentration combination of enzyme, the content of theabrownines of fermentation broth is 27.14 %, which is 18.00 % higher than CK.
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Among the toxin-producing microbes, those that produce mycotoxins are especially problematic due to their broad distribution in the environments and in foods. Several species of Aspergillus, Penicillium, and Fusarium are sources of potent mycotoxins such as aflatoxins, ochratoxins, patulin, deoxynivalenol, and fumonisins. It is, therefore, vital that mycotoxigenic fungi contaminants in food are rapidly and accurately identified for ensuring the safety of consumers. Most of the current methods are based on PCR using gene-specific or species-specific primers. However, contaminating microbes often compose a complex community and PCR-DGGE may provide a better approach than traditional single-gene and/or single-species based methods. It provides “fingerprints” for each microbial flora and has been widely used to analyze environmental and food-associated microbial communities. This review shows the advantages and disadvantages of different molecular methods for the detection of mycotoxigenic fungi including PCR-DGGE as a potent and applicable method that could overcome the difficulties associated with other methods.
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The aims of this study were to quantify and optimize the extraction of total phenolic content (TPC), total flavonoids (TF) and antioxidant activity (AA) of aqueous pu-erh (Camellia sinensis var. assamica) extracts, as well as to compare the optimized pu-erh tea extract (OPT) with toasted mate (Ilex paraguariensis), black and green (Camellia sinensis) teas. The optimization process increased the TPC and the ferric reducing antioxidant power (FRAP). The results showed that the green tea extract presented the highest values for TPC and antioxidant capacity. The pasteurized OPT showed lower TPC and TF, and higher FRAP, DPPH and Cu2+ chelating ability compared to the non-pasteurized OPT. The lyophilized OPT showed inhibition of lipid peroxidation in Wistar rat brain homogenate and displayed antibiofilm activity against Enterococcus faecalis ATCC 25212 and 19433, and Staphylococcus aureus ATCC 25923. Additionally, lyophilized OPT presented cytotoxic and antiproliferative effects against tumor cell lines (Caco-2, A549 and HepG2), inhibited the production of reactive oxygen species in A549 and IMR90 cells, and presented antihemolytic activity in human erythrocytes. The lyophilized OPT inhibited α-glucosidase (IC50 = 47.0 µg/mL) and α-amylase at 30.0 mg/mL. The main compounds detected in OPT were gallic acid, caffeine and theobromine.
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The crude tea polysaccharides (CTPS) from Qingzhuan brick tea(QZBT) were extracted and fractionated to afford two fractions, namely TPS-1 and TPS-2. Analyses were conducted concerning the structural characterization and antioxidant activities of these samples. Component analysis revealed that the carbohydrate, uronic acid, protein and polyphenol contents of these samples differed significantly. Fourier transform infrared analysis showed that these samples showed similar characteristic absorption peaks for polysaccharides. Ultraviolet-visible spectroscopy, circular dichroism, scanning electron microscopy and thermogravimetric analyses indicated that there were considerable differences in the presence of protein, surface features, conformational characteristics and thermodynamic behaviors. For antioxidant activities in vitro, CTPS, TPS-1 and TPS-2 exhibited concentration-dependent antioxidant activities, with TPS-2 showing significantly higher antioxidant activity than CTPS and TPS-1. These results provide a scientific and strong foundation for the use of tea polysaccharides(TPS) from QZBT and further research towards the relationships between the characteristics and antioxidant activities of TPS.
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Background Oxidative stress is crucial player in skeletal muscle atrophy pathogenesis. S-allyl cysteine (SAC), an organosulfur compound of Allium sativum, possesses broad-spectrum properties including immuno- and redox-modulatory impact. Considering the role of SAC in regulating redox balance, we hypothesize that SAC may have a protective role in oxidative-stress induced atrophy. Methods C2C12 myotubes were treated with H2O2 (100 μM) in the presence or absence of SAC (200 μM) to study morphology, redox status, inflammatory cytokines and proteolytic systems using fluorescence microscopy, biochemical analysis, real-time PCR and immunoblotting approaches. The anti-atrophic potential of SAC was confirmed in denervation-induced atrophy model. Results SAC pre-incubation (4 h) could protect the myotube morphology (i.e. length/diameter/fusion index) from atrophic effects of H2O2. Lower levels of ROS, lipid peroxidation, oxidized glutathione and altered antioxidant enzymes were observed in H2O2-exposed cells upon pre-treatment with SAC. SAC supplementation also suppressed the rise in cytokines levels (TWEAK/IL6/myostatin) caused by H2O2. SAC treatment also moderated the degradation of muscle-specific proteins (MHCf) in the H2O2-treated myotubes supported by lower induction of diverse proteolytic systems (i.e. cathepsin, calpain, ubiquitin-proteasome E3-ligases, caspase-3, autophagy). Denervation-induced atrophy in mice illustrates that SAC administration alleviates the negative effects (i.e. mass loss, decreased cross-sectional area, up-regulation of proteolytic systems, and degradation of total/specific protein) of denervation on muscles. Conclusions SAC exerts significant anti-atrophic effects to protect myotubes from H2O2-induced protein loss and myofibers from denervation-induced muscle loss, due to the prevention of elevated proteolytic systems and inflammatory/oxidative molecules. General significance The results signify the potential of SAC against muscle atrophy.
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Flavonoid compounds were studied in healthy and parasitized poplar branches following mistletoe (Viscum album L.) attack. Two poplar cultivars showing different degrees of resistance to mistletoe: sensitive “Fritzi Pauley” (FPL) and resistant “Vereecken” (VER) were used. Flavonoids were detected and localized using histofluorescence after treating frozen sections with two specific reagents. Total amounts of flavonoids were determined spectrophotometrically. Defence mechanisms were induced during penetration of the primary haustorium. They consisted of inner periderm development and flavonoid accumulation. These reactions were weaker in the FPL cultivar than in the VER one. In the latter, growth of the primary haustorium and the establishment of direct connections between the living host cells and parasite failed. The resistance of poplar cultivars to mistletoe was dependent on the production of defensive mechanisms against the pathogen.
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The proto-oncogene bcl-2 inhibits apoptotic and necrotic neural cell death. Expression of Bcl-2 in the GT1-7 neural cell line prevented death as a result of glutathione depletion. Intracellular reactive oxygen species and lipid peroxides rose rapidly in control cells depleted of glutathione, whereas cells expressing Bcl-2 displayed a blunted increase and complete survival. Modulation of the increase in reactive oxygen species influenced the degree of cell death. Yeast mutants null for superoxide dismutase were partially rescued by expression of Bcl-2. Thus, Bcl-2 prevents cell death by decreasing the net cellular generation of reactive oxygen species.
Chapter
Exposure of mammalian cells to oxidative stress induced by redox-active quinones and other prooxidants results in glutathione and NAD(P)H oxidation, followed by the modification of protein thiols, ATP depletion and the loss of cell viability. Protein thiol modification is normally associated with the impairment of various cell functions, including inhibition of agonist-stimulated phosphoinositide metabolism, disruption of intracellular Ca2+ homeostasis, and perturbation of cytoskeletal organization. The latter effect appears to be responsible for the formation of the numerous plasma membrane blebs, typically seen in cells exposed to cytotoxic concentrations of prooxidants. Following the disruption of thiol homeostasis in prooxidant-treated cells, there is a perturbation of intracellular Ca2+ homeostasis with a sustained increase in intracellular Ca2+ concentration.This Ca2+ overload can cause activation of various Ca2+-dependent degradative enzymes (phospholipases, proteases, endonucleases) and may contribute to the mitochondrial damage seen in oxidative stress. Severe oxidative stress is also associated with extensive DNA damage which, in turn, may lead to excessive stimulation of poly (ADP-ribose) polymerase activity and subsequent NAD+ and ATP depletion which may contribute to cell killing. In contrast with the cytotoxic effects of severe oxidative stress, low levels of oxidative stress can lead to the activation of enzymes involved in cell signaling. In particular, the activity of protein kinase C is markedly increased by redox-cycling quinones through a thiol/disulfide exchange mechanism, and this may represent a mechanism by which prooxidants can modulate cell growth and differentiation.
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Maillard reaction products (MRP) were prepared by refluxing the mixture of L-histidine and D-glucose (1:3 molar ratio) in 0.1M phosphate buffer (pH 5, 7, and 9) for up to 24h. It was found that antioxidative effect of MRP increased as a function of reaction time, particularly at the later stage of the reaction. At higher initial pH, antioxidative effect of MRP became significant. It was also revealed that antioxidative effect exponentially increased as a function of the development of reducing power. MRP also retarded autoxidation of sardine oil, but their antioxidative effect to sardine oil was less than that to linoleic acid. Since POV of sardine oils which had been already oxidized (POV about 50 or 100) was decreased to some extent by the addition of MRP, it was sug-gested that MRP worked as peroxide destroyers besides autoxidation-breakers. Application of MRP (pH 9, 24h heating) to Kamaboko-type sardine products (boiled or deep-fried) was also performed. MRP were mixed in sardine minced meats at the levels of 0-5%. and the products were stored at 4°C. It was found that MRP effectively inhibited autoxidation of sardine products during storage.
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Nineteen enzymatic activities of Maxilact 20.000 have been assayed using the API ZYM micromethod. Some of them have been found to be positive and these have been studied in more detail. Hydrolysis of lactulose by the action of β-galactosidase is slower than that of lactose. Proteolytic activity has been found in both the soluble and insoluble fractions of Maxilact. Optimum temperature and pH are 45°C and 7, respectively. The action of Maxilact on casein did not alter β-casein, but degraded αs-casein to give a peptide with electrophoretic mobility similar to that produced by the action of rennet. A weak lipolytic activity on tributyrine was also detected.
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Thirty-one wine samples differing in their origin of production and vintages were analyzed for total phenolic content, total and free sulfur dioxide contents, and superoxide radical scavenging potentials. The polyphenol content of red wine ranged from 735.9 to 2858 ppm, and that of white wine was in the range 259.4−720.5 ppm. Total sufur dioxide content ranged from 21.9 to 270.7 ppm, and had no correlation to the color of the wine. Superoxide radical scavenging activity values ranged from 39.3 to 215.9 units/mL for the white wine, and those of red varieties were 5−10 times higher. No correlation was observed between the free and total sulfur dioxide contents in the different wine samples tested and their superoxide radical scavenging activity values. A direct correlation between the color of the wine (r = 0.7517), its phenolic content (r = 0.9908), and the ability of the wine constituents to scavenge superoxide radical was, however, established by a simple regression analysis. Keywords: Wine; phenolics; radical scavenger; varietal difference
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The relationship between antioxidant activity and antimutagenicity of various tea extracts (green tea, pouchong tea, oolong tea, and black tea) was investigated. All tea extracts exhibited markedly antioxidant activity and reducing power, especially oolong tea, which inhibited 73.6% peroxidation of linoleic acid. Tea extracts exhibited a 65-75% scavenging effect on superoxide at a dose of 1 mg and 30-50% scavenging effect on hydrogen peroxide at a dose of 400 mu g. They scavenged 100% hydroxyl radical at a dosage of 4 mg except the black tea. Tea extracts also showed 50-70% scavenging effect on alpha,alpha-diphenyl-beta-picrylhydrazyl radical. The antioxidant activity and the scavenging effects on active oxygen decreased in the order semifermented tea > nonfermented tea > fermented tea. Tea extracts showed strong antimutagenic action against five indirect mutagens, i.e., AFB(1), Trp-P-1, Glu-P-1, B[a]P, and IQ, especially oolong and pouchong teas. The antioxidant effect of tea extracts was well correlated to their antimutagenicity in some cases but varied with the mutagen and antioxidative properties.
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Although aqueous superoxide often acts as a one-electron reductant or less frequently as an oxidant, it rarely undergoes covalent bond formation with simple organic or inorganic compounds in water, perhaps owing to its poor nucleophilicity in this solvent. In this communication it is shown, however, that superoxide can react with nitric oxide to form the peroxionitrite anion in deaerated aqueous solutions at pH 12-13: Oâ⁻ + NO = ⁻OONO. This reaction represents one of the few examples of a radical-radical coupling of Oâ⁻ with another odd-electron species to form a diamagnetic product. The reaction also may be of significance in natural waters or prove useful for trapping and measuring low levels of superoxide in aqueous systems. 13 references, 2 figures, 1 table.
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Reduced ascorbic acid (RAA) and Vitamin A (carotenoid) contents of six vegetables obtained from six cities in the United States at two seasons of the year were determined. Mean RAA content (mg/100g) of cabbage was 45.2, carrots 7.8, celery 6.0, corn 6.5, onions 8.4, and tomatoes 15.3. Vitamin C in cooked cabbage was 22.1, corn 6.2, and onions 5.7 mg/100g. Mean vitamin A activity (I.U.) of carrots was 15,228, cabbage 114, celery 133, corn 219, and tomatoes 750. In cooked cabbage and corn, vitamin A content was 89 and 217 I.U., respectively. The RAA and vitamin A content of vegetables from the six geographical areas varied significantly. Vitamin concentrations were generally lower than tabulated values. Retention of RAA in cooked cabbage was 52%; in onions, 58%; and in corn, 98%. Vitamin A retention in cooked cabbage was 82%, and in cooked corn was 98%.
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The antioxidant properties of a series of polyhydroxy flavonoids and related compounds have been evaluated. The results have been correlated with the structures of the compounds concerned, which hale been shown to Junction mainly as primary antioxidants. The ability of some such compounds to form complexes with copper has been demonstrated from a study of UV spectra and is probably a contributing factor to the stabilising effects of such compounds.Antioxidant activity is favoured by a multiplicity of phenolic hydroxyl groups and depends critically on the co-operation of the 4-carbonyl with either the 3- or the 5-hydroxyl groups. Dihydro-flavones are slightly more active than the corresponding flavones.
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Catechins are a major group of polyphenolic compounds contained in abundance in green tea. Using electron spin resonance spectroscopy along with a spin-trapping agent, the scavenging effect of tea catechins and their corresponding epimers against superoxide anion radicals generated by a hypoxanthine and xanthine oxidase reaction system was evaluated. The presence of 3′,4′,5′-trihydroxyl groups attached to the B-ring of the flavan skeleton of tea catechins elevated their radical-scavenging efficiency in comparison to those with 3′,4′-dihydroxyl groups. There were no significant differences between the four dominant tea catechins and their corresponding epimers with regard to radical-scavenging ability. Under the different spin-trapping agent concentrations, the sigmoid curves of reducing spin-trapping adducts produced by tea catechins were shifted leftward, suggesting that a likely possible action of tea catechins is to scavenge superoxide anion radicals directly, not to inhibit the function of xanthine oxidase. Although caffeine is also known as a major ingredient of tea, its superoxide anion radical-scavenging effect was much weaker than that of the catechin family. It is concluded that tea catechins and their epimers serve as powerful antioxidants for directly eliminating superoxide anion radicals, and may be useful in the prevention of diseases relating to in vivo oxidative stress.© 2000 Society of Chemical Industry
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Worldwide population pressures and accompanying increased demands on water supplies and tillable land has forced a reevaluation of traditional agricultural techniques and crops. Under-used semiarid lands are becoming candidates for crop production that uses stress-tolerant plants. Desert legume trees and shrubs, e.g., species ofProsopis, Leucaena, Acacia, Geoffroea andOlneya, fix nitrogen and could be sources of seed protein forage or biomass. Seeds from desert legume perennials have a high potential as protein producers.
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Antioxidative activities of vitamin E, ethylenediamine tetraacetic acid (EDTA), ferulic acid, and butylated hydroxy toluene (BHT) were monitored with lipid peroxidation systems. Formation of malonaldehyde (MA) and 4-hydroxy nonenal (4-HN) from ethyl linoleate or rat liver microsome oxidized by FeCl2/H2O2 or ADP/FeSO4 was measured by gas chromatography. Over 90% of MA and 4-HN formation was inhibited by 100 mmol/L of vitamin E. A synthetic antioxidant, BHT, showed the strongest antioxidative activity, followed by that of vitamin E, whereas EDTA accelerated formation of MA and 4-HN in the ethyl linoleate/FeCl2/H2O2 system. Vitamin E did not suppress lipid peroxidation significantly when microsome was oxidized by ADP/FeSO4. EDTA inhibited oxidation of microsome by ADP/FeSO4 considerably; in contrast, it did not in the case of oxidation by FeCl2/H2O2.
Article
Chia (Salvia sp) seeds were investigated as a source of natural lipid antioxidants. Methanolic and aqueous extracts of defatted chia seeds possessed potent antioxidant activity. Analysis of 2 batches of chia-seed oils demonstrated marked difference in the fatty acid composition of the oils. In both batches, the oils had high concentrations of polyunsaturated fatty acids. The major antioxidant activity in the nonhydrolyzed extract was caused by flavonol glycosides, chlorogenic acid (7.1 × 10−4 mol/kg of seed) and caffeic acid (6.6 × 10−3 m/kg). Major antioxidants of the hydrolyzed extracts were flavonol aglycones/kaempferol (1.1 × 10−3 m/kg), quercetin (2.0 × 10−4 m/kg) and myricetin (3.1 × 10−3 m/kg); and caffeic acid (1.35 × 10−2 m/kg). Two methods were used to measure antioxidant activities. Both were based on measuring bleaching ofβ-carotene in the coupled oxidation ofβ-carotene and linoleic acid in the presence of added antioxidants.
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For centuries green tea has been a widely consumed beverage throughout the world. It is known to contain a number of pharmacologically active compounds. In this study water extracts of green tea (WEGT) and their major constituents, green tea polyphenols (GTP), were examined for antimutagenic activity. WEGT and GTP were found to significantly inhibit the reverse mutation induced by benzo[a]pyrene (BP), aflatoxin B1 (AFB1), 2-aminofluorene, and methanol extracts of coal tar pitch in Salmonella typhimurium TA100 and/or TA98 in the presence of a rat-liver microsomal activation system. GTP also inhibited gene forward mutation in V79 cells treated with AFB1 and BP, and also decreased the frequency of sister-chromatid exchanges and chromosomal aberrations in V79 cells treated with AFB1. The addition of GTP during and after nitrosation of methylurea resulted in a dose-dependent inhibition of mutagenicity. Studies to define the mechanism of the antimutagenic activity of GTP suggest that it may affect carcinogen metabolism, DNA adduct formation, the interaction of ultimate carcinogen or the scavenging of free radicals.
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A simple and fast high performance liquid chromatography analysis method for eight tea catechins and caffeine using an ODS column and a water-acetonitrile-phosphoric acid mobile phase system was developed. The catechins, epicatechin epigallocatechin, epicatechin gallate, epigallocatechin gallate, catechin, catechin gallate, gallocatechin and gallocatechin gallate, and caffeine were separated by an acetonitrile gradient within 20 min. The detection limit of this method was approximately 0.2 ng for all nine compounds and the quantitation curves were linear between 2 ng to 2 μg. Some Japanese green tea samples were analyzed using this method. No extraneous peaks interfered with the analysis and the detection limit of each compound was less than 0.02% of the dry weight of the tea.
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A number of systems that generate oxygen free radicals catalyze the oxidative modification of proteins. Such modifications mark enzymes for degradation by cytosolic neutral alkaline proteases. Protein oxidation contributes to the pool of damaged enzymes, which increases in size during aging and in various pathological states. The age-related increase in amounts of oxidized protein may reflect the age-dependent accumulation of unrepaired DNA damage that, in a random manner, affects the concentrations or activities of numerous factors that govern the rates of protein oxidation and the degradation of oxidized protein.
Article
Tea is grown in about 30 countries but is consumed worldwide, although at greatly varying levels. It is the most widely consumed beverage aside from water with a per capita worldwide consumption of approximately 0.12 liter per year. Tea is manufactured in three basic forms. Green tea is prepared in such a way as to preclude the oxidation of green leaf polyphenols. During black tea production oxidation is promoted so that most of these substances are oxidized. Oolong tea is a partially oxidized product. Of the approximately 2.5 million metric tons of dried tea manufactured, only 20% is green tea and less than 2% is oolong tea. Green tea is consumed primarily in China, Japan, and a few countries in North Africa and the Middle East. Fresh tea leaf is unusually rich in the flavanol group of polyphenols known as catechins which may constitute up to 30% of the dry leaf weight. Other polyphenols include flavanols and their glycosides, and depsides such as chlorogenic acid, coumarylquinic acid, and one unique to tea, theogallin (3-galloylquinic acid). Caffeine is present at an average level of 3% along with very small amounts of the other common methylxanthines, theobromine and theophylline. The amino acid theanine (5-N-ethylglutamine) is also unique to tea. Tea accumulates aluminum and manganese. In addition to the normal complement of plant cell enzymes, tea leaf contains an active polyphenol oxidase which catalyzes the aerobic oxidation of the catechins when the leaf cell structure is disrupted during black tea manufacture. The various quinones produced by the enzymatic oxidations undergo condensation reactions which result in a series of compounds, including bisflavanols, theaflavins, epitheaflavic acids, and thearubigens, which impart the characteristic taste and color properties of black tea. Most of these compounds readily form complexes with caffeine. There is no tannic acid in tea. Thearubigens constitute the largest mass of the extractable matter in black tea but their composition is not well known. Proanthocyanidins make up part of the complex. Tea peroxidase may be involved in their generation. The catechin quinones also initiate the formation of many of the hundreds of volatile compounds found in the black tea aroma fraction. Green tea composition is very similar to that of the fresh leaf except for a few enzymatically catalyzed changes which occur extremely rapidly following plucking. New volatile substances are produced during the drying stage. Oolong tea is intermediate in composition between green and black teas.
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Role de l'oxygene dans l'oxydation des aliments. Activite des antioxydants. Criblage d'antioxydants dans differents produits (animaux, vegetaux, microbiologiques entre autres). Activite antimutagene. Revue bibliographique
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Oxidatively modified proteins have been implicated in a variety of physiologic and pathologic processes. Oxidative modification typically causes inactivation of enzymes and also the introduction of carbonyl groups into amino acid side chains of the protein. We describe a method to quantify oxidatively modified proteins through reduction of these carbonyl groups with tritiated borohydride. The technique was applied to purified, oxidatively modified glutamine synthetase and to bronchoalveolar lavage fluid from dogs and from humans. Since the protein content of lung lavage fluid is low, a very sensitive method was required to measure the oxidized residues. Reduction of the carbonyl group generated during oxidation of proteins with tritiated borohydride provided excellent sensitivity. Incorporation of tritium was directly proportional to the amount of protein with a range from 10 to 1000 micrograms. Should moieties other than amino acids be labeled, they are easily removed by rapid benchtop hydrolysis of the protein followed by chromatography on Dowex 50.
Article
Hydroxyl radicals, generated by reaction of an iron-EDTA complex with H2O2 in the presence of ascorbic acid, attack deoxyribose to form products that, upon heating with thiobarbituric acid at low pH, yield a pink chromogen. Added hydroxyl radical "scavengers" compete with deoxyribose for the hydroxyl radicals produced and diminish chromogen formation. A rate constant for reaction of the scavenger with hydroxyl radical can be deduced from the inhibition of color formation. For a wide range of compounds, rate constants obtained in this way are similar to those determined by pulse radiolysis. It is suggested that the deoxyribose assay is a simple and cheap alternative to pulse radiolysis for determination of rate constants for reaction of most biological molecules with hydroxyl radicals. Rate constants for reactions of ATP, ADP, and Good's buffers with hydroxyl radicals have been determined by this method.
Article
Four compounds, including two new flavonoids, were isolated from Si-pei licorice (licorice from the north-western region of China). The structures of the two new flavonoids, named glycyrrhisoflavanone and glycyrrhisoflavone, were (S)-7, 8'-dihydroxy-2', 2'-dimethyl-5-methoxy-[3, 6'-bi-2H-1-benzopyran]-4(3H)-one (6) and 3-[3, 4-dihydroxy-5-(3-methyl-2-butenyl)phenyl]-5, 7-dihydroxy-4H-1-benzopyran-4-one (9). Glycyrrhisoflavone was found to be one of the tannic substances by the measurement of the binding activity to hemoglobin (relative astringency). Licochalcone B (1) was isolated from the fraction which showed the highest binding activity to hemoglobin among the fractions obtained by centrifugal partition chromatography of the extract of Sinkiang licorice (licorice from Sinkiang in China). Licochalcone B also showed the highest activity as a radical scavenger in the experiment using 1, 1-diphenyl-2-picrylhydrazyl radical, among ten tested compounds obtained from several licorices. The order of the radical scavenging effects was the same as the order of the inhibitory effects on the 5-lipoxygenase-dependent peroxidation in arachidonate metabolism [licochalcone B (1)>licochalcone A (3)>>isoliquiritigenin (14)>liquiritigenin (13)].
Article
The effect of water extracts of Pu-Erh tea (products of Yunnan district, China, preserved for 2 or 20 years) and of green tea (products of Shizuoka prefecture, Japan) on lipid level, tissue weight, lipoprotein lipase (LPL) and adrenalin-induced lipolytic (AIL) activity in rats were examined. Female Wistar rats (8 weeks old) were fed a diet containing 1% cholesterol and given the above tea extracts in drinking water for 8 or 16 weeks ad libitum. The levels of plasma cholesterol ester in rats given Pu-Erh tea or green tea were significantly lower than those of control rats after 6-8 weeks, though the difference became smallar after 10 weeks. The triglyceride (TG) level in plasma was also low in rats given Pu-Erh tea for 16 weeks. This effect on TG was not observed in the case of green tea. Among 6 organs or tissues of rats examined, the weight of abdominal adipose tissue was significantly lower in rat fed Pu-Erh tea for 16 weeks. The LPL activity in abdominal adipose tissue tended to be low (though not statistically significant), while the activity of AIL was significantly elevated in rats given Pu-Erh tea for 8 or 16 weeks. A negative correlation was observed between AIL activity and the ratio of adipose tissue/body weight. These data suggest that the successive administration of Pu-Erh tea could stimulate the degradation of TG in adipose tissue and thereby decrease its weight.
Article
The application of ferrozine, a commercially available sulfonated ferroin, to the determination of submicrogram levels of iron in human serum is described. The effect of serum copper, which can be a potential source of error, is minimized by complexation with neocuproin in the reaction mixture without affecting adherence to Beer's Law. The large molar absorptivity of 28,000 for the iron-ferrozine complex makes the ligand an attractive color reagent for monitoring iron therapy in anemic patients.
Article
A study on peroxyl radical induced oxidation of rat liver microsomal membranes in the presence of different indolinic and quinolinic aminoxyls (Scheme 1) was carried out in order to test their efficiency as antioxidants in lipid and protein peroxidation. The extent of lipid peroxidation was quantified by the amount of malondialdehyde (MDA) produced, and the measurement of carbonyl residues was used as an index of microsomal protein oxidation. The results obtained suggest that lipid soluble indolinic and quinolinic aminoxyls are efficient in protecting lipids and proteins of biological membranes against oxidation. The efficacy of these aminoxyls as protectors of lipids and proteins was much higher than the water soluble TEMPOL. Moreover, the hydrophobic aminoxyls were more effective in preventing protein than lipid oxidation at low concentrations (1-20 microM). However, at high concentration (100 microM), lipid as opposed to protein oxidation was almost completely inhibited. The data supports the hypothesis that proteins probably have a different oxidation pattern from lipids.
Article
This chapter discusses the actions of flavonoids and coumarins on lipoxygenase and cyclooxygenase. Flavonoids and coumarins are polyphenolic compounds containing multiple substituents on the benzo-γ-pyrone nucleus and are widely distributed in the plant kingdom. Reviews have emphasized that flavonoids and coumarins possess numerous biological and pharmacological properties, some of potential therapeutic interest. Various flavonoids and coumarins which possess anti-inflammatory actions in bioassays are identified in extracts prepared from plants used for this purpose in traditional folk medicines. The chapter describes methods used for the analysis of the actions of flavonoids and coumarins on the generation of eicosanoids by stimulated leukocytes. These cells are well suited for this purpose as they readily generate eicosanoids after engulfing opsonized particles or as a result of activation by soluble stimulants such as calcium ionophores, chemotactic peptides, and arachidonic acid itself. They are directly involved in the acute inflammatory process. Both rat mixed peritoneal leukocytes and human polymorphonuclear neutrophil leukocytes (PMNs) are used, although both cell types yield essentially similar results. The eicosanoid products of arachidonate metabolism are measured by radioimmunoassay or by radiometric (radio-TLC) methods, both of which are described in the chapter.
Article
This chapter discusses the role of flavonoids and iron chelation in antioxidant action. The potential of flavonoids to inhibit lipid peroxidation in biological models is supposed to reside mainly in their free radical scavenging capacity rather than in their iron chelating activity. This property is considered as a minor mechanism in the antioxidant action, because it has not been clearly established in biological systems. The assessment of a relationship between the antioxidant effect and the iron chelating capacity of flavonoids is subsequently of interest. For this purpose, rat is used hepatocyte cultures as a biological model where lipid peroxidation is induced by iron [Fe(III)] in its complexed form with nitrilotriacetic acid (NTA). The Fe-NTA complex is known to induce a rapid accumulation of iron inside the cells. Nitrilotriacetic acid (NTA) is used to maintain ferric iron in a soluble state; it is a low-affinity iron chelator.
Article
Flavonoids are polyphenolic antioxidants naturally present in vegetables, fruits, and beverages such as tea and wine. In vitro, flavonoids inhibit oxidation of low-density lipoprotein and reduce thrombotic tendency, but their effects on atherosclerotic complications in human beings are unknown. We measured the content in various foods of the flavonoids quercetin, kaempferol, myricetin, apigenin, and luteolin. We then assessed the flavonoid intake of 805 men aged 65-84 years in 1985 by a cross-check dietary history; the men were then followed up for 5 years. Mean baseline flavonoid intake was 25.9 mg daily. The major sources of intake were tea (61%), onions (13%), and apples (10%). Between 1985 and 1990, 43 men died of coronary heart disease. Fatal or non-fatal myocardial infarction occurred in 38 of 693 men with no history of myocardial infarction at baseline. Flavonoid intake (analysed in tertiles) was significantly inversely associated with mortality from coronary heart disease (p for trend = 0.015) and showed an inverse relation with incidence of myocardial infarction, which was of borderline significance (p for trend = 0.08). The relative risk of coronary heart disease mortality in the highest versus the lowest tertile of flavonoid intake was 0.42 (95% CI 0.20-0.88). After adjustment for age, body-mass index, smoking, serum total and high-density-lipoprotein cholesterol, blood pressure, physical activity, coffee consumption, and intake of energy, vitamin C, vitamin E, beta-carotene, and dietary fibre, the risk was still significant (0.32 [0.15-0.71]). Intakes of tea, onions, and apples were also inversely related to coronary heart disease mortality, but these associations were weaker. Flavonoids in regularly consumed foods may reduce the risk of death from coronary heart disease in elderly men.
Article
The ability of a regulatory protein to sense the integrity of the bacterial flagellar structure was investigated. In response to a defective hook-basal body complex, the anti-sigma 28 FlgM protein inhibits flagellin transcription. In cells with a functional hook-basal body complex, the flagellin genes are transcribed normally and the FlgM protein is expelled into the growth medium. In strains with a defective hook-basal body structure, FlgM is absent from the media. The presence of flagellin protein in the media is substantially reduced in strains carrying a FlgM-LacZ protein fusion, suggesting that the fusion is blocking the flagellar export apparatus. These results suggest that the FlgM protein assesses the integrity of the flagellar hook-basal body complex by itself being a substrate for export by the flagellar-specific export apparatus.
Article
1. A new method has been developed for measuring the total antioxidant capacity of body fluids and drug solutions, based on the absorbance of the ABTS*+ radical cation. 2. An automated method for use on a centrifugal analyser, as well as a manual method, is described. 3. The procedure has been applied to physiological antioxidant compounds and radical-scavenging drugs, and an antioxidant ranking was established based on their reactivity relative to a 1.0 mmol/l Trolox standard. 4. The Trolox equivalent antioxidant capacity of plasma from an adult reference population has been measured, and the method optimized and validated. 5. The method has been applied to investigate the total plasma antioxidant capacity of neonates and how this may be compromised in prematurity.
Article
Peroxynitrite is a cytotoxic species generated by the reaction between superoxide and nitric oxide. The ability of catechins and their gallate esters to decrease peroxynitrite-induced nitration of tyrosine and to limit surface charge alteration of low density lipoprotein (LDL) was investigated. All compounds tested were found to be potent peroxynitrite scavengers preventing the nitration of tyrosine. The ability of the catechin polyphenols at 10 microM to minimise tyrosine nitration induced by peroxynitrite (500 microM) was ECG (38.1 +/- 3.6%) approximately EGCG (32.1 +/- 7.5%) approximately gallic acid (32.1 +/- 1.9%) > catechin (23.9 +/- 5.4%) approximately epicatechin (22.9 +/- 3.3%) approximately EGC (19.9 +/- 2.0%). Trolox (10 microM) was used as the standard for comparative purposes and was found to be less effective than the polyphenols in inhibiting tyrosine nitration (13.6 +/- 2.9%). The catechin polyphenols were also found to offer protection from peroxynitrite-induced modification of critical amino acids of apolipoprotein B-100 of LDL which contribute towards its surface charge.
Article
Chronic inflammation has been implicated as the underlying factor in the pathogenesis of many disorders. In the past decade, inflammation-related endogenous production of reactive nitrogen species, similar to oxygen free radicals, has also been suggested as a risk factor for cancer, in addition to the well-studied exogenous nitroso compounds. Epidemiological, in vitro, and animal model studies have implicated green tea to be protective against nitroso compound-induced and inflammation-related cancer. Therefore, we investigated the effect of epigallocatechin-3-gallate (EGCG), one of the known biologically active catechins contained in green tea, on the production of nitric oxide (NO.). We have shown previously that EGCG reduces NO. production as measured by nitrite accumulation in the culture medium. Expanding on this finding, in this report we show that EGCG may do so by two mechanisms: reduction of inducible nitric oxide synthase (iNOS) gene expression and inhibition of enzyme activity. Addition of 1-10 microM EGCG to lipopolysaccharide- and interferon-gamma-activated mouse peritoneal cells reduced iNOS mRNA expression concentration dependently, to 82-14%, as measured by relative reverse transcription-polymerase chain reaction. Addition of 50-750 microM EGCG, in a concentration-dependent manner, inhibited the enzyme activity of iNOS, to 85-14%, and neuronal nitric oxide synthase (nNOS), to 93-56%, as measured by citrulline formation. EGCG competitively inhibited binding of arginine and tetrahydrobiopterin, and the gallate structure is important for this action.
Article
A total of 48 (60 test samples) species of plants commonly eaten in Japan were randomly collected and their methanol extracts were tested for in vitro nitric oxide (NO) generation inhibitory activities in a murine macrophage cell line, RAW 264.7, stimulated with both lipopolysaccharide (LPS, 100 ng/ml) and interferon-gamma (IFN-gamma, 100 U/ml). Seventeen (28.3%) of the 48 extracts strongly inhibited NO generation at a concentration of 200 microg/ml by 70% or more with significant cell viability (>50%). The extracts from avocado, taro, red turnip, sereves, komatsuna, basil, mitsuba and Chinese mustard markedly inhibited iNOS activity. These results suggest that a wide variety of edible plants in Japan contain the secondary metabolites carrying cancer preventive activity through reduction of excess amounts of NO.
Article
We compared the effect of 26 types or groups of vegetables and fruit on the risk of cancer using data from two case-control studies that included 1,225 cases of cancer of the colon, 728 cases of cancer of the rectum, 2,569 cases of cancer of the breast, and 5,155 hospital controls interviewed between 1991 and 1996 in six Italian areas. Most vegetables were inversely associated with cancer of the colon and rectum, whereas only carrots and raw vegetables lowered breast cancer risk. High fruit intake was associated only with a reduction of rectal cancer. Different contents of sugar, fiber, carotenoids, and folic acid in fruits vs vegetables plus the concurrent consumption of oil with vegetables may partly explain these findings. (Epidemiology 1998;9:338-341) (C) Lippincott-Raven Publishers.
Article
In the field of inflammation research the inducible nitric oxide synthase (iNOS) became an important pharmacological target, since overproduction of nitric oxide (NO) after induction of this enzyme seems to be associated with numerous pathological conditions. NO released from cells can be detected and quantified photometrically as its stable product nitrite by a simple colorimetric reaction (Griess reaction). The aim of our study was to investigate whether this method might be suitable for the bio-guided fractionation of anti-inflammatory plant extracts. For this purpose we assayed extracts as well as fractions of the roots of Curcuma zanthorrhiza Roxb, which contain the known iNOS inhibitor curcumin, and compared the obtained activity with their curcumin content. Furthermore, leaf extracts of Betula pendula Roth, to which defined amounts of curcumin were added, were examined to clarify the question whether chlorophyll might interfere with the test system. The presented results suggest that the Griess assay is indeed suitable to guide fractionation of plant extracts in order to isolate highly active compounds. Factors, however, which might restrict the broad application of this assay are the limited selection of solvents which do not interfere with the system and high contents of chlorophyll in plant extracts.