The effect of iron and fat in a diet containing green tea extract (Camellia sinensis) on the antioxidant capacity of some organs and the mRNA expression of specific genes in mice.

Assays comprising three probes for different mechanisms of antioxidant activity in food products have been modified to allow better comparison of the contributions of the different mechanisms to antioxidant capacity (AOC). Incorporation of a common format for oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP), and iron(II) chelating activity (ICA) assays using 96-well microplates provides a comprehensive and high-throughput assessment of the antioxidant capacity of food extracts. The methods have been optimized for aqueous extracts and validated in terms of limit of quantification (LoQ), linearity, and precision (repeatability and intermediate reproducibility). In addition, FRAP and ORAC assays have been validated to assess AOC for lipophilic extracts. The relative standard deviation of repeatability of the methods ranges from 1.2 to 6.9%, which is generally considered to be acceptable for analytical measurement of AOC by in vitro methods. Radical scavenging capacity, reducing capacity, and iron chelating properties of olive mill wastewaters (OMWW), oregano, and parsley were assessed using the validated methods. OMWW showed the highest radical scavenging and reducing capacities, determined by ORAC and FRAP assays, respectively, followed by oregano and parsley. The ability to chelate Fe (2+) was, in decreasing order of activity ( p > 0.05) parsley congruent with oregano > OMWW. Total phenol content, determined by the Folin-Ciocalteu method, correlated to the radical scavenging and reducing capacities of the samples but not to their chelating properties. Results showed that the optimized high-throughput methods provided a comprehensive and precise determination of the AOC of lipophilic and hydrophilic food extracts in vitro.

Introduction: Measuring of natural antioxidants power is important in the food industry. Ferula gummosa Boiss. plant, locally called Barijeh, is a member of genus Ferula belonging to the Apiaceae family. To introduce endemic natural antioxidants, antioxidant capacity of alcoholic and hydroalcoholic extracts of aerial parts of F. gummosa Boiss. was investigated. Objective: The primary objective of this study was to compare the antioxidant levels and activities between flower and leaf extracts of Ferula gummosa Boiss. plant by different assay methods. Method: The antioxidant activity of flower and leaf extracts of F. gummosa Boiss. was assessed usingferric-reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and oxygen radical absorbance capacity (ORAC) assay. In addition, phenolic content of the extracts was measured byFolin-Ciocalteu (FC) method. Results: Ferric reducing antioxidant power assay showed that leaf extract has more antioxidant activity compared to flower extract. DPPH assay had similar results. A slow kinetic behavior was found for methanol extracts of both tissues (EC50 of 0.21 mg/mL and 0.25 mg/mL for leaf and flower methanol extracts, respectively) which was estimated by kinetic mode of DPPH assay. The ORAC assay showed higher values for methanolic extracts compared to ethanolic extracts. Except for ORAC assay, a significant positive correlation was found between antioxidant data of ferric-reducing antioxidant power, DPPH and Folin-Ciocalteu assays. Conclusion: These findings suggest that high antiradical potential and reducing power of the alcoholic and hydroalcoholic extracts of the aerial parts of F. gummosa Boiss. correspond to a high phenolic content in these plant parts. The high antioxidant activity of the F. gummosa Boiss. could propound the hydroalcoholic extracts of this plant as a therapeutic agent to prevent and treat diseases due to free radical imbalance in the body.

Long-term dietary fatty acid intake alters the development of left ventricular hypertrophy, but the linking signaling pathways are unclear. We studied the role and underlying signaling mechanisms of dietary fat intake in the early phase of the hypertrophic process. Rats assigned for 4 weeks of high-oil, high-fat, or standard diet were subjected to angiotensin II (Ang II; 33 microg/kg/h, subcutaneous) or vehicle infusion for 24 h. The Ang II-induced increase in left ventricular mRNA levels of hypertrophy-associated genes was higher in rats fed the high-oil diet compared with the standard diet. Western blotting revealed that, in parallel with changes in gene expression, the high-oil diet increased c-Jun N-terminal kinase phosphorylation (P < 0.001). Ang II increased p38 mitogen-activated protein kinase (MAPK) phosphorylation in rats fed the high-fat diet (3-fold; P < 0.01). The increase in transcription factor activator protein-1 (AP-1) DNA binding activity in response to Ang II was higher in rats fed the high-oil diet compared with those fed the standard diet (P < 0.001). Ang II downregulated inducible nitric oxide synthase mRNA levels in fatty acid-supplemented groups compared with the standard diet group. These results show that dietary fat type modulates the early activation of hypertrophic genes in pressure-overloaded myocardium involving the distinct activation of AP-1 and MAPK signal transduction pathways.

Chapter 46 - Green Tea Extract

Antioxidant capacity of extracts of different polarity obtained from two Hypericum L. species (H. juniperinum and H. mexicanum) was assessed by means of total polyphenolic content (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay, ferric reducing antioxidant power (FRAP) assay and oxygen radical absorbance capacity (ORAC) assay. Their phenolic acid composition was also determined by HPLC. The ethyl acetate extract of H. juniperinum was the most active in the ABTS, FRAP and TPC assays with 10867.48 ?mol TEAC/g, 242.80 mg AAE/g and 491.08 mg GAE/g respectively. On the other hand, the methanol extract obtained from H. mexicanum appeared as the most active extract in the DPPH assay (3714.23 ?mol TEAC/g). Similarly, the butanol fraction coming from the methanolic extract of H. mexicanum showed the highest activity in the ORAC assay (12910.06 ?mol TEAC/g). HPLC analysis of the extracts revealed the presence of phenolic acid compounds, such as chlorogenic (50.09 mg/g) and p-coumaric acids (63.36 mg/g) in H. mexicanum and p-coumaric acid (8.45 mg/g) in H. juniperinum. A high correlation between antioxidant activity and total polyphenol content was established. Specifically, H. mexicanum exhibited the highest ORAC capacity, which may be associated with the high content of chlorogenic and p-coumaric acids present in medium to polar extracts. Our results constitute a significant contribution to the study of antioxidant activity and the determination of the phenolic acid profile in both species. The analysed extracts showed promising antioxidant activity that could be useful in the pharmaceutical, cosmetic and food industries.

Fresh cheese composition favors the growth of microorganisms and lipid oxidation, leading to a short shelf life. Whey protein concentrates can be used to produce active films in which green tea (Camellia sinensis L.) extract, rich in bioactive compounds, namely catechins, can be incorporated. Thus, the main objective of this study was to evaluate the efficacy of an edible active film, incorporated with green tea extract, to preserve goat and mixture (goat and sheep) fresh cheeses. Our results demonstrated that Portuguese green teas (antioxidant activity coefficient—AAC = 746.7) had superior antioxidant capacity to that of the evaluated Asian green tea (AAC = 650). Furthermore, green tea produced from the leaves of the new Portuguese Chá Camélia tea plantation had the highest potential to retain the antioxidant capacity (97.3%). Additionally, solid–liquid extractions led to extracts with higher antioxidant activity (AAC = 1500), but Soxhlet extractions presented higher yield (43%). Furthermore, the active film incorporated with Portuguese green tea extract exhibited a high antioxidant capacity (AAC ≈ 595.4). In addition, the active film effectively delayed the lipid oxidation of the evaluated fresh cheeses (3.2 mg MDA Eq/kg) when compared with the control (4.2 mg MDA Eq/kg). Moreover, the active films effectively inhibited the growth of microorganisms, especially E. coli (1.5 × 10 CFU/g), when compared with the blank (2.2 × 102 CFU/g). This study suggests that the new whey protein film incorporated with Portuguese green tea extract has the potential to be used to extend fresh cheese shelf life.

The total antioxidant potential of a sample cannot be predicted from the antioxidant activity of its compounds; thus, scientists usually explain the overall activity through their combined effects (synergistic, antagonistic, or additive). Phenolic compounds are one of the most powerful and widely investigated antioxidants, but there is a lack of information about their molecular interactions. This study aimed to investigate the individual and combined antioxidant activity of equimolar mixtures (binary, ternary, quaternary, and quinary) of 10 phenolic acids (protocatechuic, gentisic, gallic, vanillic, syringic, p-coumaric, caffeic, ferulic, sinapic, and rosmarinic acid) at different concentrations using ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays. Gallic acid showed the highest antioxidant activity, determined using the FRAP assay (494–5033 µM Fe2+) and rosmarinic acid with the ORAC assay (50–92 µM Trolox Equivalents (TE)), while the lowest antioxidant potential was observed for p-coumaric acid (FRAP 24–113 µM Fe2+ and ORAC 20–33 µM TE). The synergistic effect (by FRAP) in the equimolar mixtures of hydroxybenzoic acids was confirmed for a large number of tested mixtures, especially at low concentrations. All mixtures containing gentisic acid showed a synergistic effect (28–89% difference). Using the ORAC method, only two mixtures of hydroxybenzoic acids showed an antagonistic effect, namely a mixture of gentisic + syringic acids (−24% difference) and gallic + vanillic acids (−30% difference), while all other mixtures showed a synergistic effect in a range of 26–236% difference. Among mixtures of hydroxycinnamic acids, the highest synergistic effect was observed for the mixtures of p-coumaric + ferulic acids and caffeic + sinapic acids with differences of 311% and 211%, respectively. The overall antioxidant activity of phenolic acids could be explained by the number or position of hydroxyl and/or methoxy functional groups as well as the compound concentration, but the influence of other parameters such as dissociation, intramolecular hydrogen bonds, and electron donating or withdrawing effect should not be neglected.

Mechanism of the combined anti-bacterial effect of green tea extract and NaCl against Staphylococcus aureus and Escherichia coli O157:H7

This experiment was conducted to determine the optimum level of green tea extract (GTE) in diets without antibiotics and to evaluate its effect on broiler performances. A total of 100 Cob broiler chicks were kept for a period of 5 weeks. Dietary treatments used in this experiment were antibiotic free group (basal diet as a control), GTE 0.5% (basal + GTE 0.5%), GTE 1% (basal + GTE 1%) and GTE 2% (basal + GTE 2%) and antibiotic added group (basal + 0.05% oxytetracycline). GTE supplemented group showed significantly higher body weight and better feed conversion ratio (FCR) than other treatments (P &lt; 0.05) where highest live weight (2034 g/bird) was recorded in broilers group provided with 0.5% GTE. The best FCR (1.58) was observed in the group supplemented with 0.5% GTE. The obtained results also revealed significant (P &lt; 0.05) difference among treatments in the lipid profile parameters (total cholesterol, HDL and triglyceride except LDL). Broilers treated with 0.5% GTE showed lowest total cholesterol (115.0 mg/dl), triglyceride (116.3 mg/dl) and highest HDL (30.75 mg/dl). In conclusion, GTE can be added in the diet @ 0.5% for better growth performances of broiler as an alternative to antibiotic without any negative effect on lipid profile.&#x0D; Res. Agric., Livest. Fish.8(1): 157-163, April 2021

Mayonnaise, is susceptible to oxidation resulting in quality deterioration and the formation of undesirable components such as free radicals and reactive aldehydes. A better understanding of the factors affecting lipid oxidation and ways of retarding oxidation in mayonnaise is essential to improve the shelf life of mayonnaise.Eliminating possible factors, which will reduce the induction period and hasten rancidity, can increase the shelf life of mayonnaise but one of the most effective means of retarding lipid oxidation in mayonnaise is to incorporate antioxidants. Due to the negative effects and perceptions of synthetic antioxidants, there has been a growing interest in using natural antioxidants in food products. Recent studies showed that incorporation of natural antioxidants in mayonnaise could increase its oxidative stability. However, natural antioxidants may exert a negative effect on sensory properties and further studies are needed to identify and overcome this problem.The aim of this project was to study the efficacy of natural antioxidants in inhibiting lipid oxidation in mayonnaise.The evolution of volatile oxidation compounds (VOxCs) in mayonnaise stored at varying temperatures for 92 days was investigated using static headspace extraction and separation by two-dimensional gas chromatography/time-of-flight mass spectrometry. Considerable differences in the headspace composition of samples stored at 4, 25 and 38 °C were found due to the different oxidation levels reached. The content of hexanal in mayonnaise at 1-5 days of storage at 38 °C could be used to predict the corresponding compound in mayonnaise at 1-62 days of storage at 25 °C. Some volatile compounds were identified that could be a useful indicator of lipid oxidation of the sunflower oil in the mayonnaise, and by using an antioxidant to reduce these compounds a good oxidative stability could be reached.Interpreting the activity of antioxidants has been difficult due to the complex effect of lipid oxidation conditions and systems. Lipid oxidation process and effect of Butylated hydroxy anisole (BHA) was evaluated in sunflower oil and mayonnaise. The rate of lipid oxidation was higher in mayonnaise compared to bulk oil that could be due to the high surface area of oil that increases lipid interactions with aqueous phase pro-oxidants. BHA, a non-polar antioxidant was more effective in mayonnaise than oil. Differences seen in the efficacy of BHA in oil and mayonnaise could be explained by its affinity towards oil-water interface in mayonnaise. Therefore, the matrix plays an important role on the antioxidant efficacy.The antioxidant capacity of five natural antioxidants (green tea extract (GTE), tocopherols (TOCs), rosemary extract containing 2.7% carnosic acid (CA, REW), oil-soluble rosemary extract containing 5.2% CA (REO) and lemon myrtle (LEM)) was evaluated in vitro and in situ and compared to BHA. The antioxidant capacity was determined by measuring ferric reducing antioxidant power (FRAP) and free radical scavenging activity (ABTS). BHA showed the highest antioxidant capacity and was stable during storage of mayonnaise. GTE and TOCs had the highest antioxidant capacity among natural antioxidants but their activity decreased during storage of mayonnaise. Although REO had higher CA, it exhibited similar ABTS and FRAP activity to REW.The antioxidative efficiency of hydrophilic GTE (500 mg/kg oil), lipophilic TOC 500 (mg/kg oil), and a green tea/tocopherol mixture (GTT) in mayonnaise was investigated by measuring hydroperoxide concentration, VOxCs, colour and sensory properties, during 60 days of storage at 38 °C. Although, GTE and TOC had high antioxidant capacity in vitro and in situ they acted as pro-oxidants in mayonnaise. The pro-oxidative effect of GTE could be due to partitioning of hydrophilic tea catechins in the water phase of the emulsion and becoming less protective and/or reducing transition metals to their catalytically active state. The combination of GTE with TOC improved the antioxidant activity compared to the individual extracts that could be due to reduction of the TOC radicals by the water-soluble reductant in GTE or reduction of the lipophilic radicals. Sensory properties showed that GTE promoted the development of unpleasant fishy and rancid aroma. Partial least square analysis elucidated the predictive ability of VOxCs for sensory terms.The antioxidant effects of TOC, LEM, REW, REO, BHA and the combination of TOC with LEM (L+T) and water-soluble rosemary extract (R+T) during storage of mayonnaise at 38 °C for 60 days were assessed. The hydroperoxides and VOxCs, colour and sensory properties were measured, and the results were compared to samples without any additive (CON). All the natural antioxidants inhibited lipid oxidation as well as BHA except REO. However, the sensory properties of LEM and REW were inferior compared to TOC and BHA. Irrespective of CA content and solubility, REW showed significantly higher antioxidant activity compared to REO in mayonnaise. A combination of TOC with LEM and REW did not exert a tendency for improving the activity of each individual antioxidant. Thus, TOC (1000 mg/kg oil) can be recommended for the food industry as a substitute for the synthetic antioxidant usually used in mayonnaise

In this study ferric reducing antioxidant power assay, 2,2-diphenyl-1-picrylhydrazyl and oxygen radical absorbance capacity assays were employed to measure the antioxidant activity of flower and leaf extracts of Ferulago angulata. Ferric reducing antioxidant power assay of the extracts showed that the antioxidant activities of leaf extracts were higher than that of flower extracts. 2,2-diphenyl-1-picrylhydrazyl values showed similar trend to ferric reducing antioxidant power assay. A slow kinetic behavior was found within methanol extracts of both plant parts (EC50 of 0.071 mg/ml and 0.12 mg/ml for leaf methanol extract and flower methanol extract, respectively), estimated by kinetic mode of 2,2-diphenyl-1-picrylhydrazyl assay. The oxygen radical absorbance capacity assay indicated higher values for methanol extracts of plant parts compared to that of ethanol extracts. Except for oxygen radical absorbance capacity assay, a significant positive correlation was found between ferric reducing antioxidant power, 2,2-diphenyl-1-picrylhydrazyl and Folin-Ciocalteu assays, suggesting that phenolic compounds have an important role in reducing power and antiradical properties of the extracts.

Context: Betula pendula Roth (Betulaceae) exhibits many pharmacological activities in humans including anticancer, antibacterial, and antiviral effects. However, the antioxidant activity of BP towards lipid degradation has not been fully determined. Objective: The BP ethanol and methanol extracts were evaluated to determine antioxidant activity by an in vitro method and lyophilized extract of BP was added to beef patties to study oxidative stability. Materials and methods: Antioxidant activities of extracts of BP were determined by measuring scavenging radical activity against methoxy radical generated by Fenton reaction 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (TEAC) radical cation, the oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) assays. The lipid deterioration in beef patties containing 0.1% and 0.3% (w/w) of lyophilized extract of BP stored in 80:20 (v/v) O2:CO2 modified atmosphere (MAP) at 4 °C for 10 days was determined using thiobarbituric acid reacting substances (TBARS), % metmyoglobin and colour value. Results: The BP methanol extract revealed the presence of catechin, myricetin, quercetin, naringenin, and p-coumaric acid. The BP ethanol (50% w/w) extract showed scavenging activity in TEAC, ORAC and FRAP assays with values of 1.45, 2.81, 1.52 mmol Trolox equivalents (TE)/g DW, respectively. Reductions in lipid oxidation were found in samples treated with lyophilized BP extract (0.1% and 0.3% w/w) as manifested by the changes of colour and metmyoglobin concentration. A preliminary study film with BP showed retard degradation of lipid in muscle food. Conclusion: The present results indicated that the BP extracts can be used as natural food antioxidants.

One of the significant danger factors for cardiovascular disease and stroke is dyslipidemia. According to long-term prospective epidemiological research, coronary heart disease is less common in those with good lipid profiles who lead better lives. In this study, on a high-fat diet, female wistar rats (Rattus norvegicus) will be tested and analyzed to see if green tea extract (Camellia sinensis) can prevent dyslipidemia when given orally. Compared to a control group that received only distilled water, the trial group that received 5 milliliters of green tea extract (Camellia sinensis) had significantly lower total and LDL cholesterol levels and higher HDL cholesterol levels. This treatment was more effective in lowering cholesterol overall. The components found in green tea (Camellia sinensis), including tannins, steroids, alkaloids, saponins, and flavonoids, can induce this. When certain bioactive substances are off, the body can bring them back into normalcy. These results suggest that white wistar rats (Rattus norvegicus), given a high-fat diet, can benefit from green tea (Camellia sinensis) extract to avoid dyslipidemia. Your lipid profile can be improved by ingesting green tea extract. The primary polyphenol in tea, catechin, is responsible for this transformation. Therefore, the Camellia sinensis plant, from which green tea is made, is a valuable plant that can halt or slow the progression of several ailments, including hypertension, metabolic disorders, and cardiovascular disorders.

Cellular damage caused by reactive oxygen species (ROS) has been implicated in several diseases, and hence antioxidants have significant importance in human health. In this study, five methods were used to test and compare the antioxidant activity at different levels involving formation and scavenging of free radicals by the extracts of four mushrooms that have medicinal values. The results were expressed as Trolox equivalent antioxidant capacity (TEAC) and ascorbic acid equivalent antioxidant capacity (AEAC). In the DPPH (1,1-diphenyl 2-picryl hydrazyl) assay, the ethyl acetate extract of Phellinus rimosus showed more potent activity than the methanolic extracts of Pleurotus florida, Pleurotus sajour-caju, and Ganoderma lucidum. The ethyl acetate extract of P. rimosus at a concentration of 0.1% showed a high TEAC value (12.488). In the ABTS (2,2-azobis-3-ethylbenzthiazoline-6-sulfonic acid) spectrophotometric assay, it possessed the most effective antioxidant activity (TEAC 4.84) compared to methanolic extracts of P. florida, P. sajour-caju, and G. lucidum. The extract of P. rimosus also possessed higher activity compared to other extracts in the ferric-reducing antioxidant power (FRAP) assay. In the pulse radiolysis studies and the ORAC (oxygen radical absorbance capacity) assay also, these mushrooms showed significant activities. Results of the DPPH, ABTS, FRAP, and ORAC assays indicate that all the four mushrooms examined showed significant antioxidant activities. Among these, P. rimosus extract seems to be the more effective antioxidant.

This review summarizes published in vitro, animal, and clinical studies investigating the effects of green tea (Camellia sinensis) extract and associated catechins on drug-metabolizing enzymes and drug transporters. In vitro studies suggest that green tea extract and its main catechin, (-)-epigallocatechin-3-gallate, to varying degrees, inhibit the activity of CYP1A1, CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2D6, and CYP3A4. UGT1A1 and UGT1A4 isoforms were also inhibited by (-)-epigallocatechin-3-gallate. Animal studies suggest green tea extract and/or (-)-epigallocatechin-3-gallate significantly increase the bioavailability of diltazem, verapamil, tamoxifen simvastatin, 5-fluorouracil, and nicardipine. Conversely, green tea extract and/or (-)-epigallocatechin-3-gallate reduce the bioavailability of quetiapine, sunitinib, clozapine, and nadolol. Of the few clinical studies available for review, it appears neither green tea extract nor (-)-epigallocatechin-3-gallate inhibit any major cytochrome P450 enzyme. Regarding drug transporters, in vitro studies indicate P-glycoprotein, organic anion transporting polypeptide 1A1, organic anion transporting polypeptide 1B1, organic anion transporting polypeptide 1B3, organic anion transporting polypeptide 2B1, organic cation transporter 1, organic cation transporter 2, multidrug and toxin extrusion 1, and multidrug and toxin extrusion 2-K are potentially inhibited by green tea extract. A clinical study indicates the organic anion transporting polypeptide 1A1 transporter is inhibited by (-)-epigallocatechin-3-gallate while P-glycoprotein is unaffected. In conclusion, the ingestion of green tea extract or its associated catechins is not expected to result in clinically significant influences on major cytochrome P450 or uridine 5'-diphospho-glucuronosyltransferase enzyme substrates or drugs serving as substrates of P-glycoprotein. However, some caution is advised in the consumption of significant amounts of green tea beverages or green tea extract in patients prescribed known substrates of organic anion transporting polypeptide, particularly those with a narrow therapeutic index.