Antioxidant activity of tea extracts in lipids and correlation with polyphenol content

Gramza, Anna; Khokhar, S.; Yoko, Shihikura; Gliszczyńska‐Świgło, Anna; Hęś, Marzanna; Korczak, Józef

doi:10.1002/ejlt.200500330

Cited by 119 publications

(85 citation statements)

References 58 publications

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“…The subject of this research was the aqueous extract of yellow tea leaves prepared according to the method presented by Gramza et al (2006). Camellia sinensis leaves were obtained from a tea company representative (Gemini, Poland).…”

Section: Methodsmentioning

confidence: 99%

Protective effect of yellow tea extract on N-nitrosodiethylamine-induced liver carcinogenesis

Kujawska

Ewertowska

Adamska

et al. 2016

Pharmaceutical Biology

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Context Yellow tea containing the same catechins as other types of tea but in different proportions has been suggested to possess potent anticancer activities. Objective This study investigates the chemopreventive effect of yellow tea aqueous extract against N-nitrosodiethylamine (NDEA)-induced liver carcinogenesis in rats by employing histological and biochemical methods. Materials and methods Wistar rats were divided randomly into four groups: control (I), yellow tea (II), NDEA (III), and yellow tea + NDEA (IV). Groups II and IV were exposed via a diet to yellow tea extract in a concentration of 10 g/kg feed; groups III and IV received 0.01% NDEA in drinking water. The experiment lasted for 13 weeks. Results Daily intake of yellow tea in an average dose of 800 mg/kg b.w. alleviated the carcinogenic effect of NDEA as evidenced by reversed histopathological changes towards normal hepatocellular architecture and decreased lipid peroxidation, protein carbonyl formation, and DNA degradation by 64%, 37% and 15%, respectively, as compared with values obtained in NDEA alone-treated rats. Treatment with yellow tea extract caused protection of superoxide dismutase (SOD) and catalase (CAT); their activity was recovered by 47% and 12%, respectively, as compared with the NDEAtreated rats. Moreover, the extract normalized the NDEA-induced activity of paraoxonase 1 (PON1) and glutathione peroxidase (GPx), while a further increase in the level of reduced glutathione (GSH) was noticed. Conclusions On the basis of these findings, it can be concluded that treatment with yellow tea partially protected the livers of rats from NDEA-induced hepatocarcinogenesis and that its antioxidant activity contributed to this effect. ARTICLE HISTORY

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Section: Methodsmentioning

confidence: 99%

Protective effect of yellow tea extract on N-nitrosodiethylamine-induced liver carcinogenesis

Kujawska

Ewertowska

Adamska

et al. 2016

Pharmaceutical Biology

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“…The supernatants collected were filtered and ethanol was removed at 50°C on a rotary evaporator (Buchi, Switzerland). All samples were frozen at -20°C for 24 hours and then freeze-dried (Alpha 1-4 LSC Freeze dryer, Christ, Germany) and stored at 4°C in a dark place (Gramza et al, 2006a).…”

Section: Preparation Of Plant Extractsmentioning

confidence: 99%

The effect of antioxidants on quantitative changes of lysine and methionine in linoleic acid emulsions at different pH conditions

Hęś

Gliszczyńska‐Świgło

Gramza‐Michałowska

2017

Acta Sci Pol Technol Aliment

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Background. Plants are an important source of phenolic compounds. The antioxidant capacities of green tea, thyme and rosemary extracts that contain these compounds have been reported earlier. However, there is a lack of accessible information about their activity against lipid oxidation in emulsions and inhibit the interaction of lipid oxidation products with amino acids. Therefore, the influence of green tea, thyme and rosemary extracts and BHT (butylated hydroxytoluene) on quantitative changes in lysine and methionine in linoleic acid emulsions at a pH of isoelectric point and a pH lower than the isoelectric point of amino acids was investigated. Material and methods. Total phenolic contents in plant extracts were determined spectrophotometrically by using Folin-Ciocalteu's reagent, and individual phenols by using HPLC. The level of oxidation of emulsion was determined using the measurement of peroxides and TBARS (thiobarbituric acid reactive substances). Methionine and lysine in the system were reacted with sodium nitroprusside and trinitrobenzenesulphonic acid respectively, and the absorbance of the complexes was measured. Results. Extract of green tea had the highest total polyphenol content. The system containing antioxidants and amino acid protected linoleic acid more efficiently than by the addition of antioxidants only. Lysine and methionine losses in samples without the addition of antioxidants were lower in their isoelectric points than below these points. Antioxidants decrease the loss of amino acids. The protective properties of antioxidants towards methionine were higher in a pH of isoelectric point whereas towards lysine in pH below this point. Conclusion. Green tea, thyme and rosemary extracts exhibit antioxidant activity in linoleic acid emulsions. Moreover, they can be utilized to inhibit quantitative changes in amino acids in lipid emulsions. However, the antioxidant efficiency of these extracts seems to depend on pH conditions. Further investigations should be carried out to clarify this issue.

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“…Ethanol extract was prepared according to Gramza et al (2006). Extracts were prepared by triplicate 24 hours maceration of grinded 100 g tea leaves with 250 ml ethanol 95% at ambient conditions.…”

Section: Green Tea Extract (Gte)mentioning

confidence: 99%

Synergistic Antioxidant Scavenging Activities of Grape Seed and Green Tea Extracts against Oxidative Stress

El-Beltagi

El-Desouky

Yousef

2016

Not Bot Horti Agrobo

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Grape seed and green tea extracts are reported to produce antioxidant scavenging activities against free radical toxicity. This study aimed to investigate the hypothesis that a specific combination of these extracts presents a synergistic antioxidant scavenging activities. The extracts of grape seed, green tea and their mixtures were characterized by phytochemical studies and tested for phenolics and flavonoids. In vitro antioxidant activity for individual extract and its mixtures was determined by DPPH, hydroxyl and superoxide free radical scavenging methods. The amount of total phenolics varied among the different extracts and ranged from 43.74 to 67.68 mg of gallic acid equivalents (GAE) / g dry weight, whereas total flavonoids content ranged from 4.25 to 11.66 mg of quercetin equivalents (QU) /g dry weight. The present results suggest that both extracts reported a highly contents of total phenolic and flavonoids compounds, also the mixtures of these extracts can synergistically enhance antioxidant activity. Antioxidant potential from mixture 2 (grape seed extract 200 mg: green tea extract 100 mg) was comparable to that of standard. HPLC results showed that the most abundant components in the mixture 2 extract were epigallocatechingallate while the lowest was the procyanidine.

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Antioxidant activity of tea extracts in lipids and correlation with polyphenol content

Cited by 119 publications

References 58 publications

Protective effect of yellow tea extract on N-nitrosodiethylamine-induced liver carcinogenesis

Protective effect of yellow tea extract on N-nitrosodiethylamine-induced liver carcinogenesis

The effect of antioxidants on quantitative changes of lysine and methionine in linoleic acid emulsions at different pH conditions

Synergistic Antioxidant Scavenging Activities of Grape Seed and Green Tea Extracts against Oxidative Stress

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