Massive Accumulation of Gallic Acid and Unique Occurrence of Myricetin, Quercetin, and Kaempferol in Preparing Old Oolong Tea

Lee

et al. 2010

AGE

106

Advanced glycation endproducts (AGE) are oxidative products formed from the reaction between carbohydrates and a free amino group of proteins that are provoked by reactive species (RS). It is also known that AGE enhance the generation of RS and that the binding of AGE to a specific AGE receptor (RAGE) induces the activation of the redox-sensitive, pro-inflammatory transcription factor, nuclear factor-kappa B (NF-kB). In this current study, we investigated the anti-oxidative effects of short-term kaempferol supplementation on the age-related formation of AGE and the binding activity of RAGE in aged rat kidney. We further investigated the suppressive action of kaempferol against AGE's ability to stimulate activation of pro-inflammatory NF-kB and its molecular mechanisms. For this study, we utilized young (6 months old), old (24 months old), and kaempferol-fed (2 and 4 mg/kg/day for 10 days) old rats. In addition, for the molecular work, the rat endothelial cell line, YPEN-1 was used. The results show that AGE and RAGE were increased during aging and that these increases were blunted by kaempferol. In addition, dietary kaempferol reduced age-related increases in NF-kappaB activity and NF-kB-dependant pro-inflammatory gene activity. The most significant new finding from this study is that kaempferol supplementation prevented age-related NF-kappaB activation by suppressing AGE-induced nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase). Taken together, our results demonstrated that dietary kaempferol exerts its anti-oxidative and anti-inflammatory actions by modulating the age-related NF-kappaB signaling cascade and its pro-inflammatory genes by suppressing AGE-induced NADPH oxidase activation. Based on these data, dietary kaempferol is proposed as a possible anti-AGE agent that may have the potential for use in anti-inflammation therapies.

Section: Discussionsupporting

confidence: 94%

Kaempferol modulates pro-inflammatory NF-κB activation by suppressing advanced glycation endproducts-induced NADPH oxidase

Lee

et al. 2010

AGE

106

“…Gallic acid, ECG, and EGCG were simultaneously found in the semifermented Dilmah oolong tea, thus showing a different phenolic profile among all tea types. Trihydroxylflavan-3-ols, such as EGCG and EGC are generally oxidized faster during the fermentation phase of black tea processing and GA is most likely produced from the degradation of EGCG (Lee et al, 2008). This would explain differences observed in the HPLC phenolic profiles of analyzed tea types in current work; however, the effect of the brand was also important.…”

Section: Hplc Analysis Of Phenolic Compounds and Camentioning

confidence: 87%

Phenolic compounds, antioxidant capacity, andin vitro α-amylase inhibitory potential of tea infusions (Camellia sinensis) commercialized in Chile

Quesille-Villalobos

Torrico

Ranilla

2013

CyTA - Journal of Food

(2013) Phenolic compounds, antioxidant capacity, and invitro α-amylase inhibitory potential of tea infusions (Camelliasinensis) commercialized in Chile, CyTA -Journal of Food, 11:1, 60-67, DOI: 10.1080/19476337.2012 To link to this article: https://doi.org/10. 1080/19476337.2012 Chile is considered the largest tea consumer in America, so a broad variety of tea types and brands are available in Chilean markets. Thirty-four commercial teas (white, green, red, oolong, and black) commonly found in Chile were evaluated according to their phenolic profiles, antioxidant capacity, and in vitro inhibition against a-amylase relevant for hyperglycemia control. Multivariate tools were used to evidence patterns among samples respect their biochemical parameters. Green and white tea groups showed higher total phenolic contents than red and black teas. All tea samples inhibited the 2,2-diphenyl-1-picrylhydrazyl free radical and black teas significantly inhibited the a-amylase enzyme. Major phenolics detected by liquid chromatography in green and white teas were epigallocatechingallate and epicatechingallate, whereas gallic acid was common in black, red, and oolong teas. Caffeine was found across all samples. The multivariate analysis evidenced a high variability among analyzed tea and even from brand to brand.Keywords: Camellia sinensis; phenolics; free radical inhibition; a-amylase inhibition Chile es considerado el mayor consumidor de te´en Ame´rica y una amplia variedad en tipos y marcas de te´existen en el mercado chileno. Un total de treinta y cuatro muestras de te´(blanco, verde, rojo, oolong y negro) fueron evaluadas de acuerdo a sus perfiles de compuestos feno´licos, capacidad antioxidante e inhibicio´n in vitro de la a-amilasa, relevante en el control de la hiperglicemia. Se utilizaron herramientas multivariantes para evidenciar patrones entre las muestras respecto a sus para´metros bioquı´micos. Los grupos de te´verdes y blancos presentaron los valores ma´s altos en feno´licos totales. Todas las muestras inhibieron el radical libre 2,2-difenil-1-picrilhidracilo, en cambio so´lo los te´s negros inhibieron significativamente la enzima a-amilasa. Los principales compuestos feno´licos detectados por cromatografı´a lı´quida en te´verde y blanco fueron la epigalocatequina-galato y epicatequinagalato, mientras que a´cido ga´lico fue detectado en las muestras de te´negro, rojo y oolong. Se detecto´cafeı´na en todas las muestras evaluadas. El ana´lisis multivariante demostro´una alta variabilidad entre las muestras de te´y aú n entre las diferentes marcas procedentes de un mismo tipo de te´.

Journal of Food Science

“…These types of polyphenols are abundant in plant diets. More and more evidences show that they have pleiotropic beneficial health effects, including antioxidative, anti‐inflammatory, anti‐cancer, anti‐virus, anti‐aging, cardioprotective, and neuroprotective activities (Feldman and others 1999; Okabe and others 2001; Claudine and others 2004; Lee and others 2008; Navarro and others 2008; Fukasawa and others 2009; Natsume and others 2009; Ohga and others 2009). …”

Section: Discussionmentioning

confidence: 99%

Activity‐Guided Isolation and Identification of Radical Scavenging Components in Gao‐Cha Tea

Lu¹,

Hu²,

Xia³

2010

Gao-Cha is a traditional Chinese health tea made from Acer ginnala. We performed a components and radical scavenging activity analysis to identify any medicinal components in this tea. High performance thin layer chromatography (HPTLC)-1,1-Diphenyl-2-picryhydrazyl (HPTLC-DPPH) assay showed that the methanolic extract contained strong radical scavengers. Quantitative analysis revealed that the IC(50) of the extract against 1 mM DPPH was 52.7 ± 0.6 μg/mL. Bioactive-guided isolations led to procurement of 3 radical scavengers with IC(50)s of 17.5 ± 2.1, 29.3 ± 2.5, and 21.6 ± 1.7 μg/mL, respectively. Analysis of the high resolution-electric spray ionization-mass spectrometer and (1)H, (13)C, distortionless enhancement by polarization transfer at 135°, heteronuclear quantum coherence, correlating spectroscopy coupling, and heteronuclear multiple bond coherence (HMBC) data revealed that the compounds were methyl 3, 4, 5-trihydroxybenzoate (1), quercetin-3-O-α-rhamnopyranoside (2), and 2,6-bis (3,4,5-trihydroxybenzoyl)-aceritol (3). Bioactive combined components analysis revealed that, apart from compounds 1, 2, and 3, the tea possibly contained radical scavengers: ginnalin A (4) and B (5), 2″-O-Galloylquercitrin (6) and 3″-O-Galloyl-quercitrin (7). Compounds 2, 6, and 7 were isolated from Acer ginnala for the first time. The positions of the 2 galloyl moieties in compound 3 were unambiguously established by the HMBC spectrum for the first time.