Applicability of an improved Trolox equivalent antioxidant capacity (TEAC) assay for evaluation of antioxidant capacity measurements of mixtures

Nam

Food Science & Nutrition

et al. 2018

The aim of this study was to investigate the skin anti‐inflammatory activity of rose petal extract (RPE) and the mechanisms underlying this phenomenon. Recently, flowers have been considered as dietary resources owing to their biological activities, such as inhibition of nephritis and hemorrhoids. The Rosa plant exerts various biological functions, including antioxidant and anti‐microbiological activities. Herein, we confirmed the skin anti‐inflammatory activity of RPE upon solar UV (sUV) exposure. RPE reduced sUV‐induced COX‐2 expression as well as expressions of several cytokines. Activation of MKK4‐JNK, MEK‐ERK, and MKK3‐p38 signaling pathways, which are associated with cytokine production, was also attenuated by RPE treatment. We hypothesized these RPE‐induced changes are because of its antioxidant activity, because RPE displayed drastic radical scavenging and oxygen radical absorbance capacity (ORAC). Furthermore, high anthocyanins, polyphenols, and flavonoids contents were found in RPE. Hence, these results indicated the skin anti‐inflammatory activity of RPE is because of antioxidant activity.

Section: Methodsmentioning

confidence: 99%

Skin anti‐inflammatory activity of rose petal extract (Rosa gallica) through reduction of MAPK signaling pathway

Nam

Food Science & Nutrition

et al. 2018

“…The results were expressed in milligrams of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) Sigma Chemical Co. equivalent antioxidant capacity (TEAC) g -1 of the extract. We used the 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) Sigma Chemical Co. method proposed by Re et al [9], Van Den Berg et al [10] and Arts et al [11], with modifications' to determine the antioxidant activity. The results were expressed in mg of Troloxequivalent antioxidant capacity (TEAC) g -1 of extract.…”

Section: Methodsmentioning

confidence: 99%

Phenolic Acid, Flavonoids and Antioxidant Activity of Common Brown Beans (Phaseolus vulgaris L.) Before and After Cooking

Huber¹,

Brigide²,

Bretas³

et al. 2016

J Nutr Food Sci

This study aimed to evaluate the impact of thermal processing and soaking on the profiles and contents of phenolic compounds in brown beans, as well as their antioxidant activity. We evaluated the antioxidant activity of extracts and the contents of phenolic acids and flavonoids by high-performance liquid chromatography (HPLC). With the exception of chlorogenic acid, the contents of all of the other phenolic acids were increased by cooking. Kaempferol was only detected in samples treated by soaking followed by cooking. Catechin and kaempferol-3-glucoside were found in all of the brown bean extracts. Cooking, with or without soaking, caused significant increases in the concentrations of quercetin and quercetin-3-glucoside only. The effect of the heat treatment increased the antioxidant activity and the concentrations of the phenolic compounds evaluated.

“…Especially carotenoids were reported to interfere in the 515 nm-absorbance measurement of DPPH [106]. Van den Berg concludes that 'quantitative evaluation of antioxidant capacity using the ABTS/TEAC can be troublesome and even impossible, but it can be used to provide a ranking order of antioxidants' [107].…”

Section: Critical Evaluation and Comparison Of Total Antioxidant Capamentioning

confidence: 99%

Comparative Evaluation of Various Total Antioxidant Capacity Assays Applied to Phenolic Compounds with the CUPRAC Assay

et al. 2007

It would be desirable to establish and standardize methods that can measure the total antioxidant capacity level directly from vegetable extracts containing phenolics. Antioxidant capacity assays may be broadly classified as electron transfer (ET)− and hydrogen atom transfer (HAT)−based assays. The majority of HAT assays are kineticsbased, and involve a competitive reaction scheme in which antioxidant and substrate compete for peroxyl radicals thermally generated through the decomposition of azo compounds. ET−based assays measure the capacity of an antioxidant in the reduction of an oxidant, which changes colour when reduced. ET assays include the ABTS/TEAC, CUPRAC, DPPH, Folin-Ciocalteu and FRAP methods, each using different chromogenic redox reagents with different standard potentials. This review intends to offer a critical evaluation of existing antioxidant assays applied to phenolics, and reports the development by our research group of a simple and low-cost antioxidant capacity assay for dietary polyphenols, vitamins C and E, and human serum antioxidants, utilizing the copper(II)-neocuproine reagent as the chromogenic oxidizing agent, which we haved named the CUPRAC (cupric ion reducing antioxidant capacity) method. This method offers distinct advantages over other ET−based assays, namely the selection of working pH at Molecules 2007, 12 1497 physiological pH (as opposed to the Folin and FRAP methods, which work at alkaline and acidic pHs, respectively), applicability to both hydrophilic and lipophilic antioxidants (unlike Folin and DPPH), completion of the redox reactions for most common flavonoids (unlike FRAP), selective oxidation of antioxidant compounds without affecting sugars and citric acid commonly contained in foodstuffs and the capability to assay -SH bearing antioxidants (unlike FRAP). Other similar ET-based antioxidant assays that we have developed or modified for phenolics are the Fe(III)− and Ce(IV)−reducing capacity methods.