Rapid determination of simple polyphenols in grapes by HPLC using a monolithic column

The development of a rapid, reliable and reproducible LC method for the determination and quantification of 13 polyphenols (gallic acid, protocatechuic aldehyde, gentisic acid, catechin, vanillinic acid, caffeic acid, vanillin, epicatechin, syringaldehyde, p-coumaric acid, ferulic acid, sinapic acid and resveratrol) in grapes and derived products is reported

Caspase Inhibitor Diminishes Caffeic Acid-induced Apoptosis in Osteosarcoma Cells

BACKGROUND: Caffeic acid has been shown to induce apoptosis in MG63 osteosarcoma cells. Along with the apoptotic induction, caffeic acid was shown to activate caspase-8, -9 and -3. However, the role of caspase in mediating caffeic acid-induced apoptosis in MG63 cells are not clear yet. In this study, caspase role was further investigated by inhibiting caspase activity in the caffeic acid-induced apoptosis system in the MG63 cells.METHODS: MG63 cells were cultured, starved, pretreated with/without Z-VAD FMK and treated with/without 10 µg/mL caffeic acid. To quantify the number of apoptotic MG63 cells, Sub-G1 method was performed. The caffeic acid-induced apoptotic morphology was confirmed with 4',6-diamidino-2-phenylindole (DAPI) staining and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Meanwhile, to detect apoptotic underlying mechanism, immunoblotting was performed to detect caspase-8, -9 and -3.RESULTS: MG63 cells were significantly induced into apoptosis with the treatment of 10 µg/mL caffeic acid for 48 hours. However, pretreatment of 100 µM Z-VAD-FMK, a pan caspase inhibitor, for 2 hours, the percentage of apoptotic MG63 cells was significantly diminished. The apoptotic phenomenon induced by caffeic acid as well as the inhibition of Z-VAD-FMK were confirmed by DAPI staining and TUNEL assay. Cleaved caspase-8, -9 and -3 were formed markedly upon the treatment of caffeic acid. Pretreatment of 100 µM Z-VAD-FMK could inhibit the cleaved caspase-8, -9 and -3.CONCLUSION: Taken together, caffeic acid has the potential to induce apoptosis in MG63 cells, specifically through the caspase signaling pathway

Effects of caffeic acid and bovine serum albumin in reducing the rate of development of rancidity in oil-in-water and water-in-oil emulsions

The antioxidant properties of caffeic acid and bovine serum albumin in oil-in-water and water-in-oil emulsions were studied. Caffeic acid (5 mmol/kg emulsion) showed good antioxidant properties in both 30% sunflower oil-in-water (OW) and 20% water-in-sunflower oil emulsions (WO), pH 5.4, during storage at 50 ºC. Although bovine serum albumin (BSA) (0.2%) had a slight antioxidant effect, the combination of caffeic acid and BSA showed a synergistic reduction in the rate of development of rancidity, with significant reductions in concentration of total volatiles, peroxide value (PV) and p-anisidine value (PA) for both emulsion types. The synergistic increase in stability of the OW and WO emulsions containing BSA and caffeic acid was 102.9 and 50.4 % respectively based on TOTOX values, which are calculated as 2PV + PA, with greater synergy calculated if based on formation of headspace volatiles, The OW emulsion was more susceptible to the development of headspace volatiles by oxidation than the WO emulsion, even though the degree of oxidation assessed by the TOTOX value was similar

Water extract of Cryphaea heteromalla (Hedw.) D. Mohr bryophyte as a natural powerful source of biologically active compounds

Bryophytes comprise of the mosses, liverworts, and hornworts. Cryphaea heteromalla, (Hedw.) D. Mohr, is a non-vascular lower plant belonging to mosses group. To the date, the most chemically characterized species belong to the liverworts, while only 3.2% and 8.8% of the species belonging to the mosses and hornworts, respectively, have been investigated. In this work, we present Folin–Ciocalteu and oxygen radical absorbance capacity (ORAC) data related to crude extracts of C. heteromalla obtained by three different extraction solvents: pure water (WT), methanol:water (80:20 v/v) (MET), and ethanol:water (80:20 v/v) (ETH). The water extract proved to be the best solvent showing the highest content of biophenols and the highest ORAC value. The C. heteromalla-WT extract was investigated by HPLC-TOF/MS (High Performance Liquid Chromatography-Time of Flight/Mass Spectrometry) allowing for the detection of 14 compounds, five of which were phenolic compounds, derivatives of benzoic, caffeic, and coumaric acids. Moreover, the C. heteromalla WT extract showed a protective effect against reactive oxygen species (ROS) generation induced by tert-butyl hydroperoxide (TBH) on the murine NIH-3T3 fibroblast cell line

Screening the effect of four ultrasound-assisted extraction parameters on hesperidin and phenolic acid content of aqueous citrus pomace extracts

Polyphenols of citrus by-products, due to their antioxidant and antimicrobial activities, could be valorized by pharmaceutical and food industries, adding a value to the citrus processing companies. A number of studies have investigated the effect of ultrasound-assisted extraction (UAE) conditions on the recovery of phenolics derived from citrus waste using both organic solvents or mixed aqueous solvent systems. To maximize efficiency, UAE conditions should be tailored to the physical parameters of the solvent(s) employed. The aim of this study was to investigate the effect of four UAE parameters: particle size (1.40–2.80 mm), extraction time (10–60 min), extraction temperature (23–50 °C) and ultrasonic power (150–250 W) on the simultaneous recovery of p-coumaric acid, caffeic acid, chlorogenic acid, and hesperidin from citrus waste using pure water as a solvent. High-performance liquid chromatography (HPLC) was employed for the identification and quantification of the cited compounds. Particle size was determined to be an important parameter affecting compound recovery, with the exception of chlorogenic acid. A particle size of 1.40 mm resulted in the highest recovery of p-coumaric and caffeic acids (0.25 and 0.58 mg/g, respectively), while higher hesperidin yields were achieved from the particle sizes of 2.00 and 1.40 mm (6.44 and 6.27 mg/g, respectively). Extraction temperature significantly affected only the recovery of the flavanone glycoside (P<0.05). As the extraction temperature increased from 30 to 50 °C the recovery of hesperidin increased from 6.59 to 7.84 mg/g, respectively. Neither extraction time nor ultrasonic power significantly affected the recovery of any individual phenolic compound

THE INHIBITORY EFFECT OF PROPOLIS AND CAFFEIC ACID PHENETHYLESTER ON CYCLOOXYGENASE ACTIVITY IN J774 MACROPHAGES.

The effect of an ethanolic extract of propolis, with and without CAPE, and some of its components on cyclooxygenase (COX-1 and COX-2) activity in J774 macrophages has been investigated. COX-1 and COX-2 activity, measaured as prostaglandin E-2 (PGE(2)) production, were concentration-dependently inhibited by propolis (C x 10(-3)-3 x 10(2) mugml(-1)) with an IC50 of 2.7 mugml(-1) and 4.8 x 10(-2) mugml(-1), respectively. Among the compounds tested pinocembrin and caffeic, ferulic, cinnamic and chlorogenic acids did not affect the activity of COX isoforms. Conversely, CAPE (2.8 x 10(-4)-28 mugml(-1); 10(-9)-10(-4) M) and galangin (2.7 x 10(-4)-27 mugml(-1); 10(-9)-10(-4) M) were effective, the last being about ten-twenty times less potent. In fact the IC50 of CAPE for COX-1 and COX-2 were 4.4 x 10(-1) mugml(-1) (1.5 x 10(-6) M) and 2 x 10(-3) mugml(-1) (6.3 x 10(-9) M), respectively. The IC50 of galangin were 3.7 mugml(-1) (15 x 10(-6) M) and 3 x 10(-2) mugml(-1) (120 x 10(-1) M), for COX-1 and COX-2 respectively. To better investigate the role of CAPE, we tested the action of the ethanolic extract of propolis deprived of CAPE, which resulted about ten times less potent than the extract with CAPE in the inhibition of both COX-1 and COX-2, with an IC50 of 30 mugml(-1) and 5.3 x 10(-1) mugml(-1), respectively. Moreover the comparison of the inhibition curves showed a significant difference (p < 0.001). These results suggest that both CAPE and galangin contribute to the overall activity of propolis, CAPE being more effective

Biotransformation of caffeoyl quinic acids from green coffee extracts by Lactobacillus johnsonii NCC 533

Acknowledgements The authors are grateful to Nicole Page-Zoerkler and Olivier Mauroux for their technical assistant. We thank David Pridmore and Kimo Makkinen for critical reading of this manuscript.Peer reviewedPublisher PD

Testing caffeic acid as a natural antioxidant in functional fish-fibre restructured products

7 páginas, 4 figuras, 5 tablasThe antioxidant effectiveness of caffeic acid addition to minced fish muscle with or without wheat dietary fibre added was studied. Wheat dietary fibre showed a significant prooxidant effect on minced fish muscle during chilled storage that was significantly inhibited in presence of 100 mg/kg caffeic acid. In samples containing caffeic acid and wheat dietary fibre, lipid oxidation was completely inhibited after 10 days. Results obtained from the instrumental texture profile analysis showed that the inclusion of wheat dietary fibre with or without caffeic acid lowered the texture profile analysis parameters. Caffeic acid did not render any changes on the water binding capacity. These results prove that caffeic acid can be successfully used as a natural antioxidant in wheat dietary fibre minced fish restructured products.This work was performed within the Integrated Research Project SEAFOODplus, contract No FOOD-CT-2004-506359 and the research project AGL2006-26016-E/GAN. The [partial] financing of this work by the European Union and the Spanish Ministerio de Educación y Ciencia is gratefully acknowledged.Peer reviewe

Phenolic content of Hypodaphnis Zenkeri and its antioxidant effects against fenton reactions’ mediated oxidative injuries on liver homogenate

Under oxidative stress conditions, endogenous antioxidant defenses are unable to completely inactivate the free radicals generated by an excessive production of reactive oxygen species (ROS). This state causes serious cell damage leading to a variety of human diseases. Natural antioxidants can protect cells against oxidative stress. Hypaodaphnis zenkeri (H. zenkiri) is a plant consumed as a spice in the Cameroonian diet, and its bark has been used in traditional medicine for the treatment of several diseases. The present study aims at investigating the antioxidant activity, which includes free radical scavenging and protective properties of an extract from H. Zenkiri against oxidative damage on a liver homogenate. The free radical assays determined the scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl (OH), nitrite oxide (NO) and 2,2-azinobis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radicals and the enzymes, whose protection was to be considered in the liver homogenate, including superoxide dismutase, catalase, and peroxidase. The antioxidative activities were studied using the ferric reducing antioxidant power (FRAP), reductive activity, and phosphomolybdenum antioxidant power (PAP) methods. In addition, the phenolic contents of the extracts were examined. The results showed that these extracts demonstrated significant scavenging properties and antioxidant activities, with the hydro-ethanolic extract of the bark of H. zenkeri (EEH) being the most potent. This extract had the highest total polyphenol (21.77 ± 0.05 mg caffeic acid (CAE)/g dried extract (DE)) and flavonoids (3.34 ± 0.13 mg quercetin (QE)/g dried extract) content. The same extract had significantly greater protective effects on enzyme activities compared to other extracts. The high performance liquied chromatography (HPLC) profile showed higher levels of caffeic acid, OH-tyrosol acid, and rutin in the leaves compared to the bark of H. zenkeri. In conclusion, the ethanolic and hydro-ethanolic extracts of the bark and leaves from H. zenkeri showed an antioxidant and protective potential against oxidative damage

A study of the antioxidant capacity of oak wood used in wine ageing and the correlation with polyphenol composition

The antioxidant capacity of oak wood used in the ageing of wine was studied by four different methods: measurement of scavenging capacity against a given radical (ABTS, DPPH), oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP). Although, the four methods tested gave comparable results for the antioxidant capacity measured in oak wood extracts, the ORAC method gave results with some differences from the other methods. Non-toasted oak wood samples displayed more antioxidant power than toasted ones due to differences in the polyphenol compositon. A correlation analysis revealed that ellagitannins were the compounds mainly responsible for the antioxidant capacity of oak wood. Some phenolic acids, mainly gallic acid, also showed a significant correlation with antioxidant capacity