Effect of consuming a grape seed supplement with abundant phenolic compounds on the oxidative status of healthy human volunteers

Abstract

BackgroundDiverse enzymatic and non-enzymatic antioxidants provide protection against reactive oxygen species in humans and other organisms. The nonenzymatic antioxidants include low molecular mass molecules such as plant-derived phenols.Aim of studyThis study identified the major phenolic compounds of a grape seed extract by HPLC and analyzed the effect of consumption of biscuits enriched with this extract on the urinary oxidative status of healthy subjects by measurement of urine redox potential.MethodsThe major phenolic compounds were characterized in a red grape seed extract separated by HPLC with detection by a photodiode array (PDA), fluorescence (FL) and quadrupole mass spectrometer (MS). A nutritional study in a healthy volunteers group was done. Each volunteer ate eight traditional biscuits with no red grape seed extract supplementation. The second day each volunteer ate eight traditional biscuits supplemented with 0.6 % (wt/wt) of grape seed extract. An overnight urine sample was obtained for each treatment. The redox potential was measured at 25 °C using a potentiometer in each urine sample.ResultsEpicatechin, catechin, procyanidin dimers B1 to B4, and the procyanidin trimer C2 were the major phenolic components in the extract. Epicatechin gallate and procyanidin dimers B1-3-G and B2-3′-G were the major galloylated flavan-3-ols. The forty-six healthy volunteers each shown a reduction of the urine redox potential after the treatment by traditional biscuits supplemented with the grape seed extract.ConclusionsThis simple dietary intervention significantly reduced (33 %) the urine redox potential, reflecting an overall increase in antioxidant status. Incorporation of plant-derived phenols in the diet may increase anti-oxidative status.

Evaluation of the Anti-Inflammatory Activity of Raisins (Vitis vinifera L.) in Human Gastric Epithelial Cells: A Comparative Study

“…It is reported that procyanidins, originally present in grapes, appear to be lost during raisins processing [ 1 ]. However, since procyanidins can be generally found in the seeds, TRE and TRE from seeds were the only samples that showed high levels of these compounds, in agreement with the literature [ 19 ].…”

Phenolic profile and antioxidant activity of different raisin (Vitis viniferaL.) samples

“…The high antioxidant activity of the seeds from Turkish raisins was attributed to the presence of significant amounts of flavan-3-ols, particularly procyanidins, as previously described [16]. The positive effects on human health of grapes and grape seeds extracts are mainly attributed to this class of compounds [5].…”

Procyanidin-Rich Extract from Grape Seeds as a Putative Tool against Helicobacter pylori

“…Solutions of 20 and 40 mg/mL of the freeze-dried GSE were prepared with ethanol/water (1/1, v/v ) (in quadruplicate) and were analyzed quantitatively by reversed phase high pressure liquid chromatography coupled to photo-diode array detector and mass spectrometry detector with electrospray ionization source (RP-HPLC-PAD-MS(ESI)) as previously described [ 38 ]. Methylgallate, ethylgallate, tryptophan, 3,4,5-THBA, 3,4-DHBA, trans -caftaric acid, quercetin-3- O -glucuronide, quercetin-3- O -glucoside, ellagic acid, C, EC, ECG, procyanidin dimers B 1 , B 2 , B 3 , B 4 , B 5 , trimer C 1 , tetramer [EC-(4α-8)-EC-(4α-8)-EC-(4α-8)-EC] and pentamer [EC-(4α-8)-EC-(4α-8)-EC-(4α-8)-EC-(4α-8)-EC] were identified unambiguously by co-elution and comparison with the retention time, order of elution, ultraviolet (UV) spectra, and pseudo-molecular and fragment ion masses of the corresponding purified reference substances and purified procyanidin extract from cocoa.…”