In vitro effects of prolonged exposure to quercetin and epigallocatechin gallate of the peripheral blood mononuclear cell membrane

Abstract

Abstract:The study aimed to assess biophysical changes that take place in the peripheral blood mononuclear cell (PBMC) membranes when exposed in vitro to 10 µM quercetin or epigallocatechin gallate (EGCG) for 24 and 48 h. PBMCs isolated from hypercholesterolemia patients were compared to those from normocholesterolemia subjects. The membrane fluidity and transmembrane potential were evaluated and the results were correlated with biochemical parameters relevant to oxidative stress, assessed in the patients' plasma. The baseline value of PBMC membrane anisotropy for the hypercholesterolemia patients was lower than that of the control group. These results correlated with the plasma levels of advanced glycation end products, which were significantly higher in the hypercholesterolemia group, and the total plasma antioxidant status, which was significantly higher in normocholesterolemia subjects. In the case of normocholesterolemia cells in vitro, polyphenols induced a decrease in membrane anisotropy (7.25-11.88% at 24 h, 1.82-2.26% at 48 h) and a hyperpolarizing effect (8.30-8.90% at 24 h and 4.58-13.00% at 48 h). The same effect was induced in hypercholesterolemia cells, but only after 48 h exposure to the polyphenols: the decrease in membrane anisotropy was 5.70% for quercetin and 2.33% for EGCG. After 48 h of in vitro incubation with the polyphenols, PBMCs isolated from hypercholesterolemia patients exhibited the effects that had been registered in cells from normocholesterolemia subjects after 24 h exposure. These results outlined the beneficial action of the studied polyphenols, quercetin and EGCG, as dietary supplements in normocholesterolemia and hypercholesterolemia patients.

Targeting the 4-1BB costimulatory molecule through single chain antibodies promotes the human T-cell response

“…All non-labeled CD3 + T cells were washed out from the column and collected in the tube (Fig. 1a) [29,30].…”

Assessment of the potential health benefits of certain total extracts from Vitis vinifera, Aesculus hyppocastanum and Curcuma longa

“…For cells exposed to hyperglycemia and oxidative stress, the susceptibility to lipid peroxidation in the control sample was greater compared to the one obtained with 11.11 mM glucose medium, as prevoiusly shown ( 34 ). The efficacy of the Vitis vinifera and Curcuma longa extracts was in the same range as that observed for the positive controls (quercetin, curcumin and ascorbic acid).…”

“…The Jurkat lymphocytes were grown for 24 h in RPMI-1640 (11.11 mM glucose; Sigma-Aldrich) supplemented with 10% heat-inactivated fetal calf serum at 37°C in 5% CO 2 atmosphere, in 24-well plates (2×10 5 cells/well). For diabetic conditions, the cells were plated for 24 h in glucose-rich medium (35 mM high glucose, equivalent to hyperglycemia associated with oxidative stress) ( 33 , 34 ).…”

“…DPPP is a fluorescent probe that has weak fuorescence characteristics in its basic form; however, its oxide, which can be specifically generated in reaction with hydroperoxides, has a strong fluorescence ( 34 , 35 ). Experimental lipid peroxidation of the cell membranes was induced treatment with 10 µM CuOOH, generating an effective production of reactive oxygen species in the cell membrane, which was further quantified with DPPP ( 36 ).…”

Prebiotics and probiotics in atopic dermatitis (Review)

“…Medical nutrition therapy plays an important role in modulation of the intestinal microflora. The use of 'functional food' as prebiotics, probiotics, natural antioxidant (55,56) was associated with good metabolic effects such as improving digestion and absorbtion of food ingredients and minerals, vitamin synthesis, and thereby improving overall nutritional status and health.…”