Biomarkers of antioxidant status following ingestion of green teas at different polyphenol concentrations and antioxidant capacity in human volunteers

Abstract

In a randomized cross-over study, 15 healthy volunteers consumed 500 mL of green tea (GTFT) with different solid contents (1.4, 1.6, 1.8 and 2.0 g/L) to induce a dose-response effect on plasma antioxidant capacity. Ingestion of GTFT 2.0 g/L significantly increased plasma reducing power (ferric reducing antioxidant power, FRAP) at 1 h (+2.9%; p<0.01), 2 h (+2.5%; p<0.05) and 4 h (+3.6%; p<0.01). GTFT 1.8 g/L showed statistical significance at 1 h (+4.3%; p<0.01) and 2 h (+4.4%; p<0.01), whereas GTFT 1.6 g/L was effective only at 1 h (+2.9%; p<0.01) and GTFT 1.4 g/L did not induce any changes. The maximum peak of increase in plasma FRAP for different GTFTs was clearly correlated with in vitro FRAP (R=0.778). GTFT 2.0 g/L significantly increased plasma antioxidant potential (total radical-trapping antioxidant parameter) at 1 h (+8.4%; p<0.01), 2 h (+4.4%; p<0.05) and 4 h (+5.9%; p<0.01). The effect of GTFT 1.8 g/L was evident at 1 h (+5.2%; p<0.05) and 2 h (+4.6%; p<0.05) but not at 4 h. No changes in plasma total radical-trapping antioxidant parameter were detected for GTFT at 1.6 and 1.4 g/L. An evidence for a linear correlation between GTFT antioxidant content and the extent of the antioxidant effect in vivo has been provided.

Plasma and Dietary Antioxidant Status as Cardiovascular Disease Risk Factors: A Review of Human Studies

“…Compared to tap water and alcohol-free white wine groups, ingestion of alcohol-free red wine caused significant increases in plasma TAC values and polyphenol concentrations 50 min after ingestion [116]. Similarly, a dose-dependent manner of the acute effects of green tea ingestion on plasma TAC was demonstrated in another randomized crossover study [119]. In these studies, the increase in plasma TAC was attributed to the polyphenols present in these foods and beverages.…”

Beverage-induced enhanced bioavailability of carbamazepine and its consequent effect on antiepileptic activity and toxicity

“…It is important to mention that the solubility of CBZ is known to increase with an increase in pH, which might be a possible reason for enhanced bioavailability of CBZ when concomitantly administered with M [19,20]. Interestingly enough, the increased bioavailabilityrelated toxicity of CBZ was found to be absent with BT, which might have some relation to the in vivo antioxidant property of BT [21,22] while similar protection was found to be j o u r n a l o f f o o d a n d d r u g a n a l y s i s x x x ( 2 0 1 4 ) 1 e9 absent in M. Therefore, among the various combinations of beverages and CBZ used in this study, BT appears to be comparatively safe. Thus, from our observation, the presence of LJ or GFJ along with CBZ leads to increased bioavailability of CBZ.…”

Tea, Coffee, and Chocolate

“…Pecorari et al [15] studied biomarkers of antioxidant status in 15 healthy volunteers after each volunteer consumed 500 mL of green tea with different solid counts (1.4, 1.6, 1.8, and 2.0 g/L). They observed that after consuming green tea with a solid count of 2.0 g/L, the total radical trapping antioxidant parameter of plasma was increased by 8.4% after 1 h of consumption of green tea; even after 4 h, the plasma antioxidant potential was still increased by 5.9% compared to the baseline.…”