title: Studies on the effects of oral administration of nutrient mixture, quercetin and red onions on the bioavailability of epigallocatechin gallate from green tea extract.
abstract: Epigallocatechin gallate (EGCG), a main anticancer component in green tea, has a poor bioavailability in rats and humans due to oxidation, metabolism and its efflux. It was hypothesized that nutrients that address these problems might result in increased bioavailability. Plasma concentrations of EGCG at various time intervals were determined to calculate and compare the pharmacokinetic parameters after oral administration of green tea extract (GTE) or GTE as a nutrient mixture (E) or E + quercetin (Q)/red onions. In rat studies, supplementation of GTE with other nutrients (E) or E + Q raised the plasma C(max) from 55.29 +/- 1.70 to 61.94 +/- 1.70 ng/mL and 94.44 +/- 1.59 ng/mL, respectively. The corresponding t((1/2)) elimination was 2.04 +/- 0.2 h, 3.63 +/- 0.66 h and 2.28 +/- 0.049 h. The AUC(0-24h) were 510.16 +/- 9.88 for GTE, 601.72 +/- 19.10 ng.h/mL for E and 794.08 +/- 15.27 ng x h/mL (p < or = 0.05) for E + Q. In human studies when GTE was fed as GTE or E or E + red onions, the C(max) values were 348.4 +/- 76.6, 384.0 +/- 78.5 ng/mL and 468.4 +/- 131.4. AUC(0-8h) was 1784.1 +/- 56.06 (GTE), 1971.5 +/- 566.5 ng x h/mL (E) and 2490 +/- 878.1 (E + Q), but the change in t((1/2)) elimination was not significant.In conclusion, it is possible to increase the bioavailability of EGCG by supplementing it with nutrients and quercetin.
authors: University Department of Biochemistry, R.T.M University, Nagpur, M.S. 440033, India.
authors: Anup
authors: A
authors: Kale
authors: Sonia
authors: S
authors: Gawande
authors: Swati
authors: S
authors: Kotwal
authors: Shrirang
authors: S
authors: Netke
authors: Waheed
authors: W
authors: Roomi
authors: Vadim
authors: V
authors: Ivanov
authors: Aleksandra
authors: A
authors: Niedzwiecki
authors: Matthias
authors: M
authors: Rath
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000818:Animals; D001682:Biological Availability; D002392:Catechin / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019697:Onions / Q000737:chemistry*; D010936:Plant Extracts / Q000493:pharmacokinetics*; D011794:Quercetin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013662:Tea / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D013662:Tea; D002392:Catechin; D011794:Quercetin; C045651:epigallocatechin gallate