Tirang R Neyestani1, A'azam Gharavi, Ali Kalayi. 1. Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute and Faculty, Shaheed Beheshti University (M.C.), Tehran, Iran. tneyestani@nnftri.ac.ir
Abstract
BACKGROUND: The effects of black tea extract (BTE) and some of its pure phenolics on human peripheral blood mononuclear cell (PBMC) cytokine secretion were examined in vitro. MATERIALS AND METHODS: The main steps of the study included chromatographic analysis of BTE and commercial green tea extract, Polyphenon 60, determination of the total antioxidant capacity of both the extracts and their phenolics, and finally evaluation of their effects on PBMCs. FINDINGS: Four major peaks in the chromatogram of BTE belonged to caffeine, gallic acid, epigallocatechin and epigallocatechin gallate, and the latter showed the highest antioxidant capacity. While pure phenolics at the concentration of 20 mM did not significantly affect PBMC cytokine secretion, BTE and Polyphenon 60 suppressed interleukin-1 beta, tumor necrosis factor-alpha and interleukin-6. Interestingly, the secretion of interferon-gamma after 24 h was slightly, but significantly, boosted by the extracts. CONCLUSION: BTE has selective pro-inflammatory cytokine-suppressing effects on human PBMCs.
BACKGROUND: The effects of black tea extract (BTE) and some of its pure phenolics on human peripheral blood mononuclear cell (PBMC) cytokine secretion were examined in vitro. MATERIALS AND METHODS: The main steps of the study included chromatographic analysis of BTE and commercial green tea extract, Polyphenon 60, determination of the total antioxidant capacity of both the extracts and their phenolics, and finally evaluation of their effects on PBMCs. FINDINGS: Four major peaks in the chromatogram of BTE belonged to caffeine, gallic acid, epigallocatechin and epigallocatechin gallate, and the latter showed the highest antioxidant capacity. While pure phenolics at the concentration of 20 mM did not significantly affect PBMC cytokine secretion, BTE and Polyphenon 60 suppressed interleukin-1 beta, tumor necrosis factor-alpha and interleukin-6. Interestingly, the secretion of interferon-gamma after 24 h was slightly, but significantly, boosted by the extracts. CONCLUSION: BTE has selective pro-inflammatory cytokine-suppressing effects on human PBMCs.
Authors: Arpita Basu; Mei Du; Karah Sanchez; Misti J Leyva; Nancy M Betts; Steve Blevins; Mingyuan Wu; Christopher E Aston; Timothy J Lyons Journal: Nutrition Date: 2010-06-02 Impact factor: 4.008