Abstract
This study investigated the effects of (-)-epicatechin (EC), its oligomers, dimer B2 (B2) and trimer C1 (C1), on calcium-dependent cell oxidation. Jurkat T cells were subjected to a Ca2+ mobilization challenge by replacing Na+ with K+ in the incubation media. A 249±38% increase in intracellular Ca2+ concentration ([Ca2+]i) was observed and that effect was prevented by the presence of inhibitors of Ca2+ mobilization and entrance. The pre-incubation of the cells in the presence of EC, B2 or C1 prevented K2+-mediated increase in [Ca2+]i. IC50 were 10, 24 and 196 nm for EC, B2 and C1, respectively. Cell membrane depolarization was affected by K2+, but neither inhibitors of Ca2+ mobilization nor EC, B2 or C1 modified the increase in membrane potential. An 84±7% increase in cell oxidants was observed after cell exposure to K+. This increase was prevented by the inhibition of Ca2+ mobilization, NADPH oxidase and protein kinase C, as well as by 10 nm EC, 10 nm B2 or 100 nm C1. In addition, EC and B2 (100 nm) significantly inhibited the activation of the [Ca2+]i-regulated transcription factor NFAT. These results indicate that EC and related oligomers, assayed at physiologically achievable concentrations, can modulate [Ca2+] i and then prevent cell oxidation and other Ca2+ -regulated events.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 864-872 |
| Number of pages | 9 |
| Journal | Free Radical Research |
| Volume | 42 |
| Issue number | 10 |
| DOIs | |
| State | Published - 2008 |
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Keywords
- Antioxidant
- Calcium channels
- Cocoa
- Flavanol
- Flavonoid
- Gastrointestinal tract
- Inflammation
- Membrane interactions
- Oxidation
- Procyanidin
ASJC Scopus subject areas
- Biochemistry
Cite this
(-)-Epicatechin and related procyanidins modulate intracellular calcium and prevent oxidation in Jurkat T cells. / Verstraeten, Sandra V.; Mackenzie, Gerardo; Oteiza, Patricia I.; Fraga, Cesar G.
In: Free Radical Research, Vol. 42, No. 10, 2008, p. 864-872.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - (-)-Epicatechin and related procyanidins modulate intracellular calcium and prevent oxidation in Jurkat T cells
AU - Verstraeten, Sandra V.
AU - Mackenzie, Gerardo
AU - Oteiza, Patricia I.
AU - Fraga, Cesar G.
PY - 2008
Y1 - 2008
N2 - This study investigated the effects of (-)-epicatechin (EC), its oligomers, dimer B2 (B2) and trimer C1 (C1), on calcium-dependent cell oxidation. Jurkat T cells were subjected to a Ca2+ mobilization challenge by replacing Na+ with K+ in the incubation media. A 249±38% increase in intracellular Ca2+ concentration ([Ca2+]i) was observed and that effect was prevented by the presence of inhibitors of Ca2+ mobilization and entrance. The pre-incubation of the cells in the presence of EC, B2 or C1 prevented K2+-mediated increase in [Ca2+]i. IC50 were 10, 24 and 196 nm for EC, B2 and C1, respectively. Cell membrane depolarization was affected by K2+, but neither inhibitors of Ca2+ mobilization nor EC, B2 or C1 modified the increase in membrane potential. An 84±7% increase in cell oxidants was observed after cell exposure to K+. This increase was prevented by the inhibition of Ca2+ mobilization, NADPH oxidase and protein kinase C, as well as by 10 nm EC, 10 nm B2 or 100 nm C1. In addition, EC and B2 (100 nm) significantly inhibited the activation of the [Ca2+]i-regulated transcription factor NFAT. These results indicate that EC and related oligomers, assayed at physiologically achievable concentrations, can modulate [Ca2+] i and then prevent cell oxidation and other Ca2+ -regulated events.
AB - This study investigated the effects of (-)-epicatechin (EC), its oligomers, dimer B2 (B2) and trimer C1 (C1), on calcium-dependent cell oxidation. Jurkat T cells were subjected to a Ca2+ mobilization challenge by replacing Na+ with K+ in the incubation media. A 249±38% increase in intracellular Ca2+ concentration ([Ca2+]i) was observed and that effect was prevented by the presence of inhibitors of Ca2+ mobilization and entrance. The pre-incubation of the cells in the presence of EC, B2 or C1 prevented K2+-mediated increase in [Ca2+]i. IC50 were 10, 24 and 196 nm for EC, B2 and C1, respectively. Cell membrane depolarization was affected by K2+, but neither inhibitors of Ca2+ mobilization nor EC, B2 or C1 modified the increase in membrane potential. An 84±7% increase in cell oxidants was observed after cell exposure to K+. This increase was prevented by the inhibition of Ca2+ mobilization, NADPH oxidase and protein kinase C, as well as by 10 nm EC, 10 nm B2 or 100 nm C1. In addition, EC and B2 (100 nm) significantly inhibited the activation of the [Ca2+]i-regulated transcription factor NFAT. These results indicate that EC and related oligomers, assayed at physiologically achievable concentrations, can modulate [Ca2+] i and then prevent cell oxidation and other Ca2+ -regulated events.
KW - Antioxidant
KW - Calcium channels
KW - Cocoa
KW - Flavanol
KW - Flavonoid
KW - Gastrointestinal tract
KW - Inflammation
KW - Membrane interactions
KW - Oxidation
KW - Procyanidin
UR - http://www.scopus.com/inward/record.url?scp=55849145504&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=55849145504&partnerID=8YFLogxK
U2 - 10.1080/10715760802471452
DO - 10.1080/10715760802471452
M3 - Article
VL - 42
SP - 864
EP - 872
JO - Free Radical Research
JF - Free Radical Research
SN - 1071-5762
IS - 10
ER -