Korean J Anesthesiol.  2012 Oct;63(4):340-345. 10.4097/kjae.2012.63.4.340.

Polyphenol (-)-epigallocatechin gallate-induced cardioprotection may attenuate ischemia-reperfusion injury through adenosine receptor activation: a preliminary study

• Lee SK
• Kim JH
• Kim JS
• Jang Y
• Kim J
• Park YH
• Chun KJ
• Lee MY

• KMID: 1767173
• DOI: http://doi.org/10.4097/kjae.2012.63.4.340

Abstract

BACKGROUND
The activation of guanine nucleotide binding protein-coupled receptors, such as adenosine receptor (ADR) and opioid receptor (OPR), protects the heart against ischemia and reperfusion injury. We hypothesized that ADR or OPR might be involved in polyphenol (-)-epigallocatechin gallate (EGCG)-induced cardioprotection.
METHODS
Langendorff perfused rat hearts were subjected to 30 min of regional ischemia and 2 h of reperfusion. Hearts were treated with 10 microM of EGCG, with or without the ADR or OPR antagonist at early reperfusion. Infarct size measured with 2,3,5-triphenyltetrazolium chloride staining was chosen as end-point.
RESULTS
EGCG significantly reduced infarct volume as a percentage of ischemic volume (33.5 +/- 4.1%) compared to control hearts (14.4 +/- 1.1%, P < 0.001). A nonspecific ADR antagonist 8-(p-sulfophenyl) theophylline hydrate (27.1 +/- 1.9%, P < 0.05 vs. EGCG) but not a nonspecific OPR antagonist naloxone (14.3 +/- 1.3%, P > 0.05 vs. EGCG) blocked the anti-infarct effect by EGCG. The infarct reducing effect of EGCG was significantly reversed by 200 nM of the A1 ADR antagonist DPCPX (25.9 +/- 1.1%, P < 0.05) and 15 nM of the A2B ADR antagonist MRS1706 (29.3 +/- 1.7%, P < 0.01) but not by 10 microM of the A2A ADR antagonist ZM241385 (23.9 +/- 1.9%. P > 0.05 vs. EGCG) and 100 nM of the A3 ADR antagonist MRS1334 (24.1 +/- 1.8%, P > 0.05).
CONCLUSIONS
The infarct reducing effect of EGCG appears to involve activation of ADR, especially A1 and A2B ADR, but not OPR.

Keyword

Adenosine; Epigallocatechin gallate; Myocardial infarction; Reperfusion injury

MeSH Terms

Adenosine
Animals
Catechin
Guanine
Heart
Ischemia
Myocardial Infarction
Naloxone
Purines
Rats
Receptors, Opioid
Receptors, Purinergic P1
Reperfusion
Reperfusion Injury
Tetrazolium Salts
Theophylline
Triazines
Triazoles
Xanthines
Adenosine
Catechin
Guanine
Naloxone
Purines
Receptors, Opioid
Receptors, Purinergic P1
Tetrazolium Salts
Theophylline
Triazines
Triazoles
Xanthines