Effect of epigallocatechin gallate on ischemia-reperfusion injury: an experimental study in a rat epigastric island flap

Abstract

Epigallocatechin gallate (EGCG), a polyphenol derived from green tea, is known to have potent antioxidant and anti-inflammatory properties. The aim of this study was to investigate the protective effects of EGCG against ischemia reperfusion injury in the epigastric artery island flap model in rats. The experiment was designed with two groups (control n=40, experiment n=40) of rats with epigastric artery island flaps. Each main group was randomly divided into five sub-groups to apply ischemia at different time intervals (0, 3, 6, 9 and 12 hours). Thirty minutes prior to reperfusion, 100 μmol/kg of EGCG was injected intraperitoneally, and this injection was repeated after 12 hours and continued as a daily injection. Similarly, 2 ml of sterile saline was administered to the rats in the control groups. Superoxide dismutase, glutathione peroxidase, malondialdehyde and tumor necrosis factor alpha levels, together with neutrophil counts, were measured in the tissues taken from the distal portions of the flaps 24 hours after reperfusion. Additionally, flap necrosis was examined on the seventh day after reperfusion. Superoxide dismutase levels were significantly lower in all control groups, and Malondialdehyde and Tumor Necrosis Factor Alpha levels were significantly higher in all control groups. Glutathione peroxidase levels were found to be significantly lower in the control groups after 0, 3, 9 and 12 hours of ischemia. There was no statistically significant difference between the groups undergoing 0, 3, 9 or 12 hours of ischemia with regard to the neutrophil count. Partial flap necrosis occurred in the 9-hour ischemia groups, and significantly lower rates of necrosis were observed in the experimental groups compared to the control groups. The findings of our study showed that EGCG has a protective effect against ischemia-reperfusion injury in skin flaps in the epigastric island flap model.

Keywords: EGCG; green tea; ischemia; reperfusion.

Figure 1

The time dependent changes of the SOD enzyme levels.

Figure 2

The time dependent changes of the GPX enzyme levels.

Figure 3

The time dependent changes of the TNF-α levels.

Figure 4

The time dependent changes of the MDA levels.

Figure 5

View of the 9-hour ischemic group flaps on day 7.

Figure 6

The time-dependent changes of the neutrophil counts.