Anti-Inflammatory Effect of Gallic Acid-Eluting Stent in a Porcine Coronary Restenosis Model

Background: Gallic acid (3,4,5-trihydroxybenzoic acid) is a natural polyphenol and strong natural antioxidant found abundantly in red wine and green tea. The aim of this study was to examine the anti-inflammatory effect of a novel gallic acid-eluting stent in a porcine coronary restenosis model. Methods: Fifteen pigs were randomized into three groups; in which a total of 30 coronary arteries (10 in each group) were implanted with gallic acid-eluting stents (GESs, n = 10), gallic acid and sirolimus-eluting stents (GSESs, n = 10), or sirolimus-eluting stents (SESs, n = 10). Histopathologic analysis was performed 28 days after stenting. Results: There were no significant differences in injury score and fibrin score among the groups, however there were significant differences in the internal elastic lamina (4.0±0.83mm^2 in GES vs. 3.0±0.53mm^2 in GSES vs. 4.6±1.43 mm^2 in SES, p ＜ 0.0001), lumen area (2.3±0.49 mm^2 in GES vs. 1.9±0.67 mm^2 in GSES vs. 2.9±0.56 mm^2 in SES, p ＜ 0.0001), neointimal area (1.7±0.63 mm^2 in GES vs. 1.1±0.28 mm^2 in GSES vs. 1.7±1.17 mm^2 in SES, p ＜ 0.05), and percent area of stenosis (42.4%±9.22% in GES vs. 38.2%±12.77% in GSES vs. 33.9%±15.64% in SES, p ＜ 0.05). The inflammation score was significantly lower in the GES and GSES groups compared to that in the SES group [1.0 (range: 1.0 to 2.0) in GES vs. 1.0 (range: 1.0 to 1.0) in GSES vs. 1.5 (range: 1.0 to 3.0) in SES, p ＜ 0.05]. Conclusions: The GES group had a greater percent area of stenosis than the SES group. Although gallic acid in the GES and GSES groups did not show a synergistic effect in suppressing neointimal hyperplasia, it resulted in greater inhibition of the inflammatory reaction in the porcine coronary restenosis model than in the SES group.