Abstract:Aim To examine the effect of epigallocatechin-3-gallate(EGCG) on intimal hyperplasia in a vein graft model by local delivery. Methods Rabbit jugular vein segments were incubated in saline containing EGCG 0.1 g/L.HPLC and FITC-labelled EGCG were used to assess the absorption characteristics of EGCG in vitro.Autogenous vein graft model was established in 20 rabbits which were randomly divided into two groups: EGCG group and control group.Vein grafts were incubated with EGCG or saline before arterial interposition grafting(n=10).Animals were sacrificed 21 days later and intimal thickening(intimal thickness and intimalto-medial ratio,I and I/M) was assessed by computerized digital morphometry.The proliferation and apoptosis of neointimal cells were determined by Ki67 staining and terminal deoxynucleotidyl transferase biotin nick end-labeling(TUNEL) method,respectively. Results At dose of 0.1 mg/L,the vein segments showed evidence of EGCG localization,EGCG was absorbed at levels of 2.9±0.9 mg/g,5.8±2.1 mg/g and 8.0±2.3 mg/g after incubation for 1 h,2 h and 4 h,respectively.All animals survived until the time of harvest,and there was 1 closed case respectively in two study groups.The EGCG group showed a significant reduction in neointimal formation at 21 days compared with the control condition(41.1±13.6 μm vs 89.9±48.3 μm,p<0.01 and 0.40±0.18 vs 0.77±0.31,p<0.05).Immunohistochemical analysis of Ki67 also indicated decreased rate of positive smooth muscle cells in the EGCG group(22.4%±8.6% vs 8.8%±(2.4%),p<0.05).Cell apoptosis was not different in two groups(0.40%±0.55% vs 0.60%±0.89%,p>0.05). Conclusions These results indicate that the local delivery of EGCG prevent intimal hyperplasia in a rabbit vein bypass grafting model through inhibition of neointimal smooth muscle cells proliferation.