SMAD2 and fibrosis: To our surprise, we did not observe obvious inhibition of cardiac fibroblast trans-differentiation via direct treatment of curcumin with NRCF, and phosphorylated SMAD2/3 levels were found to be equal in the presence or absence of curcumin in NRCF, indicating that curcumin only inhibited cardiac fibrosis through macrophages in our study.