As depicted in Figures 2H,I, the mRNA expression levels of cardiac fibrosis markers, collagen 1A1 and collagen 3A1, were greatly elevated in the Ang II–treated group when compared to the sham saline-treated group, but loganin remarkably inhibited the elevation of COL1A1 and COL3A1 mRNA levels when compared with those in the Ang II–treated group. Here, COL1A1 is linked to fibrosis.