Olmesartan inhibits transdifferentiation of rabbit’s valvular interstitial cells into myofibroblast based on α – smooth muscle actin expression

Recent studies revealed that differentiation of valvular interstitial cell (VIC) into myofibroblasts played an important role in valvular remodeling and fibrosis. Study was performed on in vitro cultured of VIC from New Zealand rabbit (Oryctolagus cuniculus). Isolated VIC was pretreated using 5 ng/mL of TGF-β1 and divided into groups of olmesartan (100 nanomol/L) as short 30 minutes exposure duration and as continuous 72 hours exposure duration. Inhibition of myofibroblast differentiation was quantified by the expression of α-SMA levels detected by immunofluorescence staining. Olmesartan administration either, as short 30 minutes exposure duration or as continuous 72 hours exposure duration, were significantly reduced TGF-β1-induced VIC differentiation into myofibroblast expressed by α-SMA levels compared to control (short 30 minutes exposure duration: 9.18 ±2.25, as continuous 72 hours exposure duration: 10.13 ±0.69, and control 22.29 ±2.78; p < 0.001), but without significant difference between the two treatment groups (p 0.403). Olmesartan both on short and continuous exposure can inhibit the differentiation of valve interstitial cells into myofibroblasts based on the expression of αSMA, but without a significant difference in the inhibitory effect.