Abstract
BACKGROUND: Rheumatic heart disease (RHD) is exacerbated by chronic inflammation that stimulates the release of proinflammatory cytokines, most notably transforming growth factor-beta 1 (TGF-β1), which promotes myofibroblast differentiation. This study aims to determine the optimal dosage of Lisinopril, an angiotensin-converting enzyme inhibitor, for mitigating the fibrotic changes associated with RHD. METHODS: This in vitro, posttest-only control group study involved obtaining valvular interstitial cells from the heart valves of 25 male New Zealand rabbits (Oryctolagus cuniculus). Valvular interstitial cells were divided into 5 groups: a control group exposed to TGF-β1, and 4 experimental groups exposed to various Lisinopril doses (1 μM, 10 μM, and 100 μM) in addition to TGF-β1. The effect of Lisinopril on myofibroblast differentiation was assessed by measuring alpha-smooth muscle actin (αSMA) expression through immunocytochemical methods. Statistical significance was determined using an independent T-test with a P value of less than 0.050. RESULTS: Independent T-tests conducted on 25 male Oryctolagus cuniculus demonstrated significantly lower αSMA expression in the groups treated with various Lisinopril doses (1 μM, 10 μM, and 100 μM) compared with the TGF-β1-induced control group (P<0.050). The most significant reduction in αSMA expression was observed in the group treated with the highest Lisinopril dose of 100 μM. CONCLUSION: Lisinopril demonstrates a significant ability to inhibit TGF-β1-induced myofibroblast differentiation in rabbit valve interstitial cells, with the 100 μM dose proving most effective. These results suggest that Lisinopril may have the potential to curb RHD progression, warranting further investigations in vivo.