International Journal of Geriatrics · Oct 19, 2026
Study of the effects of capsaicin-mediated regulation of the TGF-β1/Smad pathway on myocardial remodeling in aged hypertensive rats
By 熊枫
OBJECTIVE: To investigate the effects of capsaicin on myocardial remodeling in aged hypertensive rats and explore its mechanism of action based on the transforming growth factor (TGF)-β1/Smad pathway. METHODS: Spontaneously hypertensive rats and Wistar-Kyoto rats were raised to 16 months of age. 12 Wistar-Kyoto rats were assigned to the normal control (Normal) group, and 60 spontaneously hypertensive rats were randomly divided into the aged hypertensive (ASH), low-dose capsaicin (Capsaicin-L), medium-dose capsaicin (Capsaicin-M), high-dose capsaicin (Capsaicin-H), and valsartan (Valsartan) groups, with 12 rats per group. The Capsaicin-L, Capsaicin-M, and Capsaicin-H groups received capsaicin by gavage at 0.05 μmol/kg, 0.10 μmol/kg, and 0.20 μmol/kg, respectively, and the Valsartan group received valsartan by gavage at 30 mg/kg, 1 time/d for 8 consecutive weeks. Tail artery systolic blood pressure was measured using a noninvasive blood pressure monitor. Left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), interventricular septal end-diastolic thickness (IVSD), left ventricular ejection fraction (LVEF), and left ventricular fractional shortening (LVFS) were measured using a small-animal ultrasound system. Enzyme-linked immunosorbent assay kits were used to measure serum TGF-β1, matrix metalloproteinase (MMP)-9, tumor necrosis factor (TNF)-α, and interleukin (IL)-6, as well as myocardial tissue malondialdehyde (MDA), superoxide dismutase (SOD), angiotensin II (AngⅡ), aldosterone (ALD), and atrial natriuretic peptide (ANP). The cardiac index and left ventricular index were measured, myocardial pathological changes were examined using hematoxylin-eosin staining, and myocardial tissue protein levels of transient receptor potential vanilloid (TRPV)1, TGF-β1, phosphorylated Smad3 (p-Smad3), Smad3, phosphorylated Smad7 (p-Smad7), and Smad7 were measured by immunoblotting. RESULTS: Capsaicin dose-dependently decreased systolic blood pressure, LVEDD, LVESD, IVSD, serum inflammatory factor levels, MDA, myocardial AngⅡ, ALD, and ANP levels, and myocardial tissue TGF-β1 and p-Smad3 levels in aged hypertensive rats (P<0.05), and increased LVEF, LVFS, SOD, and myocardial tissue TR-PV1 and p-Smad7 levels (P<0.05). CONCLUSIONS: Capsaicin can lower systolic blood pressure, improve cardiac function, alleviate myocardial inflammatory injury and oxidative stress, and inhibit myocardial remodeling in aged hypertensive rats. Its mechanism may be related to regulation of the TGF-β1/Smad pathway.