Carthamus Tinctorius L. extract attenuates cardiac remodeling in L-NAME-induced hypertensive rats by inhibiting the NADPH oxidase-mediated TGF-β1 and MMP-9 pathway.

Carthamus tinctorius L. (CT) has been widely used in Asian countries as a beverage and a folk medicine. The current study investigates the effect of CT extract on cardiac remodeling and possible mechanisms involved in Nw-nitro-l-arginine methyl ester hydrochloride (L-NAME)-induced hypertensive rats. Male Sprague-Dawley rats were administrated with L-NAME (40mg/kg/day) for five weeks to induce hypertension. Hypertensive rats were treated with CT extract (300mg/kg/day) or captopril (5mg/kg/day) or vehicle for a further two weeks. Treatment of hypertensive rats with CT extract or captopril significantly decreased systolic blood pressure, left ventricular (LV) hypertrophy and fibrosis, small intramyocardial coronary artery remodeling, and cardiac weight index. CT extract or captopril increased plasma nitric oxide metabolite (NOx) levels and reduced plasma transforming growth factor β1 (TGF-β1) level, together with downregulation of cardiac TGF-β1 and matrix metalloproteinases-9 (MMP-9) expression. In addition, decreased plasma malondialdehyde (MDA) levels, consistent with downregulation of NADPH oxidase subunit gp91phox expression in heart tissue, was also observed after CT extract or captopril treatment. These findings suggest that CT extract alleviates cardiac remodeling in L-NAME-induced hypertensive rats, which is possibly related to inhibition of the NADPH oxidase-mediated TGF-β1-MMP-9 pathway.