Carthamus Tinctorius L. extract attenuates cardiac remodeling in L-NAME-induced hypertensive rats by inhibiting the NADPH oxidase-mediated TGF-ß1 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 ß1 (TGF-ß1) level, together with downregulation of cardiac TGF-ß1 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-ß1-MMP-9 pathway.

Garcinia mangostana pericarp extract protects against oxidative stress and cardiovascular remodeling via suppression of p47phox and iNOS in nitric oxide deficient rats.

Nω-Nitro-l-arginine methyl ester (l-NAME)-induced hypertension and cardiovascular remodeling are associated with oxidative stress and inflammation. Garcinia mangostana Linn., has been reported to have antioxidant and anti-inflammatory properties. This study investigated whether G. mangostana pericarp extract (GME) could prevent l-NAME-induced hemodynamic alterations, cardiovascular remodeling, oxidative stress and inflammation in rats. Male Sprague-Dawley rats were given 40mg/kg/day of l-NAME in drinking water to induce hypertension, and were simultaneously treated with GME at a dose of 200mg/kg/day. Rats that received l-NAME for five weeks had high blood pressure, left ventricular hypertrophy and thickening of aortic wall. Vascular superoxide production, plasma malondialdehyde (MDA), and plasma tumor necrosis factor alpha (TNF-α) were significantly increased in l-NAME-hypertensive rats (p<0.05). This was consistent with up-regulation of the p47phox NADPH oxidase subunit and iNOS protein expression in aortic tissues (p<0.05). Low levels of plasma nitric oxide metabolites were observed in l-NAME hypertension. GME prevented the development of hypertension and cardiovascular remodeling induced by l-NAME with reduced oxidative stress and inflammation. These data suggest that GME had a protective effect against l-NAME-induced hypertension and cardiovascular remodeling via suppressing p47phox NADPH oxidase subunit and iNOS protein expression resulting in enhancing NO bioavailability.

Ellagic Acid Prevents L-NAME-Induced Hypertension via Restoration of eNOS and p47phox Expression in Rats.

The effect of ellagic acid on oxidative stress and hypertension induced by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) was investigated. Male Sprague-Dawley rats were administrated with L-NAME (40 mg/kg/day) for five weeks. L-NAME induced high systolic blood pressure (SBP) and increased heart rate (HR), hindlimb vascular resistance (HVR) and oxidative stress. Concurrent treatment with ellagic acid (7.5 or 15 mg/kg) prevented these alterations. Co-treatment with ellagic acid was associated with up-regulation of endothelial nitric oxide synthase (eNOS) protein production and alleviation of oxidative stress as indicated by decreased superoxide production in the vascular tissue, reduced plasma malondialdehyde levels, reduced NADPH oxidase subunit p47phox expression and increased plasma nitrate/nitrite levels. Our results indicate that ellagic acid attenuates hypertension by reducing NADPH oxidase subunit p47phox expression, which prevents oxidative stress and restores NO bioavailability.