Hypotensive activity of Campomanesia xanthocarpa leaf extract: beyond angiotensin II type 1 receptor blockage

Abstract

The ability of Campomanesia xanthocarpa leaf extract (CXLE) to alter blood pressure and heart rate was evaluated in anesthetized rats. The CXLE-induced hypotension was evaluated before and after losartan, methylatropine, L-N(ω)-nitro-L-arginine methyl ester (L-NAME), hexamethonium, indomethacin, glibenclamide, or nifedipine administration. The constituents of CXLE were identified by LC-DAD-MS. CXLE decreased blood pressure in a dose-dependent manner; only the highest dose decreased heart rate. The hypotension induced by CXLE was sensitive only to losartan, nifedipine, and glibenclamide. L-NAME decreased the time to recover 50% of the hypotensive effect of CXLE without altering its magnitude. Flavan-3-ols, proanthocyanidins (dimers and trimers), and glycosylated flavonols were identified from CXLE. The chemical constituents of CXLE seem to induce not only angiotensin II type 1 receptor blockage, but also ATP-sensitive potassium channels activation and L-type voltage-dependent Ca²⁺ channels inactivation. Nitric oxide is involved in the maintenance of the hypotensive effect of CXLE.

Keywords:

• Cardiovascular
• potassium channels
• calcium channels
• flavan-3-ols
• proanthocyanidins
• glycosylated flavonols

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

We thank Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the undergraduate research program scholarship to IBM Morais (IC-CNPQ2014-0352) and to Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT).