Antihypertensive and vascular protective effects of subchronic treatment with a standardized fraction of Hancornia Speciosa Gomes
Aim: to investigate the antihypertensive and vascular protective effects of a standardized fraction from leaves of Hancornia speciosa (SFH) in hypertensive mice. Methods: Male normotensive (SHAM) and hypertensive Doca-salt (DOCA) Swiss mice were used. Systolic blood pressure (SBP) was measured by tail pletismography. SFH was given on drinking water (0.1mg/kg/day) for 35 days to SHAM and DOCA. Small mesenteric artery was used for vasodilatation experiments. Nitrite and lipid peroxidation levels were measured by spectrophotometry. Protein expression was analyzed by Western-blot and mRNA levels by real-time PCR. Results: Treatment with SFH brought SBP in DOCA to normotensive level (192±4 to 131±2mmHg; untreated and treated, respectively). Improved the endothelium-dependent vasodilation induced by acetylcholine (Emax=44.3±1.2 and 73.0±2.0%, untreated and treated, respectively). In addition, SFH also blunted the increased sensitivity to contractile agents (Emax=8.5±0.8, 4.2±0.2 and 4.1±0.4 mN/mm, in untreated, treated DOCA and SHAM mice, respectively). Treatment with SFH prevented lipid peroxidation (0.188±0.03µM and 0.044±0.01µM, in untreated and treated DOCA, respectively). Inasmuch, restored the levels of plasmatic nitrite in DOCA (19±2µM and 48±3µM, in untreated and treated, respectively) compared to SHAM (46±3µM). Levels of total eNOS and phosphorylated Ser1177 were improved in DOCA after treatment. ET-1 and pre-pro-ET-1 mRNA levels were reduced after treatment with SFH. Conclusion: SHF presents a strong antihypertensive effect at low dose accompanied by a significant protective effect in the cardiovascular system.