Hancornia speciosa Gomes induces hypotensive effect through inhibition of ACE and increase on NO

Ethnopharmacological relevanceThe leaves of Hancornia speciosa Gomes are popularly used in Brazil to treat diabetes and hypertension. Cardiovascular diseases are the main cause of death worldwide and their incidences are increasing in Brazilian population. The present study aimed to investigate the hypotensive effect and the mechanism of action of Hancornia speciosa Gomes.MethodsA fraction of the ethanolic extract of leaves from Hancornia speciosa (SFH) was obtained and standardized by its content on rutin, bornesitol and quinic acid. Systolic blood pressure (SBP) of normotensive mice was measured by tail pletismography. SFH was given orally and SBP was monitored for 5 h. Angiotensin-converting enzyme (ACE) inhibitor activity of SFH (1 mg/kg) or captopril (10 mg/kg) was measured by colorimetric methods. Serum nitrite levels were measured by spectrophotometry.ResultsSFH induced a dose-dependent hypotensive effect in normotensive mice. The serum activity of ACE and the level of angiotensin II were significantly reduced by SFH and by captopril. Administration of SFH induced a significant increase on plasmatic level of nitrites and the systemic inhibition of nitric oxide synthase by L-NAME (20 mg/kg) reduced the hypotensive effect of SFH.ConclusionsThe present work demonstrated that Hancornia speciosa has a potent hypotensive effect in normotensive mice. The inhibition of ACE leading to reduction on angiotensin II and increase on NO levels might account for the hypotensive effect. These results support the use of Hancornia speciosa by traditional medicine as antihypertensive.