Hypotensive effect of Eugenia dysenterica leaf extract is primarily related to its vascular action: The possible underlying mechanisms

• Autor(a) principal: Fidelis-de-Oliveira, Patrícia [UNESP]
• Data de Publicação: 2020
• Outros Autores: Aparecida-Castro, Samanta [UNESP], Silva, Denise Brentan, Morais, Ingrid Beatriz de Melo, Miranda, Victor Hugo Martins de [UNESP], de Gobbi, Juliana Irani [UNESP], Canabrava, Hudson Armando Nunes, Bispo-da-Silva, Luiz Borges
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.jep.2019.112520; http://hdl.handle.net/11449/198323
• topic: Eugenia dysenterica; Heart; Hypotension; Leaves; MALDI-TOF; Proanthocyanidins

Ethnopharmacological relevance: Eugenia dysenterica (ED) leaves are used in Brazil to treat cardiac diseases; however, there are no scientific data describing the effects of this species on cardiac activity. Aim of the study: To investigate the effect of ED aqueous leaf extract (EDLE) on hear rate (HR) and mean arterial pressure (MAP) of anaesthetised rats and its underlying mechanism of action. Material and methods: EDLE was analysed, and its proanthocyanidin composition was determined. After performing dose-effect curves for EDLE on HR and MAP, EDLE-induced hypotension was evaluated before and after atropine (AT), L-N(ω)-nitro-L-arginine methyl ester (L-NAME), hexamethonium (HXT), indomethacin (IND), carbenoxolone (CBX), or nifedipine (NFD) administration. The effect of proanthocyanidin-depleted extract (EDLE/P-) was also determined and compared to that of the EDLE with proanthocyanidins. Results: EDLE decreased the MAP in a dose-dependent manner; HR was decreased only with the highest and most toxic dose. Only CBX and NFD decreased EDLE-induced hypotension. Five polymeric series of proanthocyanidins were identified, which were mainly constituted by procyanidin and prodelphinidin units with B-type linkage and up to 12 flavan-3-ol units. EDLE/P- induced hypotension did not differ from that induced by EDLE. Conclusions: The cardiovascular effects of EDLE were primarily related to its vascular action. EDLE-induced hypotensive effect appeared to involve L-type calcium channel blockage as well as myoendothelial gap junction signalling. The higher molecular weight proanthocyanidins from EDLE are unlikely to contribute to its cardiovascular effect.