Hibiscus acid from hibiscus sabdariffa (malvaceae) has a vasorelaxant effect on the rat aorta

Ahmed M. Zheoat, Alexander I. Gray, John O. Igoli, Valerie A. Ferro, Robert M. Drummond

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Hibiscus sabdariffa (Malvaceae) is a plant that is widely recognised for its antihypertensive properties; however the constituent(s) responsible for this biological activity are presently unknown. The aim of this study was to identify the potential compounds that are responsible for the vasorelaxant activity of H. sabdariffa. Thereafter, the mechanisms involved in producing the vasorelaxation were investigated. The plant was extracted consecutively with hexane, ethyl acetate and methanol. The methanolic extract was subjected to bioassay-guided fractionation in order to isolate pure compounds that possessed vasorelaxant activity. The vascular effects of the pure compounds were studied on the rat aorta in vitro using myography techniques. Hibiscus acid produced a concentration-dependent relaxation of the rat aorta pre-contracted with either phenylephrine (3 μM) or KCl (60 mM), irrespective of the presence of the endothelium. When the tissue was pre-contracted with phenylephrine, the concentration required to produce 50% relaxation (IC50), was 0.09 ± 0.01 mg/ml. Hibiscus acid had no effect on the phasic contraction induced by phenylephrine in Ca2+-free physiological solution; but it did affect the component of the contraction that is due to Ca2+ influx. In parallel studies, garcinia acid, a diastereoisomer of hibiscus acid, was found to have an almost identical vasorelaxant effect. The vasorelaxant action of both compounds is most likely due to the inhibition of Ca2+ influx via voltage-dependent Ca2+ channels.

LanguageEnglish
Pages5-13
Number of pages9
JournalFitoterapia
Volume134
Early online date25 Jan 2019
DOIs
Publication statusPublished - 30 Apr 2019

Fingerprint

Malvaceae
Hibiscus
Vasodilator Agents
Aorta
Phenylephrine
Myography
Hexanes
Vasodilation
Biological Assay
Antihypertensive Agents
Inhibitory Concentration 50
Endothelium
Blood Vessels
Methanol
hydroxycitric acid

Keywords

  • Ca channels
  • garcinia acid
  • hibiscus acid
  • hibiscus sabdariffa
  • vascular smooth muscle
  • vasorelaxation

Cite this

@article{f75a30c475f44b3cbb1303faed172523,
title = "Hibiscus acid from hibiscus sabdariffa (malvaceae) has a vasorelaxant effect on the rat aorta",
abstract = "Hibiscus sabdariffa (Malvaceae) is a plant that is widely recognised for its antihypertensive properties; however the constituent(s) responsible for this biological activity are presently unknown. The aim of this study was to identify the potential compounds that are responsible for the vasorelaxant activity of H. sabdariffa. Thereafter, the mechanisms involved in producing the vasorelaxation were investigated. The plant was extracted consecutively with hexane, ethyl acetate and methanol. The methanolic extract was subjected to bioassay-guided fractionation in order to isolate pure compounds that possessed vasorelaxant activity. The vascular effects of the pure compounds were studied on the rat aorta in vitro using myography techniques. Hibiscus acid produced a concentration-dependent relaxation of the rat aorta pre-contracted with either phenylephrine (3 μM) or KCl (60 mM), irrespective of the presence of the endothelium. When the tissue was pre-contracted with phenylephrine, the concentration required to produce 50{\%} relaxation (IC50), was 0.09 ± 0.01 mg/ml. Hibiscus acid had no effect on the phasic contraction induced by phenylephrine in Ca2+-free physiological solution; but it did affect the component of the contraction that is due to Ca2+ influx. In parallel studies, garcinia acid, a diastereoisomer of hibiscus acid, was found to have an almost identical vasorelaxant effect. The vasorelaxant action of both compounds is most likely due to the inhibition of Ca2+ influx via voltage-dependent Ca2+ channels.",
keywords = "Ca channels, garcinia acid, hibiscus acid, hibiscus sabdariffa, vascular smooth muscle, vasorelaxation",
author = "Zheoat, {Ahmed M.} and Gray, {Alexander I.} and Igoli, {John O.} and Ferro, {Valerie A.} and Drummond, {Robert M.}",
year = "2019",
month = "4",
day = "30",
doi = "10.1016/j.fitote.2019.01.012",
language = "English",
volume = "134",
pages = "5--13",
journal = "Fitoterapia",
issn = "0367-326X",

}

Hibiscus acid from hibiscus sabdariffa (malvaceae) has a vasorelaxant effect on the rat aorta. / Zheoat, Ahmed M.; Gray, Alexander I.; Igoli, John O.; Ferro, Valerie A.; Drummond, Robert M.

In: Fitoterapia, Vol. 134, 30.04.2019, p. 5-13.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Hibiscus acid from hibiscus sabdariffa (malvaceae) has a vasorelaxant effect on the rat aorta

AU - Zheoat, Ahmed M.

AU - Gray, Alexander I.

AU - Igoli, John O.

AU - Ferro, Valerie A.

AU - Drummond, Robert M.

PY - 2019/4/30

Y1 - 2019/4/30

N2 - Hibiscus sabdariffa (Malvaceae) is a plant that is widely recognised for its antihypertensive properties; however the constituent(s) responsible for this biological activity are presently unknown. The aim of this study was to identify the potential compounds that are responsible for the vasorelaxant activity of H. sabdariffa. Thereafter, the mechanisms involved in producing the vasorelaxation were investigated. The plant was extracted consecutively with hexane, ethyl acetate and methanol. The methanolic extract was subjected to bioassay-guided fractionation in order to isolate pure compounds that possessed vasorelaxant activity. The vascular effects of the pure compounds were studied on the rat aorta in vitro using myography techniques. Hibiscus acid produced a concentration-dependent relaxation of the rat aorta pre-contracted with either phenylephrine (3 μM) or KCl (60 mM), irrespective of the presence of the endothelium. When the tissue was pre-contracted with phenylephrine, the concentration required to produce 50% relaxation (IC50), was 0.09 ± 0.01 mg/ml. Hibiscus acid had no effect on the phasic contraction induced by phenylephrine in Ca2+-free physiological solution; but it did affect the component of the contraction that is due to Ca2+ influx. In parallel studies, garcinia acid, a diastereoisomer of hibiscus acid, was found to have an almost identical vasorelaxant effect. The vasorelaxant action of both compounds is most likely due to the inhibition of Ca2+ influx via voltage-dependent Ca2+ channels.

AB - Hibiscus sabdariffa (Malvaceae) is a plant that is widely recognised for its antihypertensive properties; however the constituent(s) responsible for this biological activity are presently unknown. The aim of this study was to identify the potential compounds that are responsible for the vasorelaxant activity of H. sabdariffa. Thereafter, the mechanisms involved in producing the vasorelaxation were investigated. The plant was extracted consecutively with hexane, ethyl acetate and methanol. The methanolic extract was subjected to bioassay-guided fractionation in order to isolate pure compounds that possessed vasorelaxant activity. The vascular effects of the pure compounds were studied on the rat aorta in vitro using myography techniques. Hibiscus acid produced a concentration-dependent relaxation of the rat aorta pre-contracted with either phenylephrine (3 μM) or KCl (60 mM), irrespective of the presence of the endothelium. When the tissue was pre-contracted with phenylephrine, the concentration required to produce 50% relaxation (IC50), was 0.09 ± 0.01 mg/ml. Hibiscus acid had no effect on the phasic contraction induced by phenylephrine in Ca2+-free physiological solution; but it did affect the component of the contraction that is due to Ca2+ influx. In parallel studies, garcinia acid, a diastereoisomer of hibiscus acid, was found to have an almost identical vasorelaxant effect. The vasorelaxant action of both compounds is most likely due to the inhibition of Ca2+ influx via voltage-dependent Ca2+ channels.

KW - Ca channels

KW - garcinia acid

KW - hibiscus acid

KW - hibiscus sabdariffa

KW - vascular smooth muscle

KW - vasorelaxation

UR - http://www.scopus.com/inward/record.url?scp=85060905102&partnerID=8YFLogxK

UR - https://www.sciencedirect.com/journal/fitoterapia

U2 - 10.1016/j.fitote.2019.01.012

DO - 10.1016/j.fitote.2019.01.012

M3 - Article

VL - 134

SP - 5

EP - 13

JO - Fitoterapia

T2 - Fitoterapia

JF - Fitoterapia

SN - 0367-326X

ER -