Vasorelaxant property of 2-phenyl ethyl alcohol isolated from the spent floral distillate of damask rose (Rosa damascena Mill.) and its possible mechanism

J Ethnopharmacol. 2023 May 4:116603. doi: 10.1016/j.jep.2023.116603. Online ahead of print.

ABSTRACT

ETHNOBOTANICAL RELEVANCE: Rosa damascena Mill. (Rosaceae), commonly known as damask rose, is an ancient medicinal and perfumery plant used in Traditional Unani Medicine due to various therapeutic effects, including cardiovascular benefits.

AIM OF THE STUDY: This study aimed to evaluate the vasorelaxant effect of the 2-phenyl ethyl alcohol (PEA) isolated from the spent flowers of R. damascena which remain after the extraction of essential oil.

MATERIALS AND METHODS: The freshly collected flowers of R. damascena were hydro-distilled in a Clevenger’s type apparatus to extract the rose essential oil (REO). After removing the REO, the spent-flower hydro-distillate was collected and extracted with organic solvents to yield a spent-flower hydro-distillate extract (SFHE), which was further purified by column chromatography. The SFHE and its isolate were characterized by gas chromatography (GC-FID), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) techniques. The PEA, isolated from SFHE, was evaluated for vasorelaxation response in conduit blood vessels like rat aorta and resistant vessels like mesenteric artery. The preliminary screening of PEA was done in aortic preparation pre-constricted with phenylephrine. Further, a concentration-dependent relaxation response to PEA has been elicited in both endothelium-intact and endothelium-denuded arterial rings, and the mode of action was explored.

RESULTS: The SFHE revealed the presence of PEA as the main constituent (89.36%), which was further purity by column chromatography to a purity of 95.0%. The PEA exhibited potent vasorelaxation response both in conduit vessels like the rat aorta and resistance vessels like the mesenteric artery. The relaxation response is mediated without any involvement of vascular endothelium. Further, TEA sensitive BKca channel was found to be the major target for PEA-induced relaxation response in these blood vessels.

CONCLUSIONS: The spent flowers of R. damascena, which remain after the extraction of REO, could be used to extract PEA. The PEA possessed marked vasorelaxation properties in both aorta and mesenteric artery and showed promise for development into an herbal product against hypertension.

PMID:37149069 | DOI:10.1016/j.jep.2023.116603