Variations in Chemical Composition, Vasorelaxant and Angiotensin I-Converting Enzyme Inhibitory Activities of Essential Oil from Aerial Parts of Seseli pallasii Besser (Apiaceae).

The present paper describes environmental and seasonal-related chemical composition variations, vasorelaxant and angiotensin I-converting enzyme (ACE) activities of essential oil from aerial parts of Seseli pallasii Besser. The composition was analyzed by GC and GC/MS. Monoterpenes were found to be the most abundant chemical class with α-pinene (42.7 - 48.2%) as the most prevalent component. Seseli pallasi essential oil relaxed isolated endothelium-intact mesenteric arteries rings precontracted with phenylephrine with IC50  = 3.10 nl/ml (IC50  = 2.70 µg/ml). Also, S. pallasii essential oil was found to exhibit a dose-dependent ACE inhibitory activity with an IC50 value of 0.33 mg/ml. In silico evaluation of ACE inhibitory activity of the individual components showed that spathulenol exhibited the best binding affinity with ACE, and the lowest binding energy of -7.5 kcal/mol. The results suggested that combination of vasorelaxing and ACE inhibitory effects of the analyzed S. pallasii essential oil might have the potential therapeutic significance in hypertension.