Vasorelaxant effect of monoterpene carvacrol on isolated human umbilical artery

Abstract

Carvacrol is the main compound of essential oils extracted primarily from Thymus and Origanum species. Its various biological activities were confirmed: antioxidant, anti-inflammatory, antibacterial, antifungal, anti-tumour, antinematodal and vasorelaxant action. Although vasodilation mediated by carvacrol was previously described, the exact mechanism of its action has not yet been established. Hence, the aim of this study was to investigate carvacrol vasoactivity on human umbilical arteries (HUA) and different pathways involved in its mechanism of action using tissue bath methodology. Carvacrol caused a significant decrease in vascular tension of 5-HT-pre-contracted umbilical arteries, with EC50 of 442.13 ± 33.8 µM (mean ± standard error of the mean - SEM). At 300 µM, carvacrol shifted downward the 5-HT concentration-response curve with statistical significance of p < 0.001 obtained for the four highest concentrations. At concentration of 1 mM, carvacrol completely abolished BaCl2-induced contraction in Ca2+-free Krebs-Ringer bicarbonate solution (p < 0.001). Isopentenyl pyrophosphate, the antagonist of TRPV3 channel, was able to decrease the efficacy of carvacrol (p < 0.001). The vasorelaxant effect of carvacrol seems to involve the blocking of L-type of Ca2+ channels on smooth muscle cells. However, the role of TRPV3 channels in carvacrol-induced vasodilation of HUA cannot be excluded either.

Methodological challenges in using human umbilical artery as a model for in vitro studies

“…Preparations obtained from umbilical cords serve as a tool for important research fields, such as models for in vitro study of cardiovascular diseases, including pre‐eclampsia (Medina Leyte et al., 2020 ). Moreover, in vitro searches for new substances with relaxant properties are based on the use of isolated umbilical arteries and veins (Đukanović et al., 2022 ). In addition to being an excellent model for testing the vasoactivity of substances, the advantage of the umbilical blood vessels is based primarily on their good availability and harmlessness for the patient, because the umbilical cord is treated as biological waste (Stefos et al., 2003 ).…”