Effects of Resveratrol, Caffeic Acid Phenethyl Ester and Silibinin on Isolated Human Umbilical Artery

Objective: The aim of this study was to compare the vasoactive effects of resveratrol, CAPE and silibinin on the basal tone and serotonin (5-HT) induced contractile responses of isolated human umbilical arteries. Material-Method: This study was approved by the Non-Drug and Medical Device Research Ethics Committee (Decision No: 2022̸̸ 3994). In the study, umbilical cord samples separated as medical waste in the Department of Gynaecology and Obstetrics were used. The umbilical cords taken from the middle 1/3 part were brought to the laboratory in cold Krebs-Henseleit Solution (KHS). The arteries isolated from the umbilical cords were cleaned from the surrounding tissues and spirally cut into 2-3x10 mm strips. The strips were suspended in isolated tissue baths filled with 10 ml KHS continuously bubbled with a mixture of 95% O2 and 5% CO2 at 37oC. At the beginning of the experiment, the strips were stretched to an initial tension of 1.5 g and allowed to equilibrate for 60 min in KHS, which was changed every 15 min. At the end of the rest period, responses to the applied agents were recorded isometrically (Commat, Ankara, TURKEY) using a transducer (BIOPAC MP36, California USA). Effects of resveratrol, CAPE and silibinin on basal tonus in the umbilical artery strips were investigated in first group. After control contraction with 10-6 M 5-HT, the tissues were washed until resting tone was re-established. Concentration-response curves for resveratrol (10-9 M -10-4 M), CAPE (10-9 M -10-4 M) and silibinin (10-9 M -10-4 M) were obtained by cumulative addition to the organ bath. To evaluate the effects of resveratrol, CAPE and silibinin on 5-HT-induced contraction, the strips were contracted with 10-6 M 5-HT. After maximal contractile response was achieved, increasing concentrations of resveratrol (10-9 M -10-4 M), CAPE (10-9 M -10-4 M) or silibinin (10-9 M -10-4 M) were added cumulatively to the bath. Results: Resveratrol, CAPE and silibinin did not affect the basal tone of umbilical arteries. 5-HT is a potent vasoconstrictor endogenous agent in umbilical arteries. Antioxidants used in the study produced relaxation responses in arteries precontracted with 5-HT. When the sensitivity of tissues to these agents and their maximum relaxant effects were evaluated together, silibinin was found to be more effective than the others. Conclusion: The use of antioxidants for support or treatment of complications due to oxidative stress in pregnant women is being investigated. Vasoactive effects of exogenous and endogenous agents are important in the regulation of umbilical vascular tone. Resveratrol, CAPE and silibinin are polyphenol-derived natural antioxidants that have potential use in pregnant women. In our study, the vasoactive effects of these agents on umbilical arteries were investigated. Keywords: CAPE, In vitro, Resveratrol, Silibinin, Umbilical artery.