Citral relaxes umbilical vessels of normotensive and preeclamptic parturients

Citral is a low-toxicity monoterpene that has a vasodilator effect on various smooth muscles, and The present study aimed to evaluate its vasorelaxant effect on umbilical vessels of normotensive parturients (NTP) and with preeclampsia parturients (PEP).

Segments of human umbilical artery (HUA) and vein (HUV) of NTP or PEP were mounted in a bath to record the force of contraction, under tension of 3.0 gf and contracted with the contracting agents: K⁺ (60 mM), 5 -HT (10 μM) and Ba²⁺ (1-30 mM). Next, the effect of citral (1-3000 μM) on these contractions and on basal tone was evaluated.

In HUA and HUV, citral (1-1000 μM), in NTP condition, inhibited contractions evoked by K⁺ (IC₅₀ of 413.5 and 271.3, respectively) and by 5-HT (IC₅₀ of 164.8 and 574.3). In the PEP condition, in HUA and HUV, citral also inhibited the contractions evoked by K⁺ (IC₅₀ of 363.3 and 218.3, respectively) and 5-HT (IC₅₀ of 432.1 and 520.4). At a concentration of 1000 μM, citral completely or almost completely (>90 %) inhibited all contractions. At a concentration of 100-1000 μM, citral, in general, was already able to reduce the contraction induced by 1-3 mM Ba²⁺ in both AUH and VUH, under NTP and PEP conditions.

Citral has been shown to be an effective HUA and HUV vasodilator in NTP and PEP. As its toxicity is low, it suggests that this substance can be considered a potential therapeutic agent.