Vasorelaxant Effects of the Vitex Agnus-Castus Extract

Abstract

This study was undertaken to describe and characterize the relaxing effects of the medicinal plant Vitex agnus-castus (VAC) extract on isolated rabbit arterial rings. The VAC extracts (VACE) were extracted with ethanol and tested in aorta rings (3-4 mm) of rabbits suspended in an organ bath (Krebs, 37°C, 95% O2/5% CO2) under a resting tension of 1 g to record isometric contractions. After the stabilization period (1-2 hours), contractions were induced by the addition of phenylephrine (0.5 μM) or high KCl (80 mM) and VACE was added on the plateau of the contractions. Experiments were performed to determine the effects and to get insights into the potential mechanism involved in VACE-induced relaxations. The cumulative addition of VACE (0.15–0.75 mg/mL) relaxed, in a concentration-dependent manner, the rabbit aorta rings precontracted either with phenylephrine- or with high KCl thus suggesting calcium channel blocking activities. The VACE effect appeared to be endothelium-dependent. The preincubation with L-NAME (the inhibitor of nitric oxide synthases (NOS)), ODQ (the selective inhibitor of guanylyl cyclase), and indomethacin (the cyclooxygenase inhibitor), downregulated VACE-induced relaxation of aorta rings precontracted with phenylephrine, whereas the bradykinin (stimulator of NOS) and zaprinast (phosphodiesterase inhibitor) further upregulated relaxant effects induced by VACE. These results revealed that the aorta relaxation effect of VACE was mainly endothelium-dependent and mediated by NO/cGMP and prostaglandins synthesis. This vasodilator effect of VACE may be useful to treat cardiovascular disorders, including hypertensive diseases.

The mechanisms underlying the role of Vitex agnus-castus in mastalgia

“…An increase in ERα mRNA in the hippocampus may be linked to the action of VAC extract on the protection of learning and memory defi cits. However, this may not exclude other mechanisms (1,4,5), including antioxidant, anti-infl ammatory, and other VAC characteristics, which could be implicated in the plant's benefi cial effects on learning and memory. So, more research needs to be done to fully understand how exactly the VAC extract affects cognition.…”

“…1). This medicinal plant also has other effects, such as being an antioxidant, a tracheorelaxant, a chemopreventive, a vasorelaxant, an immunomodulatory, a cytotoxic, an antimutagenic, a tumoricidal, an antimicrobial, an antifungal, an insect repellant, a larvicidal, an osteopenic, a fracture healer, an antiepileptic, an antinociceptive, opioidergic, and anti-infl ammatory activity, and preventing nonalcoholic fatty liver disease (1,4,5).…”

“…Many medicinal plants are commonly used in alternative medicine due to their curative roles reported in many disorders (4,5,28,29). Moreover, herbal medicinal products are widely considered to be compatible with our body conditions and have more effi cacy and likely fewer side effects compared with synthetic drugs.…”

“…Medicinal plants have been used for the treatment of certain diseases for a long time in human history. Thousands of plant species worldwide are reported to have medicinal properties (1)(2)(3)(4)(5). These plants are still in use as part of alternative medicine.…”

Flavonoids derived from medicinal plants as a COVID‐19 treatment

“…Moreover, in some cases, the inhibition mechanism of medicinal plants and products against SARS‐CoV‐2 replication is revealed. However, more research and clinical studies are still needed to determine the safe and therapeutic levels for each natural compound, as phytochemicals may be toxic at certain concentrations (Krasniqi et al, 2020; Thaçi et al, 2022).…”