Thaçi Shpëtim, Krasniqi Berat, Dërmaku-Sopjani Miribane, Rifati-Nixha Arleta, Abazi Sokol, Sopjani Mentor
Faculty of Medicine, University of Prishtina, Prishtina 10000, Kosovo.
Faculty of Natural Sciences and Mathematics, University of Prishtina, Prishtina 10000, Kosovo.
Evid Based Complement Alternat Med. 2022 Mar 22;2022:7708781. doi: 10.1155/2022/7708781. eCollection 2022.
This study was undertaken to describe and characterize the relaxing effects of the medicinal plant (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% O/5% CO) 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 M) 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.
本研究旨在描述和表征药用植物（VAC）提取物对离体兔动脉环的舒张作用。VAC提取物（VACE）用乙醇提取，并在置于器官浴（Krebs液，37°C，95% O₂/5% CO₂）中的兔主动脉环（3 - 4毫米）上进行测试，静息张力为1克，记录等长收缩。在稳定期（1 - 2小时）后，通过加入去氧肾上腺素（0.5 μM）或高钾氯化钾（80 mM）诱导收缩，并在收缩平台期加入VACE。进行实验以确定其作用，并深入了解VACE诱导舒张所涉及的潜在机制。VACE（0.15 - 0.75毫克/毫升）的累积添加以浓度依赖性方式舒张了预先用去氧肾上腺素或高钾氯化钾预收缩的兔主动脉环，从而提示其具有钙通道阻断活性。VACE的作用似乎依赖于内皮。用L - NAME（一氧化氮合酶（NOS）抑制剂）、ODQ（鸟苷酸环化酶选择性抑制剂）和吲哚美辛（环氧化酶抑制剂）预孵育，下调了VACE对预先用去氧肾上腺素预收缩的主动脉环的舒张作用，而缓激肽（NOS刺激剂）和扎普司特（磷酸二酯酶抑制剂）进一步上调了VACE诱导的舒张作用。这些结果表明，VACE对主动脉的舒张作用主要依赖于内皮，由NO/cGMP和前列腺素合成介导。VACE的这种血管舒张作用可能对治疗心血管疾病，包括高血压疾病有用。
