EFFECTS OF DRACOCEPHALUM DIVERSIFOLIUM EXTRACT AND N-1 POLYPHENOL ON CALCIUM ION INFLUX IN AORTIC SMOOTH MUSCLE

Alikhon Khasanov*, Shoxista Melieva, Shahlo Ismailova, Kamila Eshbakova, Azizbek Abdullayev, Izzatullo Abdullaev, Kuvonchoy Tojiboeva, Sirojiddin Omonturdiev, Muxtorjon Mamajanov, Ulugbek Gayibov

This study investigated the effects of the ethyl acetate extract of Dracocephalum diversifolium and its main component, N-1 polyphenol, on rat aortic smooth muscle. The aim was to elucidate the vasorelaxant properties of these compounds and their interaction mechanisms with voltage-dependent Ca²⁺ channels (VDCCs). Experiments were conducted in vitro on aortic rings isolated from male Wistar rats. Aortic contractions were recorded using an isometric transducer, and depolarization was induced by 50 mM KCl solution. Dracocephalum diversifolium extract (10–130 µg/ml) and N-1 polyphenol (5–30 µM) significantly reduced aortic contraction in a concentration-dependent manner. The IC₅₀ values of the extract and N-1 polyphenol were 54.8 µg/ml and 20 µM, respectively. In Ca²⁺-free Krebs solution, KCl failed to induce contraction, whereas the addition of Ca²⁺ ions (0–2.5 mM) restored contractile responses. Under these conditions, the presence of the extract or N-1 polyphenol significantly attenuated Ca²⁺-dependent contractions compared to control. These results indicate that both compounds induce vasorelaxation by inhibiting VDCC activity and limiting Ca²⁺ influx. The findings suggest that Dracocephalum diversifolium extract and N-1 polyphenol may serve as natural Ca²⁺ channel blockers and potential antihypertensive agents.