Uterodilation effect of unripe fruit extract of Crataegus azarolus var. aronia L. on rat uterine smooth muscles

Crataegus azarolus var. aronia L. (C. aronia) is one of the most important medicinal plants used widely in folk medicine for the prevention of several diseases due to its content of several bioactive compounds like phenolic acid, aromatic amines, proanthocyanidins and flavonoids. This study investigated the uterodilation effect of methanol extract (ME) of C. aronia unripe fruit on the uterine smooth muscle in rats. The mechanism of action underlying the plant's extract was also screened. The unripe fruits were cleaned and extracted in methanol. The extract (1.9–4 mg/ml) was tested on rat uterine relaxation in calcium-free Kreb's solution and potassium chloride-induced uterine contraction. The plant extract was also studied in the presence of antagonists in separate experiments to determine the role of various ion channels and hyperpolarizing agents. The plant extract showed an uterodilation effect on the uterus, in which the ME produced a considerable relaxant effect. The results confirmed that the induced dilation was mediated mainly by the nitric oxide pathway and the activation of potassium channels with a limited role of the prostaglandin pathway and calcium channel activation. This in-vitro study provides the first scientific evidence of the claimed effect of C. aronia on uterine relaxation.