ETHNOPHARMACOLOGICAL RELEVANCE: Hypertension is a serious health problems and a leading cause of adult mortality worldwide. Foeniculum. vulgare Mill, a plant traditionally used for various ailments, including cardiovascular disorders such as hypertension. AIM OF THE STUDY: The objective of the study is to verify the vasorelaxant effect of fennel seeds on the isolated and perfused mesenteric vascular beds in rats. MATERIALS AND METHODS: The vasorelaxant effect of the aqueous extract of F. vulgare (AEFv) seeds was tested on mesenteric arteries, both intact and denuded, precontracted with phenylephrine. Extracts from liquid-liquid extraction of F. vulgare were screened to find the active fraction. The mechanism of action of the active butanolic fraction (BFFv) was studied using inhibitors like L-NAME (nitric oxide synthase inhibitor), ODQ (guanylate cyclase inhibitor), indomethacin (cyclooxygenase inhibitor), potassium channel blockers (tetraethylammonium TEA, and glibenclamide), and atropine (a muscarinic receptor antagonist). Moreover, the antioxidant properties of AEFv and BFFv were evaluated using DPPH radical scavenging, β-carotene linoleic acid, and ferric-reducing power assays
total flavonoids and phenolics of AEFv and BFFv were measured using Folin-Ciocalteu and aluminum chloride colorimetric assays
HPLC-DAD analysis and acute toxicity of BFFv in mice were also performed. RESULTS: AEFv caused a concentration-dependent vasodilatory response in intact mesenteric arteries (E CONCLUSION: Our findings support the traditional use of Foeniculum vulgare seeds for preventing cardiovascular disorders associated with vascular dysfunction, highlighting their vasorelaxant and antioxidant properties.