Vascular effects of Fragaria vesca L. in human arteries.

Fragaria vesca L. (wild strawberry) is traditionally used for its anti-inflammatory activity and for gastrointestinal, cardiovascular and urinary disorders. A previous study with the rat aorta showed that its leaves extract elicits endothelium-dependent vasorelaxation. Our aim was to investigate the clinical application of Fragaria vesca in vascular disease, by assessing the vascular effects of an infusion and hydroalcoholic extract in internal thoracic arteries from patients with coronary artery disease. The extracts elicited no effects on basal vascular tone and did not induce any vasorelaxation. At low concentration (0.02 mg/mL), the infusion potentiated the noradrenaline-induced contraction, while the other concentrations did not elicit significant changes in efficacy or potency. Differences between our findings and the previous report on rat aorta may result from methodological differences, e.g. vascular bed, method of extraction and extract composition. The clinical applicability of extracts of Fragaria vesca in patients with cardiovascular disease remains to be fully validated.

Agrimonia eupatoria L.: An integrative perspective on ethnomedicinal use, phenolic composition and pharmacological activity.

ETHNOPHARMACOLOGICAL RELEVANCE: Agrimonia eupatoria L., a plant which belongs to the Rosaceae family, is widespread in temperate regions, particularly throughout the northern hemisphere. In folk medicine, this plant species has been used for its astringent, anti-inflammatory, analgesic and hypotensive properties as well as in gastrointestinal disorders. As these biological properties have been linked to its phenolic composition, this plant species could be an interesting source of bioactive compounds with therapeutic potential. AIM OF THE STUDY: The aim of the present review is to provide a comprehensive overview of the scientific literature on A. eupatoria, particularly in regard to its ethnobotanics and ethnomedicinal uses, phenolic composition and biological and pharmacological activities. MATERIAL AND METHODS: Literature was retrieved from several bibliographic sources, namely PubMed, ScienceDirect and Google Scholar, since the first report on A. eupatoria in 1993. RESULTS: Regarding the phytochemical composition, A. eupatoria is rich in phenolic acids, flavonoids and tannins. The most commonly reported compounds are astragalin, cynaroside, hyperoside, isoquercitrin, isovitexin, rutin, catechin, procyanidin B3 and agrimoniin. In terms of bioactivity, extracts or fractions obtained from this plant species have shown antioxidant, antimicrobial, antidiabetic, antinociceptive and anti-inflammatory properties, among others. So far, two clinical studies with the infusion of A. eupatoria have shown hepatoprotective properties as well as a protective role in cardiovascular disease, metabolic disorders and diabetes. CONCLUSIONS: In this review, an integrative perspective on ethnomedicinal use, phenolic composition and pharmacological activity of A. eupatoria has been provided. As can be seen, this plant species exhibits several potential applications, including those beyond its traditional ethnomedicinal uses, as the safety of its consumption has been shown clinically. There still is limited pharmacological evidence that corroborates the ethnomedicinal uses of this plant species as well as regarding the specific bioactive compounds.

Vascular Effects of Polyphenols from Agrimonia eupatoria L. and Role of Isoquercitrin in Its Vasorelaxant Potential in Human Arteries.

Agrimonia eupatoria L. has been traditionally used for the treatment of inflammatory diseases but also as a hypotensive. To our knowledge, only one study has previously suggested an improvement in vascular endothelial function in diabetic conditions, as the underlying mechanisms and responsible compounds are unknown. In this study, we aimed to assess the direct vascular effects of Agrimonia eupatoria L. in human arteries. The infusion elicited a mild increase in basal vascular tone and a significant potentiation of the adrenergic contraction of 49.18% at 0.02 mg/mL, suggesting the presence of compounds with mild vasoconstrictor activity. In contrast, the ethyl acetate fraction inhibited adrenergic contraction by 80.65% at 2 mg/mL and elicited no effect on basal vascular tone. A potent concentration-dependent vasorelaxation was observed for both the infusion and the ethyl acetate fraction (maximal relaxation above 76% and 47%, respectively). Inhibition of nitric oxide synthase and cyclooxygenase elicited significant decreases in the vasorelaxation to the infusion, as, for the ethyl acetate fraction, only the cyclooxygenase pathway appeared to be involved. Isoquercitrin elicited a vasoactivity consistent with the ethyl acetate fraction, suggesting this is a major component responsible for the vasorelaxant properties of A. eupatoria. Further research is warranted to fully evaluate its vasoprotective properties with therapeutic potential in several conditions, e.g., atherosclerosis.

Vascular activity of infusion and fractions of Cymbopogon citratus (DC) Stapf. in human arteries.

ETHNOPHARMACOLOGICAL RELEVANCE: Cymbopogon citratus (DC.) Stapf has been traditionally used mainly for inflammatory diseases and hypertension. However, the mechanisms underlying its vascular activity remain to be fully characterized and the fractions responsible for its cardiovascular activity are still unknown. AIM OF THE STUDY: In this study, we aimed to assess the vascular activity of Cymbopogon citratus in human arteries and to study the role of cyclooxygenase in its vasorelaxant effects. MATERIALS AND METHODS: Vascular effects of leaves infusion and three fractions (phenolic acids, flavonoids and tannins) were studied using distal segments of human internal thoracic arteries harvested from patients undergoing coronary revascularization, which were mounted as rings in tissue organ baths and maintained at 37 °C in Krebs Henseleit buffer. The effect on basal vascular tone, the effect on the noradrenaline-induced contraction and the vasorelaxant effects were assessed. The role of cyclooxygenase was evaluated with indomethacin. RESULTS: Our results showed a mild effect on the basal vessel tone of the infusion. A significant inhibition on the adrenergic-mediated vasoconstriction was observed for the infusion (0.0002 mg/mL) and the flavonoid fraction (0.2 mg/mL), despite a potentiation was observed in some conditions. A vasorelaxant effect was observed for both the infusion (6.46% of maximal relaxation) and the tannin fraction (26.91% of maximal relaxation, P < 0.05 vs. infusion). Incubation with indomethacin (10 µM) elicited a decrease in the vasorelaxation to the infusion (P < 0.05). CONCLUSIONS: These results suggest that cyclooxygenase may be involved in the vasorelaxation to the infusion of Cymbopogon citratus and that tannins are the compound fraction mainly responsible for this vasorelaxation.