Daniela M Simões1, Jéssica Malheiros1, Pedro E Antunes2, Artur Figueirinha3, Maria Dulce Cotrim1, Diogo A Fonseca4. 1. Laboratory of Pharmacology and Pharmaceutical Care, Faculty of Pharmacy of University of Coimbra, University of Coimbra, Portugal; Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Portugal; CIBB Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Portugal. 2. Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Portugal; Centre of Cardiothoracic Surgery, University Hospital and Centre of Coimbra, Portugal; Clinical Academic Centre of Coimbra, CACC, Coimbra,Portugal. 3. Laboratory of Pharmacognosy, Faculty of Pharmacy of University of Coimbra, University of Coimbra, Portugal; LAQV, REQUIMTE, Faculty of Pharmacy ofUniversity of Coimbra, University of Coimbra, Portugal. 4. Laboratory of Pharmacology and Pharmaceutical Care, Faculty of Pharmacy of University of Coimbra, University of Coimbra, Portugal; Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Portugal; CIBB Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Portugal. Electronic address: diogo.fonseca@ff.uc.pt.
Abstract
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.
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.
Authors: Jéssica Malheiros; Daniela M Simões; Pedro E Antunes; Artur Figueirinha; Maria Dulce Cotrim; Diogo A Fonseca Journal: Pharmaceuticals (Basel) Date: 2022-05-22
Authors: Yannick Carlos Tcheutchoua; Danielle Claude Bilanda; Paul Désiré Djomeni Dzeufiet; Oriane Corine Djunie Neali; Pascal Emmanuel Owona; Ronald À Goufani Bidingha; Rodrigue Fifen Ngapout; Lohik Nguegan Mbolang; Michel Noubom; Théophile Dimo; Pierre Kamtchouing Journal: Evid Based Complement Alternat Med Date: 2022-03-09 Impact factor: 2.629