Vasoactivity and antioxidant properties of Microdesmis keayana roots

• Published in: Journal of ethnopharmacology Vol. 104; no. 1-2; pp. 263 - 269
• Main Authors: Zamblé, Alexis, Yao, Datté, Martin-Nizard, Françoise, Sahpaz, Sevser, Offoumou, Michel, Bordet, Régis, Duriez, Patrick, Brunet, Claude, Bailleul, François
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 08.03.2006; Elsevier
• Subjects: Animals; antihypertensive effect; Antioxidant; antioxidants; Antioxidants - isolation & purification; Antioxidants - pharmacology; Aorta - drug effects; Aorta - physiology; Biological and medical sciences; Cattle; Cells, Cultured; chemical constituents of plants; Dose-Response Relationship, Drug; Endothelial nitric oxide synthase (eNOS); enzyme activity; Erectile dysfunction; General pharmacology; Hippocampus - drug effects; Hippocampus - metabolism; Humans; Medical sciences; medicinal plants; medicinal properties; Microdesmis; Microdesmis keayana (Pandaceae); Neuroglia - drug effects; Neuroglia - metabolism; nitric oxide synthase; penis; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; plant extracts; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; Plant Roots; Plants, Medicinal; QPCR; Rabbits; Reactive oxygen species (ROS); reproductive disorders; roots; vasodilation; Vasodilation - drug effects; Vasodilation - physiology; Vasorelaxation; Microdesmis keayana (Pandaceae); Reactive oxygen species (ROS); Endothelial nitric oxide synthase (eNOS); QPCR; Erectile dysfunction; Vasorelaxation; Antioxidant; Root; Enzyme; Pharmacognosy; Pandaceae; Nitric-oxide synthase; Vasodilation; Endothelium; Medicinal plant; Vasomotricity; Dysfunction; Dicotyledones; Angiospermae; Plant origin; Spermatophyta; Oxidoreductases
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2005.09.016

Endothelial isoform of nitric oxide synthase (eNOS) mRNA expression increases in the corpora cavernosum, penile arteries and arterioles during erection. But eNOS expression and nitric oxide (NO), the product of its catalytic action, are inactivated by reactive oxygen species (ROS), especially by superoxide anion. ROS are involved in the impairment of endothelium-dependent relaxation and are responsible for some of the pathologies linked to erectile dysfunction (i.e. hypertension, atherosclerosis, etc.). While investigating Microdesmis keayana J. Léonard (Pandaceae) (syn. Microdesmis puberula Hook.f. ex. Planch.), used in African traditional medicine for erectile dysfunction, the hypotensive and the vasorelaxing properties of the aqueous extract of Microdesmis keayana (AEMK) were, respectively, tested using normotensive rabbits and aorta strips of guinea pigs in an organ bath experience. Interaction of AEMK in endothelial production of eNOS was measured by the quantitative polymerase chain reaction (QPCR) analysis. The scavenging activities versus ROS, such as superoxide anion (O2−), hydrogen peroxide (H2O2), hypochlorous acid (HOCl) and hydroxyl radical (HO) were evaluated. Action of AEMK on cellular generation of superoxide anion was also tested in a physiopathology model of oxidative burst using human polymorphonuclear neutrophils (PMNs) stimulated by phorbol myristate acetate. The results showed that Microdesmis keayana roots had significant hypotensive and vasorelaxing properties. These properties are due to both antioxidant activities and stimulation of eNOS mRNA expression. Therefore, AEMK stimulated indirectly NO production in the vascular bed.