Pentacyclic triterpenoids and ceramide mediate the vasorelaxant activity of Vitex cienkowskii via involvement of NO/cGMP pathway in isolated rat aortic rings

Alain Bertrand Dongmo, Anatole Guy Blaise Azebaze, Flaure Metchi Donfack, Théophile Dimo, Pepin Alango Nkeng-Efouet, Krishna Prasad Devkota, Bruno Sontia, Hildebert Wagner, Norbert Sewald, Wolfgang Vierling

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

Ethnopharmacological relevance: Vitex cienkowskii Kotschy & Peyritsch is a deciduous tree, prescribed by Cameroonian traditional healers as one of the most popular plant widely used in many disorders including cardiovascular diseases. The preliminary pharmacological studies carried out on Vitex cienkowskii showed its vasorelaxant activities on guinea-pig aortic rings. Aim of the study: The present work evaluated the vasorelaxant activity of extract and isolated compounds from Vitex cienkowskii. Materials and methods: Rat aortic rings were used to evaluate the in vitro vascular effect of the extract. The antioxidant activity was determined by measuring the reduction of the free radical 1,1-diphenyl-1-picryl-hydrazyl (DPPH). Results: Vitex cienkowskii induced significant relaxation in a concentration- and endothelium-dependent manner (EC50 = 12.12 μg/ml, CH2Cl2-MeOH, 1:1) and did not produce a vasorelaxant effect on contraction evoked by KCl (60 mM). In order to determine its mode of action, Vitex cienkowskii-induced relaxant effect was evaluated in the presence of indomethacin (10 μM), L-NAME (100 μM), ODQ (1 μM) and SQ22356 (100 μM). Relaxation was significantly blocked by L-NAME and ODQ. These results indicate that Vitex cienkowskii-mediated relaxation is endothelium dependent, probably due to NO release, and the consequent activation of vascular smooth muscle soluble guanylate cyclase (sGC), a signal transduction enzyme that forms the second messenger cGMP. Bio-guided study of Vitex cienkowskii allowed the isolation of the known pentacyclic triterpenoids and a ceramide. It is the first report of salvin A, maslinic acid and a ceramide from Vitex cienkowskii. The activity induced by these compounds indicated that they may be partly responsible for the vasorelaxant effect of the plant extract. A dose of 40 mg/kg of CH 2Cl2-MeOH (1:1) extract administered intravenously induced a decrease of mean arterial pressure but did not affect the heart rate. Moreover the plant extracts were found to be highly active in the DPPH radical scavenging assay. Conclusion: Vitex cienkowskii extract possesses antioxidant property, vasorelaxing, and hypotensive effect linked to the endothelium related factors, where nitric oxide is involved.

Original languageEnglish
Pages (from-to)204-212
Number of pages9
JournalJournal of Ethnopharmacology
Volume133
Issue number1
DOIs
StatePublished - 7 Jan 2011

Keywords

  • Aortic smooth muscle
  • Nitric oxide
  • Pentacyclic triterpenoids
  • Relaxation
  • Vitex cienkowskii
  • cGMP

Fingerprint

Dive into the research topics of 'Pentacyclic triterpenoids and ceramide mediate the vasorelaxant activity of Vitex cienkowskii via involvement of NO/cGMP pathway in isolated rat aortic rings'. Together they form a unique fingerprint.

Cite this