Planta Med 2011; 77 - PM69
DOI: 10.1055/s-0031-1282827

Seaweeds: new source of MAO-A inhibiting compounds

C Grosso 1, PB Andrade 2, P Valentão 2, T Mouga 3, AK Jäger 1
  • 1Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
  • 2REQUIMTE/Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, R. Aníbal Cunha, 164, 4050–047 Porto, Portugal
  • 3GIRM – Marine Resources Research Group, School of Tourism and Maritime Technology, Polytechnic Institute of Leiria, Santuário Na. Sra. Dos Remédios, Apartado 126, 2524–909 Peniche, Portugal

The intense phytochemical study of terrestrial ecosystems, in the past decades, resulted in the identification and characterization of several new bioactive compounds. However, along the years, the scientific community became motivated to change its route of investigation into aquatic systems, which are known to possess a rich and unexplored biodiversity.

Therefore, seaweeds are now being exploited by the pharmaceutical industry. Since they have to overcome highly competitive habitats, seaweeds developed some morphological and chemical survival strategies, and these last include the biosynthesis of a wide variety of primary and secondary metabolites that shall be studied in order to assess their bioactivities.

In the present study the antidepressant capacity of 11 seaweed belonging to Rhodophyta, Phaeophyta and Chlorophyta phyla was evaluated in vitro, by the inhibition of MAO-A enzyme. Their aqueous extracts were tested, revealing five very active brown seaweeds: Cystoseira usneoides (EC50=0.084mg/mL), C. tamarascifolia (EC50=0.073mg/mL), C. nodicaulis (EC50=0.041mg/mL), Stypocaulon scoparium (EC50= 0.265mg/mL), and Fucus spiralis (EC50=0.110mg/mL). After liquid-liquid partitioning, activity was found in the ethyl acetate fractions. These fractions were further analysed by HPLC-DAD, which showed compounds absorbing at 254, 280 and 350nm. An attempt to identify these compounds by HPLC-NMR is currently in progress.

Keywords: seaweeds, MAO-A inhibition, HPLC-NMR

Acknowledgement: Clara Grosso thanks the Fundação Para a Ciência e a Tecnologia for the Post-Doc fellowship (SFRH/BPD/63922/2009)