Planta Med 2014; 80 - P1N11
DOI: 10.1055/s-0034-1394601

Investigation of Azorean macroalgae for angiotensin I-converting enzyme (ACE) inhibitory peptides. Extraction, purification and antihypertensive activity evaluation

L Paiva 1, 3, 4, 5, E Lima 1, 2, 3, AI Neto 3, 4, 5, J Baptista 1, 2, 3
  • 1Departamento de Ciências Tecnológicas e Desenvolvimento (DCTD), Universidade dos Açores, 9501 – 801 Ponta Delgada, S. Miguel, Açores, Portugal
  • 2Centro de Investigação em Tecnologias Agrárias dos Açores (CITA-A), Universidade dos Açores, 9700 – 071 Angra do Heroísmo, Terceira, Açores, Portugal
  • 3Centro de Investigação de Recursos Naturais (CIRN), Departamento de Biologia, Universidade dos Açores, 9501 – 801 Ponta Delgada, S. Miguel, Açores, Portugal
  • 4Grupo Biologia Marinha, Departamento de Biologia, Universidade dos Açores, 9501 – 801 Ponta Delgada, S. Miguel, Açores, Portugal
  • 5Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas 289, 4050 – 123 Porto, Portugal

Recently, much attention has been paid to the potential of marine organism constituents for the treatment of hypertension. Hypertension is one of the major independent risk factors for cardiovascular diseases and is estimated to affect about 25% of the world's adult population [1]. It is well known that the angiotensin I-converting enzyme (ACE) plays an important role in the regulation of blood pressure [2] by converting angiotensin I to angiotensin II, a potent vasoconstrictor. Generally, ACE synthetic inhibitors cause a number of undesirable side effects. For this reason, there is a trend towards searching for natural ACE inhibitors as alternatives to synthetic drugs. Taking into consideration the low level of pollution in Azorean seawater [3], this present study aims to contribute to: (i) the investigation of twelve Azorean marine macroalgae by the determination, for the first time, of their in vitro ACE inhibitory properties, (ii) the discovery of novel marine ACE inhibitory peptides with potential impact on the hypertensive patients. This investigation was carried out by optimizing the protein enzymatic hydrolysis followed by the peptides purification and ACE inhibitory evaluation. The results show that half of the selected marine macroalgae: Pterocladiella capillacea, Porphyra sp., Fucus spiralis, Ulva compressa, Osmundea pinnatifida and Ulva rigida presented an ACE inhibition activity of 48.73%, 50.96%, 56.77%, 59.80%, 62.59% and 65.68%, respectively, using pepsin followed by bromelain hydrolysis. The U. rigida (UV) was further purified by size exclusion and reverse-phase C18 chromatography showing four fractions: UV1, UV2, UV3 and UV4 with 2.37%, 32.40%, 64.25% and 31.28% of ACE inhibition activity, respectively. The isolated novel peptides will consequently have impact on public health, particularly on the hypertensive patients, in the regional economy and also will provide an incentive for the marine diversity [4] conservation.

Keywords: ACE inhibitory activity, angiotensin I and II, HPLC, peptides, blood pressure, enzymes

References:

[1] Mittal, B.V., Singh, A.K. Am J Kidney Dis 2010; 55: 590 – 8

[2] Rosenthal, J. Steroids 1993; 58: 566 – 572

[3] Neto, A.I. et al. Qualidade de águas costeiras do Grupo Oriental do arquipélago dos Açores e proposta de monitorização. Departamento de Biologia: Universidade dos Açores; 2009.

[4] Neto, A.I. et al. Flora Marinha do Litoral dos Açores. Rocky shore marine flora of the Azores. Secretaria Regional do Ambiente e do Mar: Horta; 2006.