Bioactive extracts of red seaweeds Pterocladiella capillacea and Osmundaria obtusiloba (Floridophyceae: Rhodophyta) with antioxidant and bacterial agglutination potential

Daniel Barroso de Alencar; Fátima Cristiane Teles de Carvalho; Rosa Helena Rebouças; Daniel Rodrigues Dos Santos; Kelma Maria Dos Santos Pires-Cavalcante; Rebeca Larangeira de Lima; Bárbara Mendes Baracho; Rayssa Mendes Bezerra; Francisco Arnaldo Viana; Regine Helena Silva Dos Fernandes Vieira; Alexandre Holanda Sampaio; Oscarina Viana de Sousa; Silvana Saker-Sampaio

doi:10.1016/j.apjtm.2016.03.015

Bioactive extracts of red seaweeds Pterocladiella capillacea and Osmundaria obtusiloba (Floridophyceae: Rhodophyta) with antioxidant and bacterial agglutination potential

Asian Pac J Trop Med. 2016 Apr;9(4):372-379. doi: 10.1016/j.apjtm.2016.03.015. Epub 2016 Mar 9.

Authors

Daniel Barroso de Alencar¹, Fátima Cristiane Teles de Carvalho², Rosa Helena Rebouças², Daniel Rodrigues Dos Santos², Kelma Maria Dos Santos Pires-Cavalcante³, Rebeca Larangeira de Lima³, Bárbara Mendes Baracho³, Rayssa Mendes Bezerra³, Francisco Arnaldo Viana⁴, Regine Helena Silva Dos Fernandes Vieira², Alexandre Holanda Sampaio³, Oscarina Viana de Sousa², Silvana Saker-Sampaio³

Affiliations

¹ Laboratório de Produtos Naturais Marinhos, Departamento de Engenharia de Pesca, Universidade Federal do Ceará, Campus do Pici, Av. Mister Hull, s/n, Caixa Postal 6043, 60455-970 Fortaleza, CE, Brazil. Electronic address: daniellpesca@gmail.com.
² Laboratório de Microbiologia Ambiental e do Pescado, Instituto de Ciências do Mar, Universidade Federal do Ceará, Av. da Abolição 3207, 60165-081, Fortaleza, CE, Brazil.
³ Laboratório de Produtos Naturais Marinhos, Departamento de Engenharia de Pesca, Universidade Federal do Ceará, Campus do Pici, Av. Mister Hull, s/n, Caixa Postal 6043, 60455-970 Fortaleza, CE, Brazil.
⁴ Laboratório de Cromatografia, Departamento de Química, Universidade do Estado do Rio Grande do Norte, Campus Universitário Central, Setor III, Rua Prof. Antônio Campos, 59633-010, Mossoró, RN, Brazil.

PMID: 27086156
DOI: 10.1016/j.apjtm.2016.03.015

Abstract

Objective: To evaluate the antioxidant, antibacterial and bacterial cell agglutination activities of the hexane (Hex) and 70% ethanol (70% EtOH) extracts of two species of red seaweeds Pterocladiella capillacea (P. capillacea) and Osmundaria obtusiloba.

Methods: In vitro antioxidant activity was determined by DPPH radical scavenging assay, ferric-reducing antioxidant power assay, ferrous ion chelating assay, β-carotene bleaching assay and total phenolic content quantification. Antimicrobial activity was tested using the method of disc diffusion on Mueller-Hinton medium. The ability of algal extracts to agglutinate bacterial cells was also tested.

Results: The 70% EtOH extract of the two algae showed the highest values of total phenolic content compared to the Hex extract. The results of DPPH for both extracts (Hex, 70% EtOH) of Osmundaria obtusiloba (43.46% and 99.47%) were higher than those of P. capillacea (33.04% and 40.81%) at a concentration of 1000 μg/mL. As for the ferrous ion chelating, there was an opposite behavior, extracts of P. capillacea had a higher activity. The extracts showed a low ferric-reducing antioxidant power, with optical density ranging from 0.054 to 0.180. Antioxidant activities of all extracts evaluated for β-carotene bleaching were above 40%. There was no antibacterial activity against bacterial strains tested. However, the extracts of both species were able to agglutinate bacterial Gram positive cells of Staphylococcus aureus and Gram negative cells of Escherichia coli, multidrug-resistant Salmonella and Vibrio harveyi.

Conclusions: This is the first report of the interaction between these algal extracts, rich in natural compounds with antioxidant potential, and Gram positive and Gram negative bacterial cells.

Keywords: Antioxidant; Bacterial agglutination; Bioactive compounds; Rhodophyta.