Host-defense peptides AC12, DK16 and RC11 with immunomodulatory activity isolated from Hypsiboas raniceps skin secretion


Inflammation is a natural defense mechanism of the immune system; however, when unregulated, it can lead to chronic illness. Glucocorticoids are the most commonly used agents to effectively treat inflammatory conditions, including autoimmune diseases, however these substances can trigger a number of side effects. Thus, viable alternatives to the use of these drugs would be advantageous. In this study, we have analyzed the anti-inflammatory profile of three synthetic peptides first identified in skin secretion of the tree frog Hypsiboas raniceps. Structural characterization was performed using NMR spectroscopy and Mass Spectrometry, and the peptides were tested in vitro in RAW 264.7 cells and in vivo in Balb/c mice for their functional properties. The samples did not show a significant antimicrobial profile. NMR spectroscopy indicated that AC12 (ACFLTRLGTYVC) has a disulfide bond between C2 and C11 and a beta-sheet-turn-beta-sheet conformation in aqueous solution. This peptide showed no cytotoxic effect in mammalian cells and it was the most effective in reducing anti-inflammatory markers, such as NO, TNF-alpha and IL-12. Peptide DK16 (DKERPICSNTFRGRKC) demonstrated anti-inflammatory properties in vitro, while RC11 (RCFRRRGKLTC) significantly altered the cell viability in RAW 264.7 but was shown to be safe in Balb/c erythrocytes. Our results indicate that, of the three peptides studied, AC12 is the most efficient in reducing anti-inflammatory markers, and it could be a potential agent for the treatment of inflammatory diseases.




Biochemistry & Molecular Biology; Endocrinology & Metabolism; Pharmacology & Pharmacy


Popov, CSFC; Magalhaes, BS; Goodfellow, BJ; Bocca, AL; Pereira, DM; Andrade, PB; Valentao, P; Pereira, PJB; Rodrigues, JE; Veloso, PHD; Rezende, TMB

nossos autores


This study was supported by CAPES, CNPq, FAPDF and Universidade Catolica de Brasilia. We thank i3S, Faculdade de Farmacia da Universidade do Porto, Departamento de Quimica da Universidade de Aveiro and Universidade de Brasilia for collaboration. This work received financial support from National Funds (FCT/MEC, Fundacao para a Ciencia e a Tecnologia/Ministerio da Educacao e Ciencia) through project UID/QUI/50006/2013, co-financed by the European Union (FEDER under the Partnership Agreement PT2020). This work was also developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. The NMR spectrometers are part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project No 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC).

Partilhe este projeto

Publicações similares

Usamos cookies para atividades de marketing e para lhe oferecer uma melhor experiência de navegação. Ao clicar em “Aceitar Cookies” você concorda com nossa política de cookies. Leia sobre como usamos cookies clicando em "Política de Privacidade e Cookies".