Cíntia da Silva Mello1, Ligia Maria Marino Valente2, Thiago Wolff2, Raimundo Sousa Lima-Junior1,3, Luciana Gomes Fialho1, Cintia Ferreira Marinho1, Elzinandes Leal Azeredo1, Luzia Maria Oliveira-Pinto1, Rita de Cássia Alves Pereira4, Antonio Carlos Siani5, Claire Fernandes Kubelka1,+
1Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Imunologia Viral, Rio de Janeiro, RJ, Brasil
2Universidade Federal do Rio de Janeiro, Instituto de Química, Rio de Janeiro, RJ, Brasil
3Universidade do Estado do Amazonas, Escola Normal Superior, Manaus, AM, Brasil
4Embrapa Agroindústria Tropical, Fortaleza, CE, Brasil
5Fundação Oswaldo Cruz-Fiocruz, Instituto de Tecnologia em Fármacos, Rio de Janeiro, RJ, Brasil
BACKGROUND Dengue fever may present hemorrhages and cavitary effusions as result of exacerbated immune responses. We investigated hydro-alcoholic extracts from leaves (UGL) and bark (UGB) of the medicinal species Uncaria guinanensis with respect to antiviral effects in Dengue virus (DENV) infection and in immunological parameters associated with in vivo physiopathological features.
METHODS Chemical profiles from UGB or UGL were compared in thin layer chromatography and 1H nuclear magnetic resonance using flavonoid compounds and a pentacyclic oxindole alkaloid-enriched fraction as references. DENV-2-infected hepatocytes (Huh-7) were treated with extracts. Cell viability, DENV antigens and immunological factors were detected by enzyme-linked immunosorbent assay (ELISA) or flow cytometry.
FINDINGS The UGL mainly differed from UGB by selectively containing the flavonoid kaempferitrin. UGB and UGL improved hepatocyte viability. Both extracts reduced intracellular viral antigen and inhibited the secretion of viral non-structural protein (NS1), which is indicative of viral replication. Reduction in secretion of macrophage migration inhibitory factor was achieved by UGB, of interleukin-6 by UGL, and of interleukin-8 by both UGB and UGL.
MAIN CONCLUSIONS The U. guianensis extracts presented, antiviral and immunomodulatory effects for DENV and possibly a hepatocyte-protective activity. Further studies may be performed to consider these products as potential candidates for the development of an herbal product for the future treatment of dengue.
Financial support: Rede de Plataformas Tecnológicas RPT11D/VPPLR, Programa de Excelência em Pesquisa (PROEP-CNPq/IOC), Farmanguinhos FIOCRUZ, CNPq, FAPERJ, CAPES.
Received 15 July 2016
Accepted 4 March 2017