Antiviral and Antioxidant Activities of Sulfated Galactomannans from Plants of Caatinga Biome.

Ícaro Gusmão Pinto Vieira,Ana Raquel Araújo Da Silva,Fernanda Montenegro De Carvalho Araújo,Maria Izabel Florindo Guedes,Márcia Maria Mendes Marques,Danielle Malta Lima,Tadeu Rocha Pontes Filho,Naiara Dutra Barroso,Selene Maia De Morais

doi:10.1155/2015/591214

Abstract

Dengue represents a serious social and economic public health problem; then trying to contribute to improve its control, the objective of this research was to develop phytoterapics for dengue treatment using natural resources from Caatinga biome. Galactomannans isolated from Adenanthera pavonina L., Caesalpinia ferrea Mart., and Dimorphandra gardneriana Tull were chemically sulfated in order to evaluate the antioxidant, and antiviral activities and the role in the inhibition of virus DENV-2 in Vero cells. A positive correlation between the degree of sulfation, antioxidant and antiviral activities was observed. The sulfated galactomannans showed binding to the virus surface, indicating that they interact with DENV-2. The sulfated galactomannans from C. ferrea showed 96% inhibition of replication of DENV-2 followed by D. gardneriana (94%) and A. pavonina (77%) at 25 µg/mL and all sulfated galactomannans also showed antioxidant activity. This work is the first report of the antioxidant and antiviral effects of sulfated galactomannans against DENV-2. The results are very promising and suggest that these sulfated galactomannans from plants of Caatinga biome act in the early step of viral infection. Thus, sulfated galactomannans may act as an entry inhibitor of DENV-2.

Highlights

Dengue is considered the most important arthropod-borne viral disease in the world in terms of morbidity and mortality in humans
A differential susceptibility of dengue virus (DENV) serotypes to sulfated polysaccharides was showed in Vero and BHK-21 cells, in the order DENV-2 > DENV-3 > DENV-4 > DENV-1 [10]
This study showed that DENV-2 bound to sulfated galactomannans from A. pavonina (SGAP), SGDG, and SGCF (Figure 2), and this binding may be responsible for the inhibitory activity of sulfated galactomannans (Figure 3)

Summary

Introduction

Dengue is considered the most important arthropod-borne viral disease in the world in terms of morbidity and mortality in humans. Dengue represents a serious social and economic public health problem in the 21st century [1]. An estimated 50 million dengue infections and approximately 20,000 deaths occur annually [2]. The infection is caused by the dengue virus (DENV), a member of the family Flaviviridae, genus Flavivirus and has four antigenically distinct serotypes, DENV-1, DENV-2, DENV-3, and DENV-4. DENV causes a spectrum of disease in humans, ranging from acute febrile dengue fever (DF) to severe forms [3]. There is still no effective treatment against the virus. Research for dengue antiviral has focused on the different phases of the viral lifecycle (virus attachment, viral entry, trafficking, translation, or replication). Only few antiviral therapies have been tested and little is known about the effects and mechanisms of the antiviral agents [4]

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Results