New insights into the Antiviral Activity of Nordihydroguaiaretic Acid: Inhibition of Dengue Virus Serotype 1 replication

MARTINEZ, FLORENCIA; GHIETTO, LUCIA MARIA; LINGUA, GIULIANA; MUGAS, M. LAURA; AGUILAR, J. JAVIER; GIL, PEDRO; PISANO, M. BELÉN; MARIONI, JULIANA; PAGLINI, MARÍA GABRIELA; CONTIGIANI, MARTA S.; NÚÑEZ-MONTOYA, SUSANA C.; KONIGHEIM, BRENDA S.

PHYTOMEDICINE

ELSEVIER GMBH

Año: 2022

0944-7113

BACKGROUND: Dengue virus (DENV) is considered one of the most important pathogens in the world, producing 390 million infections each year. Currently, the development of vaccines against DENV presents some shortcomings and there is no antiviral therapy available for its infection. One of the challenges is that both treatments and vaccines must be effective against all four DENV serotypes. Nordihydroguaiaretic acid (NDGA), isolated from Larrea divaricata Cav. (Zygophyllaceae), has shown a significant inhibitory effect on a broad spectrum of viruses, including DENV serotype 2 and 4.PURPOSE: We evaluated the in vitro virucidal and antiviral activity of NDGA on DENV serotype 1 (DENV1), including the study of its mechanism f action, to provide more evidence on its antiviral activity.METHODS: The viability of viral particles was quantified by the plaque-forming unit reduction method. NDGA effects on DENV1 genome and viral proteins were evaluated by qPCR and immunofluorescence respectively. Lysosomotropic activity was assayed using acridine orange and neutral red dyes.RESULTS: NDGA showed in vitro virucidal and antiviral activity against DENV1. The antiviral effect would be effective within the first 2 h after viral internalization, when the uncoating process takes place. In addition, we determined by qPCR that NDGA decreases the amount of intracellular RNA of DENV1 and, by immunofluorescence, the number of cells infected. These results indicate that the antiviral effect of NDGA would have an intracellular mechanism of action, which is consistent with its ability to be incorporated into host cells. Considering the inhibitory activity of NDGA on cellular lipid metabolism, we compared the antiviral effect of two inhibitors acting on two different pathways of this type of metabolism: 1) resveratrol that inhibits the sterol regulatory element binding proteins, and 2) caffeic acid that inhibits the 5-lipoxygenase (5-LOX) enzyme. Only, caffeic acid produced an inhibitory effect on DENV1 infection. We studied lysosomotropic activity of NDGA on the host cells and found for the first time that this compound inhibited the acidification of cells vesicles, which would prevent DENV1 uncoating process.CONCLUSION: The present work contributes to the knowledge of NDGA activity on DENV. We describe its activity on DENV1, a serotype different to those that have been already reported. Moreover, we provide evidence on which stage/s of the viral replication cycle NGDA exerts its effects. We suggest that mechanisms of action of NGDA on DENV1 is related to its lysosomotropic effect, which inhibits the viral uncoating process.