NATURAL BIOACTIVE COMPOUNDS WITH ANTIVIRAL AND IMMUNOMODULATORY PROPERTIES MODULATE NUCLEAR FACTOR-KAPPAB PATHWAY

CARLOS BUENO; FLAVIA MICHELINI; LAURA ALCHÉ

Buenos Aires

Simposio; IV International Clinical Virology Symposium; 2016

Background: The extracts from the seeds of Aesculus hippocastanum (AH) have beentraditionally used as an analgesic, antipyretic and antiinflammatorial agent. Escin is the major active component of this extract, and has shown clinically anti-inflammatory activity in chronic venous insufficiency, haemorroids and traumatic brain edema. Besides, nuclear factor‑kappaB (NF-kappaB) is one of the most important proinflammatory transcription factors, and the replication of many viruses, such as HSV-1 and RSV, is regulated via this factor. Escin inhibits the activation of NF-kB induced by various inflammatory stimuli.Objective: Considering that NF-kappaB is involved in the replication of HSV-1 and RSV, and Escin inhibits NF-kappaB activation against different stimuli, we investigated whether Escin and AH exhibit antiviral activities against HSV-1 and RSV in Vero and Hep-2 cells, respectively. Besides, taking into account the anti-inflammatory activities of Escin and AH, we investigated if they modulate the production of cytokines and NF-kappaB pathway in murine macrophages (J774A.1 cells) infected with HSV-1 and RSV.Materials and methods: The effect of the compounds on cell viability was determined using the cleavage of the tetrazolium salt MTT and antiviral activity was evaluated by plaque reduction assays. Citokines TNF-α and IL-6 were quantified by commercial ELISA. NF-kappaB activity was measured in cells transfected with an NF-kappaB-Luciferase reporter plasmid.Results: When HSV-1-infected Vero cells and RSV-infected Hep-2 cells were treated with different concentrations of Escin and AH, a dose-dependent inhibition of viral yields was observed. Besides, Escin and AH proved to have no cytotoxic effect at all the concentrations tested. HSV-1 and RSV infection induced J774A.1 cells to activate NF-kappaB and to secrete increased amounts of IL-6 and TNF- in comparison with uninfected cells. When cells were treated with Escin and AH, macrophages failed to actívate NF-kappaB and to produce IL-6 and TNF-alpha in response to HSV-1 and RSV infection.Conclusion: Escin and AH exhibit antiviral and antiinflammatory properties in vitro, which would be a consequence of their NF-kappaB modulatory properties.