Anti-Rift Valley fever virus activity in vitro, pre-clinical pharmacokinetics and oral bioavailability of benzavir-2, a broad-acting antiviral compound

Abstract

Rift Valley fever virus (RVFV) is a mosquito-borne hemorrhagic fever virus affecting both humans and animals with severe morbidity and mortality and is classified as a potential bioterror agent due to the possible aerosol transmission. At present there is no human vaccine or antiviral therapy available. Thus, there is a great need to develop new antivirals for treatment of RVFV infections. Benzavir-2 was previously identified as potent inhibitor of human adenovirus, herpes simplex virus type 1, and type 2. Here we assess the anti-RVFV activity of benzavir-2 together with four structural analogs and determine pre-clinical pharmacokinetic parameters of benzavir-2. In vitro, benzavir-2 efficiently inhibited RVFV infection, viral RNA production and production of progeny viruses. In vitro, benzavir-2 displayed satisfactory solubility, good permeability and metabolic stability. In mice, benzavir-2 displayed oral bioavailability with adequate maximum serum concentration. Oral administration of benzavir-2 formulated in peanut butter pellets gave high systemic exposure without any observed toxicity in mice. To summarize, our data demonstrated potent anti-RVFV activity of benzavir-2 in vitro together with a promising pre-clinical pharmacokinetic profile. This data support further exploration of the antiviral activity of benzavir-2 in in vivo efficacy models that may lead to further drug development for human use.

Novel activities of safe-in-human broad-spectrum antiviral agents

“…Recombinant RVFV expressing the far-red fluorescent protein Katushka instead of the deleted NSs protein (rRVFVΔNSs::Katushka) was used in this study (Islam et al, 2018).…”

“…At 16 hpi the medium was removed, and cells were fixed with 3% paraformaldehyde (PFA) for 1 h and washed with phosphate-buffered saline (PBS). 300 μL PBS was added to each well and the plate was analyzed in the Trophos plate runner HD (Trophos, Roche Group) to count the number of virus infected cells per well, by identifying all individual cells expressing the far-red fluorescent protein Katushka (Islam et al, 2018). The toxicity of compounds was analysed using CTG assay.…”

Antiviral Activity of Benzavir-2 against Emerging Flaviviruses

“…Favipiravir was purchased from Selleckchem (Munich, Germany). Benzavir-1, benzavir-2, and compounds 17d and 35f were synthesized as previously described [17,19] and were dissolved in DMSO. The chemical structures of the compounds analyzed in this study is illustrated in Figure 1A.…”

“…The six compounds were analyzed using a fluorescent intensity assay that quantifies the ZsGreen expression, as previously described [19]. The day before infection, 10 4 Vero B4 cells per well were seeded in 96-well black plates with transparent bottoms (Corning, Corning, NY, USA).…”

“…We have previously identified and optimized anti-adenoviral compounds resulting in benzavir-2 ( Figure 1A), a novel antiviral compound with broad antiviral activity against both DNA viruses, human adenovirus (HAdV) [16,17], herpes simplex virus type 1 and type 2 (HSV-1, HSV-2) [18], and, recently, RNA virus, and rift valley fever virus (RVFV) [19]. Here, we explore the antiviral activity of benzavir-2 against flaviviruses that urgently need effective therapeutic interventions.…”