A novel antiviral formulation inhibits a range of enveloped viruses.

Nicola F Fletcher; Luke W Meredith; Emma L Tidswell; Steven R Bryden; Daniel Gonçalves-Carneiro; Yasmin Chaudhry; Claire Shannon-Lowe; Michael A Folan; Daniella A Lefteri; Marieke Pingen; Dalan Bailey; Clive S McKimmie; Alan W Baird

The antimicrobial properties of fatty acids have been extensively reported in the literature (for review, see Thormar et al. (Thormar and Hilmarsson, 2007) and (Churchward et al., 2018) . Previously, (Thormar et al., 1987) demonstrated the antiviral effects of 14 different free fatty acids and lipid extracts from human milk against vesicular stomatitis virus (VSV), herpes simplex virus (HSV) and visna virus revealed that short chain saturated fatty acids (butyric, caproic and caprylic) together with long chain saturated fatty acids (palmitic and stearic) had no or very little antiviral activity, whereas medium chain saturated entities including capric, lauric, myristic and long chain unsaturated oleic, linoleic and linolenic acids were anti-viral, albeit at different concentrations. Another study (Hilmarsson et al., 2005) reported similar trends in the antiviral activity of six medium chain fatty acids together with their alcohol and mono-glyceride derivatives against herpes simplex viruses 1 and 2. In contrast, Dichtelmuller et al (2002) reported that caprylic acid had antiviral activity against enveloped viruses including human immunodeficiency virus, bovine viral diarrhoea virus, Sindbis virus and pseudorabies virus (Dichtelmuller et al., 2002 , Pingen et al., 2016 . Studies investigating the antiviral properties of whole milk reported no antiviral properties of fresh human milk, whereas milk that had been stored at 4 o C possessed potent antiviral activity against several viruses in vitro. Refrigeration disrupts the milk fat globule membrane allowing ingress of milk serum lipase which results in hydrolysis of milk fat triglyceride (Thormar et al., 1987 , Isaacs et al., 1990 . It was concluded that release of fatty acids from milk triglycerides in stored milk, and that recovered from the author/funder. All rights reserved. No reuse allowed without permission.