Open Veterinary Journal (Jul 2021)

The potential anti- African swine fever virus effects of medium chain fatty acids on in vitro feed model: An evaluation study using epidemic ASFV strain circulating in Vietnam

  • Ha Thi Thanh Tran,
  • Anh Duc Truong,
  • Duc Viet Ly,
  • Tuan Van Hoang,
  • Nhu Thi Chu,
  • Huyen Thi Nguyen,
  • Anh Thi Kieu Dang,
  • Maartje De Vos,
  • Kobe Lannoo,
  • Geert Bruggeman,
  • Hoang Vu Dang

DOI
https://doi.org/10.5455/OVJ.2021.v11.i3.3
Journal volume & issue
Vol. 11, no. 3
pp. 346 – 355

Abstract

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Background: African swine fever (ASF) is an important disease affecting swine and has a significant economic loss in both the developed and developing world. Aim: In this study, we evaluated the potential effects of MCFAs in individual and synergistic forms to prevent and/or reduce ASFV infection using in vitro feed model. Methods: The cytotoxicity of MCFAs on PAM cells was evaluated by using the MTT assay. The potential effects of MCFAs, including C8 (caprylic acid), C8-C6-C10 (caprylic acid-caproic acid-capric acid; 1:1:1 ratio) and C8-C10-C12 (caprylic acid-capric acid-lauric acid; 1:1:1 ratio) against a field ASFV strain isolated in the capital Hanoi of Vietnam, were further examined by real-time PCR and HAD assays in in vitro feed model. Results: Our results indicated that all tested products do not induce cytotoxicity at the dose of 100 µg/ml and are suitable for further in vitro examination. These products have shown a strong antiviral effect against ASFV infectivity at doses of 0.375% and 0.5%. Interestingly, the synergistic MCFAs have shown clearly their potential activities against ASFV in which at a lower dose of 0.25%, pre-treatment with product 2 and 3 induced significant increases at the level of Cq value when compared to positive control and/or product 1 (P<0.05). However, the viral titre was not changed after 24h post-inoculation when compared to positive control. Our findings suggested that all tested products, both individual and synergistic forms of MCFAs, have possessed a strong anti-ASFV effect, and this effect is dose-dependence in in vitro feed model. Additionally, synergistic effects of MCFAs are more effective against ASFV when compared to individual forms. Conclusion: Together, the findings in this study indicate that MCFAs, both individual and synergistic forms, inhibit against a field ASFV strain in the feed model, which may support minimizing the risk of ASF transmission in the pig population. Further studies focusing on in vivo anti-ASFV effects of MCFAs are important to bring new insight into the mode of ASFV-reduced action by these compounds in swine feed.

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