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

• Main Authors: 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
• Format: Article
• Language: English
• Published: Tripoli University 2021-07-01
• Series: Open Veterinary Journal
• Subjects: african swine fever virus; virus isolation; mcfa; pig; vietnam
• Online Access: https://www.openveterinaryjournal.com/OVJ-2021-05-092%20H.T.T%20Tran%20et%20al.pdf
• ISSN: 2218-6050; 2218-6050

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.