Planta Med 2015; 81 - PW_45
DOI: 10.1055/s-0035-1565669

In vivo antiviral activitiy of Sanguisorba officinalis roots against viral hemorrhagic septicemia virus in olive flounder Paralichthys olivaceus

JK Seo 1, CY Do 1, MH Jung 1, SJ Jung 1, SY Kang 1
  • 1Chonnam National University, Yeosu, Korea, Republic of (South)

Viral hemorrhagic septicemia (VHS) causes significant economic losses for the flounder aquaculture in Korea and its causative agent is VHSV, a negative sense ssRNA virus in the family Rhabdoviridae [1]. Although several kinds of experimental vaccines for VHS have been developed, none of them are commercialized. In our on-going research to discover natural products to be used as antiviral agents for VHS, we previously found that an 80% methanolic extract of Sanguisorba officinalis L. (Rosaceae) roots and its methylene chloride fraction (SOMC) showed significant antiviral activity against VHSV in FHM cells. Here, we evaluated in vivo antiviral efficacies of SOMC in olive flounder and its effect on immune gene expression. Olive flounders orally pre-administered with SOMC at doses of 3, 10 and 30 mg/kg/day for 2 weeks were challenged by VHSV (106.8 TCID50/fish) and then observed for 29 days post challenge. The SOMC groups showed cumulative mortalities of 63, 63 and 40.5% (P < 0.01) at doses of 3, 10 and 30 mg/kg/day, respectively, while the virus (VC)- and naïve control (NC) groups showed cumulative mortalities of 85.5 and 0%, respectively. To investigate the mechanisms of anti-viral effects of SOMC in olive flounders, immune gene expression analyses using real-time qPCR were carried out for kidney samples from fishes of the dose of 30 mg/kg/day collected on each day (1, 2, 4, 7, 10 and 14 day since oral administration was started). SOMC significantly up-regulated transcriptions of IL-1β, IL-6, IL-8, TNFα, IFNγ, ISG15, Mx than naive control showing that immune-enhancing roles of SOMC could exert as antiviral effects in VHSV-infected olive flounders. These results suggest that Sanguisorba officinalis roots and SOMC can be proposed as antiviral materials for VHS in olive flounders.

Fig. 1: Anti-VHSV activity in olive flounder Paralichthys olivaceus fed a diet supplemented with SOMC for 2 weeks.
**p < 0.01

References:

[1] Skall HF, Olesen NJ, Mellergaard S. Viral haemorrhagic septicaemia virus in marine fish and its implications for fish farming – a review. J Fish Dis 2005; 28: 509 – 529