GN01 is a new antiviral medicine acting against Korean Sacbrood virus (KSBV) of honeybees. It contains 5 mg/mL of active ingredient, double stranded RNAs(dsRNA), that homologous to KSBV ribonucleic acid coding coat protein (VP1) of virus and inducing RNA interference (RNAi). RNA medicine is generally recognized as safe for rapid breakage by intrinsic ribonuclease and limited absorption from gastrointestinal tract. However, there were no data of repeat-dose toxicity in laboratory animals for dsRNA targeting SBV. This study was performed to investigate toxicity of GN01 in SD rats after weekly oral dosing for 28 days and to determine its no-observed-adverse-effect-level (NOAEL). Male and female SD rats were orally administered with GN01 at 0, 25, 50 and 100 mg/kg bw/day of dsRNA once per week for 28 days (total 5 administrations). The highest dose 100 mg/kg bw/day was determined based on the maximum volume injectable (20 mL/kg bw) via gavage. During treatment period, clinical signs, functional and sensory responses, body weights, food and water consumption, ophthalmological findings and urinalysis were investigated. After treatment period, hematological and clinical biochemistry tests and examination of necropsy findings, organ weights and histopathological lesions were performed. There were no significant differences between all test groups and vehicle control group in all measured parameters. Therefore, the NOAEL of GN01 was determined 100 mg/kg bw/day, the highest dose administered. In conclusion, repeated oral administration of GN01, a dsRNA medicinal product, is safe even at the maximum available dose in rats.

INTRODUCTION
MATERIALS AND METHODS
    Test facility and environmental conditions
    Animals and grouping
    Test substance preparation and dosing
    Clinical signs, functional observations and sensoryreactivity
    Body weights and food and water consumptions
    Ophthalmological examination
    Urinalysis
    Hematology and clinical biochemistry test
    Necropsy findings and organ weights
    Histopathological examination
    Statistical analyses
RESULTS
    Clinical signs, functional observations and sensoryreactivity
    Body weights, food and water consumptions
    Ophthalmological examination and urinalysis
    Hematology and clinical biochemistry test
    Necropsy findings and organ weight
    Histopathological examination
DISCUSSION
ACKNOWLEDGEMENTS
REFERENCES

• Jun Man Jung(CentralBio Co., Ltd., 14, Saebeol-ro, Bupyeong-gu, Incheon 21315, Korea)
• Ji Young Park(CentralBio Co., Ltd., 14, Saebeol-ro, Bupyeong-gu, Incheon 21315, Korea)
• Jeong-Ran Min(Biomedical Science Research Center, Hoseo University, Asan 31499, Korea)
• Chang-Hun Lee(Biomedical Science Research Center, Hoseo University, Asan 31499, Korea)
• Sang-Hee Jeong(Biomedical Science Research Center, Hoseo University, Asan 31499, Korea, Dept. Biomedical Science, College of Life and Health Science, Asan 31499, Korea) Corresponding author