In vivo antiviral efficacy of moroxydine hydrochloride against grass carp reovirus and the drug safety assessment

Our previous studies have verified that moroxydine hydrochloride (Mor) could inhibit replication of grass carp reovirus (GCRV) and suppress apoptosis of Ctenopharyngodon idella kidney cells, but be lack of information whether exists on antiviral activity in vivo. The paper was undertaken to explore the antiviral response of Mor against GCRV in grass carp and investigate the safety of drug for aquatic organisms. The results showed that injection treatment of Mor could more effectively inhibit GCRV replication than immersion administration. All the RNA systheses of vp3 and vp6 on day 7 in head kidney, gill, hepatopancreas and dorsal muscle in the Mor injection group were lesser than 0.07-fold than that of in control group. And the GCRV-inducing grass carp mortality was effectively controlled within 7 days post Mor injection therapy. Additionally, the reduction of superoxide dismutase activity, total antioxidant capacity and catalase activity in serum was effectively controlled by Mor. Moreover, drug safety assessment results showed that 500 mg/L of Mor was safe to C. idella, Bacillus subtilis, Chlorella vulgaris and Tetrahymena thermophila, which was far higher than the therapeutic concentration. The present study proved Mor as harmless formulations or products had potential value in the control of GCRV in aquaculture, with the advantage of super in vivo antiviral activity and environmental safety.