Effects of Added CeCl₃ on Resistance of Fifth-Instar Larvae of Silkworm to Bombyx mori Nucleopolyhedrovirus Infection

摘要

One of the most important agents causing lethal disease in the silkworm is the Bombyx mori nucleopolyhedrovirus (BmNPV), while low-dose rare earths are demonstrated to increase immune capacity in animals. However, very little is known about the effects of added CeCl₃ on decreasing BmNPV infection of silkworm. The present study investigated the effects of added CeCl₃ to an artificial diet on resistance of fifth-instar larvae of silkworm to BmNPV infection. Our findings indicated that added CeCl₃ significantly decreased inhibition of growth and mortality of fifth-instar larvae caused by BmNPV infection. Furthermore, the added CeCl₃ obviously decreased lipid peroxidation level and accumulation of reactive oxygen species such as O₂−, H₂O₂, ·OH, and NO and increased activities of the antioxidant enzymes including superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, ascorbate, and glutathione contents in the BmNPV-infected fifth-instar larvae. In addition, the added CeCl₃ could significantly promote acetylcholine esterase activity and attenuate the activity of inducible nitric oxide synthase in the BmNPV-infected fifth-instar larvae. These findings suggested that added CeCl₃ may relieve oxidative damage and neurotoxicity of silkworm caused by BmNPV infection via increasing antioxidant capacity and acetylcholine esterase activity.