Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing, 100093, People's Republic of China.
Institute of Environment and Plant Protection, Chinese Academy of Tropical Agricultural Sciences, Haikou, 571101, Hainan, People's Republic of China.
Virol J. 2021 Apr 21;18(1):83. doi: 10.1186/s12985-021-01550-y.
Sacbrood is an infectious disease of the honey bee caused by Scbrood virus (SBV) which belongs to the family Iflaviridae and is especially lethal for Asian honeybee Apis cerana. Chinese Sacbrood virus (CSBV) is a geographic strain of SBV. Currently, there is a lack of an effective antiviral agent for controlling CSBV infection in honey bees.
Here, we explored the antiviral effect of a Chinese medicinal herb Radix isatidis on CSBV infection in A. cerana by inoculating the 3rd instar larvae with purified CSBV and treating the infected bee larvae with R. isatidis extract at the same time. The growth, development, and survival of larvae between the control and treatment groups were compared. The CSBV copy number at the 4th instar, 5th instar, and 6th instar larvae was measured by the absolute quantification PCR method.
Bioassays revealed that R. isatidis extract significantly inhibited the replication of CSBV, mitigated the impacts of CSBV on larval growth and development, reduced the mortality of CSBV-infected A. cerana larvae, and modulated the expression of immune transcripts in infected bees.
Although the mechanism underlying the inhibition of CSBV replication by the medicine plant will require further investigation, this study demonstrated the antiviral activity of R. isatidis extract and provides a potential strategy for controlling SBV infection in honey bees.
Sacbrood 是一种由 Sacbrood 病毒（SBV）引起的传染性疾病，该病毒属于 Flaviviridae 科，对亚洲蜜蜂 Apis cerana 尤其致命。中国 Sacbrood 病毒（CSBV）是 SBV 的地理株。目前，缺乏有效的抗病毒药物来控制蜜蜂感染 CSBV。
在这里，我们通过在 3 龄幼虫中接种纯化的 CSBV，并同时用板蓝根提取物处理感染的蜜蜂幼虫，来探索中草药板蓝根对 CSBV 感染的 A. cerana 的抗病毒作用。比较对照组和治疗组幼虫的生长、发育和存活率。通过绝对定量 PCR 方法测量第 4 龄、第 5 龄和第 6 龄幼虫的 CSBV 拷贝数。
生物测定表明，板蓝根提取物显著抑制 CSBV 的复制，减轻 CSBV 对幼虫生长和发育的影响，降低 CSBV 感染的 A. cerana 幼虫的死亡率，并调节感染蜜蜂的免疫转录本的表达。
尽管该药用植物抑制 CSBV 复制的机制仍需进一步研究，但本研究证明了板蓝根提取物的抗病毒活性，并为控制蜜蜂中 SBV 感染提供了一种潜在策略。
