Hsieh Edward M, Berenbaum May R, Dolezal Adam G
Department of Entomology, University of Illinois at Urbana-Champaign, 505 S. Goodwin, Urbana, IL 61801, USA.
Insects. 2020 Oct 13;11(10):698. doi: 10.3390/insects11100698.
Honey bee viruses are capable of causing a wide variety of devastating effects, but effective treatments have yet to be discovered. Phytochemicals represent a broad range of substances that honey bees frequently encounter and consume, many of which have been shown to improve honey bee health. However, their effect on bee viruses is largely unknown. Here, we tested the therapeutic effectiveness of carvacrol, thymol, -coumaric acid, quercetin, and caffeine on viral infection by measuring their ability to improve survivorship in honey bees inoculated with Israeli acute paralysis virus (IAPV) using high-throughput cage bioassays. Among these candidates, caffeine was the only phytochemical capable of significantly improving survivorship, with initial screening showing that naturally occurring concentrations of caffeine (25 ppm) were sufficient to produce an ameliorative effect on IAPV infection. Consequently, we measured the scope of caffeine effectiveness in bees inoculated and uninoculated with IAPV by performing the same type of high-throughput bioassay across a wider range of caffeine concentrations. Our results indicate that caffeine may provide benefits that scale with concentration, though the exact mechanism by which caffeine ingestion improves survivorship remains uncertain. Caffeine therefore has the potential to act as an accessible and inexpensive method of treating viral infections, while also serving as a tool to further understanding of honey bee-virus interactions at a physiological and molecular level.
蜜蜂病毒能够造成各种各样的毁灭性影响，但尚未发现有效的治疗方法。植物化学物质是蜜蜂经常接触和食用的一大类物质，其中许多已被证明能改善蜜蜂健康。然而，它们对蜜蜂病毒的影响在很大程度上尚不清楚。在这里，我们通过使用高通量笼式生物测定法，测量香芹酚、百里香酚、对香豆酸、槲皮素和咖啡因提高接种以色列急性麻痹病毒（IAPV）的蜜蜂存活率的能力，来测试它们对病毒感染的治疗效果。在这些候选物质中，咖啡因是唯一能够显著提高存活率的植物化学物质，初步筛选表明，天然存在浓度的咖啡因（25 ppm）足以对IAPV感染产生改善作用。因此，我们通过在更广泛的咖啡因浓度范围内进行相同类型的高通量生物测定，测量了接种和未接种IAPV的蜜蜂中咖啡因有效性的范围。我们的结果表明，咖啡因可能具有随浓度增加而产生益处的作用，尽管摄入咖啡因提高存活率的确切机制仍不确定。因此，咖啡因有潜力成为一种易于获得且廉价的治疗病毒感染的方法，同时也可作为一种工具，用于在生理和分子水平上进一步了解蜜蜂与病毒的相互作用。
