A team of scientists has discovered that hawkmoths can use glucose to generate antioxidants, an ability that has never been previously recorded. The moths produce antioxidant compounds to make up for damage caused by oxidative stress. The findings are in a paper that was just published in the journal Science.
Hawkmoths are large flying insects that are sometimes mistaken for hummingbirds because of their habit of hovering around flowers. This type of flight requires a high metabolism. The constant energy expenditure results in the production of reactive oxygen species. Reactive oxygen species are byproducts of energy use that can damage cells. Without antioxidants, this can lead to serious muscle damage and fatigue. The majority of animals gain antioxidants through their diets. Hawkmoths and similar insects exclusively consume nectar, however, which contains no antioxidants. Researchers were unsure how the moths prevented oxidative damage on a diet of only nectar.
Scientists from the University of Arizona and New Mexico State University collaborated to study how hawkmoths manage to mitigate muscular oxidative damage without consuming antioxidant-rich foods. The team fed one group of hawkmoths sugary nectar and compared them to a control group which was not fed sugar. The insects on the sugar diet flew farther and had less oxidative damage at the end of the experiment. The researchers investigated further and found that hawkmoths are capable of converting glucose into antioxidant compounds. The moths don’t need to consume antioxidants because they can make their own from sugary carbohydrates.
The team’s findings show that hawkmoths convert some of the sugar from nectar into antioxidants in order to protect their cells from oxidative stress. Moths and other flying animals use a lot of energy, making this kind of chemical conversion invaluable. The authors suggest that other animals with a high metabolism may use similar chemical pathways to convert sugars to antioxidants.
Levin et al. Hawkmoths use nectar sugar to reduce oxidative damage from flight. Science (2017).