Location: Healthy Processed Foods ResearchTitle: Curcumin and quercetin as potential radioprotectors and/or radiosensitizers for x-ray-based sterilization of male navel orangeworm larvae
Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2018
Publication Date: 2/14/2019
Citation: Liang, P., Haff, R.P., Zayas, I.Y., Light, D.M., Mahoney, N.E., Kim, J. 2019. Curcumin and quercetin as potential radioprotectors and/or radiosensitizers for x-ray-based sterilization of male navel orangeworm larvae. Scientific Reports. 9:2016. https://doi.org/10.1038/s41598-019-38769-3.
Interpretive Summary: Navel orangeworm (NOW) is a major pest of California tree nuts not only by damaging the crops but also by providing entry routes for mold infection and toxin contamination. In the present study, we investigated the use of two natural compounds and their effects on sensitizing or protecting NOW larvae for x-ray-based sterilization. The results give insights into general efficiency of x-ray-based sterilization of NOW larvae and validate the idea of adding synergistic compounds to NOW diet for sterilization.
Technical Abstract: Navel orangeworm (NOW) is the major pest of California tree nuts, which combined comprises the largest agricultural commodity in the United States. NOW damage, which is the main vector for mold infestation and subsequent aflatoxin contamination in tree nuts, is a serious economic and food safety issue which is expected to increase as climate change creates conditions more favorable to the insect. Recently, a new tool has been added for NOW control as various stakeholders are working together to initiate a large scale Sterile Insect Technique (SIT) program. Insect sterilization is traditionally accomplished through gamma irradiation, which has become increasingly problematic. X-ray is being actively investigated as a replacement but suffers from insufficient power to match the throughput of sterile insects required for SIT. Past research indicates that NOW larvae can be sterilized at much lower doses than adults, making them a tempting target for x-ray-based sterilization, but suffer from high rates of mortality, thus making them unsuitable for SIT. Past research has also shown that certain treatments involving the application of natural compounds or modified atmospheres can either sensitize organisms to radiation, protect them from the normal effects of radiation, or both. In this study, quercetin and curcumin were incorporated into NOW diet and investigated for their potential to either sensitize or protect 3rd and 4th instar larvae under low energy (90 keV) x-ray sterilization. While the results did not indicate the likelihood of either of these two natural compounds sufficiently solving the high mortality problem for use in large scale SIT, they did show sufficient effects to support the validity of the approach. Given the urgent need for a replacement for gamma irradiation, the results of this study strongly suggest the need for detailed investigation into other natural compounds and treatments.