Molecular Characterization of the Disruptive Effects by two Curcuminoids, Demethoxycurcumin and Bisdemethoxycurcu-min, on the Larval Development of Drosophila melanogaster

Juvenile hormones (JH) play crucial roles in insect development, reproduction, and other physi-ological functions. Because JH is specific to arthropods, including insects, it has long been stud-ied for use in pest control. Accordingly, this study aimed to identify the substances that act as JH disruptors from edible plants. Curcuminoids generally exhibit a wide range of biological ac-tivities, such as antioxidant, anti-inflammatory, antibacterial, and insecticidal properties, and they exhibit insect growth inhibitory effects. Demethoxycurcumin and bisdemethoxycurcumin, two curcuminoids from the turmeric plant Curcuma longa L. inhibit the formation of a metho-prene-tolerant (Met)–Taiman (Tai) heterodimer complex as shown through in vitro yeast two-hybrid assays. An artificial diet containing 1% (w/v) demethoxycurcumin or bisdemethox-ycurcumin reduced the number of larvae, leading to no pupal development. Building on our re-sults regarding curcuminoids, researchers can use our study as a reference to develop eco-friendly pesticides.