Abstract
Artemisinin (ART) is an endoperoxide molecule derived from the medicinal plant Artemisia annua L. and is clinically used as an antimalarial drug. As a secondary metabolite, the benefit of ART production to the host plant and the possible associated mechanism are not understood. It has previously been reported that Artemisia annua L. extract or ART can inhibit both insect feeding behaviors and growth; however, it is not known whether these effects are independent of each other, i.e., if growth inhibition is a direct outcome of the drug's antifeeding activity. Using the lab model organism Drosophila melanogaster, we demonstrated that ART repels the feeding of larvae. Nevertheless, feeding inhibition was insufficient to explain its toxicity on fly larval growth. We revealed that ART provoked a strong and instant depolarization when applied to isolated mitochondria from Drosophila while exerting little effect on mitochondria isolated from mice tissues. Thus, ART benefits its host plant through two distinct activities on the insect: a feeding-repelling action and a potent anti-mitochondrial action which may underlie its insect inhibitory activities.