Bowman-Birk Inhibitor affects pathways associated with energy metabolism in Drosophila melanogaster

Bowman-Birk inhibitor (BBI) is toxic when fed to certain insects, including the fruit fly, Drosophila melanogaster. Dietary BBI is thought to slow growth and increase insect mortality by inhibiting the digestive enzymes trypsin and chymotrypsin. The resulting reduced supply of amino acids attenuates growth. In mammals, BBI has been shown to influence cellular energy metabolism. We tested the hypothesis that dietary BBI affects energy-associated pathways in the D. melanogaster midgut. We show that dietary BBI affects energy utilization in the midgut cells of D. melanogaster. The mode of action of BBI in insects may be more complex than previously thought.