Acetyl-para-aminophenol (acetaminophen) is a known toxin in humans, but the extent of its toxicity is not fully understood. The difference between an effective dose and an overdose of acetaminophen is very minimal, and acetaminophen overdoses resulting in hospitalizations are relatively common. This study investigates the effects of acetaminophen on the development of Drosophila melanogaster exposed to different light/dark conditions to better understand the mechanisms and antioxidant pathways that are affected by acetaminophen. Our objectives include determining the dose-response relationship of acetaminophen on Drosophila development under different light conditions and measuring the antioxidant activity in adults raised on acetaminophen food to determine oxidative stress levels. This research will increase our understanding of the toxic effects of acetaminophen on developing organisms.
To determine the acetaminophen dose-response relationship, instant food was added to fly vials and rehydrated with 30mM to 70mM acetaminophen solutions. Oregon R wild type flies were added to each vial and placed in different light cycle conditions. Once the eggs hatched, the rate of larval development was monitored and the number of adults emerging was recorded every day until all flies had eclosed (emerged). A separate trial placed collected eggs in vials containing acetaminophen food of different concentrations. Vials were placed either in constant dark or twelve-12 hour light/dark cycles. The number of flies eclosed was recorded every 12 hours until all flies had emerged. Our results show that acetaminophen doses less than 30 mM had minimal effect on development. Doses of 30 mM to 60 mM affected survival percentages and time to eclosion, and doses greater than 70 mM showed very low survival rates. Additionally, light cycles affect survival and development rates, with cultures exposed to a twelve-hour light/dark cycle experiencing the least effect of acetaminophen. Currently, assays testing oxidative stress of adult flies raised on acetaminophen food are underway. Flies will be separated according to day eclosed, sex, light conditions, and acetaminophen dosage. Fly homogenates from the most recent dosage study will be used to extract proteins and determine the relative antioxidant activity in flies exposed to different light conditions and acetaminophen concentrations. Because flies develop more slowly and show greater response to acetaminophen when reared in constant darkness, it is predicted that exposure to higher concentrations of acetaminophen and constant darkness will result in greater antioxidant activity.