Induction of mixed function oxidase activity in honey bee as a bioassay for detection of environmental xenobiotics

Abstract

The level of benzo-(a)-pyrene monooxidase (B(a)PMO) activity in honey bees exposed to a sugar syrup containing benzo(a)pyrene (B(a)P) increased after 2 days of exposure. For different doses and at all concentrations, maximal induction (5-25-fold) was obtained on the 9th day of the experiment. At the next measurement (13th day), the B(a)P activity had decreased at all concentrations. Finally, 20 days after exposure the result was near the control values. The results showed good correlation between the dose and the activity of B(a) PMO. From many drugs used for the treatment against Varroa jacobsoni, we tested the recommended and most effective drugs, Apitol and Apistan. Both drugs increased B(a)PMO activity slightly less than the lowest dose of B(a)P. The dose of 5.5 mg/kg bw (body weight of bees) B(a)P increased B(a)PMO activity by 480%. The dose of Apitol recommended by the producer increased B(a)PMO activity by 300%, and the recommended dose of Apistan increased the activity by 380%. Mixed function oxidase (MFO) activity could also measure harmful effects of pollutants in bees as early, sublethal, objectively (ie instrumentally) measurable biochemical parameters.