Effects of short-term exposure of Acheta domesticus to nanodiamonds in food: DNA damage but no histological alteration in tissues

Abstract

The aim of this work is to evaluate toxicity of nanodiamonds (ND, 20 and 200 mg g−1 food) to Acheta domesticus after short-term exposure (10 days) in food. Catalase (CAT), total antioxidant capacity (TAC), stress protein level (HSP70) and DNA damage to hemocytes were monitored every two days. On day 2 and 10, the levels of reactive oxygen species (ROS), apoptosis (annexin V and multicaspase tests), cell cycle and DNA damage to the gut were examined. The ultrastructure of the gut epithelium and testis was assessed on day 10 of the experiment. CAT, TAC, HSP70 in hemolymph, and histological morphology of gut and testis did not indicate ND toxicity. In the gut we observed a transient increase in CAT activity on day 2,4 and 6; and an increase in HSP70 level on day 6, 8 and 10. TAC level in the gut did not increase until day 10. ND did not influence ROS level in cells and the cell cycle. Yet, we observed a moderate increase in apoptosis, particularly at the higher ND concentration. ND induced dose-dependent DNA damage. We can conclude that short-term, occasional exposure to trace amounts of ND, like in medical applications, is probably safe for organisms.