Concentration- and Time-Dependent Dietary Exposure to Graphene Oxide and Silver Nanoparticles: Effects on Food Consumption and Assimilation, Digestive Enzyme Activities, and Body Mass in IAcheta domesticus/I

• Published in: Insects (Basel, Switzerland) Switzerland), 2024-01, Vol.15 (2)
• Main Authors: Seyed Alian, Reyhaneh, Flasz, Barbara, Kędziorski, Andrzej, Majchrzycki, Łukasz, Augustyniak, Maria
• Format: Article
• Language: English
• Subjects: Analysis; Crickets; Food and nutrition; Graphene; Influence; Nanoparticles; Physiological aspects; Silver
• ISSN: 2075-4450; 2075-4450
• DOI: 10.3390/insects15020089

The increasing presence or contamination of various everyday-life products (including foodstuffs) by graphene oxides and silver nanoparticles (GOs and AgNPs, respectively) raises a risk of their possibly deleterious effects on digestive functions and, consequently, nutrient and energy intake by an organism. The study addresses this issue by considering various NP concentrations and exposure times. The scarcity of relevant data makes such studies necessary for the reliable assessment of NP effects. This study on a model insect species—adult house crickets—revealed a changed profile of digestive enzymes’ activities in the gut, mainly when a high content of NPs was present in the food: stimulated digestion of carbohydrates and lipids but inhibited digestion of proteins. These changes were more pronounced in AgNP-treated than in GO-treated insects and increased with exposure time. Disturbed digestion led to decreased food consumption with exposure time in AgNP-treated crickets. Food assimilation was also affected—the cumulative food assimilation (CFA) was higher and lower compared with the control in crickets exposed to the lowest and moderate concentrations of AgNPs, respectively. These findings confirmed weak or no effects of low amounts of NPs in food and revealed that their higher concentrations may adversely influence digestive processes and resulting nutrient and energy intakes, particularly during prolonged exposure of an organism. The advancement of nanotechnology poses a real risk of insect exposure to nanoparticles (NPs) that can enter the digestive system through contaminated food or nanopesticides. This study examines whether the exposure of model insect species—Acheta domesticus—to increasing graphene oxide (GO) and silver nanoparticle (AgNP) concentrations (2, 20, and 200 ppm and 4, 40, and 400 ppm, respectively) could change its digestive functions: enzymes’ activities, food consumption, and assimilation. We noticed more pronounced alterations following exposure to AgNPs than to GO. They included increased activity of α-amylase, α-glucosidase, and lipase but inhibited protease activity. Prolonged exposure to higher concentrations of AgNPs resulted in a significantly decreased food consumption and changed assimilation compared with the control in adult crickets. A increase in body weight was observed in the insects from the Ag4 group and a decrease in body weight or no effects were observed in crickets from the Ag40 and Ag400 groups (i.e., 4, 40,