Effects of Plant Protection Products on Biochemical Markers in Honey Bees

Plant protection products (PPPs) are pesticides that protect crops and ornamental plants. PPPs include primarily insecticides, herbicides, and fungicides. Bees’ contact with PPPs can cause immediate death or, in sublethal dose, may affect their physiology and/or behavior. Understanding the effect of PPPs’ sublethal doses is especially important. Contact with a sublethal dose of PPPs generally allows the bee to return to the hive, which may expose the whole colony to the harmful substance. Biochemical changes may affect colony condition, health, and performance. Most of the research on the biochemical effects of PPP in honey bees focuses on insecticides and among them neonicotinoids (especially imidacloprid). The vast majority of research is carried out on Apis mellifera workers. A small part of the research has been conducted on drones and queens. Pesticides, including fungicides and herbicides, may alter antioxidant defense, detoxification, gene expression, and immune response of the bee. They affect the drones’ semen quality and metabolic rate of the queen. In this review, the biochemical effect of PPP products in the honey bee was examined, with a focus on the effect on cytochrome P450 monooxygenases, glutathione transferases, and carboxylesterases, which take part in toxin metabolism or the detoxification process. PPPs effects on the activity of glutathione peroxidase (GPX), catalase (CAT), superoxide dismutase (SOD), proteases, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and phenoloxidase (PO) are also presented.