DNA damage, immunotoxicity, and neurotoxicity induced by deltamethrin on the freshwater crayfish, Procambarus clarkii

Abstract

Pyrethroid pesticides are applied to both agricultural and aquacultural industries for pest control. However, information of their impact on the commercial important freshwater crayfish, Procambarus clarkii is scarce. Therefore, the present study aimed to characterize to effects of a commonly used pyrethroid pesticide, deltamethrin on DNA damage, immune response, and neurotoxicity in P. clarkii. Animals were exposed to 7, 14, and 28 ng/L of deltamethrin, which correspond to 1/8, 1/4, and 1/2 of the LC 50 (96 hours) of this pyrethroid to P. clarkii. Significant increase of olive tail moment (OTM) and 8-hydroxy-2 0-deoxyguanosine (8-OHdG) was found after deltamethrin exposure in a dose-dependent way. Total hemocyte counts (THC) and activities of immune-related enzymes including acid phosphatase (ACP), lysozyme (LZM), and phenoloxidase (PO) were all decreased and significantly lower than control at concentration of 28 ng/L after 96 hours exposure. Acetylcholinesterase (AChE) activity, an indicator of neurotoxic effect was investigated and it was decreased significantly in muscles at 14 and 28 ng/L after 24 hours exposure. The level of intracellular reactive oxygen species (ROS) in hemocytes was also measured and the significant increase of ROS was found at 14 and 28 ng/L concentrations. The results revealed that deltamethrin induced DNA damage, immunotoxicity, and neurotoxicity in P. clarkii by excessive generation of ROS. Because of the dose-dependent responses of all parameters under exposure of deltamethrin at environmentally realistic concentrations, these parameters could be used as sensitive biomarkers for risk assessment of deltamethrin in aquaculture area.

The effects of exposure to microplastics and pollutants on the arthropod microbiome

“…On the other hand, in the experiments of chapter II-IV the toxicants highly affected the host-microbiome of the aquatic organism tested (Figure 5b, 6a and b). This is not surprising, since DMT is known for its neurotoxic effects that can cause stress in the host which affects its microbiome (Mestres and Mestres 1992, Toshio 1992, Hong et al 2020, SDS is known for bactericidal and bacteriostatic effects which will directly affect the microbiome (Baker et al 1941, Brandt et al 2001, Mousavi and Khodadoost 2019, and Cr(VI) is known for being able to cross and disturb biological membranes affecting microorganism in the microbiome with no resistance mechanisms (Babich et al 1980, Breton et al 2013, Hose et al 2016, Assefa and Köhler 2020, Bojarski et al 2021. We argue that this effect depends directly on the toxicity of the toxicant itself.…”

“…Pyrethroids are extensively applied in agriculture, aquaculture, and forestry as pest control agents (Mestres andMestres 1992, Hong et al 2020), and they can enter the aquatic ecosystem via stormwater run-off from urban landscaping and home gardens as well as wastewater effluent and agricultural run-off (Jiang et al 2010, Weston et al 2013. DMT can negatively affect a variety of organisms including mammals and birds, but it is highly toxic to aquatic organisms such as fish and aquatic arthropods (Dawood et al 2020, Hong et al 2020. Esfenvalerate has also been shown to have negative effects on the survival and development on many aquatic invertebrates (Beketov 2004, Forbes and Cold 2005, Amweg et al 2006, Brady et al 2006, Rasmussen et al 2013, Rodrigues et al 2015.…”

Bioaccumulation of estrogenic hormones and UV-filters in red swamp crayfish (Procambarus clarkii)

“…Three male and three female crayfish were collected from each tank at days 0, 14, 28, 42, and 56 to measure estrogen and UVfilter concentrations in the tail tissue and examine potential differences in EDC accumulation by sex. In accordance with protocols from previous studies (Hong et al, 2020;Wei and Yang 2016), crayfish were anesthetized on ice for 30 min before dissection. The abdomen, telson, and uropod tissues (i.e., described as the "tail tissue" below) were collected, freeze-dried, massed, and kept at −20°C until analysis of estrogens and UV-filters by LC-MS/MS.…”

Microplastic Exposure Across Trophic Levels: Effects on the Host Microbiota of Freshwater Organisms

“…Pyrethroid pesticides and DMT have a half-life that ranges from 25 to 72 days depending on the substrate, and they have been found in concentrations of 0.04-24 µg/L in agricultural areas, 0.1-6.0 µg/L in water bodies and up to 100 µg/L in bottom sediments (Mestres and Mestres 1992, Pawlisz et al 1998, Liess et al 1999, Beketov et al 2013, Toumi et al 2015. Other studies used a sub-lethal dose of DMT at concentrations of 0.25 µg/L to 15 µg/L (Toumi et al 2015, Dawood et al 2020, Hong et al 2020. The chosen concentration of DMT was therefore 0.2 µg/L of aerated DMT.…”