Cypermethrin Formulation (Ustad-10 EC) Induces Genotoxicity via Apoptosis, Affects Nutritional Physiology, and Modulates Immune Response in Silkworm Philosamia ricini (Lepidoptera: Saturniidae)

Abstract

Cypermethrin is a pyrethroid insecticide with high insecticidal activity, low mammalian toxicity, and biodegradability. The present study aimed to determine the acute toxicity and evaluate the secondary toxic effects of a commercial formulation of cypermethrin on silkworm Philosamia ricini Hutt of Northeast India. The potential genotoxicity of cypermethrin on silkworm hemocyte was examined by comet assay, caspase activation, and annexin V affinity assay. Alteration in nutritional physiology and histoarchitecture of the gut region was evaluated. Additionally, immunotoxicological effect of cypermethrin was studied by phenoloxidase (PO), lysozyme assay, and abundance of circulating hemocytes. The LC50 value at 24-, 48-, 72-, and 96-h exposure period was recorded as 185.96, 105.34, 72.42, and 58.41 µg/liter, respectively. Approximately sevenfold increase in mean comet tail length was observed at 24 h posttreatment with sublethal concentrations of cypermethrin. Cypermethrin also induced apoptosis and activated caspase reaction in silkworm hemocytes. Moreover, a significant decrease in digestive enzyme activity was observed at higher concentrations of cypermethrin. In cypermethrin-exposed groups, alteration in histoarchitecture was also observed in the form of ruptured microvilli and thin, deformed, fused mucous layer. The PO enzyme and lysozyme enzyme activity was also altered with sublethal concentration of cypermethrin. Total hemocyte count was reduced to 10587.10, 10052.30, 9234.30, and 8842.60 per mm3 with 10, 20, 30, and 40 µg/liter, respectively. The results offer new insights into the negative consequences of very low concentrations of cypermethrin formulations on nonmulberry silkworm of Northeast India.

Atrazine Exposure Influences Immunity in the Blue Dasher Dragonfly, Pachydiplax longipennis (Odonata: Libellulidae)

“…These results are important because of the paucity of information on invertebrate immunity and atrazine. While the effects of atrazine on vertebrate immunity have received a great deal of attention ( Rohr and McCoy 2010 , Sifkarovski et al 2014 ) and several authors have documented effects of other agrochemicals on invertebrate immune systems ( Chen et al 2017 , Kalita et al 2017 , Zhu et al 2017 ), we did not find studies examining the impact of atrazine on invertebrate immune systems, despite the high levels of use in the United States ( Atwood and Paisley-Jones 2017 ).…”

“…Immune stress from environmental contaminants is likely to place additional strain on this cost/benefit system ( Guedes et al 2016 ). A number of authors have documented the impact of pesticides on economically important terrestrial species ( Chen et al 2017 , Kalita et al 2017 , Zhu et al 2017 ). However, fewer studies have focused on immunological impacts of pesticides on nontarget insect species, particularly in the aquatic environment.…”

Biosynthesis of Lemongrass Essential Oil and the Underlying Mechanism for Its Insecticidal Activity

“…Haemocytes are considered to have a significant part in maintaining the cellular and humoral immune system in insects (Kalita and Devi, 2016). Others (Kalita et al, 2017;Kalita and Devi, 2016) suggested that haemocytes viability can be modulated either by targeting constituents of insect immune systems or by regulating immune responses. Such alterations negatively influence the hematopoietic system along with the aberration in endocrine gland activity (Feroz, 2020).…”

Consequences of larval competition and exposure to permethrin for the development of the rodent malaria Plasmodium berghei in the mosquito Anopheles gambiae

“…Alternatively, the observed effects may be due to an indirect effect of the insecticide on mosquito physiology and immunity. Insecticides can affect insect immunity in several ways (reviewed in [55]), including effects on the number of hemocytes [56], on the activity of immune enzymes [57,58], on the melanisation and antibacterial responses [5] and on oxidative stress. Indeed, pyrethroid insecticides are a major source of reactive oxygen species (ROS) in exposed organisms [3,4,59], and ROS are a common immune defense against many pathogens [60], including Plasmodium [61][62][63].…”