Modulation of immune and antioxidant responses by azinphos‐methyl in the freshwater mussel Diplodon chilensis challenged with Escherichia coli

Abstract

The aim of the present study was to characterize the immune response-total hemocyte number, cell type proportion, hemocyte viability, lysosomal membrane stability, phagocytic activity, cellular acid and alkaline phosphatase activity, and humoral bacteriolytic and phenoloxidase activity--in Diplodon chilensis exposed to 0.2 mg/L of azinphos-methyl (AZM), using Escherichia coli as immunological and pro-oxidant challenges. In addition, glutathione-S-transferase and lipid peroxidation thiobarbituric acid reactive substances were analyzed in gill tissue. Mussels from an unpolluted site were treated for 3 d as follows: 1) experimental control; 2) solvent effects control (acetone 0.01%); 3) bacterial challenge effects control (E. coli, 5 cells/mL × 10 cells/mL); 4) pesticide effects control (AZM in acetone); 5) control for combined effects of solvent and bacterial challenge; and 6) exposed to AZM, then challenged with E. coli. The results showed increased granulocyte proportion and phagocytic activity. Partial reversion of deleterious effects of E. coli on lysosomal membranes was observed in mussels exposed to AZM and then challenged with E. coli. Total hemocyte number and humoral bacteriolytic activity were increased only by E. coli challenge. Acid phosphatase activity was increased by both E. coli and AZM, whereas the stimulating effect of E. coli on alkaline phosphatase activity was negatively modulated by AZM. Azinphos-methyl inhibited phenoloxidase activity regardless of the E. coli challenge. Gill glutathione-S-transferase activity was increased by E. coli treatment either alone or pretreated with acetone or AZM and by AZM alone. Thiobarbituric acid reactive substance levels were reduced by AZM alone or combined with the E. coli challenge and by acetone followed by the E. coli challenge. Both acetone and AZM seem to be important modulators of immune and antioxidant responses in D. chilensis. Environ Toxicol Chem 2017;36:1785-1794. © 2016 SETAC.

Biochemical responses of the golden mussel Limnoperna fortunei under dietary glyphosate exposure

“…Moreover, Neškovic et al (1996) found an increase in ALP activity in the liver and heart of the fish Cyprinus carpio exposed to 5 and 10 mg L −1 of glyphosate acid. The increase in ALP activity of L. fortunei with dietary glyphosate exposure could be related with a modulation of the immune response and/or cellular damage, as has been postulated for the clams D. chilensis and A. rhombea exposed to pesticides (Castro et al, 2017;Ranilalitha et al, 2014)…”

“…Alterations in ALP activity have been associated with the response to contaminants exposure. For example, Castro et al (2017) recorded an induction of ALP activity in hemocytes of the clam Diplodon chilensis exposed to the pesticide azinphos-methyl, Aanand et al (2010) observed an induction of ALP activity in gut and adductor muscle in the mussel Perna viridis exposed to metals and Ranilalitha et al (2014) recorded an increase in ALP activity in the digestive gland of the clam Anadara rhombea exposed to pesticide tributyltin chloride. Moreover, Neškovic et al (1996) found an increase in ALP activity in the liver and heart of the fish Cyprinus carpio exposed to 5 and 10 mg L −1 of glyphosate acid.…”

“…Thus, the lipid and protein oxidation markers (thiobarbituric reactive substances -TBARS-, and carbonyl contents), the levels of the antioxidant metabolite reduced glutathione (GSH), and the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) are commonly evaluated in pesticide exposed bivalves (Mottier et al, 2015). Other enzymes that could be altered in bivalves exposed to pesticides are the detoxification enzymes glutathione-S-transferase (GST) and carboxylesterases (CES), the general metabolism enzyme alkaline phosphatase (ALP) and the organophosphate sensitive enzyme acetylcholinesterase (AChE) (Castro et al, 2017;Galloway et al, 2002).…”

In situ experiment to evaluate biochemical responses in the freshwater mussel Diplodon chilensis under anthropogenic eutrophication conditions

“…Hemolymph (1 mL) was withdrawn from the adductor muscle of 6 individuals per time and site using a sterile syringe and working on ice. Part of the hemolymph was used for lysosomal membrane stability and the remaining was washed and resuspended in anticoagulant solution (3 g L −1 glucose and 0.36 g L −1 trisodium citrate, 60 mOsm L −1 , pH 7, Castro et al, 2017) to obtain the hemocytes fraction for measuring ROS production. Hemocytes lysosomal membrane stability was measured by the neutral red retention time (NRRT50) method (modified from Mamaca et al, 2005).…”

Effects of Dietary Copper and Escherichia coli Challenge on the Immune Response and Gill Oxidative Balance in the Freshwater Mussel Diplodon chilensis

“…In freshwater species, like Diplodon chilensis, granulocytes have higher phagocytic activity, but hyalinocytes represent >90% of the total hemocytes. Thus, hyalinocytes are the principal immune response cells (Castro et al, 2017(Castro et al, , 2018. In addition, humoral soluble factors, such as antimicrobial peptides, lectins, lysosomal hydrolases, and phenol oxidase, are released by cells into the hemolymph and participate in processes of melanization/encapsulation and wound healing.…”