Free radical generation during the activation of hemolymph prepared from the homopteran Dactylopius coccus

Abstract

Superoxide anion (O(-) (2)) and nitric oxide (NO) generation in Dactylopius coccus hemolymph obtained by perfusion and activated with zymosan was studied. Activated hemolymph reduced 3-[4,5 dimethylthiazolil-2]-2,5-diphenyl tetrazolium bromide. This reduction was prevented by superoxide dismutase (SOD) indicating O(-) (2) generation. This activity was dependent on temperature, and hemolymph incubated at 75 degrees C lost its activity. Chromatocytes incubated with zymosan released their content and produced O(-) (2). Activated hemolymph also produced NO and this activity was prevented in the presence of NG-nitro-L-arginine methyl ester, suggesting that nitric oxide synthase (NOS) might be present in D. coccus hemolymph. The probable source of O(-) (2) in the D. coccus hemolymph is the anthraquinone oxidation, since commercial carminic dye produced O(-) (2) during its oxidation by Agaricus bisporus tyrosinase. Gram+ Micrococcus luteus exposed to activated hemolymph were killed in vitro, and addition of NG-nitro-L-arginine methyl ester and D-Mannitol (a hydroxyl radical scavenger) prevented their killing. The cytotoxic effect produced by the activated hemolymph was not observed with the Gram- bacteria Serratia marcescens. These results suggest that D. coccus activated hemolymph generates reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI) that may limit M. luteus growth.

Wolbachia and the insect immune system: what reactive oxygen species can tell us about the mechanisms of Wolbachia–host interactions

“…What do we know about the involvement of ROS in innate immunity and host defense in insects other than Drosophila ? The production of ROS as a countermeasure to bacterial and/or fungal infection has been reported from species as diverse as the cockroach Blaberus discoidalis (Blattodea; Whitten and Ratcliffe, 1999 ), the silkworm Bombyx mori (Lepidoptera; Ishii et al, 2008 ), the scale insect Dactylopius coccus (Hemiptera; García-Gil de Muñoz et al, 2007 ), the greater wax moth Galleria mellonella (Lepidoptera; Bergin et al, 2005 ), the sand fly Lutzomyia longipalpis (Diptera; Diaz-Albiter et al, 2012 ), the tiger moth Parasemia plantaginis (Lepidoptera; Mikonranta et al, 2014 ), and the cattle tick Rhipicephalus microplus (Ixodida; Pereira et al, 2001 ). Hematophagous insects may also become infected by blood–borne parasites, e.g., the malaria parasite Plasmodium .…”

Carminic acid: an antioxidant to protect erythrocytes and DNA against radical‐induced oxidation

“…Recently, CarOH is found to be a ligand to form a complex with DNA and to be a molecular probe in femtosecond spectroscopic study on DNA 7. CarOH can produce superoxide anion when it is oxidized by Agaricus bisporus tyrosinase 8. But reports on the inhibition of CarOH on free‐radical‐induced oxidation of DNA and erythrocytes are seldom found.…”

Isolation and Identification of Saprolegnia Sp from Fresh Water Aquarium Fishes and the Hemolymph Immune Response of Dactylopus coccus Costa de 1835 (Homoptera: Coccoidea: Dactylopidae) against this Oomycete

“…These criteria set with variations in esterase isoenzyme patterns [12] and differences in radial growth rate [13] allow classifying isolated Saprolegnia sp. strains in different subgroups [14]. On the other hand, recent research shows that the identification of Saprolegnia species using traditional taxonomic criteria and keys on parasitic isolates, at best, has proven problematic [15].…”