title: Dichlone-induced oxidative stress in a model insect species, Spodoptera eridania.
abstract: Southern armyworm, Spodoptera eridania, larvae were provided ad libitum 0.002-0.25% w/w dichlone, 2,3-dichloro-1,4-naphthoquinone (CNQ). Larval mortality occurred in a time-and-dose dependent manner, with an LC17 of 0.01% and an LC50 of 0.26% CNQ at day-5. Extracts of larvae fed control, 0.01, and 0.25% CNQ diets for 5 days were assayed for antioxidant enzymes. While 0.01% CNQ had a mild effect, 0.25% CNQ profoundly increased levels of all antioxidant enzymes that were examined. The increases as compared to control were: 5.3-, 1.9-, 3.2-, 2.6-, 2.8-, and 3.5-fold higher for superoxide dismutase, catalase, glutathione transferase and its peroxidase activity, glutathione reductase and DT-diaphorase, respectively. At 0.01% CNQ, the thiobarbituric acid reactive substances (TBARS) were similar to the control group. However, despite the induction from 0.25% CNQ of all enzymes examined, the lipid peroxidation was not attenuated; the TBARS were 29.7% over the control value. High mortalities and CNQ-induced pathologies reflected in retarded growth, wasting syndrome, and diuresis clearly indicated that the insect sustained severe oxidant-induced injuries before appropriate defenses were fully mobilized. Thus, this quinone causes an oxidative stress in a model insect species analogous to that observed in mammalian species.
authors.affiliation: Department of Biochemistry/330, University of Nevada, Reno 89557-0014, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ahmad
authors.forename: K
authors.initials: K
authors.lastname: Zaman
authors.forename: R S
authors.initials: RS
authors.lastname: MacGill
authors.forename: J P
authors.initials: JP
authors.lastname: Batcabe
authors.forename: R S
authors.initials: RS
authors.lastname: Pardini
mesh_terms: D000818:Animals; D005659:Fungicides, Industrial; D007814:Larva / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development; D007928:Lethal Dose 50; D009285:Naphthoquinones; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000187:drug effects / Q000378:metabolism; D018411:Spodoptera / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development
chemical_list: D005659:Fungicides, Industrial; D009285:Naphthoquinones; C007332:dichlone; D010088:Oxidoreductases