20-Hydroxyecdysone prevents oxidative stress damage in adult Pyrrhocoris apterus.
Injections of 38 pmol paraquat (1,1'-dimethyl-4,4'-bypyridilium) into adult Pyrrhocoris apterus (average body weight 29.6 mg in males and 36.9 mg in females) caused a significant elevation of lipid peroxidation and protein carbonylation and a decline of membrane fluidity in the microsomal brain fraction. Another manifestation of oxidative stress was a depletion of the reduced glutathione pool and reduction of the gamma-glutamyl transpeptidase activity in the brain extracts. The damaging action of paraquat on the brain was counteracted by simultaneous injection of 1 pmol 20-hydroxyecdysone (20E). 20E restrained lipid peroxidation and the formation of protein carbonyls, ameliorated changes in microsomal membrane fluidity, enhanced the level of reduced glutathione, and upregulated the activity of gamma-glutamyl transpeptidase. At the organismic level, 20E curtailed three detrimental effects caused by paraquat injection: the disappearance of a blood protein, the suppression of fecundity and egg hatchability, and the shortening of adult life span. The data showed that 20E provided a systemic antioxidant protection but the significance of endogenous ecdysteroids in the management of oxidative stress remains to be shown.
Krishnan
Natraj
N
Department of Physiology, Institute of Entomology, Biology Centre, Czech Academy of Sciences, Ceské Budejovice, Czech Republic.
Vecera
Josef
J
Kodrík
Dalibor
D
Sehnal
Frantisek
F
D000818:Animals; D015415:Biomarkers; D004441:Ecdysterone / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006458:Hemolymph / Q000737:chemistry; D006540:Herbicides / Q000494:pharmacology; D020062:Heteroptera / Q000187:drug effects* / Q000378:metabolism*; D019476:Insect Proteins / Q000032:analysis; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects*; D010269:Paraquat / Q000494:pharmacology; D012727:Sex Characteristics; D005723:gamma-Glutamyltransferase / Q000378:metabolism
D015415:Biomarkers; D006540:Herbicides; D019476:Insect Proteins; D004441:Ecdysterone; D005723:gamma-Glutamyltransferase; D005978:Glutathione; D010269:Paraquat