Histopathological and biochemical responses to the oxidative stress induced by glyphosate-based herbicides in the rainbow trout (Oncorhynchus mykiss)

Authors : Gökhan NUR, Haci Ahmet DEVECİ

Pages : 656-665

Doi:10.37212/jcnos.418666

View : 14 | Download : 9

Publication Date : 2018-04-26

Article Type : Research Paper

Abstract :This study aimed to determine the effects of  glyphosate, a herbicide commonly used in weed control,  on aquatic life. For this purpose, 30 one-year-old  rainbow trout with an average weight of 150-165 g were  obtained from a local trout production station in  Mazmanlı insert ignore into journalissuearticles values(Hatay, Turkey); and transferred to our  laboratory, where they were allowed to adapt to the new  environment in polyethylene tanks approximately for 7  days. Three groups each containing 10 fish were formed: a  control group with no treatment, the group treated with  1.25 mg/l glyphosate-based herbicide insert ignore into journalissuearticles values(GBH);, and the  group treated with 2.5 mg/l glyphosate-based herbicide.  At the end of 14 days of treatment, blood samples were  taken from the caudal vein of the fish under anaesthesia,  and their sera were separated. Total oxidant/antioxidant  levels and paraoxonase activity were analysed in the  obtained serum samples. Also, for histopathological  examination, gill tissues were removed and fixed in  10% buffered formalin. After the fixation and routine  tissue processing insert ignore into journalissuearticles values(graded alcohols, methyl benzoate and  benzol processing);, the tissues taken were embedded in  paraffin and 5 μm serial sections were taken by  microtome from the blocks to slides pre-coated with  chrome alum gelatine. Histopathological changes were  examined at the light microscopic level by staining the  sections with haematoxylin-eosin. According to the  evaluation of the biochemical parameters obtained from  the groups, antioxidant capacity and paraoxonase  activity decreased and oxidant level increased in the  group treated with 1.25 and 2.5 mg/l glyphosate-based  herbicide as compared with the control group. In the histopathological examination of the sections, it was  observed that the primary and secondary lamellae had a  normal structure in the gill sections obtained from the  control group. Irregular secondary lamellae and epithelial hyperplasia were observed in the gill sections  obtained from the group receiving 1.25 mg/l GBH. And  in the gill sections obtained from the group receiving  2.5 mg/ l GBH, swelling in chloride cells, degeneration  in secondary lamellae, and areas of necrosis were  detected. In conclusion, results of the study suggests  that glyphosate, which is widely used in agricultural  activities and has a potential to leak into aquatic  ecosystems, may cause oxidative stress due to reactive  oxygen species formed in the rainbow trout, and may  therefore has a toxic effect.
Keywords : Oncorhynchus mykiss, Glyphosate based herbicide, Oxidative stress, Histopathology, Gill