scholarly journals Biotransformation and oxidative stress responses in fish (Astyanax aeneus) inhabiting a Caribbean estuary contaminated with pesticide residues from agricultural runoff

Freylan Mena ◽  
Seiling Vargas ◽  
Meyer Guevara-Mora ◽  
J. Mauro Vargas-Hernández ◽  
Clemens Ruepert

Abstract The estuarine ecosystem of Laguna Madre de Dios (LMD), in the Caribbean coast of Costa Rica, is exposed to contamination with pesticide residues coming from the upstream agricultural areas. Biomarkers can provide a better indication of the fitness of biota in real mixture exposure scenarios than traditional lethal dose toxicity measurements. Here, we measured biomarkers of biotransformation, oxidative stress and neurotoxicity on Astyanax aeneus, an abundant fish species in LMD. Glutathione S-transferase activity (GST), catalase activity (CAT), lipid peroxidation (LPO), and cholinesterase activity (ChE) were measured in fish collected during seven sampling campaigns, carried out between 2016 and 2018. Pesticide residues were analysed in surface water samples collected every time fish were sampled. Residues of 25 pesticides, including fungicides, insecticides and herbicides, were detected. The biomarkers measured in A. aeneus varied along the sampling moments, however, biotransformation and oxidative stress signals showed coupled responses throughout the assessment. Furthermore, significant correlations were established between three biomarkers (GST, LPO and CAT) and individual pesticides, as well as between GST and LPO with groups of pesticides with shared biocide action. Among pesticides, insecticide residues had a major influence on the responses observed in fish. This work shows that the frequent exposure to environmentally relevant concentrations of pesticides can be related to physiological responses in fish that affect their health. This early warning information should be considered to improve the protection of estuarine ecosystems in the tropics.

Sinan Xiong ◽  
Wee-Joo Chng ◽  
Jianbiao Zhou

AbstractUnder physiological and pathological conditions, cells activate the unfolded protein response (UPR) to deal with the accumulation of unfolded or misfolded proteins in the endoplasmic reticulum. Multiple myeloma (MM) is a hematological malignancy arising from immunoglobulin-secreting plasma cells. MM cells are subject to continual ER stress and highly dependent on the UPR signaling activation due to overproduction of paraproteins. Mounting evidence suggests the close linkage between ER stress and oxidative stress, demonstrated by overlapping signaling pathways and inter-organelle communication pivotal to cell fate decision. Imbalance of intracellular homeostasis can lead to deranged control of cellular functions and engage apoptosis due to mutual activation between ER stress and reactive oxygen species generation through a self-perpetuating cycle. Here, we present accumulating evidence showing the interactive roles of redox homeostasis and proteostasis in MM pathogenesis and drug resistance, which would be helpful in elucidating the still underdefined molecular pathways linking ER stress and oxidative stress in MM. Lastly, we highlight future research directions in the development of anti-myeloma therapy, focusing particularly on targeting redox signaling and ER stress responses.

2007 ◽  
Vol 66 (5) ◽  
pp. 1240-1255 ◽  
Cristina E. Alvarez-Martinez ◽  
Rogério F. Lourenço ◽  
Regina L. Baldini ◽  
Michael T. Laub ◽  
Suely L. Gomes

Drug Research ◽  
2018 ◽  
Vol 69 (03) ◽  
pp. 151-158 ◽  
Abayomi Ajayi ◽  
Benneth Ben-Azu ◽  
Samuel Onasanwo ◽  
Olusegun Adeoluwa ◽  
Anthony Eduviere ◽  

Abstract Purpose Ocimum gratissimum L. leaves has been traditionally used for management of febrile illnesses and symptoms typified of sickness behavior. In this work we investigated the modulatory effect of flavonoid-rich fraction of O. gratissimum leaves (EAFOg) on sickness behavior, inflammatory and oxidative stress responses in LPS-challenged mice. Method O. gratissimum leaf was first extracted with n-hexane, chloroform and methanol, and EAFOg was obtained by ethylacetate partitioning of a sequentially resultant methanol extract. The effect of EAFOg (25–100 mg/kg) on acute LPS-induced neurobehavioral impairment in an open field test (OFT) and depressive-like behavior in forced swimming test (FST) was investigated. Serum nitrite and TNF-α, as well as myeloperoxidase (MPO), malondialdehyde (MDA), and reduced glutathione (GSH) levels were determined in liver and brain tissues. Result EAFOg prevented the reduction in locomotor and rearing activity in OFT and the increase in immobility time in FST. The fraction significantly attenuated the elevation of serum TNF- α and nitrite levels. EAFOg reversed LPS-induced increase in MDA, MPO, and nitrite levels and attenuated GSH depletion in liver and brain tissues of mice. Conclusion Flavonoid-rich fraction of O. gratissimum leaf demonstrated significant modulation of LPS-induced sickness behavior, inflammatory and oxidative stress response in mice. This suggests an important therapeutic strategy in slowing down LPS-mediated hepatic and neuronal disease processes.

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