Quercetin-induced amelioration of deltamethrin stress in freshwater teleost, Channa punctata: Multiple biomarker analysis.

We aimed to ascertain whether ubiquitous plant-based polyphenolic flavonoid compound quercetin (Q) was capable of alleviating deltamethrin (DM) stress in a freshwater teleost, Channa punctata, with emphasis on levels of acetylcholinesterase (AChE), reduced glutathione (GSH), glutathione-S-transferase (GST), DNA/RNA contents and hematological parameters. We measured these parameters in various tissues of fish at 7 and 21 days of exposure to DM doses (0.03 and 0.15 µL L-1), Q (0.14 g L-1) and their combinations (0.03 µL DM L-1 + 0.14 g Q L-1 and 0.15 µL DM L-1 + 0.14 g Q L-1). Both the DM doses altered blood parameters, lowered DNA/RNA contents, AchE activities, GSH levels and augmented GST activities as a mark of neurotoxicity and oxidative stress in fish tissues. We found that 0.14 g L-1 Q ameliorated oxidative stress and AchE inhibitory effects, recovered DM-induced nucleic acid damage and alterations in blood parameters, with some tissue specificity and in duration-dependent manner. Thus, the results indicated that Q was capable of neuroprotection and enhancing the function of antioxidants in fish, which could be predicted to be useful for providing better protection to fish under aquaculture settings with improved Q-rich diets. Through this study with multiple biomarkers in several tissues of fish, valuable information for devising better strategies regarding pesticide risk assessment was obtained and it was recognized that an appropriate dose of Q was essential for its better functioning.

Deltamethrin Induced Alteration of Biochemical Parameters in Channa punctata, Bloch and its Amelioration by Quercetin.

We tested the impacts of pyrethroid pesticide deltamethrin and its amelioration by a flavonoid, quercetin, using tissue macromolecules (protein, amino acid, carbohydrate and glycogen) and antioxidant enzymes (superoxide dismutase, catalase and peroxidase) as biomarkers, on fish, Channa punctata, gill and liver. Our study proved that quercetin supplement alone, in the absence of pesticide, might be detrimental to fish health, in terms of depletion of major tissue macromolecules, but, such supplement may be beneficial to fish with pesticide associated oxidative stress. Multivariate analyses predicted that the antioxidant enzymes and lipid peroxidation were closely associated biomarkers; whereas tissue macromolecules formed a different cluster. Hence, oxidative stress biomarkers in fish can be considered a valuable tool in assessment of deltamethrin stress and its amelioration by quercetin. The work can pave the way for further research in establishing quercetin as a probable curative agent.