Effect of Organophosphate Pesticide Dimethoate on Ascorbic Acid Levels in Various Tissues of Freshwater Fish Channa punctatus
R. Y. Bhandare
P.G. Department of Zoology, M.G.V’s Loknete Vyankatrao Hiray Arts, Science and Commerce College (Autonomous), Panchavati, District Nashik-422003, MS, India.
A. J. Kharat *
P.G. Department of Zoology, M.G.V’s Loknete Vyankatrao Hiray Arts, Science and Commerce College (Autonomous), Panchavati, District Nashik-422003, MS, India.
K. T. Paithane
P.G. Department of Zoology, Deogiri College, Aurangabd, India.
T. S. Pathan
Department of Zoology, Kalikadevi Arts, Commerce and Science College, Shirur (Ka), Dist. Beed, MS, India.
*Author to whom correspondence should be addressed.
Abstract
Pesticide contamination may disturb biochemical homeostasis in freshwater fish; however, tissue-specific responses of antioxidant metabolites to prolonged dimethoate exposure remain poorly understood. In the present study, changes in ascorbic acid levels in the liver, gills, and muscle tissues of Channa punctatus exposed to three sublethal concentrations of dimethoate (53.4, 26.6, and 17.8 ppm) were examined. A colourimetric hydrazine-based technique was used to quantify ascorbic acid in dried tissues, and responses were compared with those of control tissues. Dimethoate caused significant, tissue-specific changes in ascorbic acid. Hepatic concentrations increased significantly from 5.6487 ± 0.4048 mg/100 mg dry weight in controls to 7.6054 ± 0.3092, 7.4705 ± 0.2024, and 7.4300 ± 0.2142 mg/100 mg at 53.4, 26.6, and 17.8 ppm, respectively. Muscle concentrations also increased, reaching 7.2681 ± 0.4048 mg/100 mg at the highest exposure. Gill concentrations, in contrast, decreased significantly and were lowest at 53.4 ppm. These divergent responses demonstrate marked tissue specificity in ascorbate homeostasis during chronic sublethal pesticide stress. The results support the use of tissue-resolved ascorbic acid responses as informative biochemical indicators of dimethoate-induced stress in freshwater fish and suggest their potential inclusion alongside other ecotoxicological assessments of freshwater contamination.
Keywords: Ascorbic acid, liver, muscle, Gills, Dimethoate, Channa punctatus