Evaluation of Intermediary and Mitochondrial Metabolic Responses to 4-nonylphenol in the Freshwater Fish, Labeo Rohita

Abstract

\n 4-Nonylphenol (4-NP) is a breakdown product of nonylphenol ethoxylate (NPE) and attains much concern because of its persistence and toxicity to aquatic organisms. 4-nonylphenol is a known endocrine disruptor and a legendary xenoestrogen. However, non-estrogenic impacts of 4-NP were scarcely studied in aquatic organisms. Hence, the present study evaluated the effects of sublethal concentrations of 4-NP (1.5, 2 and 2.5µl/l) on major carp, Labeo rohita in the intermediary and mitochondrial metabolism. Exposure to 4-NP shows significant changes in the activities of intermediary enzymes like glucose 6 phosphatase, lactate dehydrogenase, cytosolic malic enzyme and isocitrate dehydrogenase and mitochondrial enzymes like malate dehydrogenase, nicotinamide adenine dinucleotide dehydrogenase, succinate dehydrogenase and cytochrome c oxidase when compared to the control (p<0.05). Therefore, the current study indicates that 4-NP at environment concentration impairs the activity of metabolic enzymes and thereby affects the tricarboxylic acid cycle and electron transport system. Alteration in the levels of these parameters can be effectively used to surveil the impact of 4-NP in energy production in aquatic environment.