Evaluation of Metabolic Enzymes in Response to Excel Mera 71, a Glyphosate-Based Herbicide, and Recovery Pattern in Freshwater Teleostean Fishes

Abstract

Metabolic enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were evaluated in Indian teleostean fishes, namely,Anabas testudineus(Bloch) andHeteropneustes fossilis(Bloch), for an exposure to 30 days of Excel Mera 71 (17.2 mg/L), a glyphosate formulation, and subsequent depuration under Liv.52, a plant extract at a dose of 187.5 mg/d/250 L for the same period in the same tissues under laboratory condition. ALT activity was significantly increased (P<0.05) in all the tissues and raised up to 229.19% in liver ofA. testudineus(229.19%) and 128.61% in liver ofH. fossilis. AST also increased significantly (P<0.05) and was maximum in liver ofH. fossilis(526.19%) and minimum in gill ofA. testudineus(124.38%). ALP activity was also raised highly in intestine ofH. fossilis(490.61%) but was less in kidney ofH. fossilis(149.48%). The results indicated that Excel Mera 71 caused alterations in the metabolic enzymatic activities in fish tissues and AST showed the highest alteration in both the fishes, while lowest in ALP and ALT inA. testudineusandH. fossilis, respectively. During depuration under Liv.52, all the enzyme activities came down towards the control condition which indicated the compensatory response by the fish against this herbicidal stress and it was in the following order: AST > ALT > ALP, inA. testudineus, whileH. fossilisshowed the following trend: ALT > AST > ALP. Therefore, these parameters could be used as indicators of herbicidal pollution in aquatic organisms and were recommended for environmental monitoring for investigating the mechanism involved in the recovery pattern.