Histopathological and molecular responses of goldfish (Carassius auratus) exposed to sodium and manganese sulfates

Abstract

Aquatic environments are increasingly subjected to anthropogenic pollutants, including sulfate as sodium sulfate (Na2SO₄) and manganese sulfate (MnSO4), which can have deleterious effects on aquatic organisms. Our study investigates the histological alterations and gene expression changes in goldfish (Carassius auratus) exposed to Na2SO₄ and MnSO4. Goldfish with an average size of 20.42±3.25 g were divided into seven groups and reared for 96 hours. Group 1 served as the control group. Groups 2, 3, and 4 were exposed to MnSO4 at 3.76 mg/L, 7.52 mg/L, and 11.28 mg/L, respectively. Groups 5, 6, and 7 were exposed to Na2SO₄ at 1.598 g/L, 3.196 g/L, and 4.794 g/L, respectively. These doses correspond to 20%, 40%, and 60% of their respective LC50 values. Histological examinations of gill, liver, and muscle tissues were conducted to assess structural changes. Additionally, gene expression profiling for myogenic differentiation protein1 (MyoD), muscle RING Finger 2 (MURF2), and insulin like growth factor (IGF-1), was performed to elucidate molecular responses to the exposure. Preliminary findings reveal notable histological alteration, including gill epithelial damage, hepatic alterations, and renal changes, suggesting organ-specific sensitivity to Na2SO₄ and MnSO4 exposure. Furthermore, the differentially expressed genes associated with stress response, detoxification mechanisms, and inflammation pathways were identified by gene expression analysis of MyoD, MURF2, IGF-1. The results of this study shed light on potential mechanisms underlying the observed histological changes and molecular responses. Understanding these impacts is crucial for effective aquatic ecosystem management and the development of strategies to mitigate the adverse effects on aquatic organisms.