Hepato-Renal Damage of Hyaluronic Acid on the African Catfish (Clarias gariepinus)

Hyaluronic acid (HA) is a versatile polysaccharide with a broad range of biological, pharmacological, and therapeutic applications due to its anti-inflammatory properties, low immunogenicity, natural breakdown, compatibility with live tissue, and capacity to promote cell growth and specialization. However, the potential negative effects of HA on aquatic ecosystems, especially fish, have not been fully investigated. This study examines for the first time the potential physiological, immunological, and histological effects of HA in African catfish, as well as the long-term implications following recovery. Four groups, totaling 24 African catfish in triplicate, were subjected to varying concentrations of HA (500–100,000 µg/L) over a 15-day exposure period, followed by a 15-day recuperation phase, leading to physiological changes dependent on the dosage. The electrolyte levels in the plasma and the equilibrium of redox processes were significantly upset by exposure to HÀ. Fish exposed to high HA concentrations displayed dose-dependent declines in immunological function and antioxidant enzymes. Only the fish exposed to modest doses of HA showed complete recovery when compared to the control fish, indicating that exposure to HA resulted in irreversible alterations. The histological investigations showed a number of dosage-dependent pathological alterations in the renal and hepatic tissues, including perivascular and peritubular fibrosis, tubular necrosis, and vacuolar degeneration. The degree of these alterations varied according to the dose. Concluding that fish may have irreversible alterations as a result of high acidity. The present study provides a fundamental understanding of the detrimental effects of HA on fish. To fully evaluate the potential dangers associated with HA exposure and its long-term effects on aquatic life, more research is needed.