Cephalosporin-Induced Haemotoxicity, Apoptosis, DNA Damage in Clarias gariepinus: Ameliorative Role of Chlorella vulgaris.

Cephalosporin is increasingly recognized as an emerging aquatic pollutant capable of inducing systemic toxicity in non-target organisms. This study investigated the comparative toxic effects of three commonly used cephalosporins-cefepime, ceftriaxone, and cefotaxime-on African catfish (Clarias gariepinus), with emphasis on hematological, cytotoxic, genotoxic, hepatorenal, and metabolic alterations, as well as the potential protective role of dietary Chlorella vulgaris (50 g/kg feed). Fish were allocated into seven experimental groups: control, cefepime (0.5 mg/L), cefepime + C. vulgaris, ceftriaxone (1 mg/L), ceftriaxone + C. vulgaris, cefotaxime (1 mg/L), and cefotaxime + C. vulgaris, and exposed for 15 days. Exposure to cephalosporin induced significant hematological disturbances, including reductions in erythrocyte count, hemoglobin concentration, hematocrit, and total leukocyte count, together with marked changes in differential leukocyte profiles. In addition, all tested cephalosporin significantly increased erythrocyte apoptosis and DNA damage, as evidenced by elevated apoptotic cell percentages and increased comet assay tail moment values, confirming marked cytotoxic and genotoxic stress. Serum biochemical analyses revealed significant elevations in liver enzymes, renal function markers, total protein, total cholesterol, and glucose, indicating substantial hepatic, renal, and metabolic impairment, with cefepime generally exerting the most pronounced biochemical toxicity, whereas ceftriaxone produced the highest genotoxic response. Dietary supplementation with Chlorella vulgaris partially but significantly ameliorated many of these adverse effects by improving hematological indices, reducing erythrocyte apoptosis, attenuating DNA damage, and modulating hepatorenal and metabolic disturbances, although complete restoration to control levels was not consistently achieved. Collectively, these findings demonstrate that cephalosporin residues can induce multi-system toxicity in C. gariepinus, while C. vulgaris represents a promising natural dietary strategy for mitigating cephalosporin-induced physiological and cellular damage in aquatic organisms.