Diet Supplemented With <i>Tribulus terrestris</i> Improves Hepatoprotection and Oxidative Stress in Nile Tilapia ( <i>Oreochromis niloticus</i> ) Fingerlings

ABSTRACT Phytogenic additives such as Tribulus terrestris are known to promote various beneficial effects. Although most well‐documented benefits relate to reproductive performance, their consumption may also induce positive physiological effects. This study aimed to evaluate the effects of supplementing Nile tilapia diets with different concentrations of T. terrestris (200, 400, and 600 mg kg −1 ) compared to a control group (0 mg kg −1 ). The 32‐day experiment was conducted in a recirculation system with 12 tanks, each treatment replicated three times, with 15 fingerlings per tank. We assessed zootechnical performance, enzymatic activities—including alanine aminotransferase (ALT), aspartate aminotransferase (AST), superoxide dismutase (SOD), catalase (CAT), amylase and alkaline phosphatase (ALP)—fish proximate composition (moisture, crude protein, crude fat and ash), and histomorphometric analyses of liver and intestine. Results showed no significant differences in zootechnical performance or carcass composition. However, enzymatic activities varied significantly: T. terrestris enhanced amylase and ALP activities at all supplementation levels; SOD activity increased at 200 mg kg −1 but decreased at 600 mg kg −1 ; ALT and AST levels were reduced across all supplemented groups compared to control. Muscle histomorphometric showed decreased fibre diameters with supplementation, suggesting inhibition of muscle hypertrophy. Overall, T. terrestris exhibited hepatoprotective effects and improved amylase activity but did not affect zootechnical performance. In conclusion, dietary supplementation with T. terrestris influenced enzymatic activities and muscle histomorphometry in Nile tilapia, notably enhancing amylase and ALP activities, which may improve dietary nutrient absorption.