Short-term feeding with a diet supplemented with alcoholic extract of Artemisia annua enhances the resistance and growth performance of juvenile Nile tilapia ( Oreochromis niloticus )

The bioactive compounds of Artemisia annua have been used as feed supplements due to their pharmacological activities. The present study examined the effect of short-term feeding with a supplemented diet on the growth, feed efficiency, intestinal morphology, stress, immune system, and antioxidant biomarkers of juvenile Nile tilapia ( Oreochromis niloticus ) to evaluate the efficacy of using an alcoholic extract of A. annua (ae-Aa) as an additive in fish feed. Juvenile fish (200 fish, 30.43 ± 0.54 g) were distributed in 10 tanks (400 L, 20 fish/tank) corresponding to two treatments, each with five replicates. The fish were fed either a control diet (37% protein, 11% lipid: ae-Aa free) or an equivalent diet containing 0.5% ae-Aa to satiation for 15 days. Subsequently, blood, liver, and intestine samples were obtained from 10 fish per treatment group (2 fish per tank). Dietary supplementation with ae-Aa affected the leukocyte count (27.9 vs. 19.7 × 103 µL −1 , ae-Aa group vs. control group), leukocyte respiratory activity (0.3 vs. 0.2 DO), and serum lysozyme concentration (28.1 vs. 22.4 ng dL −1 ) but not blood cells or the oxygen-carrying capacity. Treatment with ae-Aa reduced the plasma cortisol level (11.0 vs. 15.1 µL −1 ) but did not affect the levels of either glucose or chloride. Dietary ae-Aa influenced hepatic catalase (453.2 vs. 255.7 µmol H 2 O 2 mg pt −1 min −1 ), glutathione-S-transferase (406.9 vs. 279.8 nmol mg pt −1 min −1 ), glutathione (4.5 vs. 2.9 nmol mg pt −1 ), and superoxide dismutase activity (22.4 vs. 20.1 U mg pt −1 ) and thus affected the antioxidant capacity, as reflected by reductions in lipid peroxidation (21.3 vs. 34.4 nmol mg pt −1 ) and DNA damage (26.7 vs. 32.2 µg DNA mg pt −1 ). Dietary ae-Aa increased the intestinal villus area and improved growth (body mass, 24.2 vs. 20.7 g; body length, 2.0 vs. 1.6 cm). Based on the above-described results, the administration of dietary ae-Aa, even for a short period, may have beneficial effects on immunity and oxidant defences and enhance the growth rate.