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.