Effects of Ocimum basilicum essential oil and ginger extract on serum biochemistry, oxidative stress and gill tissue damage of pearl gentian grouper during simulated live transport.

Abstract

This study explored the effects of the essential oil of Ocimum basilicum (EOOB) and ginger extract (GE) during the transportation of pearl gentian grouper from water quality, serum biochemistry, oxidative stress, meat flavor, and gill tissue morphology. Fish (450 ± 50g) were allocated to the following 5 treatments: control group (fish transported in water only), 5mg/LEOOB, 10mg/LEOOB, 3mg/LGE, and 6mg/LGE and transported in insulation boxes (66 × 51 × 37.8cm) for 72h. Samples were taken at 0, 12, 36, 60, and 72h immediately after transport. It was found that 10mg/LEOOB and 6mg/LGE could reduce the levels of total ammonia nitrogen (TAN), dissolved oxygen (DO), water pH, serum glucose (GLU), cortisol (COR), liver superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and glutathione peroxidase (GPX), increase the activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH), as well as significantly increase the total free amino acid (TFAA) content in muscle compared to the control group (P < 0.05). In addition, by observing the microstructure of gill tissue, it was found that compared with untreated grouper, the morphological damage of gill tissue in EOOB and GE treatment was alleviated. These results indicated that adding appropriate amounts of EOOB and GE to transport water could improve the water quality, relieve stress, and lower energy metabolism of grouper during transport. The results of this research will help to improve the survival rate of grouper after transportation and decrease economic losses to fishery.