Anesthetic efficacy and biochemical effects of 1,8-cineole on Caspian trout, Salmo caspius

In this study, Caspian trout, Salmo caspius (232 +/- 26.9 g) were exposed to 25, 50, 100, 200, 300, 400, 600, 800, and 1000 mu L/L of 1,8-cineole (cineole) to determine times needed for induction of and recovery from anesthesia (six fish concentration). Then, the fish were deeply anesthetized within 3 min [(RA); 483 mu L/L], deeply sedated within 10 min [(DS); 200 mu L/L], or lightly sedated within 180 min [(LS); 50 mu L/L] and blood-sampled (six fish concentration). There was a significant relationship between the induction time of anesthesia and cineole concentration (R-2 = 0.94). RA fish exhibited significant decrements in plasma chloride levels (P = 0.007; 108 +/- 0.48 vs. 112 +/- 0.90 mEq/L) and superoxide dismutase activity (P < 0.001; 49.7 +/- 0.42 vs. 54.5 +/- 0.76 U/L) and elevations in plasma lysozyme activity (P = 0.017; 31.7 +/- 0.44 vs. 26.9 +/- 0.49 U/L), glutathione peroxidase activity (P < 0.001; 611 +/- 5.77 vs. 363 +/- 5.56 U/L), and malondialdehyde level (P = 0.026; 170 +/- 6.19 vs. 149 +/- 1.05 mu M/L), compared to the non-anesthetized fish (NA). DS fish exhibited an elevation in plasma glutathione peroxidase activity (P < 0.001; 496 +/- 16.2 vs. 363 +/- 5.56 U/L), whereas LS fish showed the same elevation as well as elevations in plasma ammonia (P = 0.018; 312 +/- 24.2 vs. 227 +/- 11.9 U/L) and urea (P = 0.046; 2.47 +/- 0.34 vs. 1.58 +/- 0.17 U/L) levels, compared NA fish. In conclusion, cineole induces deep anesthesia in Caspian trout within 5.63-1.83 min at the concentrations of 300-1000 mu L/L. Deep sedation with 200 mu L/L cineole is the ideal anesthesia protocol for Caspian trout as it induced less physiological changes in the fish plasma.

Automated summary

The study showed that cineole can induce deep anesthesia in Caspian trout within 5.63-1.83 minutes at concentrations of 300-1000 μL/L. Deep sedation with 200 μL/L cineole is the ideal anesthesia protocol for Caspian trout, as it caused fewer physiological changes in the fish plasma.