An Evaluation of the Anesthetic Properties and Serum Biochemical Response of Ocimum Essential Oil as a New Anesthetic Agent for Goldfish (Carassius auratus)

The objective of this research was to investigate the anesthetic properties of essential oil from <i>Ocimum tenuiflorum</i> L. (OTO) and <i>Ocimum basilicum</i> L. (OBO), which belong to the Lamiaceae family. They are used as flavoring agents, food preservatives, and traditional medicines. The serum biochemical responses were examined post-recovery to assess the impacts of anesthetics on stress levels in comet goldfish (<i>Carassius auratus</i>). The results revealed that OTO at concentrations of 80, 100, and 120 mg/L could induce deep anesthesia in 257 s, 170 s, and 136 s, and the recovery time was 293 s, 270 s, and 263 s, respectively. A greater concentration of OTO led to shortened induction times. OBO at 250 and 300 mg/L induced deep anesthesia in 212 s and 190 s, and the recovery time was significantly prolonged to 263 s and 554 s, respectively. Moreover, the effective concentrations (EC₅₀) within 3 min were 85.78 mg/L (OTO) and 306.49 mg/L (OBO). The blood parameters showed that the glucose and cortisol levels in only the OTO group remained significantly lower compared to all the other treatment groups. The ALT and ALP levels were elevated in the OBO group compared to those in the OTO group. In the OBO and MS-222 groups, albumin was significantly different from that in the OTO group. Moreover, the serum calcium, phosphorus, BUN, and creatinine levels were not significantly different in any of the groups. In conclusion, OTO and OBO have been shown to be efficient natural anesthetics in goldfish, with no mortality.