Essential oil of Ocimum gratissimum (Linnaeus, 1753): efficacy for anesthesia and transport of Oreochromis niloticus.

Abstract

This study aimed to evaluate the essential oil of Ocimum gratissimum L. (EOOG) for anesthesia and in the transport of Oreochromis niloticus. Experiment I determined the time of anesthesia induction and recovery during anesthesia of O. niloticus exposed to different concentrations of EOOG (0, 30, 90, 150, and 300mgL-1). Based on data from Experiment I, Experiment II evaluated the effect of 0, 30, and 90mgL-1 EOOG on blood parameters and oxidative stress immediately after anesthesia induction and 1h after recovery. Experiment III evaluated the effect of 0, 5, and 10mgL-1 EOOG on blood variables immediately after 4.5h of transport of juveniles. Concentrations between 90 and 150mgL-1 EOOG were efficient for anesthesia and recovery. The use of 90mgL-1 of EOOG prevented an increase in plasma glucose. Other changes in blood parameters and oxidative stress are discussed. The use of 10mgL-1 EOOG in transport increased plasma glucose and decreased hematocrit values immediately after transport. It is concluded that the use of 90 and 150mgL-1 EOOG causes anesthesia and recovery in O. niloticus within the time intervals considered ideal. The use of 90mgL-1 EOOG favored stable plasma glucose soon after anesthesia induction and 1h after recovery, but caused changes in the antioxidant defense system by increasing hepatic and kidney ROS. The transport of 12g O. niloticus for 4.5h can be performed with concentration of 5mgL-1 of EOOG.