Gaultheria procumbens essential oil longevity and oxidant/antioxidant status of silver catfish Rhamdia quelen experimentally infected by Aeromonas caviae

The increase in bacterial resistance in animals and the buildup of antimicrobials in animal meat pose significant nutritional and economic challenges. Given this context, this study explored the potential of Gaultheria procumbens essential oil (GPEO) as a sustainable alternative for aquaculture, focusing on its effects against Rhamdia quelen infected with Aeromonas caviae. Longevity tests revealed that R. quelen, when treated with 5 and 10 µL/L of GPEO, displayed significantly improved survival rates compared to both the untreated infected control group and those treated with ethanol. To understand the mechanisms behind the increased survival, a subsequent experiment with a 10 µL/L GPEO treatment aimed to investigate the oxidative stress pathway. This involved measuring levels of thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS), alongside enzyme activities for superoxide dismutase, glutathione peroxidase, and glutathione S-transferase. Our findings showed elevated TBARS and ROS levels in the non-infected control group treated with GPEO, suggesting an increase in these enzymes as a response to ROS balance. Therefore, our data indicate that the mechanism leading to enhanced longevity in R. quelen infected and treated with GPEO does not involve the oxidative stress pathway.