Dietary supplementation with Lippia sidoides essential oil improves organ integrity but the specific activity of antioxidant enzymes is dose-dependent in Danio rerio

The nutritional quality of food can affect the health of animals. This study examined the effects of dietary supplementation with Lippia sidoides essential oil (LSEO) on the physiology of Danio rerio. Four hundred fourty-eight fish were divided into 28 tanks and subjected to different dietary treatments: a control group with no supplementation, a group with grain alcohol supplementation and five groups with LSEO at concentrations of 0.25%, 0.50%, 0.75%, 1.00% and 1.25%. After 15 days, histological and enzymatic analyses were conducted. The 0.25% LSEO group exhibited lower glutathione peroxidase and catalase activity compared to the 1.00% group. Additionally, fish in the 0.25% LSEO group showed improved liver, kidney and splenic integrity indices. These findings support the inclusion of 0.25% LSEO in the diet of D. rerio, suggesting potential benefits for fish physiology and encouraging further research on phytotherapeutics in fish diets.