Lippia sidoides essential oil (Verbenaceae) improves inflammatory response and histological condition in Danio rerio

This study evaluated the effect of Lippia sidoides essential oil (LSEO), at a concentration of 0.25%, on the inflammatory response and histological parameters in Danio rerio zebrafish. Three hundred and fifteen fish were equally distributed into 21 aquaria and divided into three groups with three replicates (negative control (NC), diet containing grain alcohol (GA) only, and LSEO—diet with Lippia sidoides ). After 15 days, the animals were anesthetized, and the inflammatory process was induced as follows: part of the fish did not receive intraperitoneal injection (IP) negative control (NC); part of them received IP containing 0.65% saline solution ( S ) (NC S , GA S , and LSEO S ); and another part received IP containing tumor (Ehrlich ascitic carcinoma) ( T ) (NC T , GA T , and LSEO T ). After 6 h, the exudate was collected, and the histological analysis was performed. There was an increase in the number of basophils and monocytes in LSEO T , as well as an improvement in the histological conditions in all organs of the fish in this group, suggesting a possible effect of essential oil on fish defense mechanisms. Therefore, using LSEO at a concentration of 0.25% seems to be beneficial to the health of D. rerio subjected to IP with Ehrlich ascitic carcinoma.