Efficacy of Excoecaria agallocha on hematological parameters in hybrid tilapia (Oreochromis niloticus) after experimental challenge with Streptococcus agalactiae

Abstract

The potential of milky mangrove <em>Excoecaria agallocha</em> leaf extracts has been utilized in traditional medicine in various parts of the world. Blood is an important indicator of health and is a pathological mirror of the entire body. Therefore, the effects of <em>E. agallocha</em> leaf extract on hematology indices of hybrid tilapia (<em>Oreochromis niloticus</em>) were investigated. Experimental fish were randomly divided into seven groups. Groups 1 to 5 were fed medicated feed at five different concentrations (10, 20, 30, 40 and 50 mg kg^-1) of <em>E. agallocha</em> leaf extract. Group 6 was given Flumequine (25 mg kg^-1) and group 7 was fed with untreated feed (control) for 28 days before they were intraperitoneally exposed to 4x10⁵cfu CFU ml^-1 <em>S. agalactiae</em>. The results revealed that the group fed medicated feed at 50 mg kg^-1 was the most effective concentration and showed no significant difference (<em>p </em>>0.05) compared to control and antibiotic groups on blood parameters (red blood cell, globulin, total serum protein, mean cell hemoglobin, and mean cell hemoglobin concentration) with the highest survival rate 99.67% within experimental groups. Overall, our results indicated the potential of <em>E. agallocha</em> could prove to be a hematological profile enhancer which can help fish combat bacterial infections. It was concluded that increase in the white blood cell count observed in fish administered with <em>E. agallocha</em> leaf extract at 50 mg kg^-1 suggests that <em>E. agallocha</em> extract contains agents that could stimulate the production of leucocytes and serve as an immune booster and prevent the risk of anemia.