Effects of Moringa oleifera aqueous extract on the growth performance, blood characteristics, and histological features of gills and livers in Nile tilapia

Abstract

Moringa oleifera is well known as a highly nutritious plant and a water purifier in fish culture. Tilapia fish has many impressive qualities making them very suitable for aquaculture. Therefore, this study aimed to evaluate the effect of supplementation of Moringa oleifera aqueous extract (MOAE) at varying concentrations (0, 100, 200, and 400 mg/kg diet for 90 days) on growth performance, hematological, and some biochemical parameters of Nile tilapia. Additionally, histological changes and immunohistochemical expression of caspase 3 in gills and livers were evaluated. Significant enhancements (P < 0.05) in the final weight, weight gain, specific growth rate, red blood cells, hemoglobin, packed cell volume, white blood cells, and total serum protein were observed in fish fed 200 mg MOAE/kg diet compared with other groups. However, a significant reduction (P < 0.05) of liver and kidney function tests and non-significant changes in lipid profile were recorded. On the other hand, fish fed 400 mg MOAE/kg diet revealed disturbance in the corresponding parameters. Severe histological degenerative changes were detected in the gills and liver of fish fed 400 mg MOAE/kg diet. In comparison, fish fed 200 mg MOAE/kg diet showed the best histo-architectures of these organs compared with other groups. Concomitant immune expressions of caspase 3 were determined where gills and liver of fish fed 400 mg MOAE/kg diet revealed extensive number of positive caspase 3 cells indicating severe apoptotic features. Accordingly, a dietary MOAE at 200 mg/kg diet is recommended to improve the growth performance, hematological parameters, liver and kidney functions in Nile tilapia. Meanwhile, caution must be considered when using MOAE at a concentration over 200 mg/kg diet.