Dietary Selenium Reduces the Toxic Effect of Mercury on Different Organs (Brain, Gills, Kidney and Liver) of Rohu Fish (Labeo rohita)

Because of improbably high partiality with antioxidant selenium to mercury, selenium isolates mercury and reduces its biological handiness to organisms. The present study investigates the effect of mercury (Hg) and selenium (Se) on the fingerling of Labeo rohita. The various sub-lethal concentrations of Hg i.e. 0.125µg/g, 0.250µg/g, and 0.500µg/g was used and incorporated in diet with a commercial diet (fish meal 40%, soya bean 33%, 3 % of vitamins premix, mineral premix and oil each and rice polish 18%). To understand how selenium reduces the toxic effect of mercury, fingerlings were exposed with 6ug/g Se singly and combined with doses of Hg. The effect of these heavy metals was observed after 24, 48, 72, and 96 hours in different organs of (Brain, Gills, Kidney and Liver) of Labeo rohita. The organs of exposed rohu showed significant changes in their microscopic anatomy in comparison to control. Prominent changes were observed in Hg treatments and found embody shrinkage of capillary, and dilation of the hollow lumen. In addition to the aforementioned changes vacuolation, peeling, hydropic swelling, and hyaline degeneration of hollow epithelium were also observed. Cysts and hamorrhage developed additionally seem in the organs of fish. Length of exposure seems to own a profound impact on organs because the increase in length of exposure enhanced the severity of histopathological damages. However, combined doses of metals cause reduction in the toxicity of mercury results in decrease damage in the shrinkage of capillary and dilation of the hollow lumen. During histological study vacuolation, hydropic swelling, and hyaline degeneration of hollow epithelium were also reduced. In Hg, the lethal concentration (LC50) was 0.374ug/g while when Hg and Se were combined, LC50 drops to 0.491ug/g. Results of this study suggest that exposure to Se helps to scale back the impact of mercury on mortality and different organs of Labeo rohita fingerling.   Copyright (c) Muhammad Xaaceph Khan, Beenish Anum, Ruqia Bibi, Masroor Ellahi Babar, Muhammad Ashraf, Amera Ramzan, Ayesha Aihetasham, Syed Hassan Abbas