The Efficient Role of Rice Husk in Reducing the Toxicity of Iron and Aluminum Oxides Nanoparticles in Oreochromis niloticus: Hematological, Bioaccumulation, and Histological Endpoints

The present study was the first trial to use the adsorptive capacity of the rice husk to reduce the toxicological impacts of the iron and aluminum oxides nanoparticles on Oreochromis niloticus. The fish groups were subjected to a sub-lethal concentration (10 mg/l) of both metal oxides nanoparticles (in single and combined doses) with and without rice husk water treatment for 7 days. The bioaccumulation of iron and aluminum metals showed a significant increase (p < 0.05) compared with the control groups. The results revealed a tissue-specific distribution pattern as following: liver > kidney > gills > skin > muscles for iron and liver > gills > kidney > skin > muscles for aluminum. Moreover, the bioaccumulation potency of iron was greater than that of aluminum in all studied tissues. Both studied nanoparticles caused a decrease in the red blood cells count, hemoglobin content, hematocrit values, and mean corpuscular hemoglobin concentration, with an obvious increase in mean corpuscular volume and mean corpuscular hemoglobin. While all those parameters were restored more or less to that of control groups after rice husk water treatment. The histological studies of the gills, liver, and kidneys showed different histopathological alterations ranging from compensatory histological changes in the rice husk-treated groups to severe histopathological damage in the untreated groups. Based on the all studied biomarkers, the rice husk is a good absorbent for both studied nanoparticles individually or combined.