Effect of Licorice ( <i>Glycyrrhiza glabra</i> )-Silver Nanoparticles on Liver and Kidney Histopathological Features in Common Carp Fish ( <i>Cyprinus carpio</i> )

The increasing use of silver nanoparticles (AgNPs) in aquaculture has raised concerns regarding their potential toxic effects on fish health, particularly on vital organs, such as the liver and kidneys. Licorice (<i>Glycyrrhiza glabra</i>) root, known for its medicinal and antioxidant properties, has gained attention as a natural agent capable of mitigating such toxicity. Furthermore, licorice extract can be used in the eco-friendly green synthesis of AgNPs, acting as both a reducing and stabilizing agent, as confirmed by characterization techniques including X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy. This study aimed to evaluate the protective effects of dietary licorice root powder against AgNP-induced histopathological and physiological damage in common carp (<i>Cyprinus carpio</i>). A total of 150 fish were randomly assigned to seven dietary treatment groups for 56 days, including a control group, three groups receiving increasing doses of AgNPs (2.5, 5, and 7.5 mg/kg feed), and three groups receiving corresponding combinations of same amount of AgNPs with licorice root powder (2.5, 5, and 7.5 g/kg feed). Histopathological evaluation revealed that AgNPs alone induced severe liver and kidney damage, including hydropic degeneration, necrosis, and inflammatory infiltration. In contrast, fish receiving licorice-supplemented diets showed significantly reduced tissue lesions, indicating hepatoprotective and nephroprotective effects. In conclusion, licorice root powder effectively mitigated AgNP-induced toxicity and improved organ health in common carp. The combination of licorice and AgNPs offers a promising alternative to antibiotics in aquaculture, enhancing sustainability and fish welfare. Further studies are recommended to investigate the underlying molecular mechanisms and optimize application strategies in fish diets and to investigate another model of animal.