In vivo antiparasitic activity of biogenic Iron nanoparticles on ectoparasitic branchiuran, Argulus siamensis in Labeo rohita and effect on parasite ion channel genes.

Abstract

BACKGROUND: Argulosis, caused by Argulus, is a significant parasitic disease affecting freshwater aquaculture, leading to severe economic losses and compromised fish health. This study investigates the antiparasitic efficacy of green-synthesized iron oxide nanoparticles (IONPs) synthesized using Bauhinia racemosa leaf extract against A. siamensis in Labeo rohita. The nanoparticles exhibited a spherical morphology with an average size of 157.60 ± 41.59 nm and a zeta potential of -11.3 mV, ensuring moderate stability. RESULT: The in vivo trial confirmed the antiparasitic efficacy of biogenic IONPs, with 100% parasite removal at 2.25 mg mL⁻¹ within four days of bath treatment. Acute toxicity studies in Labeo rohita established a 96-hour LC₅₀ of 4.786 mg mL⁻¹, while the therapeutic index (TI) was calculated as 3.31, indicating a moderate safety margin. Gene expression analysis revealed significant upregulation of ion channel genes - GABA, ICA1, ICA4, and NTR, indicating a neurotoxic effect of IONPs on parasites. CONCLUSIONS: Overall, biosynthesized IONPs present a promising alternative for controlling Argulus siamensis, demonstrating strong antiparasitic effects with manageable toxicity. Further studies on optimizing nanoparticle formulations and minimizing environmental risks are recommended to enhance their application in sustainable aquaculture.