Chitosan neem nanocapsule enhances immunity and disease resistance in nile tilapia (Oreochromis niloticus)

Rowida E Ibrahim; Gehad E Elshopakey; Abdelwahab A Abdelwarith; Elsayed M Younis; Sameh H Ismail; Amany I Ahmed; Mahmoud M El-Saber; Ahmed E Abdelhamid; Simon J Davies; Abdelhakeem El-Murr; Afaf N Abdel Rahman

doi:10.1016/j.heliyon.2023.e19354

Chitosan neem nanocapsule enhances immunity and disease resistance in nile tilapia (Oreochromis niloticus)

Heliyon. 2023 Aug 22;9(9):e19354. doi: 10.1016/j.heliyon.2023.e19354. eCollection 2023 Sep.

Affiliations

¹ Department of Aquatic Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, PO Box 44511, Zagazig, Sharkia, Egypt.
² Department of Clinical Pathology, Faculty of Veterinary Medicine, Mansoura University, PO Box 35516, Mansoura, Dakahlia, Egypt.
³ Department of Zoology, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia.
⁴ Faculty of Nanotechnology for Postgraduate Studies, Cairo University, Sheikh Zayed Branch Campus, Sheikh Zayed City, Giza, PO Box 12588, Egypt.
⁵ Department of Biochemistry, Faculty of Veterinary Medicine, Zagazig University, PO Box 44511, Zagazig, Sharkia, Egypt.
⁶ Biochemistry Unit, Department of Genetic Resources; Desert Research Center, PO Box 11753, El-Matareya, Cairo, Egypt.
⁷ Polymers and Pigments Department, National Research Centre, 33 El-Buhouth St. Dokki, Giza, PO Box 12622, Egypt.
⁸ Aquaculture Nutrition Research Unit ANRU, Carna Research Station, Ryan Institute, College of Science and Engineering, University of Galway, H91V8Y1, Galway, Ireland.

Abstract

Finding eco-friendly alternatives for antibiotics in treating bacterial diseases affecting the aquaculture sector is essential. Herbal plants are promising alternatives, especially when combined with nanomaterials. Neem (Azadirachta indica) leaves extract was synthesized using a chitosan nanocapsule. Chitosan neem nanocapsule (CNNC) was tested in-vitro and in-vivo against the Aeromonas sobria (A. sobria) challenge in Nile tilapia. A preliminary experiment with 120 Nile tilapia was conducted to determine the therapeutic dose of CNNC, which was established to be 1 mg/L. A treatment study was applied for seven days using 200 fish categorized into four groups (10 fish/replicate: 50 fish/group). The first (control) and second (CNNC) groups were treated with 0 and 1 mg/L CNNC in water without being challenged. The third (A. sobria) and fourth (CNNC + A. sobria) groups were treated with 0 and 1 mg/L CNNC, respectively, and challenged with A. sobria (1 × 10⁷ CFU/mL). Interestingly, CNNC had an in-vitro antibacterial activity against A. sobria; the minimum inhibitory concentration and minimum bactericidal concentration of CNNC against A. sobria were 6.25 and 12.5 mg/mL, respectively. A. sobria challenge caused behavioral alterations, skin hemorrhage, fin rot, and reduced survivability (60%). The infected fish suffered a noticeable elevation in the malondialdehyde level and hepato-renal function markers (aspartate aminotransferase, alanine aminotransferase, and creatinine). Moreover, a clear depletion in the level of the antioxidant and immune indicators (catalase, reduced glutathione, lysozymes, nitric oxide, and complement 3) was obvious in the A. sobria group. Treatment of the A. sobria-challenged fish with 1 mg/L CNNC recovered these parameters and enhanced fish survivability. Overall, CNNC can be used as a new versatile tool at 1 mg/L as a water treatment for combating the A. sobria challenge for sustainable aquaculture production.

Keywords: Aeromonas sobria; Antimicrobial activity; Chitosan neem nanocapsule; Immunity; Nile tilapia.