Potential Therapeutic Effect of ZnO/CuO Nanocomposite as an Acaricidal, Immunostimulant, and Antioxidant in Rabbits

Abstract

The present study aimed to identify a safe and novel approach using zinc oxide/copper oxide nanocomposites (AZ) to enhance growth parameters, immunity, and fight Sarcoptic mange in vitro and in vivo in rabbits. In vitro: the acaricidal activity of AZ was assessed at concentrations of AZ-25: 2.5% w/w AZ/molasses, AZ-125: 12.5% w/w AZ/molasses, and controls (normal saline, molasses, and Ivermectin) every hour for seven hours under a stereoscopic microscope. In vivo: involved 40 rabbits (10 replicates/group). G1 served as the control negative group (normal un-infected rabbits), G2 served as the control negative group (infected rabbits), the animals in the G3 group were given a combination of AZ (40 mg/kg body weight (BW)) and molasses (5 mg/mL), and G4 served as the control to the vehicle; receiving molasses 8 mL/kg BW twice weekly for 6 weeks. Blood, serum, and tissue samples were collected at the middle and the end of the trial. AZ was made using the sonication sol-gel method. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were performed to confirm the crystal structure, purity, particle size, and oxidation states. AZ showed immunostimulant, acaricidal, and antioxidant effects with normal tissue histological structure and low tissue residual levels. Additionally, there were improvements in blood interferon-gamma, immunoglobulin (Ig) M, IgG, phagocytic activity, phagocytic index, globulin, and total protein in the AZ group. The XRD patterns of AZ were coordinated by XRD reference codes Crystallography Open Database (COD): 9016326 for Tenorite (CuO) and by XRD reference COD: 9004179 for Zincite (ZnO). The CuO and ZnO crystal sizes were 21.87 Å and 24.89 Å, respectively. The XPS spectra indicated the presence of Cu as Cu (II) and Zn as ZnO.OH and ZnO. In conclusion, AZ exhibited antioxidant, acaricidal, and immunostimulant effects, with mild residues in the brain, liver, and kidney tissues, while maintaining a normal histological structure of tissues.

Keywords: S. scabies mites; ZnO/CuO nanocomposites; immunity; ivermectin; rabbits.

Figure 1

Dorsal aspects of S. scabiei mites under the light microscope. (Convex dorsally) (a) control, (b) AZ-20, (c) molasses, (d) AZ-10, and (e) iv-SD.

Figure 2

The percentage of viable adult mites.

Figure 3

XRD spectra of AZ.

Figure 4

XPS spectra of AZ. (a) survey, (b) O-1s, (c) Cu-2p, and (d) Zn-2p XPS spectra of AZ.

Figure 5

(a) Rabbits treated with AZ during the 1st week: the infected rabbit, showing the appearance of mite lesion over the back of rabbit including crusts, dandruff, exudation, and alopecia; (b) 2nd week: the infected rabbit stopping of erythema, fewer crusts, and alopecia -continuing treatment with AZ; (c) 3rd week: the infected rabbit stopping of erythema, no crusts, and rabbit’s fur starts to grow—continuing treatment with AZ; (d) 4th week: the infected rabbit showing a noticeable healing of skin lesion with longer hair; (e) 5th week: rabbit showing almost worthy healing of skin lesion with longer hair—continuing treatment with AZ; (f) 6th week rabbit showing complete healing of skin lesion with healthy fur at the last week of experiment for animals treated with AZ.

Figure 6

A photomicrograph showing the renal histopathological structure. (a) Control normal kidney tissue (X20). (b) AZ treated group. (c) Molasses-treated group (X20). Hepatic histopathological structure (X20). (d) Control normal liver tissue (X10). (e) AZ treated group (X20). (f) Molasses-treated group (X20). Splenic histopathological structure. (g) Control normal spleen tissue (X20). (h) AZ treated group (X20). (i) Molasses-treated group (X20). Scale bar 50 µm. Red arrow shows atrophy of the glomeruli, black arrow in (c) shows completely normal renal tubules, black arrow in (e) shows mild vacuolar degeneration of the hepatocytes near the central vein, and yellow arrow show newly formed bile duct near the central vein.