Dietary Curcumin Modulating Effect on Performance, Antioxidant Status, and Immune-Related Response of Broiler Chickens Exposed to Imidacloprid Insecticide

Abstract

Birds appear to be especially vulnerable to adverse impacts from insecticides. This is especially true for imidacloprid (IMI), which is considered the most toxic to avian species. Recently, prospective studies aimed at including natural alternative products to alleviate the toxic impact that comes from insecticides have been increased. Focusing on herbal growth promoters and antioxidative medicament for the poultry industry, this ongoing experiment was conducted to examine the curcumin role (CUR) in mitigating IMI-prompted detrimental effects on broilers' performance, immunity, and antioxidant status. A total number of one hundred and fifty commercial meat-type Ross 308 broilers chicks (one-day-old) were randomly allocated into equal five groups (30 chicks/group and 10 birds/replicate). The first group (C) was the control; the second group (CUR) was fed a diet containing CUR at the level of 450 mg/kg; the third group (IMI) was fed control diet for 14 days and then was fed a diet containing IMI at the level of 50 mg/kg; the fourth group (CUR+IMI co-treated) was fed a diet containing CUR+IMI; and the fifth group (CUR+IMI pro/co-treated) was fed a diet containing CUR for 14 days as protective and then a diet containing CUR+IMI for the rest of the trial. CUR supplementation either in the (CUR pro/co-treated) or (CUR co-treated) groups significantly (p < 0.05) improved final body weight and total body weight gain while decreasing the total feed intake and feed conversion ratio when compared to the IMI-exposed and non-treated birds. CUR induced a significant (p < 0.05) enhancement in hematological indices, phagocytosis %, phagocytic index, intracellular killing capacity, total proteins, globulin, liver function enzymes, lysozyme activity, and immunoglobulin-G levels compared to IMI-exposed and non-treated birds. In addition, dietary supplementation of CUR significantly (p < 0.05) modulated oxidative stress-related biomarkers in splenic tissues (total antioxidant capacity, superoxide dismutase, catalase, and glutathione peroxidase) and decreased malondialdehyde levels (p < 0.05) when compared to IMI-exposed and non-treated birds. CUR significantly down-regulated mRNA levels expression of IL-1β, TNF-α, and TLR4 and up-regulated IL-10 mRNA expression levels in spleens of birds when compared to those exposed to IMI-and non-treated. Finally, our results provided new insight into IMI-induced immuno-toxicity in broiler chickens. Furthermore, for the first time, our study informed that CUR can cause an in vivo protective effect against IMI toxicity, principally as a protective and/or as concurrent supplementation during the exposure to IMI toxicity.

Keywords: 308 Ross Broiler; curcumin; growth performance; hematological indices; imidacloprid; immune-related genes mRNA expression; immune-toxicity; oxidative stress; phagocytosis.

Figure 1

Experimental groups, doses, durations, and treatments: CUR (450 mg/kg diet) and IMI (50 mg/kg diet) in Ross 308 broilers.

Figure 2

Effect of dietary supplementation of CUR, IMI, and their combinations on Phagocytosis, lysozyme activity, and IgG of Ross 308 broiler chickens. 1st group C, 2nd group CUR, 3rd group IMI-treated, 4th group CUR+IMI Co-treated, 5th group CUR+IMI Pro/co-treated. (A): Phagocytosis % (Ph %). (B): Phagocytic index (PhI). (C): Intracellular killing capacity (ICK). (D): Lysozyme activity (LYZ). (E): Immunoglobulin G (IgG). Values are shown as mean ± SEM of (6) birds per experimental group. Means bearing different superscripts are significantly different at p < 0.05.

Figure 3

Effect of dietary supplementation of CUR, IMI, and their combinations on Phagocytosis, lysozyme activity, and IgG of Ross 308 broiler chickens. 1st group C, 2nd group CUR, 3rd group IMI-treated, 4th group CUR+IMI Co-treated, 5th group CUR+IMI Pro/co-treated. (A): Total antioxidant capacity (TAC). (B): Superoxide dismutase (SOD). (C): Catalase (CAT). (D): Glutathione peroxidase (GPx). (E): Malondialdehyde (MDA). Values are shown as mean ± SEM of (6) birds per experimental group. Means bearing different superscripts are significantly different at p < 0.05.

Figure 4

Effect of dietary supplementation of CUR, IMI, and their combinations on mRNA expression of IL-1β, TLR-4, and IL-10 genes in spleen of Ross 308 broiler chickens. 1st group C, 2nd group CUR, 3rd group IMI-treated, 4th group CUR+IMI Co-treated, 5th group CUR+IMI Pro/co-treated. (A): Interleukin 1 Beta (IL-1β). (B): Toll-Like Receptor 4 (TLR-4). (C): Interleukin 10 (IL-10). Values are shown as mean ± SEM of three birds per experimental group. Means bearing different superscripts are significantly different at p < 0.05.

Figure 5

Representative photomicrographs of H&E-stained splenic tissue sections for the effect of dietary supplementation of CUR, IMI, and their combinations splenic tissue structure showing normal histology in the control (A) and the CUR (B) groups. Histopathological alterations in the IMI-treated group (C), with reduction of these splenopathic alterations in the CUR co-treated group or CUR pro/co-treated group. (D,E). The symbols in the images denote black arrowhead; lymphoid depletion, blue arrowhead; lymphoid necrosis, black arrow; thrombus, red arrow; vascular congestion. (Scale bar is 100 μm).

Figure 6

Representative photomicrographs of the TNF-α immuno-stained splenic tissue sections for the effect of dietary supplementation of CUR, IMI, and their combinations in spleen of Ross 308 broiler chickens. (A,B): control and CUR groups for TNF-α showing weak expression in splenic tissue. (C): showing up-regulation of the TNF-α expression in the IMI-treated group in splenic tissue. (D,E): CUR-supplemented groups, showed down-regulation of TNF-α expression in the CUR co-treated group or CUR pro/and co-treated groups. (Scale bar is 25 μm).

Figure 7

Representative photomicrographs of the TLR-4 immuno-stained splenic tissue sections for the effect of dietary supplementation of CUR, IMI, and their combinations in spleen of Ross 308 broiler chickens. (A,B): control and CUR groups for TLR-4 showing weak expression in splenic tissue. (C): showing up-regulation of the TLR-4 expression in the IMI-treated group in splenic tissue. (D,E): CUR- supplemented groups, showed down-regulation of TLR-4 expression in the CUR-treated group or CUR pro/and co-treated groups. (Scale bar is 25 μm).