Dietary quercetin and vitamin E supplementation modulates the reproductive performance and antioxidant capacity of aged male breeder chickens

Abstract

Aged male chickens experience rapid declines in spermatogenesis, antioxidant capacity, immunity, and hormone synthesis. Vitamin E plays a significant role in reproduction, nervous system function, and disease resistance in animals. Quercetin also exerts many biological effects, such as antioxidant ability, immunostimulation, and protection of spermatozoal plasma membranes. This study evaluated the effects of combining dietary quercetin (Q) and vitamin E (VE) on sperm quality, antioxidant capacity, immunity, and expression of genes related to spermatogenesis, immunity, apoptosis, and inflammation in aged male chickens. A total of 120 Tianfu breeder male chickens (65 wk old) were randomly allotted to 4 treatments with 3 replicates (10 birds each). The birds were fed diets containing Q (0.4g/kg), VE (0.2g/kg), Q+VE (0.4g/kg + 0.2g/kg), and a basal diet for 11 wk. At the end of the experimental period, blood, semen, liver, testes, and spleen samples were collected from 2 birds per replicate. Serum hormones, antioxidant parameters, cytokines, and immunoglobulins were evaluated; and the mRNA expression of genes related to spermatogenesis, apoptosis, and inflammation are determined in the testes and liver tissues. The results showed that the combination quercetin and vitamin E significantly promoted the sperm count and motility, as well as elevated the levels of testosterone, follicle-stimulating hormone, and luteinizing hormone, antioxidant enzymes (Superoxide dismutase, Glutathione, and Total antioxidant capacity), and serum immunoglobulins (IgA and IgM) in the aged male chickens; also Q+VE showed protective effects on the liver against injury. In addition, Q+VE significantly increased the expression of genes related to spermatogenesis (AR, pgk2, Cyclin A1, and Cyclin A2), immunity (IFN-γ and IL-2), and anti-inflammatory cytokines (IL-10) (P < 0.05), whereas the expression of proinflammatory cytokines (IL-1β and IL-6) was decreased (P < 0.05). Taken together, these data indicate that the combination of quercetin and vitamin E improved reproductive characteristics such as spermatogenesis, sperm quality, and hormone regulation, as well as promoted antioxidant defense, hepatoprotective capacity, and immune response in aged male chickens without any detrimental effects.

Keywords: aged male chicken; antioxidant capacity; quercetin; spermatogenesis; vitamin E.

Figure 1

Tianfu Commercial Broiler Breeder Chickens.

Figure 2

Effects of dietary quercetin and Vitamin E on serum and liver biochemical indices in aged male breeders. (A) Serum TG, (B) Liver TG, (C) Serum TC, (D) Liver TC, (E) Serum AST,(F) Serum ALT. The bar values are presented as the mean ± SD. Bars without the same letter differed significantly (P < 0.05).

Figure 3

Effects of Quercetin, Vitamin E, and their combination (Q + VE) on reproductive hormones and serum immunoglobulins in aged male breeder chickens. The bar values are presented as the mean ± SD. Bars without the same letter differed significantly (P < 0.05).

Figure 4

Effects of Quercetin, VE, and their combination (Q + VE) on antioxidant capacity and MDA levels in aged male breeder chickens. The bar values are presented as the mean ± SD. Bars without the same letter differed significantly (P < 0.05). prot: protein.

Figure 5

Effects of Quercetin, VE, and their combination on mRNA expression of spermatogenesis related genes in the testes of aged male chickens. The bar values are presented as mean ± SD. Bars without the same letter differed significantly (P < 0.05).

Figure 6

Effects of Quercetin, VE, and their combination (Q + VE) on mRNA expression of apoptotic related genes in the testes and liver of aged male chickens. The bar values are presented as the mean ± SD. Bars without the same letter differed significantly (P < 0.05).

Figure 7

Effects of Quercetin, VE, and their combination on mRNA expression of immune related genes in the spleen and inflammation related genes in the liver of aged male chickens. Bars without the same letter differed significantly (P < 0.05).

Figure 8

Effects of Quercetin, Vitamin E, and their combination (Q + VE) on liver morphological and histological changes of aged male chickens. This figure shows the Hematoxylin-eosin (HE) staining and oil-red results of the livers. Control Group: severe hepatic steatosis. Quercetin Group: mild hepatic steatosis. Vitamin E Group: moderate hepatic steatosis. Q + VE Group: normal liver morphology without any steatosis. The red arrow indicates the “fatty vacuoles”, the green arrow indicates the “lipid droplets”.

Figure 9

General mechanisms of action of the combination of quercetin and vitamin E on the reproductive performance of aged male chickens. The action of the combination of Quercetin and Vitamin E decreases the risk of oxidative stress to promotes fertility in aged male chickens. Combination of Quercetin and Vitamin E most likely acts via the oxidative mechanism of action to prevent oxidative stress, promote reproductive hormone production, immunity, and liver functions. These together, improve spermatogenesis, and hence, fertility and reproductive performance and health in aging male chickens.