Potential ameliorative effect of dietary quercetin against lead-induced oxidative stress, biochemical changes, and apoptosis in laying Japanese quails.

Lead (Pb) is a widespread environmental pollutant which is a toxic threat to human and animal health. The present study was designed to evaluate the ameliorative role of quercetin in laying quails exposed to Pb. A total of 112 birds were randomly divided into four groups. The control group was fed with basal diet, the Pb group was fed with ration supplemented with Pb at the dose of 100 mg/kg (as Pb (II) acetate trihydrate), the Quercetin group was fed with ration supplemented with quercetin at the dose of 400 mg/kg, and the Pb+ Quercetin group was fed with ration supplemented with Pb at the dose of 100 mg/kg and quercetin at dose of 400 mg/kg. Results showed that serum total protein, glucose, albumin, and blood urea nitrogen (BUN) values of the Pb + Quercetin group partially improved with quercetin supplementation. Meanwhile, serum creatinine values of the Pb + Quercetin group was found to be significantly lower than that of the Pb group. Aspartate aminotransferase (AST) and alanine transaminase (ALT) enzyme activities in the Quercetin and Pb + Quercetin groups were similar to those of the Control group, unlike the Pb group. Moreover, alkaline phosphatase (ALP) enzyme activity of the Pb + Quercetin group significantly improved with the addition of quercetin. We also found that malondialdehyde (MDA) levels of the kidney, liver, and heart were significantly reduced by quercetin supplementation. The glutathione, catalase, and glutathione peroxidase activities of the kidney, liver, and heart tissue were increased by quercetin supplementation. These results were in line with the observed apoptotic markers. The expression of caspase-3 and caspase-9 were significantly decreased by quercetin supplementation. It may be concluded that dietary supplementation with quercetin ameliorates the toxic effects of Pb exposure by alleviating oxidative stress, biochemical changes, and apoptosis in quails.

Ellagic acid plays an important role in enhancing productive performance and alleviating oxidative stress, apoptosis in laying quail exposed to lead toxicity.

Lead (Pb) is one of the most toxic heavy metal environmental pollutants due to its widespread use of the industry and it is a harmful substance for human and animal health. This study was conducted to investigate the potential protective effects of ellagic acid (EA) on performance, egg quality, antioxidant parameters, and apoptotic pathway proteins in laying quails exposed to Pb toxicity. A total of 168 (15-week old) laying quails (Coturnix coturnix Japonica) were divided into 6 experimental groups (with similar initial average body weight). Birds were fed 1 of 6 diets for 8 weeks: 1 - Control (basal diet), 2 - Pb (basal diet + 100 mg/kg Pb), 3 - EA-300 (basal diet + 300 mg/kg EA), 4 - EA-500 (basal diet + 500 mg/kg EA), 5 - Pb + EA-300 (basal diet + 100 mg/kg Pb + 300 mg/kg EA), 6 - Pb + EA-500 (basal diet + 100 mg/kg Pb + 500 mg/kg EA). The results showed that adding 100 mg/kg of Pb to basal diet was adversely affected the performance parameters and, feed intake and egg production were significantly decreased by Pb supplementation (P < 0.01). However, the EA supplementation to Pb groups improved the performance parameters. Compared with the Pb alone group, in Pb + EA-500 group increased egg production by 8.4%. There were no significant differences in the Haugh unit, albumen index, and yolk index among groups (P > 0.05). Liver and kidney tissues of Pb group malondialdehyde (MDA) level increased (P < 0.001) and, GSH, GSH-Px, and CAT values decreased (P < 0.001) but, EA supplementation alleviated this condition (P < 0.001). The protein levels of caspase-3 and -9 were significantly increased in the Pb group compared to the control group, whereas EA supplementation alleviated the Pb-induced apoptosis by decreasing caspase-3 and -9 levels in the liver tissue (p < 0.001). In laying quails exposed to Pb toxicity, EA supplementation improves the performance parameters, enhances the antioxidant defense system, and suppresses apoptosis via regulates the expression of caspase-3 and -9. Thus, it was concluded that EA (especially 500 mg/kg) can ameliorate the toxic effects of Pb exposure in quails.