Improvement of antioxidant status, inflammatory responses, hematological, biochemical parameters and performance with black seed (Nigella sativa) supplementation in broiler chickens under induced physiological oxidative stress

Introduction:

Oxidative stress is inevitable in broiler chicken's production, and it affects the physiological, behavioral and biochemical status of growing chicken which ultimately deteriorates meat quality. The imbalance among free radicals and anti-oxidant enzymes within living cells or tissues leading to the oxidation of lipids, proteins, and nucleic acid is a fundamental cause of oxidative stress. When the anti-oxidant mechanism within living cells weakens, the production of free radicals increases under physiological oxygen qmetabolism, these reactive species (ROS, RNS) are needed in cells in small quantities as they also function as signaling molecules during homeostasis. However, excessive production of these species leads to oxidative stress. There is a mechanism in living cells to reduce the number of oxidative species through physiological scavenging. Numerous reactive oxygen species such as
superoxide and hydrogen peroxide are produced during oxygen metabolism. Also, there are some reports that showed following the occurrence of oxidative stress, severe inflammatory reactions occur in the involved cells, which lead to more severe tissue damage and can activate tissue apoptosis. Oxidative stress plays an essential role in the emergence of a number of chronic disorders such as diabetes and cancer by inducing inflammation. To protect against free radicals, living organisms have a combined antioxidant defense system including enzyme system (including, glutathione peroxidase, superoxide dismutase and, catalase enzymes in the cytosol and, cell membrane structure) and a non-enzymatic system (including glutathione, polyphenol, carotenoids, special dipeptides, proteins containing thiol group, polyamines, ubiquinol, flavonoids, bilirubin, uric acid, vitamin E with selenium and, vitamin C) in tissues. Black cumin (Nigella sativa) seed have been used as an alternative medicine due to its multi-systemic beneficial actions for more than 2000 years. Many active components of black cumin have been identified, including dithymoquinone, thymoquinone, nigellone, thymohydroquinone, nigilline, melanthin, nigelamine, damascenone, pinene and p-cymene. Black cumin contains minerals such as, calcium, magnesium, potassium, iron, phosphorus, cobalt, zinc and manganese and vitamins A, B, C, D and E. Moreover, black cumin is rich in essential oils, proteins, alkaloids, saponins, flavonoids, and polyphenols. The black cumin has anti-inflammatory, analgesic, anthelmintic, hypocholesteremia, appetite stimulant, antidiarrheal, diuretic, antiulcer, spasmolytic and bronchodilatory, antimicrobial, antihypertensive, antidiabetic, anticancer, hepatoprotective and renal protective activities and antioxidant properties. A study was conducted to investigate the effects of black cumin on growth performance, antioxidant, inflammatory responses, biochemical and hematological changes in broilers under oxidative stress induced by hydrogen peroxide.
Materials and methods:
A total of 200 one-day-old chickens (Ross 308) were reared in the form of a completely
randomized design with four treatments and five replications (10 chickens in each replication). Experimental treatments include 1. control group (fed with basic diet), and 2, 3, 4 groups
with levels of 50, 100 and 150 g per Kg.To induce oxidative stress, all birds received 1% hydrogen peroxide per liter of drinking water from the 14 to the 42 of age. At 42 d, two birds were randomly selected from each cage and after sampling from the wing vein, killed and dissected for liver and spleen tissue sampling. Growth performance, blood and biochemical parameters such as the number of red and white blood cells, hemoglobin, hematocrit, heterophil and lymphocyte, serum triglyceride and cholesterol, as well as serum antioxidant parameters including the level of malondialdehyde and the activity of antioxidant enzymes including glutathione peroxidase, superoxide dismutase and catalase. In addition, liver enzymes present in the serum including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were also measured. Also, to evaluate the effect of black cumin on the inflammatory state of broiler chickens under induced oxidative stress, serum interleukins including IL-10 ، IL-6 وTNF-α were measured.
Results and discussion: The results showed that black seed supplementation in birds under induced oxidative stress significantly improved growth performance, increased the activity of antioxidant enzymes and decreased MDA in serum, liver tissue and spleen (P<0.05). Black seed supplementation significantly decreased serum levels of inflammatory cytokines IL-6 and TNF-α and increased anti-inflammatory cytokine IL-10 (P<0.05). Also, black seed supplementation had no effect on red blood cells, hematocrit, hemoglobin, increased white blood cells, lymphocytes, and decreased blood heterophils (P<0.05). Serum levels of triglycerides, cholesterol, and ALT, AST, and ALP enzymes also decreased significantly under the influence of black seed The results showed that black seed supplementation in birds under induced oxidative stress significantly increased the activity of antioxidant enzymes and decreased MDA in serum, liver tissue and spleen (P<0.05). Black seed supplementation significantly decreased serum levels of inflammatory cytokines IL-6 and TNF-α and increased anti-inflammatory cytokine IL-10 (P<0.05). Also, black seed supplementation had no effect on red blood cells, hematocrit, hemoglobin, increased white blood cells, lymphocytes, and decreased blood heterophils (P<0.05). Serum levels of triglycerides, cholesterol, and ALT, AST, and ALP enzymes also decreased significantly under the influence of black seed
Conclusions: In conclusion, Based on the results of this experiment, it seems that the dietary supplement of black cumin (Nigella Sativa) seeds through its antioxidant and anti-inflammatory effects can improve growth performance in broiler chickens.
Keywords: Antioxidant, oxidative stress, black seed, broilers, inflammatory responses, blood parameters.