Pterostilbene as a protective antioxidant attenuates diquat-induced liver injury and oxidative stress in 21-day-old broiler chickens

Abstract

This study investigated the effects of pterostilbene (PT) supplementation on growth performance, hepatic injury, and antioxidant variables in a broiler chicken model with diquat (DQ)-induced oxidative stress. There were 192 one-day-old male Ross 308 broiler chicks randomly allocated to one of two treatment groups: 1) broilers fed a basal diet and 2) broilers fed a diet supplemented with 400 mg/kg PT. At 20 D of age, half of the broilers in each group were intraperitoneally injected with DQ (20 mg per kg BW), whereas the other half were injected with an equivalent amount of sterile saline. Diquat induced a rapid loss of BW (P < 0.001) 24 h post-injection, but dietary PT supplementation improved the BW change of broilers (P = 0.014). Compared with unchallenged controls, the livers of DQ-treated broilers were in severe cellular damage and oxidative stress, with the presence of higher plasma transaminase activities (P < 0.05), a greater number of apoptotic hepatocytes (P < 0.001), and an increased malondialdehyde content (P = 0.007). Pterostilbene supplementation prevented the increases in plasma aspartate aminotransferase activity (P = 0.001), the percentage of hepatocyte apoptosis (P < 0.001), and the hepatic malondialdehyde accumulation (P = 0.011) of the DQ-treated broilers. Regarding the hepatic antioxidant function, PT significantly increased total antioxidant capacity (P = 0.007), superoxide dismutase activity (P = 0.016), reduced glutathione content (P = 0.011), and the ratio of reduced glutathione to oxidized glutathione (P = 0.003), whereas it reduced the concentration of oxidized glutathione (P = 0.017). Pterostilbene also boosted the expression levels of nuclear factor erythroid 2-related factor 2 (P = 0.010), heme oxygenase 1 (P = 0.037), superoxide dismutase 1 (P = 0.014), and the glutamate-cysteine ligase catalytic subunit (P = 0.001), irrespective of DQ challenge. In addition, PT alleviated DQ-induced adenosine triphosphate depletion (P = 0.010). In conclusion, PT attenuates DQ-induced hepatic injury and oxidative stress of broilers presumably by restoring hepatic antioxidant function.

Keywords: broiler; diquat; liver injury; oxidative stress; pterostilbene.