RESUMO
Aflatoxin B1 (AFB1) is a mycotoxin which is responsible for severe damage to the immune system of humans and livestock. Licochalcone A (Lico A), a polyphenol derived from turmeric, has attracted great attention due to its wonderful antioxidant properties. Ferroptosis, an iron-dependent cell death related to oxidative stress, which plays a crucial role in the resistance of phytochemical to immune-associated injury. Nevertheless, effects of Lico A on the bursa of broilers exposed to AFB1 remain unclear. In this work, broilers were fed diets supplemented with 2 mg/kg of AFB1 and 50 mg/kg of Lico A. Meanwhile, various concentrations of Lico A and AFB1 (15 µM) were used to stimulate macrophages. These results revealed that AFB1 resulted in more severe bursa atrophy and relative weight reduction; the expression of pro-ferroptosis protein ACSL4 and the content of malondialdehyde (MDA) were significantly elevated, while the expression of anti-ferroptosis proteins GPX4, xCT, FSP1 and the content of Glutathione (GSH) was obviously reduced. However, Lico A treatment effectively reversed these effects in the bursa of broilers. Meanwhile, in bursa and macrophages, Lico A mitigated the expression of AFB1-induced apoptosis-associated protein (Caspase-3, Bax, Bcl-2) as well as antioxidant protein (Nrf2, GCLM, HO-1). Importantly, ferroptosis was also observed in macrophages induced by AFB1. Lico A efficaciously alleviated AFB1-induced mitochondrial membrane potential decrease and reactive oxygen species (ROS) production in macrophages; in contrast, Lico A evidently inhibited AFB1-triggered ROS generation and cytotoxicity, which was disabled by the addition of Erastin. Moreover, Liproxstatin-1 significantly inhibited ROS generation induced by AFB1. In summary, the present study elucidates that the main mechanism by which Lico A attenuates AFB1-induced immunotoxicity is through the suppression of ferroptosis, apoptosis, mitochondrial damage and oxidative stress, which is promising for the improvement of immunotoxic effects of AFB1.
RESUMO
BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a persistent liver condition that affects both human health and animal productive efficiency on a global scale. A number of naturally occurring compounds activate nuclear factor erythroid 2-related factor 2 (Nrf2) as a transcription factor with important protective effects against many liver diseases, including NAFLD. Raffinose (Ra), an oligosaccharide extracted from several plants, exhibits diverse biological functions. However, the uncertainty lies in determining whether the activation of Nrf2 by Ra can provide a preventive effect on liver lipotoxicity. PURPOSE: The aim of this study was to shed light on the molecular pathways by which Ra possesses its protective benefits against NAFLD. METHODS: Experimental protocols were established using WT and Nrf2-null (Nrf2-/-) mice. Liver samples from each group were collected for Western blot, RT-qPCR, H & E, Sirius red and Oil red O staining. Additionally, serums were processed for ELISA. ALM12 cells were gathered for Western blot and immunofluorescence. Moreover, to elucidate the molecular mechanism of Ra, molecular docking was performed. RESULTS: Our results indicated that Ra remarkably alleviated liver lipotoxic in vivo and in vitro. Ra treatment effectively corrected hepatic steatosis, the release of AST, ALT, TG, and TC, as well as the depletion of HDL and LDL. Meanwhile, Ra efficiently prevented inflammation by inhibiting the TLR4-MyD88-NF-κB pathway and pyroptosis. Additionally, these findings implied that Ra reduced the production of fibrosis-related proteins, which enhanced collagen deposition. Molecular docking revealed that Ra possessed the ability to bind specific regions of Nrf2, resulting in the enhancement of Nrf2 activation and nuclear translocation. Ra treatment restored serum redox factors and antioxidant enzymes to normal levels; however, these alterations were clearly reversed in Nrf2-/- mice. CONCLUSION: This study reveals novel information on Ra's protective benefits against liver injury caused by abnormal lipid metabolism; these effects are mostly mediated by Nrf2 activation, suggesting a potential new medicine or treatment strategy for NAFLD.