With the rise in living standards, the demand for poultry products has increased [1]. Nevertheless, the transition to modern, large-scale agricultural practices coupled with heat stress caused by global warming has significantly affected poultry production and the economic sustainability of poultry farming [2,3]. Heat stress increases the body temperature, breathing rate and heart rate of poultry and negatively affects their eating behavior, health and product quality [4]. The Ningdu yellow chicken, a Chinese breed, is particularly vulnerable to heat stress, resulting in significant annual economic losses. Therefore, further studies on the pathogenesis and treatment of heat stress in Ningdu yellow chickens are urgently needed.

Metabolism, immunity, detoxification, and heat production are all regulated by the liver [5]. Recent studies highlight it as a major target in heat stress and show that such stress impairs liver function and increase the secretion of inflammatory cytokines [6,7]. Necroptosis is the predominant form of liver cell death in heat stress [8]. It is triggered by cytokines and pattern recognition receptors [9]. Upon receiving a “death signal,” receptor-interacting protein kinase 1 (RIPK1) undergoes deubiquitination, a process facilitated by the enzyme cylindromatosis (CYLD) [10]. This modification facilitates the recruitment and phosphorylation of receptor-interacting protein kinase 3 (RIPK3), leading to the assembly of the ripoptosome complex [11]. After this complex enrolling and phosphorylating MLKL, a necrotic complex is formed which induces cell rupture [12]. Heat stress response can thus be controlled by inhibiting liver necroptosis.

In addition to necroptosis, heat stress disrupts the antioxidant balance in broiler liver [13,14]. Oxidative stress is defined as the disproportion‌ between oxidative and antioxidant activities, which finally leading to the generation of reactive oxygen species (ROS) [15,16]. Heat stress leads to the generation of ROS [17]. Pyruvate dehydrogenase complexes (PDC) convert pyruvate into acetyl-CoA, thereby regulating aerobic respiration and production of ROS [18]. Through activation of glycogen phosphorylase (PYGL), RIPK3, a necroptosis-associated protein, facilitates the production of ROS [19]. As an ATP-dependent metalloenzyme, glutamine ammonia ligase (GLUL) catalyzes glutamine synthesis from carbon atoms originating from the tricarboxylic acid cycle, thereby increasing the performance of the cycle [20]. Glutamate dehydrogenase 1 (GLUD1) plays a crucial role in sustaining the tricarboxylic acid cycle. Its main role is to convert glutamine into α-ketoglutaric acid to regulate the production of ROS, resulting in oxidative stress [21]. Additionally, generation of ROS was related with the binding of RIPK3 and PDC binding [22]. Subsequently, the role of necroptosis in ROS production and oxidative stress in heat-stressed chickens needs to be further discussed.

Citrus plants contain a flavonoid called naringenin, which has several biological properties, including anti-inflammatory and antioxidant capabilities [23]. Heat stress increases inflammatory cytokine secretion hepatocytes of broiler chickens [24]. In consequence of‌ its inhibition of the NF-κB pathway, naringenin reduces inflammatory-related factors [25]. In this study, as a feed addictive, naringenin's heat stress-protective properties were evaluated. Here in, we reported that naringenin exerts anti-inflammatory, antioxidant and hepatoprotective effects against heat stress in Ningdu yellow chicken. This study aims to offer a theoretical foundation and reference for developing naringenin to prevent and mitigate heat stress injury in broiler chickens, thereby guiding pharmacological decisions in real-world production setting under heat stress conditions.