Apigenin Attenuates Hepatic Ischemia-Reperfusion-Induced Lung Injury via Downregulation of MMP-3 and MCP-1: An Experimental Study in Rats.

Background/Objectives: In liver transplant surgery, ischemia-reperfusion (I-R) maneuvers are frequently employed to control bleeding; however, such interventions can result in injury not only to the liver but also to remote organs. The lungs, in particular, are highly susceptible due to their extensive vascularization and inflammatory response. While pulmonary injury secondary to hepatic I-R is recognized, and despite the fact that various antioxidant compounds have been investigated for their potential to mitigate I-R-induced damage to hepatic tissue, few studies have focused on evaluating therapeutic agents aimed at mitigating lung damage in this setting. This study aimed to evaluate the protective effect of apigenin on pulmonary tissue following liver I-R injury using an experimental rat model. Methods: Sixty-three male albino Wistar rats (approximately 15 weeks old, weighing 220-350 g) were randomly allocated into three groups: a sham group (open-close surgery; n = 7), a control (C) group subjected to liver I-R injury only (n = 28), and an apigenin (Ap) group receiving intraperitoneal apigenin administration immediately after liver ischemia and prior to reperfusion (n = 28). Both the C and Ap groups were subdivided into four equal subgroups corresponding to euthanasia at 60-, 120-, 180-, and 240 min post-reperfusion. Lung tissues were harvested for immunohistochemical analysis targeting the expression of matrix metalloproteinase-3 (MMP-3) and monocyte chemoattractant protein-1 (MCP-1). Results: The apigenin-treated groups exhibited significantly reduced expression levels of MMP-3 and MCP-1 across all time points when compared to the control groups. In contrast, no expression of MMP-3 or MCP-1 was observed in the sham group. Conclusions: The findings support the protective role of the antioxidant apigenin in reducing pulmonary injury following liver I-R. The diminished expression of MMP-3 and MCP-1 in the apigenin-treated rats provides compelling evidence for its protective effects on remote organs.