[Research progress on action mechanisms of Rheum palmatum anthraquinones in improving acute lung injury]

Acute lung injury(ALI) and acute respiratory distress syndrome(ARDS) are severe respiratory diseases characterized by uncontrolled inflammatory responses and disruption of the alveolar-capillary barrier. This type of disease is often triggered by multiple factors such as infection, sepsis, trauma, or inhalation injury, and the pathological process involves multiple sections including inflammatory cascade reactions, oxidative stress imbalance, abnormal activation of immune cells, and increased pulmonary microvascular permeability. Owing to their complex pathogenesis and high mortality, available clinical therapeutic approaches remain limited. Therefore, the development of safe and effective therapeutic agents to attenuate ALI has become a major focus of current research field. As a TCM, Rheum palmatum has a long history of use in clearing heat and toxins, purging the bowels, and regulating systemic inflammatory responses. In recent years, increasing attention has been paid to its therapeutic effect in ALI. RESULTS:: show that R. palmatum and its major bioactive anthraquinones, such as emodin and rhein, exert protective effects through multi-target and multi-pathway mechanisms. These mechanisms mainly include inhibition of inflammatory signaling pathways such as nuclear factor-κB(NF-κB), mitogen-activated protein kinase(MAPK), and NOD-like receptor protein 3(NLRP3) inflammasome, attenuation of oxidative stress response, activation of the nuclear factor erythroid 2-related factor 2(Nrf2)-mediated antioxidant defense system, regulation of programmed death in immune cells including macrophages, improvement of immunometabolic status, modulation of macrophage polarization and the gut microbiota as well as the gut-lung axis, and so on. In addition, R. palmatum has been shown to preserve the integrity of the alveolar-capillary barrier and to suppress excessive neutrophil activation and the overformation of neutrophil extracellular traps(NETs), thereby reducing inflammation amplification effect and the risk of immune microthrombi. This paper summarized the action mechanisms and research progress of R. palmatum in the treatment of ALI, aiming to elucidate the unique advantages of R. palmatum anthraquinones in intervening in the complex pathological processes of ALI through systemic regulatory networks and to provide a solid theoretical basis for the research and development of innovative R. palmatum-based medicines and their clinical combination medication.