Xinnaoxin tablets ameliorate high-altitude polycythemia-associated cardiac injury by regulating the NF-κB, MAPK, and PI3K/AKT signaling pathways

Background and Objective High-altitude polycythemia (HAPC) and its associated cardiac complications, induced by hypobaric hypoxia (HH), pose significant clinical challenges. Xinnaoxin (XNX) tablets are clinically utilized for these conditions; however, their integrated multi-target mechanisms remain poorly understood. This study aims to elucidate the novel mechanisms and therapeutic potential of XNX against HAPC and HH-induced cardiac injury. For the first time, we employed a combined strategy of systems pharmacology and multi-level analysis to comprehensively investigate how XNX confers synergistic protection by modulating both the hematopoietic microenvironment and myocardial signaling networks. Methods The metabolites of XNX were systematically identified, and its chemical profile was established using UPLC-Q-TOF-MS. An HH mouse model was generated by simulating a high-altitude hypoxic environment. Comprehensive assessments included complete blood parameters, hemorheology, the proportion and apoptosis of CD71 + bone marrow cells, and serum levels of erythropoietin (EPO) and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6). Cardiac injury was evaluated through histopathology, echocardiography, oxidative stress indicators (MDA, T-AOC, CAT, SOD), and Western blot analyses of key signaling pathways, including phosphorylation status of MAPK, JNK, ERK, IκBα, NF-κB, and Akt, as well as the expression of apoptosis-related proteins Bax and Bcl-2. Results XNX significantly reversed HH-induced elevations in red blood cell count, hemoglobin, hematocrit, white blood cell count, and plasma viscosity, while reducing serum EPO levels. Notably, XNX decreased the bone marrow population of CD71 + cells, indicating inhibition of “ineffective erythropoiesis.” Regarding cardioprotection, XNX markedly alleviated myocardial injury, reduced oxidative stress (MDA), enhanced antioxidant enzyme activities, and suppressed pro-inflammatory cytokine release. Mechanistically, XNX coordinately modulated the phosphorylation levels of multiple signaling pathways (MAPK, JNK, IκBα, NF-κB, Akt) and regulated the Bax/Bcl-2 balance, thereby creating a signaling environment favorable for cardiomyocyte survival and repair. Conclusion XNX exerts its therapeutic effects through a dual mechanism: (1) ameliorating HAPC at its source by regulating EPO expression and enhancing bone marrow erythropoietic efficiency, and (2) counteracting HH-induced cardiac injury via multi-target modulation of the MAPK-related signaling network. These findings clarify the pharmacological basis of XNX and provide a theoretical foundation for developing multi-pathway synergistic therapies for high-altitude hypoxia-related cardiovascular diseases.