Abstract: Objective To observe the effects of interventions involving sinomenine in Brassica rapa L. on pulmonary vascular remodeling and pulmonary function in mice with hypoxic pulmonary vascular injury (HPVI). Methods Forty-eight mice were randomly divided into six groups: blank control group (Con), model group (Mod), sinomenine intervention low-, medium- and high-dose groups (L, M, H, at 50, 100, 150 mg·kg^-1 respectively), and dexamethasone (Dex) administration group. When hypoxia was terminated, routine blood tests, bronchoalveolar lavage fluid (BALF) examination, small animal ultrasound, blood oxygen saturation (SaO₂) measurement, blood biochemistry analysis, pulmonary tissue pathology examination, and immunohistochemistry were conducted. Western blot (WB) was used to detect the protein expressions of HIF-1α, VEGFA, Ang2, IL-1β, and NF-κB to find out about the mechanism of action. High-resolution mass spectrometry (HRMS) technology was employed for quantitative analysis of sinomenine in Brassica rapa L. Results The content of sinomenine in a 1 g·mL^-1 aqueous extract sample of Brassica rapa L. was 3.558 mg·mL^-1. Sinomenine reduced the numbers of such inflammatory cells as WBCs, NEUTs, and lymphocytes in the serum of HPVI mice. It could significantly lower the cell count in the alveolar lavage fluid and the levels of ALP and LDH. It enhanced the cardiopulmonary function and oxygen saturation of mice, but decreased the frequency of respiration. Furthermore, sinomenine mitigated pathological injury in lung tissues, and significantly reduced the percentage of the area and thickness of the vascular wall. Compared with the model group, sinomenine interventions significantly lowered the protein expression levels of HIF-1α, Ang2, VEGFA, and IL-1β, as well as NF-κB in lung tissues of HPVI mice. Conclusion Sinomenine interventions can effectively inhibit vascular remodeling in HPVI mice, especially in the medium dose group. Sinomenine can regulate vascular homeostasis, improve vascular permeability, enhance cardiopulmonary function, facilitate oxygen uptake and transport, and induce vascular normalization by reducing the expressions of angiogenic factors in lung tissues of mice.

Key words: Sinomenine, Brassica rapa L., Hypoxic Pulmonary Vascular Injury, Vascular Remodeling, Mice