Integration of transcriptomics and metabolomics to study the mechanism of Siwei Huangqi powder in Tibetan medicine for protecting against high-altitude hypoxic brain injuries.

Background and aim: Siwei Huangqi powder (SWHQP) is a folk medicine that is extensively used in Tibetan medicine. It is widely employed at the medical institutions of various monasteries in the Tibetan region and is highly recommended by esteemed folk practitioners. It is mainly used in clinical practice for high-altitude diseases caused by an imbalance of the three bases of Tibetan medicine, namely, Long, Chiba, and Peigen, which leads to disorders of qi and blood circulation. This study aimed to investigate the potential molecular mechanism underlying the therapeutic and preventive effects of SWHQP in a high-altitude hypoxia brain injury (HHBI) rat model. Methods: An HCP-III experimental animal low-pressure simulation chamber was used to simulate high-altitude hypoxic environmental exposure in rats to establish an HHBI model. The severity of brain injury, including the brain wet/dry (W/D) ratio and H&E staining, was evaluated through a series of assessments. Transcriptomic and metabolomic analyses were performed to identify gene expression changes and metabolite alterations in brain tissue. Western blotting and immunofluorescence were used to assess the relative expression of proteins involved in the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor-kappa B p65 (NF-kB p65) pathway. The expression levels of genes related to the PI3K/AKT/NF-κB p65 signaling pathway were detected via real-time PCR. Enzyme-linked immunosorbent assays (ELISAs) were conducted to measure the serum levels of proinflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β). Results: SWHQP significantly improved brain function, reduced the wet/dry ratio, and alleviated brain tissue damage. Transcriptomic and metabolomic analyses revealed that the PI3K/AKT/NF-κB signaling pathway was significantly upregulated in the HHM group and that the expression of inflammatory factors related to amino acid metabolism and lipid metabolism was increased. A previous study also revealed that SWHQP inhibited the activation of the PI3K/AKT/NF-κB p65 signaling pathway in brain tissue, reducing the release of the downstream proinflammatory cytokines IL-6, IL-1β, and TNF-α. Conclusion: The therapeutic effect of SWHQP on brain injury in HHBI rats is attributed to its ability to regulate inflammation-related amino acid synthesis and lipid metabolism and modulate inflammation-related pathways. These findings provide a robust research foundation for the potential clinical application of SWHQP in Tibetan medicine.