Xuebijing alleviates sepsis-induced acute lung injury by inhibiting alveolar epithelial cell apoptosis via cAMP/PKA signaling pathway.

Ethnopharmacological Relevance: Xuebijing (XBJ) is derived from the Xuefu Zhuyu Decoction in "Correction on Errors in Medical Classics." It is a traditional chinese medicinal injection based on a classical formula, mainly composed of Honghua (Carthamus tinctorius L.), Chishao (Paeonia lactiflora Pall.), Chuanxiong (Ligusticum chuanxiong Hort.), Danshen (Salvia miltiorrhiza Bge.), and Danggui (Angelica sinensis (Oliv.) Diels). XBJ has been traditionally and extensively used in the treatment of heat-toxic and blood-stasis syndrome of sepsis. Currently, approved by the China Food and Drug Administration, XBJ is used as an adjunctive treatment for sepsis and MODS.

Aims Of This Study: The effects of XBJ were evaluated in this study to determine its impact on sepsis-induced acute lung injury (ALI) and to reveal the mechanisms behind its alleviation using network pharmacology and proteomics.

Methods: Sepsis-induced ALI mice were established using LPS, and XBJ was administered as an intervention. Body weight variations, survival rate, and histopathology were evaluated to determine the therapeutic effect of XBJ. Inflammatory factor levels in the lungs and serum were measured using ELISA. Subsequently, network pharmacology and proteomics were employed to elucidate the mechanism of XBJ in treating sepsis-induced ALI. The underlying mechanism was verified using in vivo experiments. TEM was used to observe apoptotic ultrastructures, while Western blot, TUNEL, and IF were performed to analyze the mechanistic effects of XBJ.

Results: This study demonstrated that XBJ inhibited inflammatory responses and protected against sepsis-induced ALI. Integrated network pharmacology and proteomic analyses revealed that the anti-apoptotic effect via the cAMP/PKA signaling pathway is a potential mechanism. In the validation of the predicted results, XBJ significantly inhibited the protein expression of APAF-1, Cyt c, Cleaved-Caspase3/Pro-Caspase3, Cleaved-Caspase9/Pro-Caspase9, and upregulated the levels of cAMP, p-PKA/PKA, and p-Bad/Bad. In addition, the TEM results suggested that XBJ alleviated the ultrastructural damage caused by apoptosis in alveolar epithelial cells. IF and TUNEL co-staining confirmed the localization of apoptosis in the alveolar epithelial cells.

Conclusion: This study demonstrated that XBJ can repair structural tissue damage in sepsis-induced ALI and reduce the inflammatory response to improve survival. Network pharmacology, proteomics, and experimental verification revealed that XBJ could prevent sepsis-induced ALI by activating the cAMP/PKA signaling pathway and alleviating apoptosis in alveolar epithelial cells.