Coelonin, an active component extract from Bletilla striata (Thunb.) Reichb.f., alleviates lipopolysaccharide-induced acute lung injury by increasing the expression of non-coding RNA Gm27505 and inhibiting the M1 polarization of macrophages caused by inflammatory responses.

Coelonin is a dihydrophenanthrene compound derived from the traditional Chinese medicine Bletilla striata (Thunb.) Reichb.f., which exhibits significant anti-inflammatory activity and effectively inhibits lipopolysaccharide (LPS)-induced inflammatory responses in RAW264.7 cells. Although previous studies have demonstrated the protective effect of Bletilla striata against LPS-induced acute lung injury (ALI), the potential protective role and underlying molecular mechanisms of its major active component, Coelonin, in ALI remain unclear. In this study, an LPS-induced mouse ALI model was established to systematically evaluate the protective effects of Coelonin on ALI. Furthermore, transcriptomic analysis was utilized to investigate the anti-inflammatory mechanisms mediated by Coelonin through the regulation of non-coding RNA (ncRNA)-associated inflammatory pathways. The results indicated that Coelonin significantly ameliorated LPS-induced pathological damage in lung tissues and markedly reduced the levels of inflammatory markers in bronchoalveolar lavage fluid (BALF). In vitro experiments using the murine alveolar macrophages (MH-S) cell line further confirmed the anti-inflammatory activity of Coelonin. Transcriptome analysis revealed that Coelonin markedly upregulates the expression of the ncRNA Gm27505, which was previously found to be downregulated in a mouse model of Alzheimer's disease. To date, there have been no reports on the biological functions of Gm27505. Bioinformatics analysis and real-time quantitative fluorescence PCR (qPCR) confirmed that this ncRNA is primarily localized within the nucleus. Overexpression of Gm27505 in MH-S cells significantly downregulated the expression of inflammation-related genes such as Il6, Tnfα, Il27, and Ccl3 induced by LPS stimulation. Moreover, overexpression of Gm27505 promoted macrophage polarization toward the M2 phenotype while suppressing M1 polarization. These findings suggest that the ncRNA Gm27505 plays an important biological role and is critically involved in the regulation of inflammatory responses. Coelonin may alleviate LPS-induced ALI in mice by up-regulating Gm27505 expression and modulating macrophage polarization. Therefore, Gm27505 may represent a potential target for the prevention and treatment of ALI, providing new research directions for future therapeutic strategies against related diseases.