Isolation, Characterization, and Anti-Idiopathic Pulmonary Fibrosis Activity of a Fucoidan from Costaria costata

Tetrastigma hemsleyanum polysaccharide ameliorates cytokine storm syndrome via the IFN-γ-JAK2/STAT pathway

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is an disease characterized by pulmonary edema and widespread inflammation, leading to a notably high mortality rate. The dysregulation of both pro-inflammatory and anti-inflammatory systems, results in cytokine storm (CS), is intricately associated with the development of ALI/ARDS. Tetrastigma hemsleyanum polysaccharide (THP) exerts remarkable anti-inflammatory and immunomodulatory effects against the disease, although its precise role in pathogenesis remains unclear. In the present study, an ALI/ARDS model was established using bacterial lipopolysaccharides. THP administration via aerosol inhalation significantly mitigated lung injury, reduced the number of inflammatory cells, and ameliorated glycerophospholipid metabolism. Furthermore, specific CS-related pathways were investigated by examining the synergy between tumor necrosis factor-α and interferon-γ used to establish CS models. The results indicated that THP effectively decreased inflammatory damage and cell death. The RNA sequencing revealed the involvement of the Janus kinase (JAK) 2-signal transducers and activators of transcription (STAT) signaling pathway in exerting the mentioned effects. Additionally, THP inhibited the activation of the JAK-STAT pathway, thereby alleviating the CS both in vivo and in vitro. Overall, THP exhibited marked therapeutic potential against ALI/ARDS and CS, primarily by targeting the IFN-γ-JAK2/STAT signaling pathway.

Bletilla striata polysaccharide attenuated the progression of pulmonary fibrosis by inhibiting TGF-β1/Smad signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Bletilla striata, a traditional medicinal plant, has been utilized as a folk medicine for many years because of its superior biological activity in China. However, Bletilla striata polysaccharide (BSP) has received less attention, and its specific mechanism for ameliorating pulmonary fibrosis is completely unclear.

AIMS OF THE STUDY

In this study, we aim to assess BSP on the treatment of PF and explore potential mechanisms.

MATERIALS AND METHODS

BSP was successfully extracted and purified from Bletilla striata. The mechanisms were assessed in bleomycin-induced pulmonary fibrosis model and lung fibroblasts activated by transforming growth factor-β1 (TGF-β1). Histological analysis, immunofluorescence, Western blot and flow cytometry were used to explore the alterations after BSP intervention.

RESULTS

The results in vivo showed an anti-PF effect of BSP treatment, which reduced pathogenic damages. Furthermore, TGF-β1-induced abnormal migration and upregulated expression of collagen I (COL1A1), vimentin and α-smooth muscle actin (α-SMA) were suppressed by BSP in L929 cells. Moreover, the abnormal proliferation was retarded by inhibiting the cell cycle of G1 to S phase. Immunofluorescence assay showed that BSP activated autophagy and played an antifibrotic role by inhibiting the expression of p62 and phospho-mammalian target of rapamycin (p-mTOR). Last but not least, the suppression of TGF-β1/Smad signaling pathway was critical for BSP to perform therapeutic effects in vitro and in vivo.

CONCLUSION

The possible mechanisms were involved in improving ECM deposition, regulating cell migration and proliferation, and promoting cellular autophagy. Briefly, all of the above revealed that BSP might be a novel therapy for treating pulmonary fibrosis.