The members of Pleione (Orchidaceae) are popular worldwide for their ornamental appeal and medicinal properties. Pleione bulbocodioides , a CITES Appendix II-listed species, has been traditionally used in dermatological therapies but remains pharmacologically understudied. In this study, the in vitro anti-inflammatory effects of extracts from artificially cultivated P. bulbocodioides were investigated. We found the P. bulbocodioides extract (PE) significantly suppressed TNF-α/IFN-γ-induced expression of IL-6, IL-1β, CCL5, CCL8, CXCL8, CXCL3, and TMEM173 (STING) genes in both HaCaT cells and NHEKs. Transcriptomic analysis and Western blotting confirmed the inhibitory effects on STING/NF-κB signaling pathway of PE. And phytochemical characterization identified militarine and batatasin III as principal bioactive constituents responsible for STING/NF-κB pathway inhibition by PE. PE also demonstrated comparable anti-inflammatory efficacy in LPS-induced RAW 264.7 macrophages and SLS-irritated 3D reconstructed human epidermis. Thus, these findings indicate the potential of PE as a natural anti-inflammatory therapeutic or skincare ingredient for dermatological applications.
Pseudobulbs of Pleione bulbocodioides have been used as traditional Chinese medicine for a long time to treat cancers through decoction with water. However, as its main water-soluble ingredient, the structure of polysaccharide has not been elucidated yet. To obtain its polysaccharide with antitumor activity, a series of isolation, structural identification and antitumor evaluation experiments were performed. As a result, a newly discovered glucomannan, named PBP, was isolated and purified from the pseudobulbs of P. bulbocodioides . The molecular weight of PBP is 1.11 × 10 5 Da. Its monosaccharide composition comprises mannose and glucose at a molar ratio of 5:3. The fine structure of PBP was confirmed as a linear glucomannan backbone primarily comprising repeating →4)-β- d -Glc-(1 → 4)-β- d -Man-(1 → 4)-β- d -Glc-(1 → 4)-β- d -Man-(1 → 4)-β- d -Glc-(1 → 4)-β- d -Man-(1→4)-β- d -Man-(1 → 4)-β- d -Man-(1 → via a combination of analytical techniques and enzymolysis methods. PBP effectively inhibited the growth of 4T1 tumors with low toxicity in vivo . Furthermore, a noteworthy augmentation in the expression levels of CD4+ and CD8+ T cells suggested the existence of an elevated immune response. In summary, a new glucomannan with anti-breast tumor activity was obtained, which has the potential to contribute to breast cancer therapy.