Structural characteristics of pectin polysaccharide CWP-3 and its protective effect on primary dysmenorrhea mice with qi stagnation and blood stasis

Curcumae wenyujin Rhizoma (CWR) is extensively implemented in clinical practice for treating primary dysmenorrhea (PD) resulting from qi stagnation and blood stasis. However, the development of CWR-derived polysaccharides remains poorly investigated. In this study, the polysaccharide CWP-3 was isolated from CWR, and structurally characterized through FT-IR, HPLC, GC–MS, and NMR, which identified it as an RG-I-type pectin polysaccharide with a molecular weight of 423.6 kDa. CWP-3 consists of the monosaccharides Rha, GalA, Gal, and Ara (25.7: 28.6:42.8:2.9). The main backbone consisted of alternating 1,2-linked Rha p and 1,4-linked GalA p residues, with Gal and Ara forming the side chains, respectively. SEM revealed a porous, sheet-like morphology, while Congo Red staining and AFM analyses confirmed a triple helix structure with a height of 3.37 nm, and TG-DSC analysis indicated good thermal stability. In a mouse model of PD, 160 mg/kg CWP-3 reduced writhing by 70.3 %, prolonged coagulation time by 37.5 %, restored uterine and hepatic indices, and decreased AST, ALT, D2D, TXB2, IL-6, IL-1β, and TNF-α, while normalizing PGF₂α/PGE₂ levels. These results indicate that CWP-3 exerts blood-activating and analgesic effects through cytokine-mediated COX-2 suppression, suggesting its potential as a therapeutic candidate for PD with qi stagnation and blood stasis.