Polysaccharide fractions from Polygoni cuspidati rhizoma et radix decoction promote human gingival fibroblast proliferation relevant to oral wound healing

Ethnopharmacological relevance: Polygoni cuspidati rhizoma et radix, derived from Reynoutria japonica Houtt., a medicinal and invasive plant, has traditionally been used in East Asia for inflammatory and suppurative conditions, including ailments affecting the oral cavity, and is listed in both the Chinese and European Pharmacopoeias. While polyphenolic and anthraquinone constituents have been extensively studied, the role of polysaccharides in aqueous decoctions remains insufficiently understood. Aim of the study: To determine whether polysaccharides isolated from decoctions of Polygoni cuspidati rhizoma et radix influence human gingival fibroblast proliferation as a cellular process relevant to oral tissue repair. Materials and methods: Decoctions prepared from pharmacopoeial and wild-collected rhizomes were fractionated by stepwise ethanol precipitation to obtain polysaccharide-rich fractions (POS1-POS3). Their effects on human gingival fibroblast viability, proliferation (Ki-67), and cell-cycle progression were evaluated in vitro. Chemical characterization was performed using HPLC-MS, HPLC-RI and FTIR spectroscopy. Results: High-molecular-weight polysaccharides (POS1) significantly enhanced fibroblast proliferation, cell-cycle progression and viability. POS2 and POS3 exerted complementary biological effects: both improved cell viability, POS3 increased the proportion of Ki-67-positive cells, whereas POS2 promoted transition of cells into the S phase of the cell cycle. Differences between pharmacopoeial and wild material influenced the magnitude of biological response. Conclusions: High-molecular-weight polysaccharides from Polygoni cuspidati rhizoma et radix decoctions stimulate proliferation and cell-cycle progression of human gingival fibroblasts in vitro, indicating that they represent the principal contributors to the regenerative activity of the decoction and potential biological mediators underlying reported traditional applications of the plant