GRP40-F1

This manuscript reports the extraction and characterization of two novel pectin-like polysaccharides, GRP40-F₁ and GRP75-F₁, from the Gastrodiae rhizome, and explores their potential as anti-inflammatory agents. The molecular weights of GRP40-F₁ and GRP75-F₁ were estimated to be 4.71 × 10⁶ and 3.28 × 10⁶ Da, respectively. Both polysaccharides were found to be primarily composed of rhamnose, galactose, glucose, mannose, and galacturonic acid in varying molar ratios. Methylation and NMR analysis revealed the presence of 4)-α-D-GalpA-(1→, Glcp-(1→, →2)-Rhap-(1→, and →2,6)-D-Manp-(1→ glycosidic residues in both polysaccharides. In vitro assays demonstrated that GRP40-F₁ and GRP75-F₁ significantly alleviated inflammation by inhibiting nitric oxide (NO) and prostaglandin E₂ (PGE₂) production in LPS-activated macrophages (RAW 264.7), with NO inhibition IC₅₀ values of 90.89 μg/mL and 86.80 μg/mL, respectively. Furthermore, GRP75-F₁ was found to significantly inhibit the activated MAPK signaling pathway in RAW 264.7 cells by down-regulating the expression of p-p38, p-ERK, and p-JNK in a dose-dependent manner, without affecting p38, ERK, and JNK expression levels. These findings suggest that the pectin-like polysaccharide fractions from Gastrodiae rhizoma possess strong anti-inflammatory properties, and may be key bioactive components contributing to the rhizome's anti-inflammatory effects.