Polysaccharides from Balanophora harlandii Hook: Isolation, Characterization, and Anti-Inflammation Activities

Balanophora harlandii Hook (B. harlandii), a folk medicine, has been traditionally employed to treat traumatic bleeding, gastroenteritis, icteric hepatitis, hemorrhoids, and other conditions. In this work, polysaccharides with anti-inflammatory effects were extracted and purified from B. harlandii. The extraction conditions were optimized, and the properties of one purified neutral fraction, denoted as BHPs-W-S3, were analyzed. Gel permeation chromatography (GPC) was carried out to measure the molecular weight. The structure of BHPs-W-S3 was assessed based on monosaccharide composition analysis, Fourier transform infrared (FT-IR) spectroscopy, methylation analysis, and nuclear magnetic resonance (NMR) spectroscopy. BHPs-W-S3 has a molecular weight of 14.1 kDa, and its three main monosaccharides are glucose, galactose, and mannose with a molar ratio of 6.4:1.7:1.1. Its main chain consists of →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, →6)-β-D-Galp-(1→, →3,6)-β-D-Galp-(1→, and it has branch chains at the O-4 and/or O-3 positions. In addition, in vitro experiments show that the polysaccharides from B. harlandi can decrease the phosphorylation level of p65 and IKB-α in LPS-induced RAW264.7 cells to reduce the expression of the pro-inflammatory genes such as TNF-α, IL-6, and IL-1β.