# Sulfated Polysaccharides of Potamogeton lucens as a Promising Immunostimulatory Agent in Activation of RAW264.7 and NK Cells

## TL;DR

A new sulfated polysaccharide from Potamogeton lucens activates immune cells, suggesting potential use in functional foods.

## Contribution

A novel sulfated polysaccharide from Potamogeton lucens is shown to stimulate immune responses in macrophage and NK cells.

## Key findings

- PLF2 activated RAW264.7 cells to produce NO, TNF-α, IL-1β, and IL-6.
- PLF2 also activated NK-92 cells to produce TNF-α, IFN-γ, granzyme-B, perforin, NKG2D, and FasL.
- Activation occurred via NF-κB and MAPKs signaling pathways.

## Abstract

Sulfated polysaccharides are naturally occurring biomacromolecules with complex structures and promising therapeutic effects, the mechanism of which remains to be fully understood. This study isolated a novel sulfated polysaccharide from
Potamogeton lucens
, followed by fractionation by a DAEA Sepharose FF column to assess its immunostimulatory effects on NK‐92 and RAW264.7 cells. The primary components within the crude polysaccharides and fractions (PLF1, PLF2 and PLF3) were predominantly neutral sugars, with comparatively lower proportions of sulfate and uronic acids. The isolated polysaccharides exhibited a range of weight average molecular weights (M
w) from 488.7 to 918.9 × 103 g/mol. Polysaccharide composition included glucose, galactose, arabinose, rhamnose, mannose, and xylose units linked through various glycosidic linkages, including (1 → 4)‐Galp, (1 → 6)‐Galp, (1 → 3)‐Galp, (1 → 3)‐Arap, (1 → 2,4)‐Rhap, (1 → 2)‐Glcp and (1 → 4)‐Glcp residues. The PLF2 polysaccharide showed remarkable efficacy by activating RAW264.7 macrophage cells to synthesize NO, TNF‐α, IL‐1β and IL‐6, while also activating NK‐92 cells to synthesize TNF‐α, INF‐γ, granzyme‐B, perforin, NKG2D, and FasL via the NF‐κB and MAPKs signaling pathways. Collective findings indicated that polysaccharides derived from
P. lucens
have the potential to serve as potent immunostimulatory compounds in functional foods, capable of eliciting responses in both RAW264.7 and NK cells.

The polysaccharide showed remarkable efficacy by activating RAW264.7 macrophage cells to synthesize NO, TNF‐α, IL‐1β and IL‐6, while also activating NK‐92 cells to synthesize TNF‐α, IFN‐γ, granzyme‐B, perforin, NKG2D, and FasL via the NF‐κB and MAPKs signaling pathways.