Table 2.

The sources, structural characterization and anti-pulmonary fibrosis activities of natural polysaccharides from seaweeds.

Source/name	Structural characterization	Experimental model	Effects	Reference
L. japonica/ LMWF	Mw: 8−10 kDa; Containing Rha, Fuc, Xly, Man, Glc, Gal, GlcA, Gala; Linkage: backbone →3)-Galp-(1→, →6)-Glcp-(1→, →6)-Galp-(1→, →3,6)-manp-(1→ with →3)-Fucp-(1→, →4)-Glcp-(1→ and sulfated end units.	In vivo: BLM-induced male C57BL/6 mice; In vitro: TGF-β1 induced A549 cells.	After LMWF administration in BLM-induced PF model mice, lung fibrotic histopathology and lung hydroxyproline content was significantly improved, levels of TGF-β1 expression (in BALF and lung tissue) and the lung EMT phenotype (the expression trends of E-cadherin, α-SMA and fibronectin) was attenuated, as well as ERK signaling was downregulated.	Cui et al. (2016), Wang et al. (2019)
			In vitro TGF-β1-induced A549 cells, LMWF significantly inhibited the cell morphologic alterations and proliferation, attenuated EMT phenotype (less expression of E-cadherin and over expression of vimentin, α-SMA and fibronectin mRNA), and downregulated the over expression of p-ERK1/2 induced by TGF-β1.
S. hemiphyllum/ FSH	Mw: 0.8 kDa; Containing rich l-fucose and sulfated ester groups with some d-xylose, d-galactose, d-mannose, glucuronic acid and a mixture of fatty acid methyl esters.	In vivo: radiotherapy (10 Gy/shot)-induced pneumonitis and lung fibrosis in C57BL/6 mice.	Fucoidan administration attenuated the increasing of pro-collagen 1α deposition, neutrophil (over expression levels of Ly6G mRNA) and macrophages (over expression levels of F4/80 mRNA) infiltration in lung tissues, reduced cytokine expression (TIMP-1, CXCL1, MCP-1, MIP-2, IL-1Ra, TREM-1, SDF-1/CXCL12 and IL-16) in the pleural fluid induced by radiation in mice.	Yu et al. (2018), Zheng, Li, Liu, Yuan & Lu (2001)
A kind of seaweed/ MS80	Mw: 8 kDa; Backbone →4)-α-d-Glcp-(1→ with sulfated residues and hydroxymethylated group.	In vivo: BLM-induced pathogen-free adult Wistar rats; In vitro: TGF-β1 induced HEPF cells.	After MS80 administration in BLM-induced PF model rats, there were some improvements in morphology and increasing hydroxyproline content of lung tissue.	Jiang & Guan (2009)
			In vitro, MS80 inhibited the combining capacity of TGF-β1 with heparin examined by surface plasm on resonance and the proliferation, collagen deposition and matrix metalloproteinase activity of HEPF cells with TGF-β1 or BALF.