Sulfated modification of arabinogalactans from Larix principis-rupprechtii and their antitumor activities.

A highly branched arabinogalactan isolated from Larix principis-rupprechtii and subjected to sulfation derivatization to promote their antitumor bioactivity. Several structural features of the sulfated arabinogalactans (S-LAG) were investigated: molecular weight, monosaccharide constitution, and chemical structures. Spectral analysis indicated that sulfate groups were successfully introduced on arabinogalactan. Sulfated products showed different degrees of substitution (DS) ranging from 0.61 to 0.80, and different Mw ranging from 19.24 to 22.03 kDa. Monosaccharide composition before and after sulfation indicated some level of derivatization selectivity. In vitro cancer cell tests demonstrated that S-LAGs were effective inhibitors to cancer cell growth depending on their dosage. The toxicity mechanisms were further investigated, and assay results revealed that S-LAGs mainly induced cancer cellular apoptosis to promote atrophy and inhibit cell proliferation. The results obtained in this work offer strong demonstration of modified arabinogalactans as a potential medical substance for treating different forms of cancer.