Depolymerized products of chitosan as potent inhibitors of tumor-induced angiogenesis

• Published in: Biochimica et biophysica acta Vol. 1722; no. 1; pp. 22 - 29
• Main Authors: Harish Prashanth, K.V., Tharanathan, R.N.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 11.02.2005
• Subjects: Angiogenesis Inhibitors - metabolism; Animals; Anti-angiogenesis; Apoptosis; Cell Shape; Cells, Cultured; Chick Embryo; Chitooligosaccharide; Chitosan - chemistry; Chitosan - metabolism; Chorioallantoic Membrane - blood supply; Decapoda (Crustacea); DNA; Low molecular weight chitosan; Mice; Molecular Weight; Neovascularization, Pathologic; Oligosaccharides - chemistry; Oligosaccharides - metabolism; Peritoneum - blood supply; Anti-angiogenesis; Chitooligosaccharide; DNA; Low molecular weight chitosan; Apoptosis
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2004.11.009

Water-soluble low-molecular weight chitosan (LMWC) and chitooligosaccharides (COs) were obtained from chitosan (16% N-acetylation) by depolymerization induced by potassium persulfate under nitrogen atmosphere for 2 h. They were characterized by IR, X-ray, HPLC and 13C-NMR. Splitting of C3/C5 signals in the latter indicated a newer conformation, and also showed prominence of acetyl groups in LMWC, may be due to cleavage between two consecutive deacetylated residues. Molecular weight of LMWC, determined by HPSEC, showed a single peak of ∼37 kDa. HPLC analysis of the solvent-extracted fraction revealed COs enriched with pentamer, hexamer and higher oligomers. The effect of LMWC and COs on the growth of Ehrlich ascites tumor (EAT) cells and tumor-induced neovascularization was studied. COs (50 μg) were more effective compared to LMWC (100 μg) and proved to be potent angioinhibitory and antitumor compounds, as shown by inhibition of angiogenesis and inducing apoptosis as a function of DNA fragmentation.