Cytotoxic effect of crude and purified pectins from Campomanesia xanthocarpa Berg on human glioblastoma cells.

A new source of pectin with a cytotoxic effect on glioblastoma cells is presented. A homogeneous GWP-FP-S fraction (M_w of 29,170 g mol^-1) was obtained by fractionating the crude pectin extract (GW) from Campomanesia xanthocarpa pulp. According to the monosaccharide composition, the GWP-FP-S was composed of galacturonic acid (58.8%), arabinose (28.5%), galactose (11.3%) and rhamnose (1.1%), comprising 57.7% of homogalacturonans (HG) and 42.0% of type I rhamnogalacturonans (RG-I). These structures were characterized by chromatographic and spectroscopic methods; GW and GWP-FP-S fractions were evaluated by MTT and crystal violet assays for their cytotoxic effects. Both fractions induced cytotoxicity (15.55-37.65%) with concomitant increase in the cellular ROS levels in human glioblastoma cells at 25-400 μg mL^-1, after 48 h of treatment, whereas no cytotoxicity was observed for normal NIH 3T3 cells. This is the first report of in vitro bioactivity and the first investigation of the antitumor potential of gabiroba pectins.