Pectic Oligosaccharide from tomato exhibiting anticancer potential on a gastric cancer cell line: Structure-function relationship.

Pectic Polysaccharide (PP) from dietary sources has been known to prevent cancer growth and hence impede cancer progression. We evaluated anticancer effect of Pectic-Oligosaccharide isolated from Sour Raw Tomato (SrTPO); its bioavailability and structure elucidated from purified fraction (SrTPO1). SrTPO1 inhibited galectin-3 activity with MIC of 0.25 ug/mL (100 fold better than standard galactose), inhibited the growth of AGS cells (IC50 3.4μg/mL) and induced apoptosis (70% inhibition at 30μg/mL concentration). Normal- NIH 3T3 cells were not affected by SrTPO as opposed to doxorubicin, a known anticancer drug, which reduced 76% viability at equivalent dose. SrTPO1 was identified as RhamnogalacturonanI-arabinogalactan (RGI-AG), where repeated alternative rhamnose and galacturonic acid residues were observed while arabinose in the branch point and β-1,4 linked galactose in the linear chain form. SrTPO was found to be bioavailable as evaluated by FITC labelled oligos inside the cell, which was in reciprocal proportion with apoptosis.