There is a global need to discover effective anti-cancerous compounds from natural sources. Cultivated wheat cells can be a valuable source of non-toxic or low toxic plant-derived polysaccharides. In this study, we evaluated the anti-cancer ability of seven fractions of wheat cell culture polysaccharides (WCCPSs) in the HCT-116 colon cancer cell line. Almost all (6/7) fractions had an inhibitory effect on the proliferation of colon cancer cells, and two fractions (A-b and A-f) had considerable therapeutic indexes. The WCCPS fractions induced cell cycle arrest in the G1 phase and induced different rates of apoptosis (≤48%). Transmission and scanning electron microscopy revealed that WCCPS fractions caused apoptotic changes in the nucleus and cytoplasm, including damage to mitochondria and external morphological signs of apoptosis. In addition, the WCCPSs induced an increase in the levels of Bax, cytochrome c, and caspases 8 and 3, indicating that cell death progressed through intrinsic and extrinsic pathways of apoptosis. Furthermore, some fractions caused a significant decrease of c-Myc, b-catenin, NFkB2, and HCAM (CD 44) levels, indicating enhanced cell differentiation. Thus, for the first time, our results provide a proof of concept of the anti-cancer capacity of WCCPS fractions in colorectal cancer.

Plant polysaccharides with technical and physiologic traits attract researchers by their high physiological activity in regulation of the growth, development and protective reactions. Cell cultures allow to regulate chemical composition of synthesized substances by changing media composition and are widely used to enhance or change the biosynthesis of metabolites. The aim of this study was to investigate the influence of phytohormones 2,4-dichlorphenoxyacetic acid (2,4 –D) and abscisic acid (ABA) of culture medium on chemical composition of polysaccharides (PS), extracted from cells and extracellular liquid of wheat suspension culture. It was shown for the medium with ABA that monosaccharide composition of extracellular PS mainly represented by glucose (87%), whereas PS isolated from cells were rich for xylose and glucuronic acid. Monosaccharide composition of extracellular PS from media with 2,4-D showed 6-fold increase of arabinose, 8-fold ‒ of galactose, 5-fold ‒ of xylose and glucuronic acid, compared to extracellular PS from ABA medium. Composition of cellular PS from media with 2,4-D were mainly similar to ABA and differed by the increased amount of mannose (3-fold), and galacturonic acid (2,5-fold). Thus, regulative effect of the use of two different types of phytohormones was demonstrated on the biosynthesis of variously composed polysaccharides.

Polysaccharides were extracted from wheat suspension culture and cultivated cells. Gaz-liquid chromatography of wheat suspension culture allowed identifying the composition of polysaccharides that were found to contain arabinose, xylose, galactose, glucose, and a little amount of mannose and rhamnose. In dried cultivated cells the polysaccharide structure consisted mainly from arabinose, xylose, and galactose. It was found that the percentage of the amount of monosaccharides was positively correlated with the concentration of 2,4-D at the suspension media.

Polysaccharides (PS) from wheat cell culture were isolated by liquid-liquid extraction. The molecular mass distribution was determined by gel-permeation chromatography (GPC) using dual detectors for the simultaneous detection. It was supposed that PS sample from wheat cell culture has molecular weight of 1632 Da. The physic-chemical properties of PS such as solubility in different solvents, surface activity, ξ-potential, the pH value, polydispersity (PDI) were determined. The PS sample was soluble in water and insoluble in ethanol, acetone and chloroform. ξ-potential of PS was evaluated in order to determine its charge at different pH value from 3 to 9. As a result, the ξ values for the PS solution were negative throughout the pH range studied, varying from -2.85 mV (pH 3.0) to -21.1 (pH 9). Using tensiometry method, surface tension of the PS at the liquid/air interface was investigated. At 0.05% concentration interfacial tension decreases slowly and reaches an equilibrium value after ~ 8-8.5 hours. The pH was equal to 5.6±0.05. For a PS solution of 0.001% at pH 5.5 PDI was equal to 0.595.