Abstract: In order to explore the anti-tumor activity of Perilla frutescens seed polysaccharide (PFSP), the crude polysaccharide was obtained from Perilla frutescens seeds by traditional solvent extraction and purified by DEAE-52 cellulose and dextran G-100 column chromatography, and the effect of the purified polysaccharide on the immune system of H22 tumor bearing mice was determined. The results showed that the yield of the crude polysaccharide was 8.38%. After separation and purification, three polysaccharide fractions, named PFSP-1, PFSP-2 and PFSP-3, were obtained. PFSP-1 was composed of mannose, galactose, xylose and arabinose (at a molar ratio of 0.01:0.06:0.11:0.81). PFSP-2 was composed of mannose, xylose and arabinose (at a molar ratio of 0.28:0.28:0.41). PFSP-3 was composed of rhamnose, glucuronic acid, glucose, galactose, xylose and arabinose (at a molar ratio of 0.013:0.024:0.040:0.080:0.120:0.700). The three polysaccharides all displayed absorption peaks characteristic of polysaccharides and were identified as pyran-type polysaccharides. The anti-tumor effect of PFSP-2 was significantly higher than that of PFSP-1 and PFSP-3 (P < 0.05). Furthermore, PFSP-2 could significantly reduce the concentrations of lactate dehydrogenase and aldolase and interleukin (IL)-10 (P < 0.05), increase the concentrations of IL-2 and tumor necrosis factor α, down-regulate the expression of antiapoptotic protein Bcl-2, and up-regulate the expression of apoptotic protein Bax compared with the model group (P < 0.05). These results indicate that PFSP-2 can inhibit the growth of tumor cells in vivo by improving the immune system of mice.

Key words: Perilla frutescens seed; polysaccharide; separation and purification; immune; anti-tumor activity