Separation and purification of an anti-tumor peptide from rapeseed (Brassica campestris L.) and the effect on cell apoptosis.

Rapeseed peptides were prepared by means of the combined methods of the laboratory bacteria enzyme synergy and the solid-state fermentation of rapeseed meal. The rapeseed peptides were separated and purified with the tumor cell in vitro anti-proliferative activity as an index. Moreover, a kind of rapeseed peptide component RSP-4-3-3 (rapeseed anti-tumor peptide RSP-4-3-3) with high activity was selected. Furthermore, by using reversed-phase high performance liquid chromatography (RP-HPLC) coupled with electrospray ionization mass spectrometry (ESI-MS/MS), the analysis result of its possible amino acid sequence showed that it was Trp-Thr-Pro (408.2 Da). Inverted microscope observation technology and western blot experiments were applied to explore the antitumor impact of the rapeseed peptide RSP-4-3-3 on tumor cells. The results showed that the rapeseed antitumor peptide RSP-4-3-3 could significantly change the morphological features of the HepG2 cells in vitro and cause apoptosis, thus inhibiting the proliferation of the HepG2 cells.