Purification and anti-tumour activity of cyanidin-3-O-glucoside from Chinese bayberry fruit

Chinese bayberry (Myrica rubra Sieb. & Zucc.) is a rich source of cyanidin-3-O-glucoside (C3G). Purification of C3G was established by using high-speed counter-current chromatography (HSCCC) at 520 nm. The optimised flow rate was 2 ml/min and rotational speed was 850 rpm, and n-butanol–methyl tertiary butyl ether–acetonitrile–trifluoroacetic acid–water (30:20:40:1:100, v/v/v/v/v) solvent showed the highest partition coefficient (K = 1.50) to purify C3G. Different HSCCC fractions showed significant different anti-tumour effect on SGC7901, AGS, and BGC823 gastric cells, which were correlated with their C3G concentrations and DPPH• scavenging activities. Cells treated with C3G resulted in reduced cell proliferation, decreased cell adherence, and abnormal morphological changes characteristics of apoptosis, all in dose-dependent manners. In addition, increased concentrations of C3G treatment resulted in increased inhibition of matrix metalloproteinase 2 (MMP-2) in SGC7901 cells, which may provide important information for the possible mechanism of C3G-induced anti-tumour activity against gastric adenocarcinoma cells.