Characterisation and anti-cancer activities of polysaccharides obtained from Punica granatum L. by different extraction methods

Pomegranate peel is a by-product during the processing of pomegranate products, which is rich in many active components, such as phenols, polysaccharides, vitamins and alkaloids. Two different extraction technologies including hot water extraction and enzyme assisted extraction were employed to extract crude pomegranate peel polysaccharides, then decolourised and deproteinized to purify the crude polysaccharide. The differences of two different extraction polysaccharides in chemical composition, characterisation and antitumor activities were further compared. The molecular weights and monosaccharide composition were different. Moreover, HWE-PPPs and EAE-PPPs showed strong inhibitory effects on MDA-MB-231 and HCT116 cancer cells. At the maximum tested concentration of 1 mg/mL, its inhibition rates against MDA-MB-231 and HCT116 cells were 95.28% and 97.18% respectively; the inhibition rates of EAE-PPPs against MDA-MB-231 and HCT116 cells were also 94.50% and 97.03% respectively. These findings suggest that pomegranate peel polysaccharides have potential as anticancer agents, although their underlying mechanisms require further investigation.