Polysaccharides extraction from Opuntia stricta and their protective effect against HepG2 cell death and hypolipidaemic effects on hyperlipidaemia rats induced by high-fat diet.

The aim of this study was to analyse cytoprotective effect of polysaccharides compound from Opuntia stricta (O. stricta) cladode (POS) in vitro including its radical scavenging activities and protective effects against hypercholesterolaemia. Our results showed that glucose was the dominant monosaccharides (30.35%). Arabinose, pyranose, fructose, galactose, glucose, sorbitol, S-inositol, M-inositol, trehalose and saccharose found in this species. O. stricta polysaccharides did not cause any cytotoxic effect on HepG2 cells within the range of concentrations tested (0-400 μgml(-1)). Pre-treatment of HepG2 cells with POS (100 μgml(-1)) significantly (p < .05) protected against cytotoxicity induced by DPPH and ABTS radicals. The POS showed strong antioxidant potential in vitro. The results indicated also that POS significantly prevented hypercholesterolaemia-induced elevation of serum biomarkers and induced increase in serum lipid profile. Moreover, the hypercholesterolaemia characterised by elevated lipid peroxidation (MDA) and reduced antioxidant enzyme defences (SOD, CAT and GPx) was restored by POS treatment.