Preparation and cellular protection against oxidation of Konjac oligosaccharides obtained by combination of γ-irradiation and enzymatic hydrolysis.

Konjac glucomannan (KGM) is an important source for preparation of Konjac oligo-glucomannan (KOG), but high molecular weight and viscosity in KGM inhibited its full degradation into KOG. In this study, KOG with a degree of polymerization between 2 and 9 was obtained by combining γ-irradiation and enzymatic hydrolysis in high yield. We investigated the protective effect of KOG against H2O2 - induced oxidative damage in vitro, using human hepatic cell line (LO2) as a cell model. Our results demonstrated that pretreating LO2 with KOG significantly increases cellular survival and antioxidant activities of GSH-Px and CAT enzymes, and reduces levels of LDH, MDA, intracellular accumulation of ROS and Ca2+ concentration within the cell. Marked protective effect against oxidative damage, in addition to obtained high yield of KOG, supports its potential use as an abundant source of antioxidant. To conclude, our study provided a theoretical perspective for future uses of KGM.