Effect of γ-irradiation on structure and nutraceutical potential of β-D-glucan from barley (Hordeum vulgare).

This paper reports the characterization and potential antioxidant activity of β-D-glucan isolated from barley treated with γ-rays. The β-D-glucan was irradiated with 0, 2, 4 and 8 kGy by gamma ray. The samples were characterized by Fourier transform-infrared spectroscopy, gel permeation chromatography (GPC) and quantitative estimation by Megazyme β-D-glucan assay kit. The average molecular weight of non-irradiated β-D-glucan was 177 kDa that decreased to 79 kDa at 8 kGy. Antioxidant activity was evaluated by five complementary assays including DPPH, lipid peroxidation, reducing power, metal chelating ability and oxidative DNA damage assays. Further, the antiproliferative potential of irradiated β-D-glucan was tested against three human cancer cell lines including Colo-205, T47D and MCF7 using MTT assay. Irradiated β-D-glucan exhibited dose dependent cancer cell growth inhibition. In conclusion, the present study demonstrates that irradiation leads to the formation of low molecular weight β-D-glucan with enhanced antioxidant and antiproliferative activities.