Sulfated modification enhanced the antioxidant activity of Mesona chinensis Benth polysaccharide and its protective effect on cellular oxidative stress.

The effect of sulfated modification on the physicochemical properties and antioxidant activities of polysaccharide (MP) from Mesona chinensis Benth were investigated by chemical methods, Fourier transform infrared spectroscopy, high performance anion exchange chromatography, and establishing oxidative stress model and free radical model. Results showed that sulfated modification caused a significant change in chemical composition and the apparent structure of MP, but the degradation of the main chain of MP was inconspicuous. Sulfated Mesona chinensis Benth polysaccharide (SMP) exhibited excellent free radical scavenging activities and improved the protective effect of MP on cellular oxidative stress by increasing superoxide dismutase (SOD) activity and decreasing malondialdehyde (MDA) content. This study suggested that sulfated modification is an effective method to improve the antioxidant activities of MP, so as to expand the development and application of MP.