Sulphation can enhance the antioxidant activity of polysaccharides produced by Enterobacter cloacae Z0206.

The protective effects of sulfated polysaccharide derivatives produced by Enterobacter cloacae Z0206 against H₂O₂-induced oxidative damage in RAW264.7 murine macrophages as well as the possible mechanisms governing the protective effects were studied. Sulfated polysaccharides protected RAW264.7 cells from oxidative damage and apoptosis induced by H₂O₂ by protecting the cellular structure; improving the activity of antioxidant enzymes, such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px); and inhibiting caspase-3 activation and DNA fragmentation. In addition, the sulfated polysaccharides conferred higher levels of protection from H₂O₂-induced oxidative damage in RAW264.7 murine macrophages compared to the native polysaccharide lacking sulfation. These results indicated that sulfated modifications might be an effective approach to enhance the antioxidant activity of polysaccharides produced by E. cloacae Z0206, and the sulfated derivatives of these polysaccharides may act as potent antioxidant agents.