ROS can also regulate many signalling pathways, such as infiltration of mono- cytes in intima and vascular smooth muscle cell proliferation. A potentially important clinical corollary of the atherosclerosis oxi- dation theory is that inhibition of LDL oxidation may also inhibit atherosclerosis independent of lowering plasma cholesterol con- centrations. Thus, it is essential to develop and utilise effective and natural antioxidants so that they can protect the human body from free radicals and retard the progress of many chronic dis- eases. Published data indicates that plant polysaccharides in gen- eral have antioxidant activities and can be explored as novel potential antioxidants (Ng et al., 2004; Jiang, Jiang, Wang, & Hu, 2005; Wang & Luo, 2007). Different polysaccharide fractions ex- tracted and purified from litchi fruit pericarp tissues exhibited strong antioxidant activities (Yang et al., 2006). Tea polysaccha- rides were also shown to exert significant inhibitory effects on hy- droxyl and superoxide radicals and lipid peroxidation.