Antiviral effects
Wang et al60 prepared four sulfated L. barbarum polysaccharides (sLBPs), sLBPS(0.7), sLBPS(1.1), sLBPS(1.5), and sLBPS(1.9), and compared their effects on the cellular infec-tivity of Newcastle disease viruses (NDVs) in chick embryo fibroblasts. Four sLBPSs at five concentrations, within the safety concentration scope, and NDVs were added into the cultivating system of chick embryo fibroblasts in three modes, pre- and post-adding polysaccharide, and simultaneous adding of polysaccharide and viruses after being mixed. The effects of sLBPSs on cellular infectivity of NDVs were assayed by MTT method taking the nonmodified LBPS as the control.60 The results showed that sLBPS(1.5), sLBPS(1.9), and sLBPS(1.1) in three sample-adding modes, sLBPS(0.7) in simultaneous adding after being mixed, significantly inhibited the infectivity of NDVs. The viral inhibitory rate of sLBPS(1.5) in pre-adding and simultaneous adding, and sLBPS(1.9) in post-adding, was the highest. Nonmodified LBPS did not present significant effect in any sample-adding mode.60 These results indicated that sulfated modification significantly enhanced the antiviral activity of LBPs, which was correlated with the degree of sulfation of LBPs. The mechanisms for the antiviral activity of LBPs are unknown.