The Study On Antiviral Action Of Eucheuma Gelatinae Polysaccharide

Research background: Eucheuma gelatinae polysaccharide was a mixture extracted from red algae. The source of Eucheuma gelatinae was rich because there is a large-scale artificial cultivation base in Hainan Island. The polysaccharide extracted from eucheuma, also known as carrageenan, was widely used in the food industry. Researches show that Eucheuma gelatinae polysaccharide has many biology activities which are beneficial to human’s health, including anti-oxidation, anti-tumor, preventing radiation injury activities and so on. However, at present there’s rarely report was about Eucheuma gelatinae polysaccharide used as a therapeutic drug or medical device applications, mostly the application of Eucheuma gelatinae polysaccharide was as a food additive. Our experiments detected the antiviral bioactivity and its mechanism of Eucheuma gelatinae polysaccharide, and try to develop new medical apparatus and instruments, produced a hydrogel with antiviral activity which using Eucheuma gelatinae polysaccharide as a raw material.Research methods and results:MTT and cytopathic effect(CPE) methods were used to evaluate the ctotoxicity of Eucheuma gelatinae polysaccharide(EGP) on some cell lines. Then uncover the antiviral activities and the sensitive step of the virus replication to EGP. The results show that both crude Eucheuma gelatinae polysaccharides(CEGP) and the large molecular weight components(MW>500KDa, LEGP) was no toxic effect to the cell lines used in the experiments, but showed significant and similar inhibition effects on the influenza virus(H1N1, H5N3 and H3N2), CVB3 and RSV-long. CVB3 and RSV were more sensitive to EGP(CEGP and LEGP) compared to influenza virus. Both CEGP and LEGP have strong antiviral activity when the cells were pre-treatment with them before virus infection. However, CEGP and LEGP show no effect if the cells has been infected with virus.EGP prevented early HSV-2 infection through directly inactivation and impairment of virus attachment. RT-PCR demonstrated that EGP inhibited the RNA synthesis of HSV-2, including early gene(UL52) and late gene(UL27), but didn’t cause any change in viral replication.A hydrogel was prepared using EGP as a raw material. The gels stability and anti-HSV-2 activity were tested. The results show that the gels can significantly inhibit the infection of HSV-2 in vitro. But the stability of the gels was not very satisfy.Conclusion and Significance: Our study evaluated the anti-respirovirus and anti-HSV-2 activity of Eucheuma gelatinae polysaccharide, proving that this polysaccharide has a broad spectrum antiviral activity. The antiviral mechanism was also explored and the results show that Eucheuma gelatinae polysaccharide suppress the virus infection mainly through directly inactivation and impairment of virus attachment, which indicating that Eucheuma gelatinae polysaccharide play a role in prevention the Virus invade. Our study also explored the feasibility of prepare gels with EGP which have antiviral activity, EGP and the gels contained EGP may be used in medical device need further research.