Jin Fujun, Zhuo Cuiqin, He Zhe, Wang Huailin, Liu Wei, Zhang Rong, Wang Yifei
Biomedicine Research and Development Center, Guangdong Provincial Key Laboratory of Bioengineering Medicine, National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou, 510632, China.
World J Microbiol Biotechnol. 2015 Mar;31(3):453-60. doi: 10.1007/s11274-015-1798-1. Epub 2015 Jan 21.
Acyclovir is a commonly-used drug for treating herpes simplex virus (HSV) infections, but with its wide clinical application, more and more resistant strains have been found. Therefore, seeking a drug that can act against acyclovir-resistant virus has become an important goal of drug screening and development. In this study, plaque reduction assay, real-time PCR, Western blot, and immunofluorescence technique were used to investigate the antiviral effect of Eucheuma gelatinae polysaccharide (EGP) on HSV and to preliminarily clarify the in vitro anti-HSV mechanism of EGP. EGP was found to significantly inhibit HSV infection in vitro and displayed a good inhibitory effect on acyclovir-resistant strains. More detailed experiments have shown that EGP prevented early HSV-1 infection through directly inactivating HSV-1 particles and impairing virus attachment, but without effect on viral penetration. EGP also inhibited the RNA synthesis of HSV-1 early gene and late gene as well as viral DNA replication; no effect on immediate-early gene synthesis was observed. Besides, through immunofluorescence and western blot, we found that EGP significantly affected the protein synthesis of HSV-1. Taken together, these results demonstrate that EGP exerts its anti-HSV activity mainly through impeding early HSV-1 infection and inhibiting viral RNA and DNA syntheses. The weak cytotoxicity, strong viral inactivation as well as attachment inhibition activity enable EGP to be a virucide candidate for HSV therapy, especially for drug-resistant strains.
阿昔洛韦是一种常用于治疗单纯疱疹病毒（HSV）感染的药物，但随着其在临床上的广泛应用，越来越多的耐药菌株被发现。因此，寻找一种能够对抗阿昔洛韦耐药病毒的药物已成为药物筛选和开发的一个重要目标。在本研究中，采用蚀斑减少试验、实时荧光定量PCR、蛋白质免疫印迹法和免疫荧光技术来研究琼枝麒麟菜多糖（EGP）对HSV的抗病毒作用，并初步阐明EGP的体外抗HSV机制。结果发现，EGP在体外能显著抑制HSV感染，且对阿昔洛韦耐药菌株显示出良好的抑制作用。更详细的实验表明，EGP通过直接灭活HSV-1颗粒和损害病毒附着来阻止HSV-1早期感染，但对病毒穿透没有影响。EGP还抑制HSV-1早期基因和晚期基因的RNA合成以及病毒DNA复制；未观察到对立即早期基因合成有影响。此外，通过免疫荧光和蛋白质免疫印迹法，我们发现EGP显著影响HSV-1的蛋白质合成。综上所述，这些结果表明，EGP主要通过阻碍HSV-1早期感染以及抑制病毒RNA和DNA合成来发挥其抗HSV活性。EGP较弱的细胞毒性、较强的病毒灭活能力以及附着抑制活性使其成为HSV治疗尤其是耐药菌株治疗的一种杀病毒剂候选药物。
