Analysis of Anti-Herpes Simplex Virus Type 1 Activity from Roystonea regia Extract

• Main Authors: Chi-Chang Hsieh, 謝繼璋
• Other Authors: Yuh-Chi Kuo
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/00992048815506767272

碩士 === 輔仁大學 === 生命科學系碩士班 === 96 === Herpes simplex virus type 1 (HSV-1) belongs to Herpesviridae and causes cold sores in human. Although nucleotide analogs have been used as anti-viral drugs, there are drug-resistant HSV-1 strains found in clinical. Therefore, it’s important to identify new medicines against HSV-1 infection. In behalf to find new anti-HSV-1 compund, this study discocery extracts from Roystonea regia significantly blocked HSV-1. In the present study, the extracts from Roystonea regia significantly blocked HSV-1 replication in Vero cells without apparent cytotoxicity. Its IC50 is 46.94 μg/ml. To elucidate R. regia anti-HSV-1 activity in vivo, BALB/c mice were injected subcutaneous with HSV-1 ( 4×106 PFU ), treated orally with acyclovir ( 60 mg/Kg ) or R. regia ( 140 and 210 mg/Kg ) for 7 days, and inspected daily for signs of disease. Data from the scoring system indicated that animals infected with HSV-1, developed progressive zoster lesions. In marked contrast to the results with control mice, treatment with acyclovir or R. regia resulted in a sustained protective effect. No toxic effect of R. regia on liver and kidney functions was apparent. In order to realize what point of R. regia inhibits HSV-1 activity, I used time of addition experiment to figure out its mechanism. When pre-treat or treat R. regia at the same time, R. regia can significantly inhibit HSV-1 activity. So, it suggested that R. regia may have an effect on HSV-1 replication due to block the adsorption of HSV-1. To confirm above suggestion, first I pre-treat Vero cells and R. regia at 4C and then add 100 PFU of HSV-1 into cell. In plaque reduction assay result indicated that there was no difference between control and experiment groups, R. regia may not block the receptor of cell to reduce HSV-1 activity. In another way, I pre-treat HSV-1 and R. regia at 37C 1hr and then add 100 PFU of HSV-1 into cell. Also in plaque reduction assay and Real-time PCR results indicated that there were significant differences between DMSO and R. regia groups even there was a dose dependant on plaques and expression ratio. Results indicated that R. regia may disrupt or change conformation of HSV-1 and account for inhibition of HSV-1 replication in vitro.EMSA results also improves that R.r extracts can decrase HSV-1 activity and inhibit NFB activation.These results indicated that R. regia was a potent inhibitor of the in vitro and in vivo replication of HSV-1. Moreover, this study not only demonstrates Chinese herbs are potential therapeutic drugs for the viral infection but also support a model for future protocol design in preclinical studies.