RSUSSH 2020
IN20-239 Anti-herpes simplex virus effect of algal polysaccharide extract from Ulva reticulata
Presenter: Pitchayuth Srisai
Chiang Mai University, Thailand
Abstract
Herpes simplex virus (HSV) is the causative agent of fever blister, genital herpes and neonatal herpes. Treatment of HSV infection was performed by acyclovir. Acyclovir remains to have side effect in the case of a long-term usage and the virus may develop drug resistance. Therefore, these problems are interesting to study the natural substance for treatment of HSV infection and drug resistant HSV infection. Nowadays, edible algae are supplied as a healthy food because algae contain high nutrition and have many active compounds that are beneficial to health. Therefore, the algal extract can be used as an alternative agent for treatment of HSV infection. The purpose of this research was to investigate the inhibitory effect of the algal polysaccharide extracts from Ulva reticulata against herpes simplex virus type 1 and type 2 infection in Vero cell. The structure of polysaccharide was analyzed by FT-IR technique. The algal polysaccharide extract from U. reticulata represent S=O and C–O–S of sulfate group. The toxicity of algal polysaccharide extract on Vero cell was evaluated by MTT assay. The algal polysaccharide extract from U. reticulata showed low toxicity on the cells with 50% cytotoxic concentration was greater than 5000 µg/mL. Inhibition of HSV infection was determined on Vero cell using plaque reduction assay. The results indicated that the algal polysaccharide extracts from U. reticulata showed antiviral activity against HSV-1 upon treatment before, meanwhile and after viral adsorption with 50% effective concentration of 2,525.90, 58.32 and 263.95 µg/mL, respectively. Additionally, the algal polysaccharide extracts from U. reticulata showed antiviral activity against HSV-2 upon treatment before, meanwhile and after viral adsorption with EC50 of 163.26, 9.70 and 527.28 µg/mL, respectively. Moreover, HSV-1 and HSV-2 viral particles was inactivated by the polysaccharide extract from U. reticulata. In summary, the polysaccharide extract from U. reticulata could protect Vero cell from HSV infection, inhibit HSV infection and inactivate HSV particles. Therefore, it will be useful to apply U. reticulata polysaccharide extract as a potential anti-HSV agent.
Citation format:
Srisai, P., Pekkoh, J., & Tragoolpua, Y.. (2020). Anti-herpes simplex virus effect of algal polysaccharide extract from Ulva reticulata. Proceeding in RSU International Research Conference, May 1, 2020. Pathum Thani, Thailand.QUESTIONS & ANSWERS
Thank you very much for your nice presentation! In this research, the polysaccharide extract from U. reticulata could protect Vero cells from HSV infection, inhibit HSV infection, and inactivate HSV particles. How about your next plan to do with this research?
What should be the mechanism of polysaccharide for protection from HSV infection? Are there any metabolites that can cause the protection effect or inhibition effect?
Thank you for your presentation.
Without any purification steps, the algal extract was directly subjected to the HSV activity test after the extraction. Also, there are several components, apart from polysaccharides, present in the extract, how do the authors make sure that the polysaccharides are main components responsible for the obtained anti-HSV effect in this study?
Dear Assoc. Panya Maneechakr
Thank you for your questions,
After the study, I would like to develop a product with effective against herpes simplex virus infection. For example, pharmaceutical products for applying on the lesion area or food supplement product containing algal polysaccharide extract that can prevent and inhibit herpes simplex virus infection. Moreover, the products may be developed with drug delivery systems to provide high effective and specific to infectious region.
Best regards,
Pitchayuth Srisai (Presenter)
Dear Asst. Prof. Dr.Chaiyavat Chaiyasut
Thank you for your questions,
In this study, possible mechanism of algal polysaccharide extract protected the cells from HSV infection by blocking viral receptor and resulted in inhibition of viral attachment and infection. Previous study showed that sulfate polysaccharide in algal extract has been reported to exert protection effect against HSV infection. Moreover, phenolic compounds in the green algal extract could inhibit the enveloped virus. Therefore, the phenolic compounds may show the inhibitory effect on HSV infection.
Best regards,
Pitchayuth Srisai (Presenter)
Dear Dr.Nanthaphong Khamthong
Thank you for your questions,
In this study, a crude algal polysaccharide extract was used. Although, boiling and precipitation of the extract in the extraction process slightly eliminated other compounds from algal polysaccharide extract, the chemical analysis showed that the algal extract contained sugar (>50%) and protein. Furthermore, the previous studies shown that the algal polysaccharide extract could inhibit the various viruses, including herpes simplex virus, Japanese encephalitis virus, dengue virus, influenza virus and measles virus. Therefore, they can be assumed that the algal polysaccharide can inhibit the herpes simplex virus.
However, we also interested in the purification step for increase the efficacy and specificity of the algal polysaccharide extract. Moreover, further study about the structure of algal polysaccharide that contains anti-HSV activity should be performed.
Best regards,
Pitchayuth Srisai (Presenter)