ASSESSMENT OF IN VITRO ANTIVIRAL ACTIVITY OF <i>Ocimum sanctum</i> (TULSI) AGAINST PANDEMIC SWINE FLU H1N1 VIRUS INFECTION

G. JOSHI¹, S. SHARMA², J. ACHARYA³, M. PARIDA^4
1Division of Virology, Defence R&D Establishment (DRDE), Gwalior- 474 002, MP, India.
²Division of Virology, Defence R&D Establishment (DRDE), Gwalior- 474 002, MP, India.
³Process Technology Development Division, Defence R&D Establishment (DRDE), Gwalior- 474 002, MP, India.
⁴Division of Virology, Defence R&D Establishment (DRDE), Gwalior- 474 002, MP, India.

Received : 20-06-2014     Accepted : 05-08-2014     Published : 14-08-2014
Volume : 3     Issue : 1       Pages : 62 - 67
World Res J Antimicrob Agents 3.1 (2014):62-67

Keywords : Swine Flu (H1N1) virus, Ocimum sanctum (Tulsi), Antiviral, Traditional medicine
Conflict of Interest : None declared
Acknowledgements/Funding : The authors are thankful to Dr. M.P. Kaushik, Director, Defence Research and Development Establishment, Ministry of Defence, Government of India, for his support. The authors are thankful to Anthem Biosciences for HPLC analysis. GJ is thankful to ICMR, In

The emergence of resistance to oseltamivir has necessitated looking for more effective and safe alternate antiviral drugs to combat the increasing threat of swine flu pandemic. Ocimum sanctum (Tulsi), a traditional Indian medicinal plant that has been reported to have both immunomodulatory as well as anti-viral activity. Thus, the antiviral activity of ethanolic extract of Ocimum sanctum against H1N1pdm virus was assessed in MDCK cells through different virus inhibition assays. viz. cytopathic reduction assay, cell viability assay, hemagglutination assay, immunofluorescence, real-time reverse transcription-PCR, western blotting and flow cytometry. The CC50 value of Ocimum ethanolic extract was 726.2±3.1 µg/ml implying very low toxicity. A dose dependent inhibition was observed against 10, 5, 1 and 0.1 MOI of the virus with IC50 values 55.5±0.9, 54.1±1.4, 44.7±0.7 and 38.6±2.2 µg/ml respectively. Further studies on different treatment modalities indicated that post treatment mode was more effective than pretreatment and simultaneous treatment, thus inhibiting viral replication and protein synthesis. This is the first report that highlights the antiviral potential of Ocimum sanctum that can be used as an alternate medicine in pandemic situation to currently available anti-influenza therapies.