Anti-viral activity of Azadirachta indica leaves against Newcastle disease virus: A study by in vitro and in vivo immunological approach

Amit Gupta¹, Ramesh B Jagtap¹ and Sushama R Chaphalkar^{1, 2 
1}Department of Immunology and Virology, Vidya Pratishthan’s School of Biotechnology (VSBT) Vidyanagari, Baramati, District Pune, India
²Director, Vidya Pratishthan’s School of Biotechnology (VSBT) Vidyanagari, Baramati, District Pune, India

Abstract
The objective of our study is to present a reliable method for the determination of anti-viral activity of leaf of Azadirachta indica against new castle disease virus (NDV).  To achieve this objective, aqueous extract of leaf of Azadirachta indica were subjected to qualitative estimation of metabolites and also estimate the Azadirachitin content using HPTLC. To determine the anti-viral activity, variable doses of aqueous extract against NDV in vitro as well as in vivo in mice to observe the effect on spleen cells by proliferation assay and estimate the cell surface markers i.e. CD3/CD4/CD8 population, Th1 (IFN-gamma, TNF alpha) type of cytokines in cell culture supernatant and also observed the effect of variable doses of aqueous effect on human PBMC and chicken whole blood against optimized dose of NDV. The results showed that Azadirachta indica leaf showed dose-dependently and significantly decreased the in vitro and in vivo lymphocyte population of spleen cells with serial dilutions of Azadirachta indica leaf along with NDV in mice. Furthermore, variable doses of aqueous extract increased the CD3, CD4/CD8 count and decreased the Th1 (IFN-gamma, TNF alpha) cytokines at higher doses in mice. On the other hand, variable doses of aqueous extract showed anti-viral activity in human PBMC, mice and chicken whole blood as compared to optimized dose of NDV and control. The results showed that at higher concentration of aqueous extract in mice, human and chicken against NDV showed antiviral activity.
Keywords: Azadirachta indica, Newcastle disease virus, aqueous extract