Evaluation of Antiviral Activity of Azadirachta indica (Neem) Bark Extract against Newcastle Disease Virus

Abstract

In the present research, the in-vitro and in-ovo antiviral activity of Neem (Azadirachta indica) bark extract against Newcastle disease virus (NDV) was evaluated. Various dilutions of Azadirachta indica extract were used against NDV. In-vitro evaluation was done by performing spot assay and micro-hemagglutination test, while in-ovo antiviral activity was assessed by injecting the extracts in 11 days old embryonated eggs. During in-vitro evaluation, it was found that the stock solution and 1:2 dilution of Neem bark extract exhibit antiviral activity but at the same time these concentrations showed cytotoxic activity as well, while higher dilution (1:8) showed non-significant antiviral activity. Same was true for in-ovo evaluation, higher dilutions showed non-significant activity. Taking together, it may be concluded there was no significant difference in the antiviral effects of different concentrations of Neem bark extracts but the exposure time was a significant variable for cytotoxicity. 2017 PVJ.