Comparative study to evaluate the anti-viral efficacy of Glycyrrhiza glabra extract and ribavirin against the Newcastle disease virus.

Background: The Newcastle disease represents as one of the most infectious viral disease, which afflicts almost every species of the birds. The causative agent of the disease is a single-stranded RNA virus with rapid replication capability.

Objective: This study was performed to evaluate the comparative anti-viral efficacy and toxicity of Glycyrrhiza glabra aqueous extract and ribavirin against the Newcastle disease virus.

Materials And Methods: The embryonated eggs were divided into six groups (A, B, C, D, E and F). Groups A, B, C, and D were further subdivided into three subgroups. The virus was identified by hemagglutination inhibition test. Spot hemagglutination test and viability of embryos were also evaluated. Three different concentrations i-e., 30 mg/100 ml, 60 mg/100 ml, and 120 mg/100 ml of the Glycyrrhiza aqueous extract and 10 μg/ml, 20 μg/ml, and 40 μg/ml ribavirin in deionized water were evaluated for their toxicity and anti-viral activity in the embryonated eggs.

Results: 60 mg/100 ml concentration of Glycyrrhiza extract did not produce any toxicity in the embryonated eggs and showed anti-viral activity against the virus. Similarly, 20 μg/ml ribavirin was non-toxic in the embryonated eggs and contained anti-viral activity.

Conclusion: It may conclude from the presented study that 60 mg/100 ml Glycyrrhiza extract inhibits replication of Newcastle disease virus and is non-toxic in the embryonated eggs. So, Glycyrrhiza glabra extract may be further evaluated in future to determine the potentially active compounds for their anti-viral activity against Newcastle disease virus. Furthermore, the mechanism of action of these active phytochemicals as an antiviral agent would be helpful to elucidate the pathogenesis of the disease.