Antiviral screening of crude methanolic extract of Harungana madagascariensis (Lam. ex Poir) roots against Newcastle disease virus in embryonated hens’ eggs

Abstract

Background: Newcastle Disease Virus (NDV) causes Newcastle disease in avian species, especially poultry, and has remained a perennial problem plaguing the poultry industry in both developing and developed countries. Despite the challenge posed by this disease, a curative treatment modality has not been developed and prophylactic vaccines available are not potent enough to eliminate the virus. Thus, efforts to develop novel and more effective preventive strategies remain a priority. The present study was conducted to determine the antiviral activity of the methanolic extract of Harungana madagascariensis roots on Newcastle disease virus in embryonated hens’ eggs. Method: Seventyfive (75) embryonated hens’ eggs were arranged in fifteen groups of five. A toxicological assay was carried out with an extract concentration of 250 mg/ml on two groups, and another two groups served as negative and diluent controls. The antiviral assay was carried out by inoculating 0.2 ml of the 100 LD50 of the virus in four groups, followed by oral administration of graded concentrations of the extract (250 mg/ml, 200 mg/ml, 100 mg/ml and 50 mg/ml) to four (4) groups. Virus control and uninoculated or egg control (negative) were also set up. Rapid haemagglutination assay was used to determine virus clearance by the extract. Result: The extract exhibited mild toxic potentiality (p > 0.05) on the embryonated hens’ eggs as well as had antiviral properties on Newcastle Disease Virus at all used doses. Significant viral clearing was observed (p<0.05) at all concentration of the extract. Conclusion: The study indicated a strong inhibitory effect of the plant extract on Newcastle Disease Virus and thus we call for further investigation on the safety profiles of the plant to shed light on the toxicological effects and potential benefits as anti-Newcastle Disease Virus agents.