Flavonoids Extracted from Fruit Pulp of Cucumis metuliferus Have Antiviral Properties

Aim: To investigate the antiviral property of flavonoids from Cucumis metuliferus fruit pulp in chicken embryo fibroblast (CEF) cells and embryonated chicken eggs (ECE) induced with infectious bursal disease virus (IBDV).
Study Design: Extraction and administration of bioactive extract.
Place and Duration of Study: Department of Pharmacology, University of Jos, Nigeria and Virology Department, National Veterinary Research Institute, Vom, Nigeria between June, 2011 and August, 2011.
Methodology: The CEF cells were first exposed to 100, 50, 25, 12.5, 6.25, 3.125, 1.563, 0.782, 0.391 and 0.195 mg/ml of the sterile flavonoids to test for cytotoxicity and the cells monitored visually daily using a light microscope for evidence of cytopathic effects at 24, 48 and 72 hours. Toxicity of flavonoids in embryonated eggs and antiviral assay for flavonoids using IBDV were then carried out. Hemagglutination test for antigenicity of the virus was also performed to confirm antiviral activity.
Results: The flavonoids (100 to 0.195 mg/ml concentrations) were not cytopathic when exposed to CEF cells. After 24 and 48 hours, all the embryonated eggs died at 100 and 50 mg/ml of the flavonoids respectively, but mortalities were not recorded at other concentrations of the flavonoids. Concentrations of the flavonoids at 100, 50, 25, 12.5 and 6.25 mg/ml were found to be toxic against IBDV, but viral replication was not inhibited from flavonoids concentrations of 3.125, 1.563, 0.782, 0.391 and 0.195 mg/ml.
Conclusion: This investigation revealed that flavonoids from Cucumis metuliferus fruit pulp were relatively safe in chickens and possess antiviral activity against IBDV.