Abstract

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Background/Aim: The lack of effective therapies and/or vaccines for several viral infections, and the rapid emergence of new drug-resistant viruses have necessitated the need for developing new and effective antiviral agents. In this study we evaluate the antiviral potentials of three plants indigenous to Nigeria on vaccine strains of Yellow fever virus (YFV) and Polio virus (PV) in order to inform their usefulness in antiviral drug design. Fresh leaves of Bambusa vulgaris Schrad., Moringa oleifera (L), and seed of Citrus paridisi Macfad were collected from Lagos State, South Western Nigeria. Extraction of the plant materials was done with analar grade methanol using the Soxhlet extractor and concentrated using the rotary evaporator. Results showed that the crude extracts of the three plants inhibited YFV in vitro, with the virus being more susceptible to C. paridisi Macfad at all the concentrations tested. B. vulgaris Schrad., and M. oleifera (L) inhibited the virus at two concentrations of 0.031 and 0.016 ug \xh'\ andO.063 and 0.031 ug uL~',respectively. PV was resistant to all the extracts at all the concentrations. Results of pre and post- infection antiviral activities of the extracts on the replicative cycle of the viruses showed both adsorption/entry, and post infection inhibitors. Phytochemical screening of the extracts showed the presence of terpenes, alkaloids, flavonoid, tannins, combined and free anthraquinones, cardiac glycosides, and saponins. This study revealed that some Nigerian medicinal plants could serve as alternative agents for treating and/or preventing infections caused by RNA viruses.

Keywords: Yellow fever virus, polio virus, Bambusa vulgaris, Moringa oleifera, Citrus paridisi, antiviral drugs