Virucidal potential of some edible Nigerian vegetables

Extracts from four leaves: Ceratotheca sesamoides (Endl.), Lactuca taraxacifolia (Willd.), Euphorbia lateriflora (Schum. & Throes) and Amaranthus viridis (Linn.) used in Nigeria as edible vegetables weretested for antiviral activities using the measles virus on Human Epidermoid carcinoma (HEP-2) cell line. The efficacy of each extract in preventing viral penetration into a living cell as well as its effect on thevirus itself and the toxicity of same on the cell were all determined. All the extracts showed dosedependent antiviral activities. The inhibitory action of the extracts from C. sesamoides and L. taraxacifolia were greatest at high concentrations of 15 mg/ml when the virus had already penetrated the cell. E. lateriflora only inhibited the virus activity at very high concentrations of 15 mg/ml when the virus was treated with the extract and also when the HEP-2 cell was treated with the extract before the virus suspension was added. Amaranthus viridis concentrations of 10 and 15 mg/ml were contaminated but the extract at a low concentration of 5 mg/ml was able to exhibit antiviral activity when the cell was treated with the extract before the virus was added. In view of the efficacy of these extracts in inhibiting the cytopathic effect (CPE) of measles virus without harming the host, the utilization of the extracts in the formulation of new antiviral drugs is strongly recommended especially when the availability and the very low cost of these vegetables are considered