In vitro anti-viral activity of aqueous extracts of Kenyan Carissa edulis Prunus africana and Melia azedarach against human cytomegalovirus.

Abstract

The aqueous extracts of three medicinal plants, Carissa edulis (Forssk.) Vahl
(Apocynaceae), Prunus africana (Hook.f.) Kalkm (Rosaceae) and Melia azedarach L.
(Meliaceae) have shown significant reduction in the replication of human
cytomegalovirus (HCMV) in human embryonic lung (HEL) fibroblasts cells in vitro.
Using the plaque inhibition assay for the determination of anti-viral activity, the HEL
fibroblast cells cultured in 24 well plates were infected with 1 x 102 PFU 91S HCMV and
treated with various concentrations of the extracts. The plaques formed were counted
after 7 days incubation at 370C in 5% CO2 and the percent plaques inhibited were
calculated against infected untreated control. The effective concentrations inhibiting
plaque formation by 50% (EC50) was found between 40 to 80 μg/ml for all the extracts. The cell cytotoxic concentrations (CC50) for each of the three extracts, by the trypan blue exclusion test, gave a safe therapeutic index. These results have demonstrated the potential anti-viral activities of the extracts of the three medicinal plants at non-cytotoxic
concentrations.

African Journal of Health Sciences Vol. 14 (3-4) 2007: pp. 143-148