In vitro Antiviral Activity of Nauclea latifolia Root Bark Extract Against the Respiratory Syncytial Virus

Extract of Nauclea latifolia (NL) root bark collected from the Nigerian flora was examined for anti-RSV activity. Preliminary data showed anti-RSV activities with IC50 =75.62 µg/ml when tested against the recombinant strain rgRSV expressing the green fluorescent protein. Corresponding assays for the cytotoxic effect of the extract against utilized cell lines gave TC50 = 333.82 µg/ml. Further screening of against the circulating RSV A2 strain established their promising anti-RSV utility. Time of additional studies for the elucidation of the possible mechanism of action gave 74.38, 69.42, and 71.90% reduction of RSV plaque forming units at the respective 0, 2, and 4 hours post-infection addition times.