Antiviral Activity of Crude Hexane Extracts From Allamanda Cathartica on the Replication of Autographa Californica Multiple Nucleopolyhedrovirus

The purpose of this research was to investigate the antiviral activity of crude hexane extracts from the stem and leaf of Allamanda cathartica L. on the replication of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in Spodoptera frugiperda cell line (Sf9). The cytotoxic effect of crude hexane extracts from A. cathartica on Sf9 cell line was studied using neutral red assay and the results show that the 50% cytotoxicity concentration (CC50) values of crude hexane extracts from the stem and leaf of A. cathartica against Sf9 cells after 96 hours of exposure were 326.44 and > 1,000 μg/ml, respectively. The effects of crude hexane extracts from the stem and leaf of A. cathartica at the concentration of 31.25 μg/ml on the replication of AcMNPV grown in Sf9 cell line were investigated by observing the reduction percentage of virus titer, the percentage of infected cells and the number of occlusion bodies (OBs)/ml). When the extracts were added after 1 h postinfection of AcMNPV at the multiplicity of infection (MOI) of 1, in Sf9 cell line cultivated in vitro, the results show that the average virus titer was 1.56 x 108 PFU/ml for the infected control cells (cell incubated with virus), 4.56 x 107 PFU/ml for stem extract and 5.82 x 107 PFU/ml for leaf extract. Based on the productive control, the average percent reduction of virus titer produced by AcMNPV grown in Sf9 cell line was 60.79% for stem extract and 59.08 % for leaf extract. The average percentage of infected cells in the infected control cells the stem extract and the leaf extract were 89.59, 92.80 and 90.59, respectively. The results of the average number of occlusion bodies (OBs)/ml of infected control cells, the stem extract and the leaf extract were 7.49 x 105 OBs /ml, 4.95 x 105 OBs /ml and 5.96 x 105 OBs /ml, respectively. It can be concluded that hexane crude extract from the stem and leaf of A. cathartica affected DNA replication of AcMNPV in Sf9 cell line when the extract was added at 1 h post- infection.

Keywords: Allamanda cathartica, Spodoptera frugiperda cell line, multiplicity of infection AcMNPV, crude hexane extract, CC50

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