Potential Effect of Acacia arabica. on Peste des Petits Ruminants. Virus Replication

Abstract

An aqueous preparation from Acacia arabica. var. indica. Benth (Mimosaceae) (locally known as “babul”) leaves (BExt) was assessed for its in vitro. antiviral activity using peste des petits ruminants. virus (PPRV) as a test model in the Vero cell system. Cytopathic effect (CPE) inhibition, virus titration, cell ELISA, sandwich-ELISA (s-ELISA), and PCR assays were used to determine the antiviral effects (at maximum noncytotoxic concentrations 150 and 200 μg/mL) against PPRV, and in vitro. cytotoxicity assays established the relative safety concentration of the BExt for the cells. BExt inhibited viral infectivity drastically in terms of decreased virus titer and antigen load in a dose-dependent manner either when added to cell monolayers postinfection or when preincubated with virus before adsorption on the cells. Inhibition of cell-free and cell-associated PPRV during replication in presence of BExt in Vero cells, using a multistep growth curve experiment, were assessed by s-ELISA. BExt (200 μg/mL) completely inhibited PPRV replication in Vero cells that were infected with PPRV at 0.01 multiplicity of infection. Incubation of PPRV with BExt (150 and 200 μg/mL) followed by infection had a virucidal effect on subsequent progeny virus yield by a 3 log10 TCID50 reduction. This indicates that active principle(s) of BExt either inactivated the virus or inhibited the viral release. Real-time PCR data based on nucleoprotein gene showed 196.7-and 770.6-fold reduction in the viral load in the presence of BExt concentrations of 150 and 200 μag/mL, respectively, indicating the efficacy of BExt in inhibiting PPRV multiplication. These data suggest that extracts of A. arabica. could be a potential natural antiviral agent for management of PPR disease and also a possible addition in the traditional phyto-antiviral repertoire for viral disease control.