The present study was aimed at determining the compounds available in Eleusine indica methanol extract and the effects on
herpes simplex virus type 1 (HHV1) replication cycle and progeny infectivity. Twelve compounds mostly from the flavonoid
and phenolic groups were identified by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) analysis. The
effect on replication phases of HHV1 was determined by time-of-addition, time-removal and virus yield reduction assays
with expression of selected genes analysed by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The extract
inhibited plaque formation the most during the first 2 h and at 24 h of infection. Plaque formation inhibition was also
noted at all other time points but at lesser percentage. Treatment with E. indica reduced progeny infectivity when treated
for 10 h and was dose-dependent. E. indica methanol extract inhibited immediate early, early and late phases of HHV1
replication cycle by modifying the expression of UL
54, UL
27 and UL
30 genes during the infection. Immunostaining of
infected cells confirmed that E. indica inhibited mainly Glycoproteins B but not Glycoprotein C and D. Thus, the methanol
extract of E. indica has the ability to alter HHV1 replication cycle at almost all stages and reduce progeny infectivity.