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.
A study was conducted to investigate the antiviral activity of aqueous extracts from Orthosiphon stamineus (OS).
Extraction was done using different parts of OS. The whole plant except root (WPOS), leaves (LOS) and flowers (FOS) of
OS were extracted using aqueous extraction method. Cytotoxicity was assessed using 3-(4,5-dimethylthiazol-2,5-diphenyl
tetrazolium bromide (MTT) assay. Plaque reduction assays were carried out to evaluate the antiviral activity of OS extract
against herpes simplex virus type 1 (HSV-1). These include post-treatment, pre-treatment and virucidal assays. High
antiviral activity was observed in post-treatment and virucidal assay with 100% reduction of HSV-1 plaque at 0.39 mg/
mL in LOS, FOS and WPOS. In pre-treatment assay, 79%, 84% and 97% plaque reduction using the same concentration
was observed in FOS, LOS and WPOS, respectively. In conclusion, this study showed that OS aqueous extract has promising
potential to be explored as anti-HSV-1 agent regardless of the mode of treatment.