Abstract:
Dengue viral infection is one of the most important mosquito borne viral infections in the world.
Nonetheless, there are no effective antiviral agents for treatment at present. For centuries plants
and plant extracts have been used in traditional medicine for the treatment of various infections.
As Psidium guajava (Guava) leaves, Solanum xanthocarpum (Katuwelbatu) whole plant,
Munronia pinnata (Bin kohomba) whole plant, Glycyrrhiza glabra (Wal-mee) roots and Aegle
marmelos (Bael) dried flowers have been used for treating fever patients in folk medicine, they
were selected for a preliminary study of anti -dengue activity. Plants were collected and crude
aqueous extracts were prepared. Cell cytotoxicity assay with (4,5-dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium bromide (MTT) was performed on Vero cells and 50% cytotoxic concentration
(CC50) was calculated for all plants. Plaque reduction anti-viral assay was performed on Vero cells
for dengue-4 virus and half maximal inhibitory concentration (IC50) was calculated. Munronia
pinnata [SI index = 8.3; CC50 =217.9 µg/ml; IC50 = 26.12µg/ml; Maximum non toxic dose (MNTD)
125ug/ml] and Glycyrrhiza glabra [SI index = >16 CC50 = >500ug/ml; IC50 = <31.25.; MNTD >500
µg/ml] were identified as having the highest SI indices with good MNTDs. These two plants have
shown good inhibitory activity against dengue virus serotype 4 in Vero cells. However, these
findings need to be confirmed with dengue virus serotypes 1, 2 and 3 and in human cell lines.
Based on in vitro studies, Munronia pinnata and Glycyrrhiza glabra are candidates for identifying
biologically active compounds with anti-dengue activity.
