Abstract:
Dengue infection is a major health care problem in tropical and subtropical countries. The recently
approved dengue vaccine has limitations, and there is no antiviral drug for treatment at present.
For centuries plants and plant extracts have been used in traditional medicine for the treatment of
various infections. The whole plant of Munronia pinnata, which has been used for treating fever patients
in Sri Lankan traditional medicine, was tested for anti-dengue viral activity.
The cytotoxicity assay of M. pinnata on Vero cells using 4,5-dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium bromide (MTT) revealed Maximum Nontoxic Dose (MNTD) as 125 µg/ml and 50%
cytotoxic concentration (CC50) as 428.9 ± 21.55 µg/ml. Plaque reduction antiviral assay performed on
dengue-4 virus infected Vero cells demonstrated half-maximal inhibitory concentration (IC50) as 26.12 ±
0.91 µg/ml. The selectivity index (SI) of M. pinnata was 16.42.
Based on the selectivity index, Munronia pinnata appears to be a viable candidate for identifying
biologically active compounds with anti-dengue viral activity.
