In vitro study on cytotoxic effect and anti-DENV2 activity of Carica papaya L. leaf

Abstract

Dengue fever is the most deleterious and rapidly spreading mosquito-borne viral disease, and to date it has resisted attempts to eradicate it. Carica papaya L. leaf extract is traditionally used to cure dengue fever and its associated symptoms. However, no in vitro studies have been reported for the anti-dengue efficacy of this extract. So, the present study attempted to determine the phytochemicals present in Carica papaya L. leaf extracts, as well as their cytotoxic effect and anti-DENV2 activity on the LLC-MK2 cell line. Methanolic extracts, containing triterpenoids and flavonoids, showed cytotoxic effects (CC50=0.6156 mg ml−1), whereas a chloroform extract, rich in alkaloids, tannin and saponin, was non-cytotoxic (CC50= >1 mg ml−1) to LLC-MK2 cells and it showed inhibitory activity (EC50= >1 mg ml−1) against DENV2 with a selectivity index value of±>1. This indicates that the crude chloroform extract has moderate or less inhibitory action against DENV2 growth in in vitro conditions. The current study will help in the future development of new and novel drugs against dengue pathogens with high efficacy.