Dengue and chikungunya are two important mosquito-borne infections which are known to occur extensively in tropical and subtropical areas. Presently, there is no treatment for these viral diseases. In vitro antiviral screening of 25 extracts prepared from the plants of Vitex negundo, Plumeria alba, Ancistrocladus heyneanus, Bacopa monnieri, Anacardium occidentale, Cucurbita maxima, Simarouba glauca, and Embelia ribes using different solvents and four purified compounds (anacardic acid, chloroquinone, glaucarubinone, and methyl gallate) were carried out for their anti-dengue virus (DENV) and anti-chikungunya virus (CHIKV) activities. Maximum nontoxic concentrations of the chloroform, methanol, ethyl acetate, petroleum ether, dichloromethane, and hydroalcoholic extracts of eight plants were used. The antiviral activity was assessed by focus-forming unit assay, quantitative real-time RT-PCR, and immunofluorescence assays. Extracts from Plumeria alba, Ancistrocladus heyneanus, Bacopa monnieri, and Cucurbita maxima showed both anti-DENV and CHIKV activity while extract from Vitex negundo showed only anti-DENV activity. Among the purified compounds, anacardic acid, chloroquinone and methyl gallate showed anti-dengue activity while only methyl gallate had anti-chikungunya activity. The present study had identified the plant extracts with anti-dengue and anti-chikungunya activities, and these extracts can be further characterized for finding effective phytopharmaceutical drugs against dengue and chikungunya.

Purpose: Globally, 859 million people in 50 countries are threatened by lymphatic filariasis. Due to its severity, the available drugs are mainly used for microfilaricidal and do not kill efficiently the adult parasites, which continue to produce microfilariae. Therefore, the present study aims to develop a plant-based macrofilaricidal drug. Methods: The inhibitory activity of the various solvent extracts of the leaves of Anacardium occidentale L. (Anacardiaceae) was tested against the recombinant hexokinase of B. malayi (BmHk). BmHK, an enzyme of the glycolytic pathway that plays a vital role in the replication/survival of filarial parasites, was chosen as a target. A preliminary phytochemical test and GC-FID analysis of the extract were carried out. Results: The hydroalcoholic extract of A. occidentale showed the highest inhibition (65.80±1.60%) of activity of BmHk, compared to other extracts, which showed less than 50% inhibition. Conclusion: The present study showed that hydroalcoholic extract of A. occidentale has inhibitory activity against BmHk and can be explored further for developing the herbal-based anti-filarial drug.