Antiviral activity of Distictella elongata (Vahl) Urb. (Bignoniaceae), a potentially useful source of anti-dengue drugs from the state of Minas Gerais, Brazil.

AIMS

To investigate the in vitro antiviral activity of Distictella elongata (Vahl) Urb. ethanol extracts from leaves (LEE), fruits (FEE), stems and their main components.

METHODS AND RESULTS

The antiviral activity was evaluated against human herpesvirus type 1 (HSV-1), murine encephalomyocarditis virus (EMCV), vaccinia virus Western Reserve (VACV-WR) and dengue virus 2 (DENV-2) by the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. LEE presented anti-HSV-1 [EC(50) 142.8 ± 5.3 μg ml(-1); selectivity index (SI) 2.0] and anti-DENV-2 activity (EC(50) 9.8 ± 1.3 μg ml(-1) ; SI 1.5). The pectolinarin (1) isolated from LEE was less active against HSV-1 and DENV-2. A mixture of the triterpenoids ursolic, pomolic and oleanolic acids was also obtained. Ursolic and oleanolic acids have shown antiviral activity against HSV-1. A mixture of pectolinarin (1) and acacetin-7-O-rutinoside (2) was isolated from FEE and has presented anti-DENV-2 activity (EC(50) 11.1 ± 1.6 μg ml(-1) ; SI > 45). Besides the antiviral activity, D. elongata has disclosed antioxidant effect.

CONCLUSIONS

These data shows that D. elongata has antiviral activity mainly against HSV-1 and DENV-2, besides antioxidant activity. These effects might be principally attributed to flavonoids isolated.

SIGNIFICANCE AND IMPACT OF THE STUDY

Distictella elongata might be considered a promising source of anti-dengue fever phytochemicals.