Cultivars of Tagetes minuta L. (Asteraceae) as a source of potential natural products with antiviral activity

This study aims to evaluate the in vitro inhibitory effect of ethanol extracts obtained from three cultivars of Tagetes minuta on Herpes Simplex virus type I (HSV-I) and the arboviruses: Saint Louis encephalitis (SLEV), West Nile (WNV), Venezuelan equine encephalitis (VEEV) and Dengue (DENV). Vero and LLC-MK2 cell lines were employed as host cells. The in vitro viral inactivation and antiviral effect of each extract were assayed by plaque reduction test. Extracts were characterized by HPLC-DAD-ESI-QTOF, and the main compound found in all the extracts was myricetin glycoside. Extracts from the cultivars Don Monje, Serrano and Aromisky were able to inhibit mainly the HSV-I and WNV viruses, to a lesser extent SLEV and DENV and had no activity on VEEV. This is the first report of bioactivity for this vegetable species against arboviruses. The potential of cultivars with specific chemical profiles has great importance for obtaining certain compounds or natural products with concrete bioactivities, to be used as potential sources of antiviral compounds.