Potent antiviral action detected in Tontelea micrantha extracts against Alphavirus chikungunya

Abstract

Background: Tontelea micrantha, a notable plant species, has garnered interest for its medicinal properties, including anti-inflammatory, antibacterial and antiviral effects. A vaccine for Chikungunia virus is still under evaluation and no specific antiviral drug has been licensed to date.

Objective: The work investigated antiviral activity of ethyl acetate (EAEF) and methanolic (EMF) extracts from T. micrantha leaves in mammalian cells exposed to Alphavirus chikungunya (CHIKV).

Methods: The cytotoxicity, antiviral activity, selectivity index, effect on viral gene expression, virus production, and mechanisms of action were evaluated.

Results: EAEF and EMF extracts showed anti-CHIKV effects at non-cytotoxic concentrations, with CC₅₀ above 300 μg/mL, EC₅₀ of 18 and 43 μg/mL respectively, and selectivity Index above 4. These concentrations drastically reduce viral yields and CHIKV gene expression and have shown activity both directly on viral particles and at different stages of the viral cycle.

Conclusion: EAEF and EMF showed robust antiviral activity against CHIKV, making them promising candidates for the development of anti-CHIKV drugs.

Keywords: Alphavirus chikungunya; Tontelea micrantha extracts; anti-CHIKV effect; antiviral mechanisms; selectivity index; virucidal activity.