Rosmarinic acid inhibits Rift Valley fever virus: in vitro, computational and analytical studies

Aim: The antiviral potentials of rosmarinic acid (RA) against Rift Valley fever (RVF) virus were investigated. Methods: Antiviral activity was investigated by evaluating the reduction in the viral infectivity titer. Computational and LC–MS studies were performed for investigating the mechanism of action. This is via testing the interaction between RA and its major metabolite with the key infectivity proteins and determination of RA cellular permeability. Results: A superior reduction in RVF infectivity titer (45.5%) was observed when RA was applied post-infection compared to 17.7% reduction following its application before infection in addition to time-dependent inactivation kinetics. Recorded data showed in-silico inhibitory potential of RA and its metabolite against RVFV cap-binding protein and glycoprotein C, which are integral for viral transcription. LC–MS revealed cellular inclusion of RA, supporting its intracellular viral interaction. Conclusion: These antiviral potentials might suggest a promising foundation for future anti-RVF drug development.