Antiviral Activity of an Extract from Leaves of the Tropical Plant Cynometra cauliflora

Background: Cynometra cauliflora is a species of tree in the family Fabaceae and has been used in folk medicinal preparation. Objectives: In this study, Cynometra cauliflora methanolic leaves extract was tested against clinical isolate herpes simplex virus type-1 (HSV-1). Materials and Methods: The leaves of C. cauliflora plant was extracted using methanol extraction method. Cytotoxicity was assessed using 3-(4,5-dimethylthiazol-2,5-diphenyltetrazolium bromide (MTT) assay. Plaque reduction assays were carried out to evaluate the antiviral activity of C. cauliflora extract against HSV-1. These include post-treatment, pre-treatment and virucidal assays. Results: The value of cytotoxic concentration, CC₅₀ of C. cauliflora extract was 36 mg/ mL. High antiviral activity was observed in post-treatment. C. cauliflora extract treatment was found to not interfere directly to infectious particle and confer mild protection when given as prophylaxis. Conclusion: This study provides important novel insights on the phytomedicinal properties of C. cauliflora extracts on HSV-1.