In Vitro Anti-rotaviral Activity of Achillea kellalensis

Background: Achillea kellalensis, which is frequently used by Chaharmahal va Bakhtiarians residing in, Southwest of Iran, as a traditional herbal medicine for the treatment of acute diarrhea, has been selected to examine its antiviral activities against bovine rotavirus and cell toxicity activity in MA-104 cells. Objectives: The aim of this study was to evaluate the in vitro cytotoxic and anti-rotavirus properties of crude extracts of A. kellalensis. Materials and Methods: The dried and powdered flowers of Achillea kellalensis were extracted with hot water and ethanol 50% (v/v). The cell viability and toxicity of the extracts were evaluated on MA-104 cells using four methods; trypan blue dye, NR, crystal violet and MTT assay. The in vitro anti-rotavirus properties were determined via four different assays, in order to evaluate the direct inhibition and/or the inhibition of viral replication. Results: Cytotoxicity of two A. kellalensis extracts showed different concentrations. Hydro-alcoholic extract had low CC50 at 600 μg/mL by the NR assay while the aqueous extract had high CC50 at 1000μg/mL by the crystal violet method. In the simultaneous treatment assay and post treatment assay, the extracts were able to prevent viral replication and inhibit the viral CPE on MA-104 cells at 10 TCID50, but the extracts did not exhibit direct antiviral activity on rotavirus adsorption. The effective concentration (EC50) of both extracts was observed to be 100 μg/mL. Conclusions: These results indicate that A. kellalensis extracts exert potent anti-rotaviral activity only after viral adsorption. The two extracts from A. kellalensis showed a good selectivity index. Also these results suggest that extracts prepared from the flowers of A. kellalensis may be potential anti-rotaviral agents in vivo and be useful in veterinary medicine.