Antiviral Activity of Total Flavonoid Extracts from Selaginella moellendorffii Hieron against Coxsackie Virus B3 In Vitro and In Vivo

The antiviral activity of total flavonoid extracts from Selaginella moellendorffii Hieron and its main constituents amentoflavone were investigated against coxsackie virus B3 (CVB3). When added during or after viral infection, the extracts and amentoflavone prevented the cytopathic effect (CPE) of CVB3, as demonstrated in a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay, with a 50% inhibitory concentration (IC50) from 19 ± 1.6 to 41 ± 1.2 μg/mL and 25 ± 1.2 to 52 ± 0.8 μg/mL, respectively. KM mice were used as animal models to test the extracts' activity in vivo. Oral administration of the total flavonoid extracts at 300 mg/kg/day significantly reduced mean viral titers in the heart and kidneys as well as mortality after infection for 15 days. The experimental results demonstrate that in vitro and in vivo the model mice infected with CVB3 can be effectively treated by the total flavonoid extracts from Selaginella moellendorffii Hieron.