Fig. 1.

Antiviral activity of two Sinupret^® preparations against a broad panel of viruses. To test the efficacy of the two Sinupret^® preparations – oral drops and dry extract – on virus replication, virus susceptible cells (MDCK, HEp-2, HeLa and BGM) were infected with a multiplicity of infection (M.O.I.) of 0.0004 (FluA, Para 3, RSV, HRV and CA9) or 0.008 (Adeno 5), without or in presence of five descending non-cytotoxic concentrations of the test substances oral drops (open squares) and dry extract (closed triangles). The antiviral activity (y-axis, % virus inhibition) of the test candidates (x-axis, concentration in μg/ml) was determined in plaque-reduction assays (PFU) for FluA, Para 3, RSV, HRV 14, and CA9 or in analyses of a cytopathogenic effect (CPE) for Adeno 5. The relative inhibitions (% inhibition, ordinate) were calculated by analysing the number of plaques or lesions of the viral CPE of the respective groups and standardised by the virus control representing 100% infectivity (0% inhibition). Positive controls confirmed the procedure (FluA, 5 μg/ml amantadine, 58% inhibition; Para 3, laboratory standard 10 μg/ml, 57% inhibition; HRV 14, laboratory standard 20 μg/ml, 54% inhibition; Adeno 5, laboratory standard 7.5 μg/ml, 57% inhibition; RSV, 6 μg/ml ribavirin, 60% inhibition). All data represent means and SEM from two independent experiments with two (Adeno 5, RSV) or three (FLuA, Para 3, HRV 14 and CA9) replicates. Stars indicate statistically significant differences for the EC₅₀ values between dry extract and oral drops (***p < 0.001).