Protective efficacy of an aerosol preparation, obtained from Geranium sanguineum L., in experimental influenza infection.

A polyphenol-rich extract from the aerial roots of the medicinal plant Geranium sanguineum L. (PC) protected mice from mortality in the experimental influenza A/Aichi/2/68 (H3N2) virus infection. To provide evidence how a maximum therapeutic benefit can be derived of this preparation, it was inoculated by 6 different routes. It was found that the aerosol application of PC was highly effective. In the dose 5.4 mg/ml, applied according to a prophylactic-therapeutic schedule, the extract exhibited a marked protective effect. The protective index reached the value of 70.1% and the mean survival time was prolonged with 2.9-4.9 days. The lung infectious virus titres and the lung consolidation of virus-infected and PC-treated animals were all reduced in comparison with control. The application of PC according to schedules, excluding the pretreatment of mice, proved that this condition was essential for protection.