Anti-influenza properties of herbal extract of Althaea rosea in mice

Althaea rosea has been used in traditional Chinese medicine to treat numerous diseases, but no studies have investigated its anti-influenza properties to date. In this study, we investigated the anti-influenza effects of Althaea rosea. BALB/c mice orally pretreated with Althaea rosea (200 μL, 0.1 mg/mL concentration in phosphate-buffered saline) and followed by infection of influenza A virus nasally showed higher survivability and lower lung virus titer against divergent subtypes of influenza A virus infection. We also found that oral administration of Althaea rosea elicited antiviral innate immune responses in serum, bronchoalveolar lavage fluid, small intestinal fluid, and the lungs. Taken together, these findings suggest that aqueous extracts of Althaea rosea are a potential candidate for use as an anti-influenza drug.