Therapeutic Effects of a Dry Powder Prepared from the Green Microalga Coccomyxa sp. KJ in Mice Infected with Influenza A Virus

Influenza virus is a seasonal respiratory pathogen that produces global pandemics by genome reassortments. This rapid evolution creates difficulty in producing vaccines. Although several anti-influenza drugs have been developed, acquisition of rapid drug resistance by viruses is common. Therefore, it is important to develop novel therapeutic and prophylactic strategies. In this study, we evaluated the antiviral effects of a microalgae Coccomyxa sp. KJ (IPOD FERM BP-22254) extract in a BALB/c mouse model of influenza. Oral administration of dry algal powder (5 mg/day or 20 mg/day) before infection with influenza A virus (IFV) suppressed viral proliferation in the lungs and bronchoalveolar lavage fluid (BALF). It also exhibited stimulatory effects on systemic and local production of neutralizing antibodies. These results suggest that this powder is a promising candidate for the therapeutic and prophylactic management of influenza.