Polygalasaponin XXXI (Onjisaponin F) also enhances anti-HA IgA and IgG Ab titers in the nasal wash, whereas Onjisaponins E and G enhances only anti-HA IgA Ab titer significantly. Polygalasaponin XXXI can induce protective immunity against intranasal infection by influenza virus.
Polygalasaponin XXXI (Onjisaponin F) (1 or 10 µg/mL) also induces ChAT mRNA level in rat basal forebrain cells.