Pinus trees contain Shikimic acid in their needles and this prevents the reproduction of an influenza virus and similar variant viruses in the human cell and the virus eventually dies.
Various Pinus varieties have been used for a long time specifically by the Native American Indians for a variety of medicinal purposes but mostly for respiratory diseases.
Lemongrass has a history of medicinal use among several cultures worldwide for a variety of conditions. It is also known as "Fever Grass" due to its ability to bring down fevers