11. Olive Leaf Extract
The leaf of the olive tree has been found to be rather healthy just like the olive and olive oil. Since as early as the 1800s, olive leaf extract has been used to reduce fever. It also has been effective in treating malaria.
Researchers claim that the antibiotic properties in olive leaves stem from oleanolic acid. This is touted to kill bacteria, fungi, and viruses. It is rather handy to have them available in the house at all times.