**10. Conclusions**

At present, there is a growing demand to explore the vast variety of plant species with biological activities, and their EOs with therapeutic potentials that can help in the alternative treatment of different diseases. But there is also a need to increase awareness of the risks and benefits associated with the medicinal uses of EOs, which is still a matter of research.

Use of plant molecules to treat, for example, infectious diseases is a complementary alternative. The use of EOs in the treatment of malignancy, artemisinin (isolated from *Artemisia annua*) and the anticancer drug, taxol (from *Taxus brevifolia*) are successful examples of the use of these popular medicines, obtained from these plant species at a cost much smaller than conventional medications.
