With its strong and enveloping aroma, oregano has earned a prominent place on our tables, added to pizza and salads, to flavor mozzarella or meat dishes. Its essential oil is also commonly used to enrich cosmetic products and lotions to clean surfaces since it is believed that oregano oil has antibacterial and antioxidant properties. But is it really so? A group of Polish researchers answered this question by publishing a work in the journal Molecules (Kosakowska et al, Molecules, 2021).
Plants rich in active ingredients such as phenols, flavonoids and volatile compounds such as thymol, carvacrol and eugenol are considered remedies with antibacterial and antioxidant action. Oregano in general is a valuable source of these active ingredients but care must be taken, in fact, not all types of oregano contain the same substances and therefore not all of them perform the same action. Oregano includes six subspecies, including common oregano, which is the oregano that we can most easily find at the supermarket or as a spice to add to dishes, and Greek oregano, or Origanum vulgare L subsp hirtum. Scientists compared the essential oils extracted from the two types of oregano to evaluate their antioxidant and antibacterial action against a wide range of bacterial strains, including Escherichia coli, Salmonella and Staphylococcus. What emerged is that, if we analyze the antioxidant action, this is absolutely similar in common oregano and in Greek oregano. Therefore, if we use the essential oil of oregano in a cosmetic product in order to fight wrinkles, we can choose one of the two types of oregano indifferently. The situation is different with regard to the antibacterial power, which we often hear so much about that it is even recommended to use the essential oil of oregano to disinfect surfaces against the action of bacteria. In this case, in fact, the Greek oregano is to be preferred, which has shown an antibacterial action three times higher than that of common oregano. Greek oregano proved effective in inhibiting the growth of all the bacteria tested while common oregano, in addition to having a milder action, proved to be ineffective in inhibiting the development of the Staphylococcus bacterium. This difference in action of the two types of oregano is explained by a different composition of essential oils, Greek oregano in fact contains more carvacrol than common oregano.
Therefore, if the aim is to include oregano in antibacterial preparations, it is necessary to look at Greek oregano and not common oregano.