The Antibacterial Activity of Essential Oil

Eucalyptus Essential Oil Vials

Many essential oils and other plant extracts have antimicrobial properties which can be helpful for health and wellness applications. There is an incredible diversity of essential oils and other plant extracts available on the market today. This selection provides a plethora of options for both professional and casual practitioners of Naturopathic remedies for many health issues, including acne.

Antimicrobial Properties of Essential Oil

Clove Flowers
Clove Flowers

Much of what makes up an essential oil are molecules which are part of a plant’s natural defense system. These molecules have been designed by millions of years of evolution to protect the plant against potential enemies. These enemies can be bacteria, fungi, viruses, other plants, insects and other animal predators.

Some components of essential oil have antibacterial, anti-viral and anti-fungal activity. Other components in the essential oil are designed to prevent predation by insects and other animals. Some essential oils may even be toxic to other plants and are designed to help inhibit the growth of competing plants.

In the last twenty years, a great deal of scientific research has been done to characterize the antimicrobial activity of many essential oils. Using this knowledge can help guide better decisions when designing effective Naturopathic treatments for acne.

The Antibacterial Activity of an Essential Oil Depends on the Species of Bacteria

Some essential oils are highly toxic to certain species of bacteria, but are harmless to others. While some essential oils are effective against a broad spectrum of different bacteria, others are only useful against very specific types of bacteria.

Propionibacterium acnes (Toyoda, et al)
Propionibacterium acnes (Toyoda, et al)

When designing a Naturopathic acne treatment that includes essential oils, it is important to be aware of these differences. To better improve the design of acne treatments, we have compiled scientific reports from many sources in order to help identify which essential oils are likely to be most effective against acne-causing bacteria, such as Propionibacterium acnes (P. acnes) and Staphylococcus aureus (S. aureus).

Many essential oils also have anti-inflammatory properties which may  also help in the treatment of acne symptoms.

What Essential Oils are Effective Against Propionibacterium acnes Bacteria?

Tea Tree Flowers
Tea Tree Flowers

Scientific research reports indicate that there are many types of essential oil that are active against P. acnes bacteria. Tea Tree essential oil is one of the most popular essential oils for skin care applications, and the research shows that it is indeed toxic to P. acnes bacteria (although not as much as some other essential oils). Thyme, Clove and Cinnamon essential oil have broad spectrum antibacterial properties, and are also effective against P. acnes as well.

Unfortunately, many of the essential oils with significant antibacterial activity against P. acnes bacteria can also be fairly irritating to the skin, particularly at higher concentrations. However, there are several essential oils which have excellent antibacterial properties and a lower risk of skin irritation. For example, several different kinds of Citrus essential oils, were highly toxic to P. acnes bacteria but tend to be fairly mild to the skin. Lemongrass essential oil is another a potentially useful option for acne treatments.

Antibacterial Activity of Essential Oil Against Other Bacterial and Fungal Infections

There have been many research studies which examine the ability of different essential oils to inhibit or kill different kinds of infectious bacteria and fungi. No matter what kind of application you have in mind – whether it is designing a Naturopathic acne treatment or developing a natural disinfectant – understanding the antimicrobial properties of different essential oils is a critical first step. To help improve the understanding of these properties, we are working on developing a comprehensive database that about essential oils and their antimicrobial activities.

Selected Results from Research Studies on the Antibacterial Activity of Essential Oils

Minimum Inhibitory Concentrations of Many Essential Oils Against 5 Strains of Propionibacterium acnes (Luangnarumitchai)
Minimum Inhibitory Concentrations of Many Essential Oils Against 5 Strains of Propionibacterium acnes (Luangnarumitchai)
Inhibition of Propionibacterium acnes Growth by 10 Essential Oils (Zu)
Inhibition of Propionibacterium acnes Growth by 10 Essential Oils (Zu)
Antimicrobial Activity of 21 Essential Oils Against Propionibacterium acnes and Other Bacteria (Prabuseenivasan)
Antimicrobial Activity of 21 Essential Oils Against Propionibacterium acnes and Other Bacteria (Prabuseenivasan)
Antibacterial Activity of Many Essential Oils Against 10 Species of Bacteria (Hammer)
Antibacterial Activity of Many Essential Oils Against 10 Species of Bacteria (Hammer)

References

Activities of Ten Essential Oils towards Propionibacterium acnes and PC-3, A-549 and MCF-7 Cancer Cells. Zu, et al. 2010.
Antimicrobial Activity of Essential Oils Against Five Strains of Propionibacterium acnes. Luangnarumitchai, et al. 2007.
Antimicrobial activity of essential oils and other plant extracts. Hammer, et al. 1999.
Antioxidant Activities and Volatile Constituents of Various Essential Oils. Wei, et al. 2007.