Aromatherapy and Influenza Viruses

By Salvatore Battaglia

In light of the concern about the 2019 novel coronavirus (2019-nCoV), I wish to examine the role of essential oils in minimising the risk of influenza viruses. Unfortunately, there are very few therapeutic agents available for the control of influenza viruses.

What is the coronavirus?   

Coronaviruses are a large family of viruses that can cause illness ranging from the common cold to more severe conditions such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS-CoV). The recent coronavirus first detected in Wuhan, China, is referred to as 2019 novel coronavirus (2019-nCoV).¹

There are several known coronaviruses found in animals that have not yet infected humans.¹

Common signs of infection include respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death.¹

As with all respiratory viruses, there are many simple preventative actions one can take. Most government and medical agencies such as the Center for Disease Control and Prevention provide us with practical and simple measures to prevent the spread and risk of infection. This includes:²

Washing your hands with soap and water for at least 20 seconds. Use an alcohol-based hand sanitiser that contains at least 60% alcohol if soap and water are not available.

• Avoid touching your eyes, nose and mouth with unwashed hands.
• Avoid close contact with people who are sick.
• Cover your cough or sneeze with a tissue, and then throw the tissue in the rubbish bin.
• Clean and disinfect frequently touched objects and surfaces.

It is believed symptoms may take as few as two days or as long as 14 days after exposure to the virus to appear.²

The World Health Organisation (WHO) recommends in view of the limited knowledge of the illness caused by 2019-nCoV infection and its transmission, all suspected cases of the 2019-nCoV infection should be isolated and monitored in a hospital setting. Additionally, those with an underlying chronic health condition such as lung or heart disease, renal failure, or immunocompromising conditions are at greater risk of becoming severely ill with the virus.³

Essential oils and influenza viruses

Many studies have demonstrated that essential oils have potent antimicrobial and antiviral properties.^4,5,6,7

Most of these studies are invitro and use essential oils in their liquid phase with the essential oils administrated internally. This is often not very practical and presents some safety concerns. Therefore, I was very excited to read of some clinical trials that had examined the antiviral activity of essential oils vaporised on airborne influenza viruses.

One study found in the vapour phase, essential oils such as bergamot, eucalyptus, geranium, cinnamon, lemongrass and thyme oil were very active against influenza virus after only 10 minutes exposure.⁵

Eucalyptus and bergamot displayed the most significant activity against influenza virus after only 10 minutes, while the other essential oils showed activity after 30 minutes. It was also interesting that the researchers also tested the essential oils in the liquid phase and found Eucalyptus globulus had very little activity in the liquid phase, but had a prominent activity after 10 minutes in the vapour phase.⁵

The researchers also suggested it is likely that 1,8-cineole, one of the main constituents found in eucalyptus oil, may not be responsible for the antiviral activity.⁵ Hence, the reason for always using a botanically pure eucalyptus oil that has not been rectified.

It was also noted the essential oil vapours displayed no measurable adverse effect on lung epithelial cells. The report stated that only cinnamon possessed the most potent anti-influenza activity in both liquid and vapour phase.⁵

The researchers reported that the essential oils antiviral activity may be on the principal membrane proteins of the influenza virus, hemagglutinin (HA) and neuraminidase (NA). The results of this study found most of the essential oils inhibited viral HA activity. However, only cinnamon was able to inhibit HA and NA activity.⁵

This is interesting as HA and NA proteins of the influenza virus are responsible for virus ability to enter and exit from cells. This suggests inhibiting these viral functions may decrease the spread of the virus.⁵

While the essential oils tested in liquid phase demonstrated cytotoxic effects in human lung epithelial cells, the same essential oils tested in vapour phase did not display adverse reactions following exposures of at least 10 minutes.⁵

The results of an Australian study demonstrated that vaporised tea tree oil was very effective as an antiviral for airborne influenza virus. The study found tea tree oil was able to achieve complete virus inactivation whereas eucalyptus oil, while demonstrating strong antiviral activity, was slightly less effective than tea tree oil. The study concluded that tea tree oil in an aerosol may also be used on a filter surface to achieve antiviral activity.⁶

While the antimicrobial effects of eucalyptus oil are well known, less is known of the oil’s immune modulatory effect. Studies have confirmed that eucalyptus oil increases phagocytic activity and the number of monocytes and macrophages and significantly decreases and inhibits IL-4, IL-6, TNF-α and NF-kB when inflammation is present.^8.9

1,8-cineole has often been reported to not have antimicrobial activity. However, it was found to significantly inhibit cytokine production from human lymphocytes and monocytes. It was found to be a strong inhibitor of TNF-α and IL-1β. This suggests that 1,8-cineole can control airway mucus hypersecretion, reducing exacerbations in asthma, sinusitis and obstructive pulmonary disease.^8.9

Practical tips

Apart from following the very important sanitary advice provided by health authorities such as regular washing of hands, using an alcohol-based hand sanitiser (preferably one that also has natural essential oils such as tea tree or eucalyptus) you may also incorporate methods of vaporising essential oils in your work and living space. This will not only reduce risk of infection, but also boost and support your immune system.

I went down to the local pharmacy today to get hold of some face masks for my upcoming trip to Japan in February. Unfortunately, they had sold out. If you do use a face mask and are wearing it for preventative measures, I would suggest you add five drops of blue mallee eucalyptus, four drops of trea tree and one drop of lemon to the mask before wearing it.

Alternatively, you could make up a spray by diluting the essential oils in some ethanol and spraying this directly onto the mask before wearing it.

If you are making up a blend for a diffuser, based on the recent research into vaporising essential oils, I would recommend the following blend:

• 5 drops of blue mallee eucalyptus
• 4 drops tea tree
• 1 drop of cinnamon bark

I would love to share with you an interesting formula Dr Valnet recommends for colds and influenza, as long as it is taken as soon as the first symptoms appear.

A tot of whisky, to which is added a squeezed lemon, a tablespoon of honey and a large glass of hot water in which a small piece of cinnamon and a clove have been boiled for 2 – 3 minutes. Leave to infuse for 20 minutes.¹⁰

My version is very similar. As much as I enjoy a drop of whisky, I leave out the whisky. I add some sage leaves with the cinnamon quill and clove bud to the water and boil for a few minutes. I then add a teaspoon of manuka honey and once it has infused for 10 minutes, I add the juice of a squeezed lemon and 20 drops of a good quality echinacea tincture.

Next week I will provide you with a more holistic, naturopathic approach of supporting the immune system with lifestyle advice, botanicals and nutrition.

References

1. Coronavirus. Downloaded on 31 Jan 2020 from https://www.who.int/westernpacific/health-topics/coronavirus
2. Centers for Disease Control and Prevention, 2019 Novel Coronavirus – Prevention and Treatment. Downloaded on 31 Jan 2020 from https://www.cdc.gov/coronavirus/2019-ncov/about/prevention-treatment.html
3. World Health Organization. Home care for patients with suspected novel coronavirus (nCoV) infection presenting with mild symptoms and management of contacts – Interim guidance 20 January 2020. Document number WHO/nCov/IPC. Accessed on 30 Jan 2020.
4. Astani A et al. Comparative study on the antiviral activity of selected monoterpenes derived from essential oils. Phytotherapy Research. 2009;24(5):673-679. Doi:10.1002/ptr.2955
5. Vimalanathan S et al. Anti-influenza virus activity of essential oils and vapors. American Journal of Essential Oils and Natural Products. 2014;2(1):47-53.
6. Pyankov QV et al. Inactivation of airborne influenza virus by tea tree and eucalyptus oils. Aerosol Science and Technology. 2012;46:1295-1302. doi: 10.1080/02786826.2012.708948
7. Swamy MK et al. Antimicrobial properties of plant essential oils against human pathogens and their mode of action: an updated review. Evidence-Based Complementary and alternative Medicine. 2016;Article ID 3012462. doi: 10.1155/2016/3012462
8. Pyankov QV et al. Inactivation of airborne influenza virus by tea tree and eucalyptus oils. Aerosol Science and Technology. 2012;46:1295-1302. doi: 10.1080/02786826.2012.708948
9. Sadlon AE et al. Immune-modifying and antimicrobial effects of eucalyptus oil and simple inhalation devices. Alternative Medicine Review. 2010;15(1): 33-47.
10. Serafino A et al. Stimulatory effect of eucalyptus essential oil on innate cell-mediated immune response. BMC Immunology. 2008;9:17. doi:10.1186/1471-2172-9-17
11. Valnet J. The practice of aromatherapy. C.W Daniels Company, Saffron Walden, 1980.