Essential Oils Could Offer Natural Treatment for Lung and Liver Conditions Caused by Air Pollution

24 Aug 2016 --- Essential oils found in plants such as cloves, anise, fennel and ylang-ylang, could serve as a natural treatment for lung and liver conditions caused by air pollution, a new study has revealed.

The study is the first of its kind to evaluate the value of using certain essential oil compounds to treat inflammation caused by the fine particles that are typical of hazy, polluted air, and that are known to be carcinogenic.

The researchers looked at a group of organic compounds called phenylpropanoids, found in the essential oils of some plants, and show promise as possible anti-inflammatory substances. Among these are trans-anethole (a flavor component of anise and fennel), estragole (found in basil), eugenol (which occurs in clove bud oil) and isoeugenol (contained in ylang ylang).

For the study, the team collected air pollutant samples containing fine particles, from Beirut, Lebanon. In laboratory tests, the samples were then introduced to human cell cultures of normal bronchial epithelial cells (BEAS-2B) and cancer derived hepatic cells (HepG2).

The fine particle matter was found to induce inflammation in the cells - these started to secrete the pro-inflammatory cytokines IL-6 and IL-8 (substances that are secreted during infections and tissue damage). Cytokin levels normally increase when the body's immune system is fighting a specific infection.

Next, the researchers established that the trans-anethole, estragole, eugenol and isoeugenol all have so-called cytotoxicity, which means that they could cause cell death at relatively high concentrations. In this evaluation, they were able to determine the level of cytotoxicity of these oil compounds. 
This was important in order to establish the maximum dose to be selected in the next step, namely the assessment for anti-inflammatory properties. 

In the second round of tests, the four compounds were introduced to the combination of cell lines and air pollutants to see whether these could protect liver and lung cells damaged by fine particle air pollutants. 

It was found that the essential oil compounds tested decreased the levels of the two types of cytokines in the samples. The levels of cytokine IL-6 decreased up to 96 percent, and the levels of cytokine IL-8 by 87 percent.

"The findings provide the first evidence that natural essential oil components counteract the inflammatory effects of particulate matter, such as that contained in polluted air,” said Miriana Kfoury, lead author of the study.