Natural oils may calm nasal inflammation
MedWire News: Study findings show that topical application of natural oils, such as coconut and orange oil, may reduce inflammation of the nasal mucosa.
The antioxidant properties of these oils are likely to be responsible for this benefit, explain the authors.
Writing in the open-access journal Respiratory Research, they say: "The ability of oil pretreatment to inhibit the pro-inflammatory action of subsequent bacterial endotoxin exposure of human respiratory epithelial cells suggests the potential usefulness of such a preparation in mitigating a broader array of inflammatory and cytotoxic exposures to the upper respiratory system."
The findings are reported by Ernst Spannhake (Johns Hopkins University, Baltimore, Maryland, USA) and colleagues.
The team recruited nine healthy individuals aged 22-40 years and administered a 50 µl spray of placebo or one of five naturally occurring plant oils (coconut, vitamin E, peppermint, aloe, or orange) into the nostrils of each participant.
After receiving a dose of oil, all participants were exposed to ozone, defined as 0.25 ppm of O3 administered for 120 minutes, in addition to performing two cycles of 30 minutes of rest followed by 30 minutes of light exercise.
Nasal mucosa samples were obtained 18 hours after exposure to ozone.
Spannhake and team found that in the presence of placebo, ozone exposure produced a nine-fold higher inflammatory cell concentration than treatment with any of the five oils.
To determine the mechanism behind the oils' anti-inflammatory effect, Spannhake and colleagues assessed antioxidant enzyme gene expression in the nasal epithelial cell lines BEAS-2B and NCI-H23.
When the cell lines were exposed to a control oil and each of the five treatment oils for 2 minutes, antioxidant enzyme genes were expressed in cells exposed to the treatment oils but not in those exposed to the control oil.
Orange oil had the greatest anti-inflammatory effect, as reflected by a mean relative luciferase activity of 52.5, 6.6, 5.7, 5.7, and 5.0 induced by orange, coconut, aloe, peppermint, and vitamin E oil, respectively.
"The identification of naturally occurring, well-tolerated and potent activators of cytoprotective mechanisms within these cells, such as the oil preparation investigated here, will expand our ability to develop new tools for preventive and therapeutic intervention at this critical respiratory interface," say Spannhake et al.
They conclude that natural oil therapy may provide an ideal solution for individuals who do not respond well to conventional respiratory therapies.
By Lauretta Ihonor