Itchy skin; Possible atopic dermatitis? Lavender essential oil may be just what you are looking for

In a recent study published in the journal PLoS One, researchers investigated the efficacy of lavender essential oils in suppressing atopic dermatitis (AD) using an AD cell line. They didn’t just establish the anti-AD benefits Lavandula essential oils of the genus and its derivative, linalyl acetate, but they did so without the need for human clinical trials or animal testing. They further established the non-sensitizing nature of the essential oil, highlighting its potential as a stand-alone or adjunctive suppressor of AD-induced skin pruritus.

Study: Aromatic lavender oil as a suppressant of atopic dermatitis. Image credit: PhotoStockPhoto / Shutterstock

What is AD, what causes it and how can we fight it?

Atopic dermatitis (AD) is a condition that causes dry, itchy and inflamed skin, most commonly seen in young children. It is characterized by repeatedly worsening eczema and is a growing concern in today’s world, resulting in a significant reduction in the quality of life of patients suffering from the condition. Reports estimate that 15-20% of all children and 1-3% of adults play host to the disease.

Although the underlying causes of AD have not yet been identified, a combination of genetic and environmental factors are believed to contribute to the condition, with mutations in the filaggrin gene found in 20% of AD patients. The filaggrin gene is essential for the proper functioning of the epidermal barrier, with modifications in the gene facilitating antigen invasion, thereby producing inflammatory cytokines. Environmental factors, including dust mites, pollen, and chemical air pollutants, exacerbate these cytokines, causing an exaggerated immune response, which normally manifests as itchy skin, especially on patients’ arms and behind the knees.

Current treatments for AD consist of immunosuppressants and steroids. Unfortunately, these treatments are symptomatic, reducing itching while leaving the condition untreated. Recent research has identified new therapeutic agents approved by the United States Food and Drug Administration (FDA), such as dupilumab, tralokinumab, and baricitinib, which target the treatment of the pathogenic mechanisms of AD, but remain expensive and inaccessible. Therefore, there is still a pressing need for cost-effective, natural, and easily accessible interventions capable of effectively controlling AD.

Folk medicine has long assumed the use of lavender essential oils to treat itchy skin. Given the wide availability of oils (lavender oils are one of the most commonly distributed cosmetic additives worldwide) in perfumes and lotions, their relative cost-effectiveness, and their environmental “greenness,” these oils may be the key to healing. of AD and similar skin diseases.

Three main ones Lavandula species are used in the production of essential oils – Lavandula angustifolia, L. spica and L. stoechas. From those, L. angustifolia contains the highest concentrations of potentially beneficial bioactive terpenes – linalyl acetate and linalool. Depending on the region and harvest season, these bioactives vary in concentration between 1.2-59.4% and 9.3-68.8%, respectively. Encouragingly, mouse models have clarified that both compounds can effectively inhibit edema, inflammation and cytokine production.

Lavandula angustifolia flowers. Image credit: nnattalli / Shutterstock

“L. angustifolia essential oil is traditionally thought to have anti-inflammatory and healing properties, used as a massage oil in aromatherapy. For many years, the scientific basis for such use was unknown, but in recent years, in addition to its anti-inflammatory and healing of wounds, more and more evidence supports the traditional use of L. angustifolia essential oil, albeit inconclusive, for its antibacterial and analgesic effects.”

About the study

In the present study, researchers developed a xenobiotic response reporter assay (XRE-NLuc) using the immortalized human keratinocyte cell line (HaCaT) to test the efficacy of L. angustifolia essential oils, linalyl acetate and linalool in AD. The xenobiotic response represents the reaction of AD patients to air and UV pollutants and therefore serves as a surrogate for the environmental exposure of AD patients to acute agents.

They further used an ARE reporter assay to investigate the degree of skin sensitization accompanying different concentrations L. angustifolia or its terpene extracts. To assess gene expression levels of HaCaT used in both assays, clone DNA (cDNA) libraries were constructed and subjected to quantitative polymerase chain reaction (qPCR) analyses.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) combined with western blotting was used to detect and quantify protein expression from tested HaCaT cells. Finally, flow cytometric measurements were used to assess cell viability and the Stimulation Index (SI) of the treatment versus control cells.

Study findings

The results of the study show that large. angustifolia The essential oil, linalyl acetate and linalool are all capable of inhibiting AD through inhibition of the aromatic hydrocarbon receptor (AhR). The AhR receptor is responsible for activating the AD cascade upon exposure to environmental pollutants (mainly air and UV).

“Both linalyl acetate and linalool inhibited AD in a concentration-dependent manner with IC₅₀ values ​​of 519 µM and >1000 µM, respectively, indicating that the former was more potent.’

The tested compounds were further found to inhibit Artemin induced expression. Artemin is a neurotrophic factor (ARTN) that causes stretching of the skin, directly leading to increased skin sensitivity and itching.

“Linalyl acetate and linalool also reduced Artemin induced expression with IC₅₀ Values ​​of 3.6 and 194 µM, respectively, indicating that linalyl acetate exerted a stronger inhibitory effect.’

Together, these results highlight that lavender essential oils can effectively combat air pollution-induced AD. Body lotions containing lavender essential oils or their pure extracts can both act as a barrier against exposure to air pollution while soothing pre-existing itching. In addition, SDS-PAGE and western blotting experiments show that linalyl acetate intrinsically promotes the degradation of AhR and ARNT proteins, further highlighting its ability to inhibit AD.

Encouragingly, results from skin sensitization assays revealed that lavender oils and their main components had either neutral or negative skin sensitization effects, confirming their safety when applied directly to human skin.

conclusions

In the present study, researchers investigated the potential of lavender essential oils in the prevention and treatment of AD. Their results revealed that the oils, especially linalyl acetate, effectively inhibited the mechanistic AD cascade while remaining safe for human use.

“Our results show that linalyl acetate in L. angustifolia essential oil contributes significantly to the inhibitory effects of AD, and lavender oils high in linalyl acetate would be effective for the treatment of AD, although other components in the essential oil of L. angustifolia, which we did not test, others may contribute. The results presented here may be limited due to the oils and assays used in this study. Importantly, similar to several other agents, their effectiveness is highly dependent on the range of optimal concentrations. Therefore, we respectfully suggest that their use at higher concentrations may not have the desired therapeutic effects.”