Essential oils have been the go-to remedy for a variety of ailments since ancient times, and the health and safety threats posed by the pandemic have turned many back to these basics, as the market figures—and even our own website search stats—show.
Essential oils has appeared within the top five user search terms for several weeks in a row on CosmeticsandToiletries.com, now (at press). Furthermore, in May 2020, Grand View Research estimated the global market demand for essential oils at ~247.08 kilotons, which is expected to increase at a CAGR of 7.5% from 2020 to 2027.
Considering the current popularity of essential oils, we offer the following brief literature review of recent and upcoming publications on their research and development.
Antimicrobial Effects of Zataria Essential Oil
Isfahanian, S.F., Sadmia, M., Nasri, S. and Sobhanian, H.; Complementary Medical Journal, Arak University of Medical Sciences; available at: https://cmja.arakmu.ac.ir/article-1-700-en.pdf
Zataria is a native plant of Iran that is widely used for the treatment of diseases. This study investigated the antimicrobial effects of Zataria essential oil against Staphylococcus aureus, Corynebacterium and Staphylococcus epidermidis bacterial strains taken from the skin of six wistar rats. The minimum growth inhibitory concentration and minimum bactericidal concentration for the bacteria were measured by disk diffusion and microbroth dilution. Results indicated the oil imparted antibacterial effects in low concentrations and could be used to replace antiseptics and preservatives in cosmetics.
See related: Comparatively Speaking, Essential vs. Natural Oils
Nepeta Curvifloria (Syrian Catnip) Essential Oil for Antioxidant, Wound Healing Benefits
Jaradat, N., Al-Maharik, N., Abdallah, S., Shawahna, R., Mousa, A. and Qtishat, A.; Industrial Crops and Products; available at: https://doi.org/10.1016/j.indcrop.2020.112946
This work examined Nepeta curviflora Boiss (Syrian catnip) essential oil for various attributes including its in vitro antioxidant, porcine pancreatic lipase, α-glucosidase and α-amylase inhibitory activities—primarily to assess its potential against cervical cancer cell lines. Its antioxidant activity was notable, measured as 6.3 ± 0.43 μg/mL in comparison with Trolox (positive control). Moreover, anti-cancer activity was established, exploiting wound healing and cell proliferation assays against cervical cancer cell lines.
Antifungal Activity of Cinnamomum Zeylanicum (Cinnamon) Bark and Leaf Essential Oils
Tran, H.N.H., Graham, L. and Adukwu, E.C.; Applied Microbiology and Biotechnology; available at: https://link.springer.com/article/10.1007/s00253-020-10829-z
This research tested the effects of Cinnamomum zeylanicum (cinnamon) leaf and bark essential oils (CEOs) against the pathogens Candida albicans and C. auris. Results indicated greater inhibitory activity by the bark extract in comparison with the leaf extract. Morphological interference assays confirmed damage in the pathogen cell membranes. The authors concluded that at low concentrations, the CEOs had potent antifungal and antihaemolytic activities in vitro against C. albicans and C. auris.
Antioxidant Potential of Indian Araucaria Columnaris (G. Forst.) Hook
Patial, P.K. and Cannoo, D.S.; Food and Chemical Toxicology; available at: https://doi.org/10.1016/j.fct.2020.111376
This study investigated the aroma composition, phenolic acid, antioxidant activities and computational analysis of essential oils from five parts of the "New Caledonia pine" conifer, or A. columnaris (G. Forst.) Hook, from India. Density Functional Theory (DFT) studies were carried out on the main phytochemicals to give details of antioxidants and reactivity parameters. The results suggested essential oils of A. columnaris have high antioxidant potential due to the presence of phenolic acids and aroma compositions.
Personality vs. 'B.S.' and/or Perceived Efficacy of Essential Oils
Ackerman, L.S. and Chopik, W.J.; PLoS ONE; available at: https://doi.org/10.1371/journal.pone.0229779
Essential oil use is growing in popularity and used to treat various ailments. Yet, while a vast amount of research explores the antioxidant, antimicrobial, antibacterial, etc., properties of essential oils, and evidence may support these effects, according to these authors, research on the psychosocial predictors of essential oil use and perceived efficacy by consumers is sparse.
Note: The following views are strictly those of the authors and do not necessarily reflect the views of Cosmetics & Toiletries or Allured Business Media in general.
These authors examined a variety of individual differences in the "Big Five" personality traits, along with "bullshit receptivity" (BSR) and need for cognition (NFC) as predictors of essential oil use in a sample of 1,202 participants (61.7% women, 75.6% Caucasian). Results indicated a "receptivity to pseudo-profound fabricated statements and religiosity" were the most consistent predictors of use, perceived efficacy and willingness to purchase essential oils.
Pervaporation via Chitosan Membranes to Separate Essential Oil Components
Silvestre, W.P., Baldasso, C. and Tessaro, I.C.; Carbohydrate Polymers; available at: https://doi.org/10.1016/j.carbpol.2020.116676
This research reviews the potential of chitosan-based membranes to separate terpenes and other essential oil components via the emerging process of pervaporation, which is proposed as an alternative process to fractionation. According to the authors, pervaporation is well-established in the foods industry, mainly to obtain aroma compounds, although it has drawbacks. Here, different chitosan-based membranes are explored that could help to overcome these drawbacks and aid in essential oil separation.
Multidimensional Chromatography to Advance Essential Oil Analysis
Rasheed, D.M., Serag, A., Shakour, Z.T. and Farag, M.; Talanta; available at: https://doi.org/10.1016/j.talanta.2020.121710
In this new work, to be published in February 2021, the authors explain that fast, comprehensive and effective analytical tools for essential oil analysis are of interest. As such, they propose a means to study volatiles by coupling the separation power of multidimensional chromatography with selective detectors as mass spectrometers. The authors believe this strategy could enable the high-throughput and global analysis of hundreds of metabolites in a single step. Additional details are disclosed in the article abstract.