Enhanced Biological Activity of a Novel Preparation of Lavandula angustifolia Essential Oil

Phytochemical Composition and Antimicrobial Properties of New Lavandula angustifolia Ecotypes

The purpose of this study was to characterize ethanol extracts from leaves and flowers of two ecotypes (PL-intended for industrial plantations and KC-intended for cut flowers) of Lavandula angustifolia Mill. The plant was cultivated in 2019 in southern Poland as part of a long-term research plan to develop new varieties resistant to difficult environmental conditions. The collected leaves and flowers were used to prepare ethanol extracts, which were then analyzed in terms of phytochemical composition and antioxidant, bactericidal, and fungicidal properties. Using UPLC techniques, 22 compounds belonging to phenolic acids and flavonoids were identified. UPLC test results indicated that ethanol extracts from leaves and flowers differ in phytochemical composition. Lower amounts of phenolic acids and flavonoids were identified in leaf extracts than in flower extracts. The predominant substances in the flower extracts were rosmarinic acid (829.68-1229.33 µg/g), ferulic acid glucoside III (810.97-980.55 µg/g), and ferulic acid glucoside II (789.30-885.06 µg/g). Ferulic acid glucoside II (3981.95-6561.19 µg/g), ferulic acid glucoside I (2349.46-5503.81 µg/g), and ferulic acid glucoside III (1303.84-2774.17 µg/g) contained the highest amounts in the ethanol extracts of the leaves. The following substances were present in the extracts in trace amounts or at low levels: apigenin, kaempferol, and caftaric acid. Leaf extracts of the PL ecotype quantitatively (µg/g) contained more phytochemicals than leaf extracts of the KC ecotype. The results obtained in this study indicate that antioxidant activity depends on the ecotype. Extracts from the PL ecotype have a better ability to eliminate free radicals than extracts from the KC ecotype. At the same time, it was found that the antioxidant activity (total phenolic content, ABTS•+, DPPH•, and FRAP) of PL ecotype leaf extracts was higher (24.49, 177.75, 164.88, and 89.10 μmol (TE)/g) than that determined in flower extracts (15.84, 125.05, 82.35, and 54.64 μmol (TE)/g). The test results confirmed that leaf and flower extracts, even at low concentrations (0.313-0.63%), significantly inhibit the growth of selected Gram-negative and Gram-positive bacteria and Candida yeasts. Inhibition of mold growth was observed at a dose extract of at least 1 mL/100 mL.

Recent Advances in Chemistry and Antioxidant/Anticancer Biology of Monoterpene and Meroterpenoid Natural Product

Monoterpenes and meroterpenes are two large classes of isoprene-based molecules produced by terrestrial plants and unicellular organisms as diverse secondary metabolites. The global rising incidence of cancer has led to a renewed interest in natural products. These monoterpenes and meroterpenes represent a novel source of molecular scaffolds that can serve as medicinal chemistry platforms for the development of potential preclinical leads. Furthermore, some of these natural products are either abundant, or their synthetic strategies are scalable as it will be indicated here, facilitating their derivatization to expand their scope in drug discovery. This review is a collection of representative updates (from 2016-2023) in biologically active monoterpene and meroterpenoid natural products and focuses on the recent findings of the pharmacological potential of these bioactive compounds as well as the newly developed synthetic strategies employed to access them. Particular emphasis will be placed on the anticancer and antioxidant potential of these compounds in order to raise knowledge for further investigations into the development of potential anti-cancer therapeutics. The mounting experimental evidence from various research groups across the globe regarding the use of these natural products at pre-clinical levels, renders them a fast-track research area worth of attention.

Enhancing Wound Healing: A Novel Topical Emulsion Combining CW49 Peptide and Lavender Essential Oil for Accelerated Regeneration and Antibacterial Protection

Wound healing is a complex process involving blood cells, extracellular matrix, and parenchymal cells. Research on biomimetics in amphibian skin has identified the CW49 peptide from Odorrana grahami, which has been demonstrated to promote wound regeneration. Additionally, lavender essential oil exhibits anti-inflammatory and antibacterial activities. Given these considerations, we propose an innovative emulsion that combines the CW49 peptide with lavender oil. This novel formulation could serve as a potent topical treatment, potentially fostering the regeneration of damaged tissues and providing robust antibacterial protection for skin wounds. This study investigates the physicochemical properties, biocompatibility, and in vitro regenerative capacity of the active components and the emulsion. The results show that the emulsion possesses appropriate rheological characteristics for topical application. Both the CW49 peptide and lavender oil exhibit high viability in human keratinocytes, indicating their biocompatibility. The emulsion induces hemolysis and platelet aggregation, an expected behavior for such topical treatments. Furthermore, the lavender-oil emulsion demonstrates antibacterial activity against both Gram-positive and Gram-negative bacterial strains. Finally, the regenerative potential of the emulsion and its active components is confirmed in a 2D wound model using human keratinocytes. In conclusion, the formulated emulsion, which combines the CW49 peptide and lavender oil, shows great promise as a topical treatment for wound healing. Further research is needed to validate these findings in more advanced in vitro models and in vivo settings, potentially leading to improved wound-care management and novel therapeutic options for patients with skin injuries.

Use of Lavandula angustifolia essential oil as a complementary therapy in adult health care: A scoping review

Background

In addition to its low toxicity risk, Lavender (Lavandula angustifolia Mill.) essential oil is recognised worldwide for its sedative, antidepressant, antiseptic, antifungal, relaxing, and antiemetic properties. Thus, the action mechanism of lavender oil has attracted significant attention from researchers interested in improving the physical, emotional, and spiritual well-being of patients.

Objective

To investigate the scope of knowledge regarding the use of L. angustifolia essential oil as a complementary therapy in adult health care.

Methods

A scoping review was carried out using a PRISMA-ScR checklist followed by a critical assessment being performed using the Joanna Briggs Institute level of evidence. The following databases were used: SCOPUS, MEDLINE/PubMed, Web of Science, Science Direct, SCIELO, Cochrane Library, LILACS, Wiley Online Library, CAPES, and FIOCRUZ Dissertations.

Results

Eighty-three articles published between 2002 and 2022 were selected for the analysis; More articles came from Iran than from any other country and most articles reported clinical trials. The applicability of lavender essential oil and its route of administration in different clinical situations were the main topics addressed in the articles.

Conclusions

Most studies demonstrate the efficacy of L. angustifolia Mill. essential oil in relieving pain and decreasing anxiety. Few studies evaluated the anti-psoriatic, anti-toxoplasmotic, and wound healing properties and the protective actions against cerebral ischemia. One study reported on its safety, specifically the allergenic potential of linalool, the main chemical component of L. angustifolia essential oil. However, most studies did not involve the extensive investigations on this topic or report the safe quantities of this oil for human treatment, meaning further research into the safety of this treatment is required.

Immunomodulatory effects of trans-anethole-treated Staphylococcus aureus Newman strain

In our former studies based on a human whole-blood model infected with trans-anethole (TA)-treated Staphylococcus aureus Newman strain, we have observed that selected parameters/mechanisms of innate and acquired immune response were more enhanced in comparison to samples infected with non-treated bacteria. Due to this observation, the current study aimed to evaluate the concentration of selected proteins involved in both types of responses (IL-1α, IL-1β, IL-2, IL-6, IL-12, IL-17, TNF-α, IFN-γ, G-CSF, C5a, CCL1-CCL5, CXCL1, CXCL2, CXCL9-CXCL11, MMP-8, TLR2, and PGLYRP1) in healthy participants' plasma after blood stimulation of TA-treated S. aureus Newman strain. Determination of analyzed protein concentration was conducted using Luminex and ELISA assays. Based on the results, it has been proven that the immunomodulatory potential of TA-treated S. aureus Newman strain on increasing IL-1β, IL-6, TNF-α, IL-12, G-CSF, C5a, CCL2-CCL4, CXCL1, CXCL2, MMP-8 and PGLYRP1 levels in plasma. Moreover, it has been also demonstrated an association between TNF-α and CCL4 in a blood model infected with TA-treated cells. More research is warranted to find more underlying mechanisms involved in the effects of TA-treated S. aureus Newman in human blood, mainly whether the observed "immunity boost" can be regulated after bacteria elimination. Therefore, the potential of TA should be further explored to understand under which conditions it might help treat or prevent infections caused by S. aureus.

Bioactive Lavandula angustifolia essential oil-loaded nanoemulsion dressing for burn wound healing. In vitro and in vivo studies

The aim of this study was to develop a dressing with bioactive lavender in a new form of nanoemulsion, and to verify its biosafety and effectiveness in burn wound healing. As part of this research, the composition of the bioactive carrier of lavender oil in the form of a nanoemulsion obtained using ultrasound was optimised. The mean particle size of the internal phase and polydispersity were determined using the dynamic light scattering method using a Zestasizer NanoZS by Malvern and using cryo-transmission electron microscopy (TEM). These studies confirmed that the selected formulation had a particle size of approximately 180 nm and remained stable over time. The preparation was also subjected to rheological analysis (viscosity approximately 480 mPa·s) and a pH test (approximately 6). A macroemulsion (ME) with the same qualitative composition was developed as a reference. Nanoformulations and MEs were tested for skin penetration using Raman spectroscopy in an in vitro model. Research has shown that both formulations deliver oil to living layers of the skin. Subsequently, studies were conducted to confirm the effect of lavender oil in emulsion systems on the mitigation of the inflammatory reaction and its pro-regenerative effect on the wound healing process in an in vitro cell culture model. The safe concentration of the oil in the emulsion preparation was also determined based on preliminary in vivo tests of skin sensitisation and irritation as well as an hemocompatibility test of the preparation.

Physicochemical Characterization and Prospecting Biological Activity of Some Authentic Transylvanian Essential Oils: Lavender, Sage and Basil

Essential oils are a category of agro-based industrial products experiencing increasing demand. In this research, three essential oils obtained by steam distillation from lavender, sage and basil plants cultivated in temperate continental conditions of Transylvania were investigated for chemical composition, physical characteristics and biological activity (antimicrobial and cytotoxic effect on cancer cell lines). The number of identified compounds varied: 38 for lavender, 29 for sage essential oil and 41 for basil. The volatile profile was dominated by terpenes and terpenoids (>80%). Major components were beta-linalool and linalool acetate in lavender essential oil; thujones and camphor in sage essential oil; beta-linalool, thujone, camphor and eucalyptol in basil essential oil. Refractive index of the essential oils was lowest for lavender and highest for sage. Antibacterial activity was strongest for basil, moderate for lavender and weakest for sage essential oil. The most active on both colon adenocarcinoma (Caco-2) and ovary carcinoma (A2780) was sage essential oil.

Terpenoids and their gene regulatory networks in Opisthopappus taihangensis 'Taihang Mingzhu' as detected by transcriptome and metabolome analyses

'Taihang Mingzhu' is the hybrid offspring of Opisthopappus taihangensis, and it has an excellent characteristic of whole-plant fragrance. At present, the genes and metabolites involved in the synthesis of its aromatic compounds are unknown because of the paucity of molecular biology studies on flowering in the Opisthopappus Shih genus. To elucidate the biosynthetic pathways of terpenoids, the main aromatic compounds in 'Taihang Mingzhu', we conducted transcriptome and metabolite analyses on its leaves and bud, inflorescences at the color-development, flowering, and full-bloom stages. A total of 82,685 unigenes were obtained, of which 43,901 were annotated on the basis of information at the protein databases Nr, SwissProt, KEGG, and COG/KOG (e-value<0.00001). Using gas headspace solid-phase microextraction chromatography - mass spectrometry (HS-SPME-GC/MS), 1350 metabolites were identified, the most abundant of which were terpenoids (302 metabolites). Analyses of the gene regulatory network of terpenoids in 'Taihang Mingzhu' identified 52 genes potentially involved in the regulation of terpenoid synthesis. The correlations between genes related to terpenoid metabolism/regulation and metabolite abundance were analyzed. We also extracted the essential oil from the leaves of 'Taihang Mingzhu' by hydrodistillation, and obtained 270 aromatic compounds. Again, the most abundant class was terpenoids. These results provide guidance for the extraction of essential oil from 'Taihang Mingzhu' leaves and flowers. In addition, our analyses provide valuable genetic resources to identify genetic targets to manipulate the aromatic profiles of this plant and other members the Opisthopappus Shih genus by molecular breeding.

Exploitation of Marginal Hilly Land in Tuscany through the Cultivation of Lavandula angustifolia Mill.: Characterization of Its Essential Oil and Antibacterial Activity

Lavandula angustifolia Mill., known as one of the best essential oil-bearing plants, is an aromatic plant that is well cultivated in many Mediterranean regions due to its adaptability to variations in climatic and edaphic conditions. Therefore, its essential oil (EO) composition and its antimicrobial activity change as a consequence of abiotic and biotic factors. The chemical composition of L. angustifolia EO collected during four consecutive years of growth was one of the aims of this work. The volatile profile evidenced the prevalence of linalool and linalool acetate even though they switched their positions according to age. Plants in their first year were characterized by a high amount of sesquiterpene compounds (22.1% of the identified fraction). This percentage decreased during plant growth, not representing more than 5.3% in the fourth year. It is interesting to note that both the third- and fourth-year plants showed a content of monoterpenes that exceeded 90% of the total identified constituents. The EO extracted from the oldest plants evidenced higher activity on the studied strains, with more sensitivity on the Gram-positive ones. Tuscan lavender EO, especially that obtained from the four-year-old plants, is of great interest for its potential industrial applications and constitutes an example for the valorization of marginal Tuscan land and good-quality production.

Anti-inflammatory effect of lavender (Lavandula angustifolia Mill.) essential oil prepared during different plant phenophases on THP-1 macrophages

BACKGROUND

Pseudomonas aeruginosa is the most common Gram-negative bacterium associated with nosocomial respiratory infections. Lavender essential oil is mainly used in aromatherapy, but it has several pharmacological and therapeutic properties. Furthermore, it possesses antifungal and antibacterial activities. The anti-inflammatory activity of essential oils may depend on the composition and the ratio of the compounds. The constitution of the essential oils extracted from the different stages of flowering period varies, which makes it plausible that the collection time of the flowers influences the anti-inflammatory effects. Different types of essential oils reduce inflammation acting similarly by modulating the activity and action of the NFκB signalling pathway, which is the major regulator of the transcription of pro-inflammatory cytokines.

METHODS

Lavender essential oils were distilled from lavender plant cultivated in Hungary and the flowers were harvested at the beginning and at the end of flowering period. The experiments were carried out on THP-1 human monocyte/macrophage cell line as in vitro cell culture model for monitoring the effects of lavender essential oils and the main compound linalool on P. aeruginosa LPS stimulated inflammation. The mRNA and protein levels of four pro-inflammatory cytokines, IL-6, IL-1β, IL-8 and TNFα were determined by Real Time PCR and ELISA measurements. The effects of essential oils were compared to the response to two NFκB inhibitors, luteolin and ACHP.

RESULTS

Linalool and lavender essential oil extracted from plants at the beginning of flowering period were successful in decreasing pro-inflammatory cytokine production following LPS pretreatment. In case of IL-8 and IL-1β lavender oil showed stronger effect compared to linalool and both of them acted similarly to NFκB inhibitors. Pretreatments with linalool and lavender essential oil/beginning of flowering period prevented pro-inflammatory cytokine production compared to LPS treatment alone. Although lavender essential oil/end of flowering period decreased IL-6, IL-1β and IL-8 mRNA expression in case of LPS pretreatment, it was not capable to reduce cytokine secretion.

CONCLUSION

Based on our results it has been proven that lavender essential oil extracted at the beginning of flowering period is a potent inhibitor of the synthesis of four pro-inflammatory cytokines IL-6, IL-8, IL-β and TNFα of THP-1 cells. This supports the relevance of the collection of the lavender flowers from early blooming period for essential oil production and for the utilization as an anti-inflammatory treatment.

Topical Emulsion Containing Lavandula stoechas Essential Oil as a Therapeutic Agent for Cutaneous Wound Healing

Background and objectives: The present research was designed to evaluate the chemical composition of Lavandula stoechas essential oil (EOLS) as well as the in vivo wound-healing property. The chemical composition of EOLS was identified by gas chromatography mass spectrometry. Nineteen compounds of EOLS were reported. Linalool was identified as the major chemical compound (24.87%), followed by linalyl acetate (19.10%). EOLS showed a high content of oxygenated compounds (63.54%). In vivo wound healing activity of the topical cream prepared from EOLS (0.5% w/w) was assessed using a circular excision wound model. The wound area (mm2) in all animal groups was estimated and measured on day 0, 4, 8, 11, and 16. Results: The EOLS formulation cream (0.5% v/w) showed the highest effect on wound models when compared to reference Madecassol® (Asiaticoside). On days 4, 11, and 16, wound contractions were 26.4%, 78%, and 96.3% for the EOLS-treated group, and 8.5%, 64.1%, and 86.1% for the vehicle cream-treated group. Animals treated with EOLS cream showed a significant decrease in the epithelization period, wound area, and scar thickness, whereas the rate of wound contraction significantly increased. This is the first such report to be published. Histological analyses were also consistent with the results of the excision experimental method. Treatment with EOLS cream formulation resulted in decreased inflammation and an increased rate of tissue perfusion and proliferation as well as remodeling, along with re-epithelization. Conclusions: Our results support the use of EOLS in the development of pharmaceuticals for the management of wounds, and/or inflammatory-related diseases. Additional studies are needed to elucidate and explain the exact mechanism of its pharmacological activity.