Chemical Profile, In Vitro Biological Activity and Comparison of Essential Oils from Fresh and Dried Flowers of Lavandula angustifolia L

Antimicrobial Properties and Assessment of the Content of Bioactive Compounds Lavandula angustifolia Mill. Cultivated in Southern Poland

Lavender is a valued plant due to its cosmetic, perfumery, culinary, and health benefits. A wide range of applications is related to the composition of bioactive compounds, the quantity and quality of which is determined by various internal and external factors, i.e., variety, morphological part of the plant, and climatic and soil conditions during vegetation. In the presented work, the characterization of antimicrobial properties as well as the qualitative and quantitative assessment of bioactive compounds in the form of polyphenols in ethanol extracts from leaves and flowers of Lavandula angustifolia Mill. intended for border hedges, cultivated in the region of southern Poland, were determined. The composition of the fraction of volatile substances and antioxidant properties were also assessed. The conducted research shows that extracts from leaves and flowers significantly affected the viability of bacterial cells and the development of mold fungi. A clear decrease in the viability of bacteria and C. albicans cells was shown in the concentration of 0.32% of extracts. Leaf extracts were characterized by a much higher content of polyphenols and antioxidant properties than flower extracts. The composition of volatiles measured by GC-MS was significantly different between the extracts. Linalyl acetate and ocimene isomers mix dominated in flower extracts, whereas coumarin, γ-cadinene, and 7-methoxycoumarin were identified as dominant in leaf extracts.

Lavender Essential Oil Modulates Hepatic Cholesterol Metabolism in HepG2 Cells

Cholesterol is an essential lipid that guarantees several biological processes in eukaryotic cells. Its metabolism is regulated by a complex protein network that could be significantly influenced by numerous exogenous sources, such as essential oils (EOs). For instance, it has been speculated that monoterpenoid and sesquiterpenoid compounds contained in lavender essential oil (LEO) may exert important hypocholesterolemic activities. However, the molecular mechanisms by which LEO influences cholesterol homeostasis are not characterized. In this work, we evaluated the ability of LEO to regulate the protein network that controls cholesterol metabolism in the HepG2 cell line. The main findings indicate that LEO administration increases intracellular cholesterol content. Concurrently, LEO affects the expression of proteins involved in cholesterol uptake, biosynthesis, and trafficking. These effects are partially mediated by terpinene-4-ol, one of the most abundant compounds in LEO. These results demonstrate that LEO modulates cholesterol metabolism in hepatic cells.

Chemical Profiles, In Vitro Antioxidant and Antifungal Activity of Four Different Lavandula angustifolia L. EOs

Lavandula angustifolia L., known as lavender, is an economically important Lamiaceae due to the production of essential oils (EOs) for the food, cosmetic, pharmaceutical and medical industries. The purpose of this study was to determine the chemical composition of EOs isolated from four inflorescences of L. angustifolia L. collected in different geographical areas: central-southern Italy (LaCC, LaPE, LaPS) and southern France (LaPRV). The essential oils, obtained by steam distillation from plants at the full flowering stage, were analyzed using gas chromatography coupled with mass spectrometry (GC-MS). More than 70 components identified in each sample showed significant variability among the main constituents. The four EOs analyzed contained the following as main component: linalool (from 30.02% to 39.73%), borneol (13.65% in LaPE and 16.83% in La PS), linalyl acetate (24.34% in LaCC and 31.07% in LaPRV). The EOs were also evaluated for their in vitro antifungal activity against two white rot fungi (Phanerochaete chrysosporium and Trametes cingulata) as potential natural biodeteriogens in the artworks field, and against Sclerotium rolfsii, Botrytis cinerea and Fusarium verticilloides responsible for significant crop yield losses in tropical and subtropical areas. The results confirm a concentration-dependent toxicity pattern, where the fungal species show different sensitivity to the four EOs. The in vitro antioxidant activity by DPPH assay showed better scavenging activity on LaCC (IC₅₀ 26.26 mg/mL) and LaPRV (IC₅₀ 33.53 mg/mL), followed by LaPE (IC₅₀ 48.00 mg/mL) and LaPS (IC₅₀ 49.63 mg/mL). The potential application of EOs as a green method to control biodeterioration phenomena on a work of art on wood timber dated 1876 was evaluated.

Effects of EOs vs. Antibiotics on E. coli Strains Isolated from Drinking Waters of Grazing Animals in the Upper Molise Region, Italy

The health and safety of grazing animals was the subject of microbiological monitoring on natural source of drinking waters in the upper Molise region, Italy. Surface water samples, on spring-summer season, were collected and submitted to analyses using sterile membrane filtration, cultural medium, and incubation. The level of environmental microbial contamination (Total viable microbial count, yeasts and fungi) and faecal presence (Total and faecal coliforms, E. coli, and Salmonellae spp.) were carried out. By the selective microbiological screening, twenty-three E. coli strains from drinking waters were isolated and submitted to further studies to evaluate antibiotic resistance by antibiograms vs. three animal and two diffuse human antibiotics. Furthermore, after a fine chemical characterization by GC and GC-MS, three Essential Oils (EOs) of aromatic plants (Timus vulgaris, Melaleuca alternifolia, Cinnamomun verum) aromatograms were performed and results statistically compared. The effects of EOs vs. antibiotics on E. coli strains isolated from drinking waters showed a total absence of microbial resistance. In our experimental conditions, even if some suggestions will be further adopted for better managements of grazing animals, because the health and safety represent a guarantee for both animals and humans.

Plants with Antimicrobial Activity Growing in Italy: A Pathogen-Driven Systematic Review for Green Veterinary Pharmacology Applications

Drug resistance threatening humans may be linked with antimicrobial and anthelmintic resistance in other species, especially among farm animals and, more in general, in the entire environment. From this perspective, Green Veterinary Pharmacology was proven successful for the control of parasites in small ruminants and for the control of other pests such as varroa in bee farming. As in anthelmintic resistance, antimicrobial resistance (AMR) represents one of the major challenges against the successful treatment of infectious diseases, and antimicrobials use in agriculture contributes to the spread of more AMR bacterial phenotypes, genes, and proteins. With this systematic review, we list Italian plants with documented antimicrobial activity against possible pathogenic microbes. Methods: The literature search included all the manuscripts published since 1990 in PubMed, Web of Science, and Scopus using the keywords (i) “antimicrobial, plants, Italy”; (ii) “antibacterial, plant, Italy”; (iii) “essential oil, antibacterial, Italy”; (iv) “essential oil, antimicrobial, Italy”; (v) “methanol extract, antibacterial, Italy”; (vi) “methanol extract, antimicrobial, Italy”. Results: In total, 105 manuscripts that documented the inhibitory effect of plants growing in Italy against bacteria were included. One hundred thirty-five plants were recorded as effective against Gram+ bacteria, and 88 against Gram−. This will provide a ready-to-use comprehensive tool to be further tested against the indicated list of pathogens and will suggest new alternative strategies against bacterial pathogens to be employed in Green Veterinary Pharmacology applications.

Effect of Response Surface Methodology-Optimized Ultrasound-Assisted Pretreatment Extraction on the Composition of Essential Oil Released From Tribute citrus Peels

The traditional hydrodistillation (HD) and ultrasound-assisted pretreatment extraction (UAPE) methods were proposed to obtain essential oil (EO) from Tribute citrus (TC) peels. The Box-Behnken design was employed to optimize the HD and UAPE procedures. Moreover, gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-nose) were applied to identify the discrepancy of the extraction methods. The yield of EO extracted by UAPE (114.02 mg/g) was significantly higher than that by HD (85.67 mg/g) (p < 0.01) undergoing 40 min short time-consuming UPAE. A total of 28 compounds were extracted from the TC peels as terpenes were the predominant components. d-Limonene was the most vital compound in the T. citrus essential oil (TCEO), accounting for 86.38% of the total volatile concentration in HD and 86.75% in UAPE, respectively, followed by α-pinene, sabinene, γ-myrcene, and β-phellandrene. The chart of radar and graphic of the principal component analysis by E-nose displayed no significance, which was similar to the GC-MS results. This study demonstrated that UAPE is an efficient and short time-consuming method for TCEO extraction, which provides a promising method for the separation of EO from aromatic plant materials.

Molecular Distillation of Lavender Supercritical Extracts: Physicochemical and Antimicrobial Characterization of Feedstocks and Assessment of Distillates Enriched with Oxygenated Fragrance Components

Lavandula angustifolia is one of the most widely cultivated non-food crops used in the production of essential oil; it is used in perfumery, aromatherapy, pharmaceutical preparations, and food ingredients. In this study, supercritical fluid extraction (SFE) and molecular distillation (MD) were combined, primarily to enrich scCO₂ extracts with lavender oxygenated monoterpenes, avoiding thermal degradation, hydrolysis, and solvent contamination, and maintaining the natural characteristics of the obtained oils. Molecular distillation was developed for the first time for the extraction of crucial lavender fragrance ingredients, i.e., from two scCO₂ extracts obtained from dry flower stems of lavender cultivated in Poland and Bulgaria. The best results for high-quality distillates were obtained at 85 °C (EVT) and confirmed that linalyl acetate content increased from 51.54 mg/g (initial Bulgarian lavender extract, L-Bg-E) and 89.53 mg/g (initial Polish lavender extract, L-Pl-E) to 118.41 and 185.42 mg/g, respectively, corresponding to increases of 2.3 and 2.1 times in both distillate streams, respectively. The distillates, light oils, and extracts from lavender were also evaluated for their antimicrobial properties by determining the minimum inhibitory concentration (MIC) by the broth microdilution method. Generally, Gram-positive bacteria and Candida spp. were more sensitive to all distilled fractions and extracts than Escherichia coli (Gram-negative bacteria).

Comparative Study on Microencapsulation of Lavender (Lavandula angustifolia Mill.) and Peppermint (Mentha piperita L.) Essential Oils via Spray-Drying Technique

Essential oils have been studied for various applications, including for therapeutic purposes. There is extensive literature regarding their properties; however, their low stability limits their application. Generally, the microencapsulation of essential oils allows enhanced stability and enables the potential incorporation in solid dosage forms. Lavender and peppermint oils were encapsulated in microparticles using a spray-drying technique under optimized conditions: 170 °C temperature, 35 m³/h aspiration volume flow, and 7.5 mL/min feed flow. Arabic gum and maltodextrin were used as coating polymers individually in varying concentrations from 5 to 20% (w/v) and in combination. The microparticles were studied for morphology, particle size, oil content, and flowability. The formulated powder particles showed a high yield of 71 to 84%, mean diameter 2.41 to 5.99 µm, and total oil content of up to 10.80%. The results showed that both the wall material type and concentration, as well as the type of essential oil, significantly affected the encapsulation process and the final particle characteristics. Our study has demonstrated that the encapsulation of lavender and peppermint oils in Arabic gum/maltodextrin microparticles by spray-drying represents a feasible approach for the conversion of liquids into solids regarding their further use in powder technology.