Insecticidal activity of two essential oils used in perfumery (ylang ylang and frankincense)

Flower Power: An Overview on Chemistry and Biological Impact of Selected Essential Oils from Blossoms

Natural raw materials such as essential oils have received more and more attention in recent decades, whether in the food industry, as flavorings and preservatives, or as insecticides and insect repellents. They are, furthermore, very popular as fragrances in perfumes, cosmetics, and household products. In addition, aromatherapy is widely used to complement conventional medicine. This review summarizes investigations on the chemical composition and the most important biological impacts of essential oils and volatile compounds extracted from selected aromatic blossoms, including Lavandula angustifolia, Matricaria recutita, Rosa x damascena, Jasminum grandiflorum, Citrus x aurantium, Cananga odorata, and Michelia alba. The literature was collected from PubMed, Google Scholar, and Science Direct. Blossom essential oils discussed in this work are used in a wide variety of clinical issues. The application is consistently described as safe in studies and meta-analyses, although there are notes that using essential oils can also have side effects, especially dermatologically. However, it can be considered as confirmed that essential oils have positive influences on humans and can improve quality of life in patients with psychiatric disorders, critically ill patients, and patients in other exceptional situations. Although the positive effect of essential oils from blossoms has repeatedly been reported, evidence-based clinical investigations are still underrepresented, and the need for research is demanded.

Plant Essential Oils: Dual Action of Toxicity and Egg-Laying Inhibition on Tetranychus urticae (Acari: Tetranychidae), Unveiling Their Potential as Botanical Pesticides

Tetranychus urticae, a prominent pest mite in strawberry and vegetable cultivation in China, has developed escalating resistance due to extensive chemical pesticide application. Consequently, there is an urgent need to identify safe and efficacious methods to reduce resistance development. In this study, 38 commercially available plant essential oils (EOs) were screened for their acaricidal potential and ability to inhibit oviposition. The findings revealed that 13 EOs exhibited notable acaricidal activity, with lemon EO demonstrating the highest toxicity, followed by sage, patchouli, frankincense, lemongrass, palmarosa, and oregano EOs. In addition, 18 EOs displayed significant inhibitory effects on oviposition, with lemon EO exhibiting the highest inhibition rate (99.15%) and inhibition index (0.98). Subsequently, sage, frankincense, clove, lemongrass, oregano, patchouli, myrrh, black pepper, palmarosa, and geranium EOs also showed inhibition rates exceeding 50%. Despite black pepper, clove, myrrh, and oregano EOs demonstrating relatively low toxicity against T. urticae, they exhibited heightened efficacy in inhibiting oviposition and suppressing population expansion. This study conducted a comparative assessment of the acaricidal and oviposition inhibition activities of EOs and their principal constituents, thus providing a theoretical basis for the development of botanical acaricides against T. urticae.

Boric acid crosslinked chitosan microcapsules loaded with frankincense oil for the development of mosquito-repellent, antibacterial, antioxidant, and flame-retardant cotton

In ancient times, textiles were only used for covering the human body. Nowadays, people are looking for functional textiles to provide additional functional properties. In the present work, an attempt was made to develop chitosan and boric acid-based microcapsules loaded with frankincense oil. Application of these microcapsules was done on cotton using a pad-dry method. The release rate, encapsulation efficiency and microencapsulation yield of microcapsules, and functional properties of finished fabric were studied. The prepared microcapsules were also characterised by different techniques like SEM, FTIR, TGA, and EDX. The finished fabric exhibited mosquito repellency (100 %), antioxidant activity (>66 %), antibacterial activity against E. coli (88.69 %) and S. aureus (94.5 %), and LOI of 24 with a pleasant aroma.

Omani Frankincense nanoemulsion formulation efficacy and its latent effects on biological aspects of the spiny bollworm Earias insulana (Boisd.)

Our research shed light on the perspective of formulation technology regarding its responsibility to provide phyto-insecticides that are worthy of research into potential novel applications. There has been an increase in interest in using nanoemulsion as a new formulation in a variety of sectors during the last several decades. Boswellia sacra essential oil (Fam: Burseraceae) from the resin of frankincense trees has been recently proposed as a promising ingredient in a new generation of botanical insecticides. Frankincense nanoemulsion was formulated in 5% ratios comprising frankincense oil, surfactants, and water. A frankincense nanoemulsion was prepared using a high-energy ultra-sonication process and characterized by dynamic light scattering transmission electron microscopy surface tension, viscosity, and zeta potential value. Gas chromatography/mass spectrometry (GC/MS) was used to identify the chemical profiles of frankincense essential oil. Furthermore, insecticidal effects against second instar larvae of the spiny bollworm, Earias insulana, as well as their latent effects on the larvae were studied. In the present study, the formulation was a good nanoemulsion. The surface tension was 53.69, the viscosity was 4.76 cPs, the zeta potential was-10 mV, and the size distribution was 41.30 nm. The polydispersity index (PDI) of the nanoemulsion was found to be 0.26, and the morphology of the frankincense nanoemulsion was visualized in a spherical shape. The main constituents identified in frankincense oil were α-pinene (15.52%); monolinolenin (12.92%); and geranylgeranyl acetate (9.99%). The results showed significant insecticidal activity against the larval stage and considerably decreased the pupation percentage with increasing the volume of the frankincense nanoemulsion. On the other hand, the latent effects of the frankincense nanoemulsion on E. insulana resulted in a higher prolongation of larval and pupal durations as well as a significant reduction in the weight of larvae and pupae of E. insulana. Additionally, frankincense nanoemulsion dramatically influenced the adult emergence percentage. It also caused a significantly lower hatchability percentage compared to the untreated control. The concentrations used and the types of mating combination have a significant effect on the fecundity of E. insulana. This novel frankincense nanoemulsion formulation could be used in strategies to control the spiny bollworm on cotton plants.

Enhancing Rubisco gene expression and metabolites accumulation for better plant growth in Ficus deltoidea under drought stress using hydrogen peroxide

Growth improvement of the medicinal plant, Ficus deltoidea (Mas Cotek) under drought conditions is a vital issue in Malaysia since it is a slow-growing plant and disposed to leaf damage under the stresses of drought. Therefore, investigation was done to examine the outcomes of hydrogen peroxide (H2O2) application on Rubisco gene expression and metabolites accumulation of stressed F. deltoidea plants, and thereby to record the changes in leaf histology, photosynthesis, biochemical properties, and the growth of the plant. H2O2 at the rates of 0, 5, 10, 15, and 20 mM were foliar sprayed biweekly on the drought stressed plants using a hand sprayer. The application of 20 mM H2O2 amplified leaf number, tallness, stomatal conductance, and photosynthetic yield by 143, 24, 88, and 18%, respectively, over the control plant. A reduced transpiration rate and improved chlorophyll fluorescence were also noted in H2O2-treated plants. The treatment produced a greater amount of chlorophyll a, total phenols, total flavonoids, sugar content, and antioxidant activities by 1.61-, 1.30-, 1.98-, 1.92-, and 1.53-fold, respectively. Application of 15 mM H2O2 enhanced net photosynthetic rate and internal CO2 concentrations by 1.05- and 1.25-fold, respectively. Additionally, H2O2 treatments promoted stomatal closure, increased stomata size, the number of stomata, improved vein structure, and reduced the damage of the leaf margin and mesophyll cells of drought stressed plants. The application of H2O2 also accumulated significantly higher contents of sodium (Na+), calcium (Ca2+), potassium (K+), magnesium (Mg+), and iron (Fe2+) in stressed plants. Although the amount of Arsenic (As+) and Antimony (Sb3+) increased to some extent, the increases were not at a toxic level. The use of H2O2 enhanced the Rubisco gene expression to a greater level and the ratio of Rubisco expression increased up to 16-fold. Finally, thirteen (13) identified and five (5) unmatched volatile compounds with a quality score above 70% were identified by gas chromatography-mass spectrometry (GCMS). The GCMS analysis showed that the foliar application of H2O2 accumulates a higher percentage of volatile components in plants which helps to mitigate the negative effects of drought stress. It is concluded that under drought stressed conditions the F. deltoidea plants should be treated with 10-15 mM of H2O2 twice a week to improve leaf histology, photosynthesis, the level of Rubisco gene expression and volatile compounds accumulation, and plant growth and development.

Physiological response and secondary metabolites of three lavender genotypes under water deficit

Lavandula genus is a considerable medicinal plant in pharmaceutical and cosmetics industries. Considering increasing threat of drought in the world, it is important to identify genotypes which can tolerate drought. It is also important to characterize quantity and quality of essential oils, and tolerance indicators of these genotypes against drought stress. Therefore, an experiment was conducted in Gorgan University of Agricultural Sciences and Natural Resources, Iran, during 2017 and 2018, to investigate these factors. It was a factorial experiment based on randomized complete block design with two treatments, three genotypes (Lavandula angustifolia cv. Hidcote, Lavandula angustifolia cv. Munstead, and Lavandula stricta), and four levels of drought stress (irrigation regimes) (I₁: 100–90% (control), I₂: 80–70%, I₃: 60–50% and I₄: 30–40% of field capacity) which was done with three repetitions. Drought increased amount of proline in leaves, antioxidant activity, activity of catalase, peroxidase, ascorbate peroxidase, and superoxide enzymes, malondialdehyde content, total flavonoids, total phenol, total sugar and essential oil percentage. The PCA analysis of different irrigation regimes showed that in the first component, the best traits are antioxidant enzymes CAT, SOD, APX, while in the second component, only the trait Catalase is the best trait. The results of PCA analysis in lavender genotypes showed that L. stricta exhibits the most affected physiological changes while trying to adjust to changes in the water status of the environment, under the imposed conditions and shows the highest resistance. But it reduced dry weight of aerial parts, relative water content of leaves, and efficacy of essential oil. Lavandula stricta genotype had the highest amount of essential oil, but the highest dry weight of the aerial parts and essential oil yield were related to L. angustifolia cv. Hidcote and L. angustifolia cv. Munstead genotypes. In all evaluated genotypes, with increasing drought stress, monoterpene compounds were decreased and sesquiterpene compounds were increased. Totally it was shown that drought effect on evaluated traits depends on genotype and nature of traits; this indicates that by choosing drought-tolerant genotypes in breeding programs, high quantity and quality of essential oil, as well as tolerance to drought stress can be achieved.

Volatile Compounds and Physicochemical Quality of Four Jabuticabas (Plinia sp.)

The jabuticaba is a native Brazilian fruit that has aroused worldwide interest in terms of its nutritional composition and biological activity. However, research on the profile of volatile compounds (VOCs) emitted by these fruits is rare. This study presents the first identification of VOCs from four jabuticaba species. The aim of the study was to characterize the aromatic profile of the following species: ‘Sabará’ (Plinia jaboticaba), ‘Escarlate’ (Plinia phitrantha × Plinia cauliflora), ‘Otto Andersen’ (Plinia cauliflora), and ‘Esalq’ (Plinia phitrantha). The analysis was performed by headspace solid-phase microextraction combined with gas chromatography/mass spectrometry (SPME-GC-MS). Multivariate analysis techniques applying the partial least squares-discriminant analysis (PLS-DA) and heatmap were used to compare the results. Fruit quality parameters were determined in terms of fresh mass (g), skin color, soluble solids, and titratable acidity. A total of 117 VOCs was identified including terpenoids, esters, alcohols, aldehydes, alkanes, ketones, and carboxylic acids, with 36 VOCs common to all four species. Terpenes were the majority for all jabuticabas with smaller contributions from other volatile classes, especially β-cubebene, β-elemene, and D-limonene for the ‘Otto Andersen’ jabuticaba.