This comprehensive review endeavors to illuminate the nuanced facets of linalool, a prominent monoterpene found abundantly in essential oils, constituting a massive portion of their composition. The biomedical relevance of linalool is a key focus, highlighting its therapeutic attributes observed through anti-nociceptive effects, anxiolytic properties, and behavioral modulation in individuals affected by dementia. These findings underscore the compound\'s potential application in biomedical applications. This review further explores contemporary formulations, delineating the adaptability of linalool in nano-emulsions, microemulsions, bio-capsules, and various topical formulations, including topical gels and lotions. This review covers published and granted patents between 2018-2024 and sheds light on the evolving landscape of linalool applications, revealing advancements in dermatological, anti-inflammatory, and antimicrobial domains.

Among the ESKAPE pathogens, Pseudomonas aeruginosa is an extensively notorious superbug that causes difficult-to-treat infections. Since quorum sensing (QS) directly promotes pseudomonal virulence, targeting QS circuits is a promising approach for disarming phenotypic virulence. Hence, this study scrutinizes the anti-QS, antivirulence, and anti-biofilm potential of citral (CiT; phytochemical) and triclosan (TcN; disinfectant), alone and in combination, against P. aeruginosa PAO1/PA14. The findings confirmed synergism between CiT and TcN and revealed their quorum quenching (QQ) potential. At sub-inhibitory levels, CiT-TcN combination significantly impeded pyocyanin, total bacterial protease, hemolysin, and pyochelin production alongside inhibiting biofilm formation in P. aeruginosa. Moreover, the QQ and antivirulence potential of CiT and TcN was positively correlated by molecular docking studies that predicted strong associations of the drugs with QS receptors of P. aeruginosa. Collectively, the study identifies CiT-TcN as an effective drug combination that harbors QQ, antivirulence, and anti-biofilm prospects against P. aeruginosa.

Hemerocallis L. possesses abundant germplasm resources and holds significant value in terms of ornamental, edible, and medicinal aspects. However, the quality characteristics vary significantly depending on different varieties. Selection of a high-quality variety with a characteristic aroma can increase the economic value of Hemerocallis flowers. The analytic hierarchy process (AHP) is an effective decision-making method for comparing and evaluating multiple characteristic dimensions. By applying AHP, the aromatic character of 60 varieties of Hemerocallis flowers were analyzed and evaluated in the present study. Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) was employed to identify volatile components in Hemerocallis flowers. Thirteen volatile components were found to contribute to the aroma of Hemerocallis flowers, which helps in assessing their potential applications in essential oil, aromatherapy, and medical treatment. These components include 2-phenylethanol, geraniol, linalool, nonanal, decanal, (E)-β-ocimene, α-farnesene, indole, nerolidol, 3-furanmethanol, 3-carene, benzaldehyde and benzenemethanol. The varieties with better aromatic potential can be selected from a large amount of data using an AHP model. This study provides a comprehensive understanding of the characteristics of the aroma components in Hemerocallis flowers, offers guidance for breeding, and enhances the economic value of Hemerocallis flowers.

Ferulic acid (Fer) and geraniol (Ger) are natural compounds whose antioxidant and anti-inflammatory activity confer beneficial properties, such as antibacterial, anticancer, and neuroprotective effects. However, the short half-lives of these compounds impair their therapeutic activities after conventional administration. We propose, therefore, a new prodrug (Fer-Ger) obtained by a bio-catalyzed ester conjugation of Fer and Ger to enhance the loading of solid lipid microparticles (SLMs) designed as Fer-Ger delivery and targeting systems. SLMs were obtained by hot emulsion techniques without organic solvents. HPLC-UV analysis evidenced that Fer-Ger is hydrolyzed in human or rat whole blood and rat liver homogenates, with half-lives of 193.64 ± 20.93, 20.15 ± 0.75, and 3.94 ± 0.33 min, respectively, but not in rat brain homogenates. Studies on neuronal-differentiated mouse neuroblastoma N2a cells incubated with the reactive oxygen species (ROS) inductor H2O2 evidenced the Fer-Ger ability to prevent oxidative injury, despite the fact that it appears ROS-promoting. The amounts of Fer-Ger encapsulated in tristearin SLMs, obtained in the absence or presence of glucose, were 1.5 ± 0.1%, allowing the control of the prodrug release (glucose absence) or to sensibly enhance its water dissolution rate (glucose presence). These new \"green\" carriers can potentially prolong the beneficial effects of Fer and Ger or induce neuroprotection as nasal formulations.

Transdermal drug delivery offers a promising alternative for administering medications like ibuprofen, known for its analgesic and anti-inflammatory properties, with reduced gastrointestinal side effects compared to oral administration. This study explored the potential synergistic effects of combining ibuprofen with lavender essential oil (LEO) in transdermal patches. The composition of LEO was analyzed, revealing predominant compounds such as linalyl acetate and linalool, which are known for their analgesic and anti-inflammatory properties. The physicochemical properties of the patches were investigated, indicating improved cohesion with the addition of LEO. Additionally, thermal stability assessments demonstrated enhanced stability with LEO incorporation with an increase in onset decomposition temperature from 49.0 to 67.9 °C. The antioxidant activity of patches containing LEO was significantly higher with a free radical scavenging ability of 79.13% RSA compared to 60% RSA in patches without LEO. Release and permeation studies showed that patches with LEO exhibited an increased permeation of ibuprofen through the skin with 74.40% of the drug released from LEO-containing patches compared to 36.29% from patches without LEO after 24 h. Moreover, the permeation rate was notably faster with LEO, indicating quicker therapeutic effects. The inclusion of LEO in transdermal patches containing ibuprofen holds promise for enhancing drug delivery efficiency and therapeutic effectiveness, offering a potential strategy for improved pain management with reduced side effects.

The thrust of the study was to determine the chemical composition of the essential oils extracted from Thymus pallescens de Noé and Cymbogon citratus Stapf. as well as to evaluate their efficacy in controlling Sitophilus zeamais Motschulsky and Tribolium castaneum (Herbst) in either single or combined populations. Carvacrol (56.04%) and geraniol (20.86%) were identified as the major constituents of T. pallescens and C. citratus respectively. The tested essential oils showed pronounced insecticidal activity against the pest species in relation with the applied doses. T. pallescens EO had the highest efficacy and S. zeamais was found to be more susceptible to both individual and combined treatments. With reference to the contact and fumigation assessments, T. pallescens EO effectuated corrected mortality rates ranging from 42.5-100% to 25-100% in S. zeamais with corresponding lethal concentration (LC50) values of 17.7 µl/ml and 15µL/L air respectively. Whereas, the T. pallescens EO exhibited corrected mortality rates of 42.5-100% and 20-100% with corresponding LC50 values of 18.1 µl/ml and 15.5 µL/L air against T. castaneum in contact and fumigation assessments, respectively. The corrected mortality rates increased for both insect species when using combination treatments, with significant increases in the LC50 values, ranging from 8.59 to 49.9% for both pest species. Analysis of energy biomarkers in the treated insects indicate significantly increased protein and carbohydrate contents and decreased lipids levels. The study therefore demonstrated the bio-insecticidal toxicity of the EOs from T. pallescens and C. citratus against two important maize post-harvest pests, concurrently revealing significant positive and negative insecticidal activity gradients in relation to single or combined populations.

Breast cancer (BC) is a common cancer for women. This study aims to construct a prognostic risk model of BC and identify prognostic biomarkers through machine learning approaches, and clarify the mechanism by which linalool exerts tumor-suppressive function. Three mRNA microarray/RNA sequencing data sets (GSE25055, GSE103091, and TCGA-BRCA) were obtained from Gene Expression Omnibus database and The Cancer Genome Atlas database, and prognostic genes were obtained by univariate COX analysis. Multiple machine learning methods were used to screen core genes and construct prognostic risk models. The enrichment analysis of crucial genes was analyzed using the DAVID database. UALCAN, human protein atlas, geneMANIA, and LinkedOmics databases were used to analyze gene expression and co-expressed genes. Molecular docking and molecular dynamics simulation was applied to verify the binding affinity between linalool and phosphoglycerate kinase 1 (PGK1). Cell counting kit 8 (CCK-8, Edu, transwell, flow cytometry, and Western blot assay were used to analyze cell activity, apoptosis, cell cycle and protein expression. Eight prognostic genes were obtained by bioinformatics analysis and machine learning, and prognostic risk models were constructed. This model could well predict the prognosis of patients, and the risk score could be used as an independent risk factor for BC. Overall survival (OS) and immune cell infiltration characteristics were distinct between high and low risk groups. PGK1 was highly expressed in BC and the OS of patients with high PGK1 expression was shorter. PGK1 was related to cell cycle and PPAR signaling pathway. Linalool and PGK1 had good binding activity, and linalool could inhibit the viability, proliferation, migration, and invasion of BC cells, promote cell apoptosis, and induce G0/G1 arrest. In addition, linalool can promote PPARγ protein expression and inhibit PGK1 expression. Machine learning and molecular docking were promising for exploration of new drug targets for BC, and linalool exerts tumor-suppressive effects in BC by inhibiting PGK1 expression and activating PPAR signaling pathway.

The excessive and indiscriminate use of synthetic insecticides has led to environmental pollution, wildlife destruction, and adverse effects on human health, while simultaneously giving rise to resistance in insect pest populations. This adaptive trait is expressed through various mechanisms, such as changes in the cuticle, heightened activities of detoxifying enzymes, and alterations in the sites of action that reduce their affinity for insecticides. In this context, we associate variation in toxicological response with genomic variation, to identify genetic polymorphisms underlying the different steps of the insect (genotype)-response (phenotype)-insecticide (environment) interaction. Under this framework, our objective was to investigate the genetic factors involved in the toxicological response of D. melanogaster lines when exposed to citronellal and eucalyptol vapors (monoterpenes of plant origin). We quantified KT50 in adult males, representing the time necessary for half of the exposed individuals to be turned upside down (unable to walk or fly). Since the genomes of all lines used are completely sequenced, we perform a Genome Wide Association Study to analyze the genetic underpinnings of the toxicological response. Our investigation enabled the identification of 656 genetic polymorphisms and 316 candidate genes responsible for the overall phenotypic variation. Among these, 162 candidate genes (77.1%) exhibited specificity to citronellal, 45 (21.4%) were specific to eucalyptol, and 3 candidate genes (1.5%) namely CG34345, robo2, and Ac13E, were implicated in the variation for both monoterpenes. These suggest a widespread adaptability in the response to insecticides, encompassing genes influenced by monoterpenes and those orchestrating resistance to the toxicity of these compounds.

Insects detect and discriminate a diverse array of chemicals using odorant receptors (ORs), which are ligand-gated ion channels comprising a divergent odorant-sensing OR and a conserved odorant receptor co-receptor (Orco). In this work, we report structures of the ApOR5-Orco heterocomplex from the pea aphid Acyrthosiphon pisum alone and bound to its known activating ligand, geranyl acetate. In these structures, three ApOrco subunits serve as scaffold components that cannot bind the ligand and remain relatively unchanged. Upon ligand binding, the pore-forming helix S7b of ApOR5 shifts outward from the central pore axis, causing an asymmetrical pore opening for ion influx. Our study provides insights into odorant recognition and channel gating of the OR-Orco heterocomplex and offers structural resources to support development of innovative insecticides and repellents for pest control.

BACKGROUND: Hepatic ischemia/reperfusion (I/R) injury is a significant clinical condition that can arise during liver resections, trauma, and shock. Geraniol, an isoterpene molecule commonly found in nature, possesses antioxidant and hepatoprotective properties. This study investigates the impact of geraniol on hepatic damage by inducing experimental liver I/R injury in rats.
METHODS: Twenty-eight male Wistar Albino rats weighing 350-400 g were utilized for this study. The rats were divided into four groups: control group, I/R group, 50 mg/kg geraniol+I/R group, and 100 mg/kg geraniol+I/R group. Ischemia times were set at 15 minutes with reperfusion times at 20 minutes. Ischemia commenced 15 minutes after geraniol administration. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactic acid were measured, along with superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity levels in liver tissues. Liver tissues were also examined histopathologically.
RESULTS: It was observed that intraperitoneal administration of 50 mg/kg and 100 mg/kg geraniol significantly reduced AST, lactic acid, and tumor necrosis factor-alpha (TNF-α) levels. The serum ALT level decreased significantly in the 50 mg/kg group, whereas no significant decrease was found in the 100 mg/kg group. SOD and GPx enzyme activities were shown to increase significantly in the 100 mg/kg group. Although there was an increase in these enzyme levels in the 50 mg/kg group, it was not statistically significant. Similarly, CAT enzyme activity increased in both the 50 mg/kg and 100 mg/kg groups, but the increase was not significant. The Suzuki score significantly decreased in both the 50 mg/kg and 100 mg/kg groups.
CONCLUSIONS: The study demonstrates that geraniol reduced hepatic damage both biochemically and histopathologically and increased antioxidant defense enzymes. These findings suggest that geraniol could be used to prevent hepatic I/R injury, provided it is corroborated by large-scale and comprehensive studies.