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Simple Summary: The implications of intestinal barrier function improvement in immune-stressed weaning piglets by terpinen-4-ol(TER) are observed. Enhanced nutrient absorption, reduced gastrointestinal disease incidence, and improved overall growth performance can be achieved through improved intestinal barrier function. A promising alternative is offered by the use of TER as a natural plant extract. Far-reaching implications on animal health, economic viability, environmental sustainability, and animal welfare are observed from the use of TER to improve intestinal barrier function in immune-stressed weaning piglets. The importance of natural alternatives in enhancing livestock productivity and health is underscored by this promising approach, paving the way for more sustainable and ethical farming practices. The aim of this study was to investigate the effects of terpinen-4-ol (TER) supplementation on the intestinal barrier function of pigs. Five groups of fifty 28-day-old piglets with comparable body weights were randomly assigned to the following groups: the control group (CON), the lipopolysaccharide group (LPS), the low TER group (PLT), the middle TER group (PMT), and the high TER group (PHT). The basal diet was given to the CON and LPS groups, and 30, 60, or 90 mg/kg TER was added to the basal diet for the TER groups. After the 21-day trial period, piglets in the LPS and TER groups received an intraperitoneal injection of 100 μg/kg body weight of LPS, whereas the piglets in the CON group received an injection of 0.9% normal saline solution. The results showed that LPS stimulation resulted in a decrease (p < 0.05) in the depth of colonic crypts in piglets, which was greater (p < 0.05) in the TER group. Compared with those in the CON group, the number of goblet cells and MUC2 expression were decreased in the colon of piglets in the LPS group, while these parameters were increased in the PMT group (p < 0.05). The malondialdehyde (MDA) content was greater in the colon of the LPS group than in that of the CON group, while the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) were lower in the colon of the LPS group; conversely, the MDA content was lower in the colons of the PLT and PMT groups than in those of the LPS group (p < 0.05). TER also reduced (p < 0.05) LPS-induced upregulation of IL-1β and TNF-α expression, along with the relative gene expression of NLRP3, ASC, and caspase-1 in the colon of piglets (p < 0.05). Compared with those in the CON group, the abundances of Firmicutes and UCG-005 in the LPS group were lower (p < 0.05), and those in the TER group were significantly greater than those in the LPS group. Compared with those in the CON group, the abundance of Proteobacteria in the LPS group increased (p < 0.05), while the abundance of Actinobacteria and Phascolarctobacterium increased (p < 0.05) in the colon of the PHT group compared with that in the LPS group. In conclusion, TER effectively improved the intestinal barrier function of the colon in weaning piglets. Based on the results of this study, the appropriate dose of TER in the diets of weaning piglets was 60 mg/kg. [ABSTRACT FROM AUTHOR]

Tea tree oil (TTO), acquired from Melaleuca alternifolia (Maiden & Betche) Cheel, Myrtaceae, is a widely utilized essential oil (EO) due to its bioactive properties. The identification and quantification of TTO ingredients is generally performed by GC-MS, which provides the most accurate results. However, in some instances, the cost and time of analysis may pose a challenge. Thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC) offer a simpler, faster, cost-effective alternative capable of simultaneously analyzing and quantifying multiple samples. In addition, for more complex oils, two-dimensional (2D) or multigradient development (MGD) TLC provide better separation. Nevertheless, further development is sometimes necessary for the isolation of comigrating components. This study showcases a combined 2D-MGD TLC/HPTLC method for the successful separation of TTO components of interest. While human error, limited separation, and the partial evaporation of volatile components may still present a challenge during the process, considerable recovery of mono- and sesquiterpenes was achieved. This protocol also resulted in the successful isolation of target oxygenated monoterpenes (OMs) producing highly pure terpinen-4-ol (100%) and α-terpineol (≥94%), confirmed by GC-MS. The accurate enantiomeric distribution of these major OMs was verified by GC-FID through the use of a chiral cyclodextrin-based stationary phase. The observed positive enantiomer range (area percent) as well as (+)/(−) ratio for each terpinen-4-ol and α-terpineol were within acceptable ISO criteria. [ABSTRACT FROM AUTHOR]

In order to improve the hydrophobicity and volatility of terpinen-4-ol and extend its duration of action, β-cyclodextrin-based metal-organic framework (β-CD-MOF) was first prepared by the modified vapor diffusion method, and then terpinen-4-ol was encapsulated with the β-CD-MOF to prepare a terpinen-4-ol/β-CD-MOF inclusion complex by the solvent incubation method. The mass ratio of the prepared β-CD-MOF or β-CD used as the control to terpinen-4-ol was optimized for encapsulation. The morphological characteristics, spectral absorption properties and thermogravimetric characterisation of the terpinen-4-ol/β-CD-MOF complex were analyzed. Through in vitro bacteriostatic assays, the inhibitory effects of the complex on three food-borne pathogens were determined. The results showed that the highest drug loading and encapsulation efficiency were achieved when the mass ratio of terpinen-4-ol to β-CD-MOF was 1:1, superior to the same preparation conditions using β-CD as a carrier. Scanning electron microscope (SEM) observations indicated that irregularly arranged β-CD molecules stacked together under the bridging action of K+, forming an orderly arranged rectangular β-CD-MOF. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis demonstrated terpinen-4-ol was successfully encapsulated in β-CD-MOF with hydrogen bond interactions between them. Thermogravimetric analysis (TGA) proved that the volatilization rate of terpinen-4-ol could be retarded when encapsulated by β-CD-MOF, extending its application temperature range from 30~160 ℃ to 30~350 ℃. In vitro antibacterial experiments showed that the terpinen-4-ol/β-CD-MOF complex exhibited long-lasting antibacterial abilities against three common cold-chain microorganisms, including Escherichia coli, Staphylococcus aureus and Listeria monocytogenes. In conclusion, encapsulating terpinen-4-ol in β-CD-MOF allows for effective preservation, providing a theoretical basis for the development of novel, green and safe antimicrobial materials for cold-chain applications.

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of tea tree oil obtained from leaves and terminal branchlets of Melaleuca alternifolia (Maiden & Betche) Cheel when used as a sensory additive for all animal species. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that tea tree oil was very unlikely to be of safety concern for long‐living and reproductive animals and is of no concern for target species for fattening at the following concentrations in complete feed: 1.1 mg/kg for chickens for fattening, 1.5 mg/kg for turkeys for fattening, 1.7 mg/kg for laying hens, 2.0 mg/kg for piglets, 2.4 mg/kg for pigs for fattening, 3.1 mg/kg for sows, 5.0 mg/kg for veal calves (milk replacer) and salmonids, 4.4 mg/kg for cattle for fattening, sheep/goats and horses, 2.9 mg/kg for dairy cows, 1.8 mg/kg for rabbits, 0.9 mg/kg for cats, 5.3 mg/kg for dogs, 6.6 for crustaceans and 15 mg/kg for ornamental fish. These conclusions were extrapolated to other physiologically related species. For any other species, the additive is very unlikely to be of safety concern at 1.1 mg/kg complete feed. No concerns for consumers and the environment were identified following the use of the additive up to the highest safe use level in feed. Regarding user safety, tea tree oil should be considered as an irritant to skin and eyes and as a dermal and respiratory sensitiser. It is classified as a reprotoxic substance (category 1B) following CLP criteria and should be handled accordingly. Since M. alternifolia and its preparations were recognised to flavour food and its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary. [ABSTRACT FROM AUTHOR]

This study investigated the antistress effects of yuzu synthetic fragrances by employing three experiments on humans and mice using two yuzu synthetic fragrances and five single compounds. We prepared two synthetic fragrances based on the component analysis of two natural yuzu essential oils extracted by cold-pressed and steam-distilled extraction methods. Chromogranin A (CgA) and heart rate (HR) were used as stress indices in human experiments. Immobility time during the forced swim test was used as a stress index in mice experiments. We analyzed brain mechanisms by measuring the expression of neurotrophic factors, brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophin-3 (NT-3) in the mice experiments. Synthetic yuzu fragrance mimicked steam-distilled oil (SD) significantly reduced participants' heart rate in experiment 1. In the forced swim test conducted in experiment 2, SD significantly reduced immobility time, and increased the expression of neurotrophic factors BDNF, NGF, and NT-3 in the hippocampus of mice. In experiment 3, focusing on single compounds, terpinen-4-ol significantly reduced immobility time in the forced swim test. These findings indicate that inhalation of SD and terpinen-4-ol has antistress effects. Terpinen-4-ol is a strong candidate for further investigation as a potential stress-reducing agent. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Chiliadenus montanus(Vahl.) Brullo is a wild herb that grows in narrow parts of Jordan and is locally named Hneedeh. Despite being used for treating mild abdominal and respiratory ailments, Hneedeh is still locally known on a very small scale, and its healing capabilities are still waiting for a solid scientific justification. No previous studies were made to explore the antibacterial potential of Jordanian Hneedeh as well as its chemical composition despite being researched by scientists from neighboring countries. For this reason, this research aimed to unveil the active compounds behind the medicinal properties of wild C. montanus collected from Garissa-Jordan by analyzing the essential oil using the GC MS system. Also, the antibacterial activity was explored in two extracts (methanolic and ethanolic) collected from the succulent branches of C. montanus was examined using Microdilution and Disc Diffusion Assays. Data revealed the presence of 23 compounds grouped into eight classes and oxygenated monoterpenes were the predominant class (40.36%).Terpinen-4-ol, which is known for its super curative antibacterial and antitumoral powers, was indicated to be the major chemical compound in the essential oil of Hneedeh as it comprised (23.3%) of the essential oil, which disagreed with other previous studies made on the same plants growing in neighboring counties. Moreover, both extract types restricted growth in most tested bacterial types. The results recorded in the Microdilution Assay showed that the inhibitory effect of both extract types was stronger thanthose obtained in the antibiotic treatment (control) in E. coli and Staphylococcus aureus. Meanwhile, both methanolic and ethanolic extracts were as effective as the antibiotic when administrated to Bacillus subtilis and Salmonella sp. at similar minimal inhibition concentration (MIC) values. Moreover, Disc Diffusion Assay showed that both extract types could prevent the development of six bacteria types while no effect was recorded in Klebsiella pneumoniae. However, E coli bacteria was the most affected strain. The presence of the oxygenated monoterpenes, especially Terpinen-4-ol at premium levels, might be the causal agent behind the remarkable antibacterial powers of C. montanus extract. To our knowledge, this is the first time that C. montanus which grows wild in the village of Ghareesa is reported to contain Terpinen-4-ol as the main active ingredient, which is unlike results reported in other studies conducted on similar plant species growing in other countries. [ABSTRACT FROM AUTHOR]

Terpinen-4-ol (T-4-O) is an important component of tea tree oil and has anti-inflammatory effects. Currently, there are very few studies on the mechanisms by which T-4-O improves lipopolysaccharide (LPS)-induced macrophage inflammation. In this study, LPS-stimulated mouse RAW264.7 macrophages were used as a model to analyze the effects of T-4-O on macrophage inflammatory factors and related metabolic pathways in an inflammatory environment. The results showed that T-4-O significantly decreased the expression levels of inflammatory cytokines induced by LPS. Cellular metabolism results showed that T-4-O significantly decreased the ratio of the extracellular acidification rate and oxygen consumption rate. Non-targeted metabolomics results showed that T-4-O mainly affected glutamine and glutamate metabolism and glycine, serine, and threonine metabolic pathways. qPCR results showed that T-4-O increased the transcript levels of GLS and GDH and promoted glutamine catabolism. Western blotting results showed that T-4-O inhibited the mTOR and IκB, thereby decreasing NF-κB activity. The overall results showed that T-4-O inhibited mTOR phosphorylation to promote glutamine metabolism and increased cell oxidative phosphorylation levels, thereby inhibiting the expression of LPS-induced inflammatory cytokines. [ABSTRACT FROM AUTHOR]

This study investigated the antistress effects of yuzu synthetic fragrances by employing three experiments on humans and mice using two yuzu synthetic fragrances and five single compounds. We prepared two synthetic fragrances based on the component analysis of two natural yuzu essential oils extracted by cold-pressed and steam-distilled extraction methods. Chromogranin A (CgA) and heart rate (HR) were used as stress indices in human experiments. Immobility time during the forced swim test was used as a stress index in mice experiments. We analyzed brain mechanisms by measuring the expression of neurotrophic factors, brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophin-3 (NT-3) in the mice experiments. Synthetic yuzu fragrance mimicked steam-distilled oil (SD) significantly reduced participants’ heart rate in experiment 1. In the forced swim test conducted in experiment 2, SD significantly reduced immobility time, and increased the expression of neurotrophic factors BDNF, NGF, and NT-3 in the hippocampus of mice. In experiment 3, focusing on single compounds, terpinen-4-ol significantly reduced immobility time in the forced swim test. These findings indicate that inhalation of SD and terpinen-4-ol has antistress effects. Terpinen-4-ol is a strong candidate for further investigation as a potential stress-reducing agent.

Abstract Green manure (GM) may reduce the use of chemical fertilizers, been an ecologically appropriate strategy to cultivation of medicinal plants. Crotalaria juncea, is one of the most used because it adapts to different climatic and high nitrogen content. Origanum vulgare. is widely used in cooking, pharmaceutical, cosmetic industries and food products. The objectives of this study were to evaluate the GM on biomass, essential oil (EO), phenolic and antioxidant. The experiment consisted: control; 150, 300, 450, and 600 g (Sh= leaves+steam) more 200 g roots (R); 600 g aerial part; 200 g roots; and soil with 300 g cattle manure per pot. The highest dry weights were observed in the presence of GM and cattle manure (90 days). The control had an EO production 75% lower in relation to the dose of 450 g GM (Sh+R). Principal component analysis showed that GM and cattle manure positively influenced the dry weight, content, yield, and EO constituents, and total flavonoids. The GM contributed to the accumulation of the major EO compounds (trans-sabinene hydrate, thymol, terpinen-4-ol). The GM management may be beneficial for cultivating, because it can increase the production of biomass and the active components, in addition to being an inexpensive resource.

Lung cancer is the second most commonly diagnosed cancer and has the highest mortality rate worldwide despite the remarkable advances in its treatment. Origanum majorana Essential Oil (OMEO) has been shown to be effective against non-small cell lung cancer (NSCLC) cells, decreasing their viability and colony growth in vitro, as well as inhibiting tumor growth in chick embryo chorioallantoic membranes (CAM) and nude mice in vivo. OMEO is mainly composed of four monoterpenes, namely terpinen-4-ol, sabinene hydrate, α-terpinene, and γ-terpinene. In this study, we aimed to investigate the potential anticancer effects of these monoterpenes, either alone or in combination, on NSCLC. Our findings indicate that these four monoterpenes significantly decreased NSCLC cell viability in a concentration-dependent manner, reduced their colony growth in vitro, and also downregulated survivin expression in these cells. Moreover, different combined mixtures of these monoterpenes further enhanced their anticancer effects on cellular viability, with a terpinen-4-ol and sabinene hydrate combination being the most potent. We also found that terpinen-4-ol, in combination with sabinene hydrate, markedly enhanced the anticancer effect of the individual monoterpenes on NSCLC viability within a shorter treatment duration through, at least in part, survivin downregulation. Furthermore, this combination enhanced the inhibition of colony growth in vitro and the tumor growth of NSCLC cells xenografted onto chick embryo CAM in vivo. Altogether, our study highlights the potential of these monoterpenes for use in further pre-clinical investigations against various cancer hallmarks. [ABSTRACT FROM AUTHOR]

Objective To investigate the synergistic bacteriostatic effect of terpinen-4-ol (T4O) and α-bisabolol (Bis) on Staphylococcus aureus (S.aureus) and Cutibacterium acnes (C.acnes). Methods The microdilution checkerboard technique was used to determine the minimum inhibitory concentration (MIC) of T4O combined with Bis on the two etu perimental bacteria, and fractional inhibitory concentration index (FICI) was calculated. An MIC group (T4O and Bis at a concentration of MIC), a 2×MIC group (T4O and Bis at a concentration of 2×MIC), and a negative control group (no T4O or Bis added) were set up for each experimental bacterium; the time-bactericidal curve was plotted for each experimental bacterium after the addition of both T4O and Bis; each group of the two experimental bacteria was measured in terms of Zeta potential (ZP) on the surface of the strain, leakage of intracellular nucleic acid and protein, damage of bacterial biofilm, and respiratory chain dehydrogenase activity in S.aureus after the addition of both T4O and Bis; a transmission electron microscope was used to observe the influence of T4O combined with Bis on the morphology of the two experimental bacteria. Results The combination of T4O and Bis for S.aureus and C.acnes had an FICI of

Terpinen-4-ol (T-4-O) is an important component of tea tree oil and has anti-inflammatory effects. Currently, there are very few studies on the mechanisms by which T-4-O improves lipopolysaccharide (LPS)-induced macrophage inflammation. In this study, LPS-stimulated mouse RAW264.7 macrophages were used as a model to analyze the effects of T-4-O on macrophage inflammatory factors and related metabolic pathways in an inflammatory environment. The results showed that T-4-O significantly decreased the expression levels of inflammatory cytokines induced by LPS. Cellular metabolism results showed that T-4-O significantly decreased the ratio of the extracellular acidification rate and oxygen consumption rate. Non-targeted metabolomics results showed that T-4-O mainly affected glutamine and glutamate metabolism and glycine, serine, and threonine metabolic pathways. qPCR results showed that T-4-O increased the transcript levels of GLS and GDH and promoted glutamine catabolism. Western blotting results showed that T-4-O inhibited the mTOR and IκB, thereby decreasing NF-κB activity. The overall results showed that T-4-O inhibited mTOR phosphorylation to promote glutamine metabolism and increased cell oxidative phosphorylation levels, thereby inhibiting the expression of LPS-induced inflammatory cytokines.

Terpenes and their derivatives in essential oil have been raising an upstream interest due to their unwavering health-promoting effects and safety profiles, although the individual essential oil components are inadequately assessed for their biological potential. Terpinen-4-ol, a bioactive natural terpene-derivative unambiguously distributed in most essential oil sources, is displaying a very remarkable role as a phytometabolite. This review, therefore, deciphered the health-promoting effects of Terpinen-4-ol in oxidative stress-linked diseases including neurodegenerative disorders, cancers, cardiovascular diseases, diabetes, and inflammatory disorders. Using Google as a search engine, this systematic review unraveled 217 relevant articles out of 857 search results from Web of Science, PubMed, and ScienceDirect. Terpinen-4-ol is reported to increase superoxide dismutase, decrease glutathione-S-transferase and acetylcholine esterase, inhibit NF-κB and NLRP3 inflammasome activation pathway, downregulate the α-amylase activity and increase insulin sensitivity, and substantially inhibit the generation of inflammatory mediators such as IL-1β, IL-6, IL-10. Despite several beneficial actions of Terpinen-4-ol, it has hardly been expedited to use as pharmaceutical therapeutic target for unveiled biological activities. In that context, this review has focused on the role of Terpinen-4-ol in attenuating oxidative stress and stress-linked pathophysiological conditions unraveling a research gap on it to manifest its best pharmaceutical and therapeutic uses.

Context: Tea tree oil (TTO) is an essential oil derived from Melaleuca alternifolia, with high antimicrobial and antifungal potential. Unfortunately, its topical antifungal efficacy is limited because it is volatile, thermolabile and easily oxidized. A formulation has been developed to overcome this problem by encapsulating TTO in a nanostructured lipid carrier (NLC). Aims: To determine the effect of the liquid to solid lipid ratio on the physicochemical properties and the stability of TTO-loaded NLC. Methods: Five formula of TTO-loaded NLCs were produced by high shear homogenization method and characterized according to their particle size, size distribution, polydispersity, zeta potential, thermal characteristics, X-ray diffraction, and terpinen-4-ol concentration. In addition, a stability study was conducted by observing its physical and chemical characteristics during storage in the refrigerator (4 ± 2°C) and at room temperature (27 ± 2°C) for six months. Results: The resulting TTO-loaded NLC had an average droplet size under 400 nm. The particle size increases with increasing amount of liquid lipid in the formula. There were insignificant changes in organoleptic properties, polydispersity index, zeta potential and terpinene-4-ol concentration during stability study for six months. However, the particle size slightly increased during the six months of storage. Furthermore, the NLC 3, which formulated with a 25:95 ratio liquid to solid lipid, was be chosen as the best formula, since it demonstrated the best physicochemical characteristic and stability. Conclusions: TTO-loaded NLC with good physicochemical characteristics and stability has been successfully developed. In addition, NLC 3 is considered as the best NLC formula, which exhibits characteristics and stability that meet the requirements.

Azorean Cryptomeria japonica is widely used for local wood production, generating large amounts of aerial-part biomass residues that can be a sustainable source of value-added bioproducts. This comparative study aimed (i) to determine the yield and chemical profile of the essential oils (EOs) extracted by hydrodistillation from Azorean C. japonica foliage, leaves, male cones (MCs), and female cones (FCs), and (ii) to investigate the antimicrobial and brine shrimp lethality (BSL) effects of the obtained EOs and some major components. The EOs yield revealed a wide range (ca. 1–3%, w/d.w.) and their chemical composition, analysed by GC–MS and GC–FID, showed the presence of seventy-one components. Monoterpene hydrocarbons (38–71%) dominated in all the studied EOs, mainly α-pinene (17–45% of total EOs), decreasing as follows: cone EOs > leaf EOs > foliage EOs. Oxygen-containing monoterpenes (mainly terpinen-4-ol) also dominated in cone EOs. Contrariwise, oxygen-containing sesquiterpenes (mainly elemol) and diterpene hydrocarbons (mainly phyllocladene) dominated in foliage/leaf EOs. The studied EOs exhibited activity against Gram-positive bacteria but no activity against Gram-negative bacteria. A similar trend was displayed by α-pinene. Only the cone EOs showed antifungal activity against Penicillium chrysogenum, but this was significantly lower than those of α-pinene and terpinen-4-ol. Moreover, FC EO should also be considered for further investigation due to its high toxicity on BSL bioassay. In conclusion, this study demonstrated the variability of yield, chemical profile, and bioactivities in the EOs from different parts of the Azorean C. japonica, expanding the knowledge of the potentialities of C. japonica aerial-part EOs, particularly the ones from the cone samples. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Zhejiang University: Science B is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

According to previous research, turmeric seeds exhibit anti-inflammatory, anti-malignancy, and anti-aging properties due to an abundance of terpinen-4-ol (T4O). Although it is still unclear how T4O works on glioma cells, limited data exist regarding its specific effects. In order to determine whether or not glioma cell lines U251, U87, and LN229 are viable, CCK8 was used as an assay and a colony formation assay was performed using different concentrations of T4O (0, 1, 2, and 4 μM). The effect of T4O on the proliferation of glioma cell line U251 was detected through the subcutaneous implantation of the tumor model. Through high-throughput sequencing, a bioinformatic analysis, and real-time quantitative polymerase chain reactions, we identified the key signaling pathways and targets of T4O. Finally, for the measurement of the cellular ferroptosis levels, we examined the relationship between T4O, ferroptosis, and JUN and the malignant biological properties of glioma cells. T4O significantly inhibited glioma cell growth and colony formation and induced ferroptosis in the glioma cells. T4O inhibited the subcutaneous tumor proliferation of the glioma cells in vivo. T4O suppressed JUN transcription and significantly reduced its expression in the glioma cells. The T4O treatment inhibited GPX4 transcription through JUN. The overexpression of JUN suppressed ferroptosis in the cells rescued through T4O treatment. Taken together, our data suggest that the natural product T4O exerts its anti-cancer effects by inducing JUN/GPX4-dependent ferroptosis and inhibiting cell proliferation, and T4O will hope-fully serve as a prospective compound for glioma treatment. [ABSTRACT FROM AUTHOR]

Highlights The chemical composition of M. alternifolia EO was identified by GC–MS. The EO of M. alternifolia and its components, terpinen-4-ol and γ-terpinene, had potent bioactivity against S. littoralis. M. alternifolia EO and their components, terpinen-4-ol and γ-terpinene have great potential as a biopesticide in integrated pest management programs.

The antimicrobial properties of essential oil from Lavandula sp. raise hopes related to its use in phytotherapy. This study aimed to evaluate the antimicrobial activity of essential oils from cultivars of L. angustifolia ('Hidcote Blue Strain', 'Hidcote Blue') and L. × intermedia ('Phenomenal', 'Grosso') grown in central-eastern Poland, that is, at the border of the northern lavender cultivation range. The chemical composition of the essential oils was determined by GC/MS. Essential oil concentrations (20, 10, 5, 2.5, 1.25, 0.6, 0.3, 0.16, 0.08, and 0.04 mg/mL) were tested to determine the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) towards ten strains of Gram-positive bacteria, five Gram-negative bacteria, and eight yeasts in vitro culture. Essential oils from the Lavendula cultivars showed antimicrobial activity against all microorganisms analysed. The yeasts were characterised by higher sensitivity to lavender oil compared to bacteria, while Gram-positive bacteria were more sensitive than Gram-negative bacteria. The lowest MIC values for bacteria and fungi were obtained for 'Grosso'. Furthermore, the 'Grosso' oil showed the highest fungicidal activity, while the highest bactericidal activity was found in 'Hidcote Blue' and 'Grosso'. Using Staphylococcus aureus as an example, it was shown that different bacterial strains of the same species show varying sensitivity to the essential oil. A higher oil content was noted for the cultivars L. × intermedia, especially for the 'Phenomenal'. Linalyl acetate and linalool were the main components of the essential oil in all cultivars. However, in the 'Grosso' oil, a high content of terpinen-4-ol (18.08%) was also recorded. An analysis of the relationships between the content of the main components in the analysed essential oils and the antimicrobial activity of essential oils suggested that linalool and terpinen-4-ol were compounds potentially responsible for antimicrobial activity. The obtained results allow us to conclude that essential oil with significant antimicrobial activity can be obtained from Lavandula sp. plants harvested in the northern part of the cultivation range. [ABSTRACT FROM AUTHOR]

Origanum majorana is a medicinal and aromatic plant that belongs to the Lamiaceae family. It is cultivated in several parts of the world and, due to its splendid aroma and taste, is widely used for culinary purposes and in perfumes. The essential oil of the plant, to which is attributed its aroma, contains many secondary metabolites with valuable biological activity. One of them is the pesticide activity, which has attracted much interest. Given the necessity of replacing synthetic pesticides, essential oils are studied in an attempt to find naturally derived products. Thus, the aim of this review paper is to discuss the chemical profile of O. majorana essential oil and to present data regarding its insecticidal, repellent and fumigant activity. Data were collected from 1992 to 2022. Databases, including PubMed, Google Scholar, ScienceDirect and Scopus, were used for the research, and keywords, including O. majorana, sweet marjoram, essential oil, volatiles, pesticide, insecticide and repellent activity, were used. The results of this review paper indicate that O. majorana essential oil can be an alternative agent to manage pests. However, still, much research should be conducted to evaluate its toxicity against beneficial insects and to ensure its safety for human health. [ABSTRACT FROM AUTHOR]

Abstract In this paper, the chemical constituents, larvicidal and antimicrobial activities of hydrodistilled essential oils from Zingiber castaneum Škorničk. & Q.B. Nguyễn and Zingiber nitens M.F. Newman were reported. The main constituents of Z. castaneum leaf were bicyclogermacrene (24.8%), germacrene D (12.9%), cis-β-elemene (11.2%) and β-pinene (10.3%), while sabinene (22.9%) and camphene (21.2%) were the significant compounds in the rhizome. However, the dominant compounds in the leaf of Z. nitens includes β-pinene (45.8%) and α-pinene (10.7%). Terpinen-4-ol (77.9%) was the most abundant compound of the rhizome. Z. castaneum rhizome oil displayed larvicidal activity against Aedes aegypti and Culex quinquefasciatus with LC50 values of 121.43 and 88.86 µg/mL, respectively, at 24 h. The leaf oil exhibited activity with LC50 values of 39.30 µg/mL and 84.97 µg/mL, respectively. Also, the leaf and rhizome oils of Z. nitens displayed greater larvicidal action towards Ae. aegypti with LC50 values of 17.58 µg/mL and 29.60 µg/mL, respectively. Only the rhizome oil displayed toxicity against Cx. quinquefasciatus with LC50 value of 64.18 µg/mL. All the studied essential oils inhibited the growth of Pseudomonas aeruginosa ATCC25923 with minimum inhibitory concentration (MIC) value of 50.0 µg/mL. This paper provides information on the larvicidal and antimicrobial potentials of Z. castaneum and Z. nitens essential oils.

Antimicrobial resistance is a major public health issue raising growing concern in the face of dwindling response options. It is therefore urgent to find new anti-infective molecules enabling us to fight effectively against ever more numerous bacterial infections caused by ever more antibiotic-resistant bacteria. In this quest for new antibacterials, essential oils (or compounds extracted from essential oils) appear to be a promising therapeutic option. In the present work, we investigate the potential antibacterial synergy between a combination of terpinen-4-ol and α-terpineol (10:1) compared to standard tea tree oil. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. Then, time kill assays, in vitro cytotoxicity and bactericidal activity on latent bacteria (persisters) were investigated. Finally, an in silico study of the pharmacokinetic parameters of α-terpineol was also performed. Altogether, our data demonstrate that the combination of terpinen-4-ol and α-terpineol might be a precious weapon to address ESKAPE pathogens. [ABSTRACT FROM AUTHOR]

Abstract Background This study investigated the effects of terpinen-4-ol on methicillin-resistant Staphylococcus aureus (MRSA) and its biofilm, and the possible mechanisms governing this effect. Results We observed that terpinen-4-ol has good antibacterial activity and inhibits the formation of MRSA biofilm. The MIC and MBC values for terpinen-4-ol against S. aureus were 0.08% ~ 0.32%. And terpinen-4-ol at 0.32% could kill all bacteria and clear all biofilms. Untargeted metabolomic and transcriptomic analyses showed that terpinen-4-ol strongly inhibited DNA and RNA biosynthesis in MRSA at 2 h after treatment by affecting genes and metabolites related to purine and pyrimidine metabolic pathways. Some differential genes which play important roles in DNA synthesis and the production of eDNA from biofilm exposed to terpinen-4-ol was also significantly decreased compared with that of the control. Conclusions Terpinen-4-ol has good antibacterial activity and significantly inhibits the formation of MRSA biofilm by inhibiting purine and pyrimidine metabolism.

Legionella pneumophila (Lp), responsible for a severe pneumonia called Legionnaires' disease, represents an important health burden in Europe. Prevention and control of Lp contamination in warm water systems is still a great challenge often due to the failure in disinfection procedures. The aim of this study was to evaluate the in vitro activity of Terpinen-4-ol (T-4-ol) as potential agent for Lp control, in comparison with the essential oil of Melaleuca alternifolia (tea tree) (TTO. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of T-4-ol were determined by broth micro-dilution and a micro-atmosphere diffusion method to investigate the anti-Lp effects of T-4-ol and TTO vapors. Scanning Electron Microscopy (SEM) was adopted to highlight the morphological changes and Lp damage following T-4-ol and TTO treatments. The greatest antimicrobial activity against Lp was shown by T-4-ol with a MIC range of 0.06–0.125% v/v and MBC range of 0.25–0.5% v/v. The TTO and T-4-ol MIC and MBC decreased with increasing temperature (36 °C to 45 ± 1 °C), and temperature also significantly influenced the efficacy of TTO and T-4-ol vapors. The time-killing assay showed an exponential trend of T-4-ol bactericidal activity at 0.5% v/v against Lp. SEM observations revealed a concentration- and temperature- dependent effect of T-4-ol and TTO on cell surface morphology with alterations. These findings suggest that T-4-ol is active against Lp and further studies may address the potential effectiveness of T-4-ol for control of water systems. [ABSTRACT FROM AUTHOR]

Background: Spodoptera littoralis is mostly controlled by the use of synthetic insecticides. Nonetheless, the use of these insecticides causes a slew of issues. On this pest, the antifeedant activity of Melaleuca alternifolia essential oil (EO) and its two principal components was investigated. Results: The gas chromatography–mass spectrometry (GC/MS) analysis revealed that the M. alternifolia EO was composed of eleven compounds. Terpinen-4-ol (40.1%) and γ-terpinene (21.9%) were chosen as the major constituents. In terms of antifeedant efficacy, treatment with M. alternifolia EO and these components reduced leaf consumption and the efficiency of food conversion in larvae in a concentration-dependent manner. When compared to untreated larvae, weight, growth, and pupation percentage were all significantly lower. Conclusions: The findings show that M. alternifolia EO and its components, terpinen-4-ol and γ-terpinene can be effectively combined for cotton leafworm management. Highlights: The chemical composition of M. alternifolia EO was identified by GC–MS. The EO of M. alternifolia and its components, terpinen-4-ol and γ-terpinene, had potent bioactivity against S. littoralis. M. alternifolia EO and their components, terpinen-4-ol and γ-terpinene have great potential as a biopesticide in integrated pest management programs. [ABSTRACT FROM AUTHOR]

Simple Summary: Long noncoding RNAs (lncRNAs) are important regulatory factors in multiple biological processes, including genomic imprinting, cancer, RNA interference, and protein translation. Several lncRNAs can respond to insecticides. However, lncRNA functions associated with terpinen-4-ol resistance in the red flour beetle (Tribolium castaneum) have not yet been identified. In previous work, we found terpinen-4-ol to have strong fumigation activity against store-product pests. As a pesticide from plants, terpinen-4-ol shows nearly no residual danger to the environment; however, resistance is inevitable if people use terpinen-4-ol immoderately. To avoid resistance to terpinen-4-ol occurring in the red flour beetle, we deeply sequenced and tried to find some lncRNAs that can regulate target mRNA expression to reduce terpinen-4-ol. Long noncoding RNAs (lncRNAs) are important regulatory factors in multiple biological processes, and several lncRNAs are known to respond to insecticides. However, the lncRNA functions that are associated with terpinen-4-ol resistance in the red flour beetle (Tribolium castaneum) have not yet been identified. In this study, we determined the differentially transcribed lncRNAs between fumigated and control experimental groups. In the six libraries that underwent RNA sequencing, 34,546 transcripts were identified, including 8267 novel lncRNAs, 4155 novel mRNAs, 1151 known lncRNAs, and 20,973 known mRNAs. Among these, we found that the expression of 1858 mRNAs and 1663 lncRNAs was significantly different in the fumigated group compared with the control group. Among the differentially transcribed lncRNAs, 453 were up-regulated and 1210 were down-regulated lncRNAs. In addition, we identified the regulatory function targets of the lncRNAs. Functionally, all lncRNAs and target genes associated with terpinen-4-ol metabolism were enriched in several metabolic pathways, like the ATP-binding cassette transporter, pentose interconversion, and glucuronate interconversion. To the best of our knowledge, this study represents the first global identification of lncRNAs and their potential association with terpinen-4-ol metabolism in the red flour beetle. These results will provide reference information for studies on the resistance to terpinen-4-ol and other essential oil compounds and chemical pesticides, as well as an understanding of other biological processes in T. castaneum. [ABSTRACT FROM AUTHOR]

Numerous plant-based repellents are widely used for personal protection against host-seeking mosquitoes. Vitiveria zizanioides (L.) Nash essential oil and its constituents have demonstrated various mosquito repellent activities. In this study, three chemical actions of vetiver oil and five constituents (terpinen-4-ol, α-terpineol, valencene, vetiverol and vetivone) were characterized against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus by using the high-throughput screening assay system (HITSS). Significant contact escape responses in Ae. aegypti and Ae. albopictus to all test compounds at concentrations between 2.5 and 5% were observed. Spatial repellency responses were also observed in some tested mosquito populations depending upon concentrations. The most significant toxic response on mosquitoes was found at the highest concentration, except for vetivone which had no toxic effect on Ae. aegypti and Ae. albopictus. Results on phototoxic and genotoxic hazard revealed that vetiver oil and their constituents showed no phototoxic potential or any significant genotoxic response. In conclusion, vetiver oil and two constituents, valencene and vetiverol, are potentials as active ingredients for mosquito repellency and present no toxicity.

Purpose: To report a successful treatment of chronic rosacea associated ocular demodicosis with lid scrub containing terpinen-4-ol (T4O). Observations: A 72-year old woman presented with recurrent and refractory ocular erythema, irritation, dryness, and photophobia despite conventional medical treatment (artificial tears, hypochlorous acid lid hygiene, doxycycline, and erythromycin) for 5 years. Examination revealed facial erythema, telangiectasias on cheeks, nose and lids, and cylindrical dandruff (CD) on bilateral upper and lower lashes. Epilation sampling confirmed demodicosis. After treatment with lid wipe containing T4O (Cliradex, Biotissue, Miami, FL) over face and lids, ocular discomfort, CD, facial and eyelid erythema, telangiectatic vessels were significantly reduced. Complete eradication of demodex mites and resolution of symptoms and signs lasted 8 months of follow-up. Conclusions: This case suggests that T4O is effective in treating chronic rosacea associated ocular demodex blepharitis.

Background: This study investigated the effects of terpinen-4-ol on methicillin-resistant Staphylococcus aureus (MRSA) and its biofilm, and the possible mechanisms governing this effect. Results: We observed that terpinen-4-ol has good antibacterial activity and inhibits the formation of MRSA biofilm. The MIC and MBC values for terpinen-4-ol against S. aureus were 0.08% ~ 0.32%. And terpinen-4-ol at 0.32% could kill all bacteria and clear all biofilms. Untargeted metabolomic and transcriptomic analyses showed that terpinen-4-ol strongly inhibited DNA and RNA biosynthesis in MRSA at 2 h after treatment by affecting genes and metabolites related to purine and pyrimidine metabolic pathways. Some differential genes which play important roles in DNA synthesis and the production of eDNA from biofilm exposed to terpinen-4-ol was also significantly decreased compared with that of the control. Conclusions: Terpinen-4-ol has good antibacterial activity and significantly inhibits the formation of MRSA biofilm by inhibiting purine and pyrimidine metabolism. [ABSTRACT FROM AUTHOR]

Riadh Messaoud,1 Lamia El Fekih,2,3 Anis Mahmoud,1 Hager Ben Amor,4 Radhouane Bannour,5 Serge Doan,6,7 Moncef Khairallah41Department of Ophthalmology, Tahar Sfar University Hospital, Mahdia, Tunisia; 2Department of Ophthalmology, Internal Security Forces Hospital, La Marsa, Tunisia; 3Faculty of Medicine, Tunis-El Manar University, Tunis, Tunisia; 4Fattouma Bourguiba University Hospital, Monastir, Tunisia; 5Ophthalmology Private Practice, Monastir, Tunisia; 6Department of Ophthalmology, Bichat Hospital, Paris, France; 7Fondation A de Rothschild, Paris, FrancePurpose: To evaluate the clinical improvement in ocular symptoms and signs in patients suffering from Demodex anterior blepharitis after using a novel cleansing wipe impregnated with 2.5% terpinen-4-ol and 0.2% hyaluronic acid.Study design: This was an exploratory, multicenter, open, randomized, two-parallel group comparative study.Methods: Forty-eight patients with Demodex anterior blepharitis were randomly assigned to apply the sterile wipe T1172 (Blephademodex®), either once daily (n=24, Group 1) or twice daily (n=24, Group 2) for 29 days. Overall ocular discomfort and other individual symptoms were measured using a 0–10 numeric rating scale at Day 8 and Day 29. Ocular signs, including eyelid margin hyperemia and number of cylindrical dandruff, were examined at slit lamp. Overall treatment performance by investigator, patient satisfaction and tolerance were evaluated with questionnaires.Results: Overall ocular discomfort was significantly reduced from baseline (p

Abstract Origanum vulgare L. (Lamiaceae) is a widespread flavoring culinary and medicinal herb. The present study aimed at investigating the antimicrobial activity of Origanum vulgare (OV) essential oil (EO) through illustrating its biostatic, biocidal and the dynamics of the biocidal activity against 11 different microorganisms. GC/MS of OV EO allowed the identification of 32 compounds representing 99.94% of the oil. The two major identified compounds were terpinen-4-ol (38.35%) and trans-sabinene hydrate (10.06%). Different methods were employed to illustrate the biostatic activity of OV EO. Results of the biostatic studies on OV EO using agar and broth dilution methods showed that Staphylococcus aureus (S. aureus) was the most sensitive organism; with a Minimum inhibitor concentration (MIC) 1.18 mg/ml. Agar diffusion method showed that the highest activity was observed against Bordetella bronchiseptica (Br. bronchiseptica), Saccharomyces cerevisiae (S. cerevisiae), Bacillus subtilis (B. subtilus) and Staphylococcus epidermidis (S. epidermidis) with inhibition zones 38 ± 1.5, 29.5 ± 0.8, 26.9 ± 0.9 and 26.9 ± 1.1 mm, respectively. Studying the dynamics of 1% v/v OV essential oil emulsion over a period of 6 h revealed that Escherichia coli (E. coli), B. subtilis, S. epidermidis and S. cerevisiae had the fastest response. Also increasing concentrations of OV oil emulsion increased the rate of cell killing and the duration of growth lag phase increased correspondingly. These data indicated that OV EO produces a concentration and time-dependent antimicrobial activity.

Legionella pneumophila (Lp), responsible for a severe pneumonia called Legionnaires’ disease, represents an important health burden in Europe. Prevention and control of Lp contamination in warm water systems is still a great challenge often due to the failure in disinfection procedures. The aim of this study was to evaluate the in vitro activity of Terpinen-4-ol (T-4-ol) as potential agent for Lp control, in comparison with the essential oil of Melaleuca alternifolia (tea tree) (TTO. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of T-4-ol were determined by broth micro-dilution and a micro-atmosphere diffusion method to investigate the anti-Lp effects of T-4-ol and TTO vapors. Scanning Electron Microscopy (SEM) was adopted to highlight the morphological changes and Lp damage following T-4-ol and TTO treatments. The greatest antimicrobial activity against Lp was shown by T-4-ol with a MIC range of 0.06–0.125% v/v and MBC range of 0.25–0.5% v/v. The TTO and T-4-ol MIC and MBC decreased with increasing temperature (36 °C to 45 ± 1 °C), and temperature also significantly influenced the efficacy of TTO and T-4-ol vapors. The time-killing assay showed an exponential trend of T-4-ol bactericidal activity at 0.5% v/v against Lp. SEM observations revealed a concentration- and temperature- dependent effect of T-4-ol and TTO on cell surface morphology with alterations. These findings suggest that T-4-ol is active against Lp and further studies may address the potential effectiveness of T-4-ol for control of water systems.

ABSTRACT The aim of this study was to evaluate the efficacy and safety of several anesthetics in the brachyuran crab Neohelice granulata, an emergent experimental model. The essential oils (EOs) of Lippia alba, Aloysia tryphilla, and Melaleuca alternifolia (tea tree oil; TTO), the isolated compounds eugenol, menthol, terpinen-4-ol, and the nanoencapsulated form of TTO, were administered in one or more of the following ways: added to the water (immersion), through an arthrodial membrane (injected), or by oral gavage. Unexpectedly, most EOs did not produce an anesthetic effect after immersion. Only TTO and eugenol induced anesthesia by immersion, with very long induction and recovery times compared to anesthesia of other crustaceans. However, a good anesthetic effect was observed with the injection of terpinen-4-ol and nanoencapsulated TTO in N. granulata; both demonstrated ideal induction and recovery times. These substances appear to be promising anesthetic alternatives for crustaceans.

Tea tree oil (TTO) and its two characteristic components (terpinen-4-ol and 1,8-cineole) have been shown to inhibit Botrytis cinerea growth. In this study, we conducted a transcriptome analysis to determine the effects of TTO and its characteristic components, alone and in combination, against B. cinerea. Most differentially expressed genes (DEGs) from B. cinerea cells treated with terpinen-4-ol participated in the biosynthesis of secondary metabolites, and the metabolism of amino acids, carbohydrates, and lipids. All treatments containing terpinen-4-ol potentially induced mitochondrial dysfunction and oxidative stress. These were further confirmed by the decreased activities of several enzymes (e.g., succinate dehydrogenase (SDH), malate dehydrogenase (MDH), α-ketoglutarate dehydrogenase (α-KGDH), isocitrate dehydrogenase (ICDH)), the increased activities of certain enzymes (e.g., catalase (CAT), peroxidase (POD), superoxide dismutase (SOD)), and increased content of hydrogen peroxide (H2O2). 1,8-Cineole mainly affected DEGs involved in genetic information processing, resulting in cell death. This study provides insight into the molecular mechanism of B. cinerea inhibition by TTO, and explains the synergistic effect of terpinen-4-ol and 1,8-cineole on B. cinerea. [ABSTRACT FROM AUTHOR]

CYP102A1 from Bacillus megaterium is an important enzyme in biotechnology, because engineered CYP102A1 enzymes can react with diverse substrates and produce human cytochrome P450-like metabolites. Therefore, CYP102A1 can be applied to drug metabolite production. Terpinen-4-ol is a cyclic monoterpene and the primary component of essential tea tree oil. Terpinen-4-ol was known for therapeutic effects, including antibacterial, antifungal, antiviral, and anti-inflammatory. Because terpenes are natural compounds, examining novel terpenes and investigating the therapeutic effects of terpenes represent responses to social demands for eco-friendly compounds. In this study, we investigated the catalytic activity of engineered CYP102A1 on terpinen-4-ol. Among CYP102A1 mutants tested here, the R47L/F81I/F87V/E143G/L188Q/N213S/E267V mutant showed the highest activity to terpinen-4-ol. Two major metabolites of terpinen-4-ol were generated by engineered CYP102A1. Characterization of major metabolites was confirmed by liquid chromatography-mass spectrometry (LC-MS), gas chromatography-MS, and nuclear magnetic resonance spectroscopy (NMR). Based on the LC-MS results, the difference in mass-to-charge ratio of an ion (m/z) between terpinen-4-ol and its major metabolites was 16. One major metabolite was defined as 1,4-dihydroxy- p -menth-2-ene by NMR. Given these results, we speculate that another major metabolite is also a mono-hydroxylated product. Taken together, we suggest that CYP102A1 can be applied to make novel terpene derivatives.

Purpose: Demodex folliculorum is a ubiquitous mite that can infest the eyelash follicles. Two commercial lid hygiene products have asserted their effectiveness in killing Demodex mites, yet there has never been a comparative trial between these two products. This study evaluated the demodicidal activity of 0.01% hypochlorous acid (HOCl) solution (Avenova; NovaBay Pharmaceuticals; Emeryville, CA) and 4% terpinen-4-ol (T4O) solution (Cliradex, Bio-Tissue; Miami, FL) in comparison to mineral oil (MO), a negative control. Methods: Live Demodex mites were obtained from volunteers. Samples were immersed in 1–2 drops of test solution: 0.01% HOCl, 4% T4O, or 100% MO. Samples were observed under the microscope every 10 mins for up to 90 mins. Kill time was defined as the elapsed time between the addition of test solution and all cessation of movement of the body, legs, mouth and pedipalps for a minimum of 60 seconds. Results: T4O demonstrated a mean kill time of 40±0.0 mins. HOCl had a mean kill time of 87.86±4.23 mins, with 79% of samples surviving the full 90 mins. In the MO group, all samples survived through the 90 min mark. Kill time was statistically significant in favor of T4O as compared to HOCl (p=0.0005). There was no statistically significant difference in kill time between HOCl and MO (p=0.25). Conclusion: 4% T4O effectively killed all adult mite samples within 40 mins of exposure. In contrast, the demodicidal activity of 0.01% HOCl was minimal, and comparatively similar to 100% MO. [ABSTRACT FROM AUTHOR]

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) poses a major threat to fruit and vegetable production in the United States and throughout the world. New attractants and detection methods could improve control strategies for this invasive pest. In this study, we developed a method that combined thin-layer chromatography (TLC) of tea tree essential oil (TTO) (Melaleuca alternifolia) with short-range bioassays to isolate attractive kairomones for male C. capitata. After development, the TLC chromatogram indicated that TTO separated into five major spots, designated as zones 1 to 5. When the TLC plate was exposed to flies, zones 1 and 3 were strongly attractive to male C. capitata. To confirm activity, the developed TLC plate was cut into five zones which were then tested in short-range bioassays. Again, flies were observed to aggregate around zones 1 and 3, which corresponded with Rf values of 0.93 and 0.59. In addition, zones 1 to 5 were separated using preparative-TLC, and olfactory responses to volatile emissions from the five fractions were quantified by electroantennography (EAG). Highest amplitude EAG responses were recorded with fractions 1 and 3, further supporting the bioactivity of these samples. In conclusion, a TLC-based bioassay system can provide an effective, rapid screening protocol for initial isolation of insect kairomones from complex mixtures such as essential oils or plant extracts. Further analysis of TTO fractions 1 and 3 is needed to identify the specific constituents attractive to male C. capitata.

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Abstract Terpenes – the essential oil components - due to confirmed antimicrobial effect can be applied e.g. as ecological pesticides instead of synthetic and environmentally hazardous compounds. A practical use of these systems must be proceeded by the analysis of the properties and activity of a given mixture. In this paper the monolayers at the air/water solution interface were applied to verify the influence of eucalyptol/terpinen-4-ol mixtures on plant pathogen Botrytis cinerea model membrane. The experiments included the measurements of the surface pressure – area isotherms for model membranes on water and terpene solutions as well as terpenes penetration into lipid monolayers. In the studies done for particular terpenes stronger ability of terpinen-4-ol over eucalyptol to incorporate into membrane, alter the membrane lateral elasticity and decrease its stability was found. Based on the results for the mixtures composed of terpenes in various concentrations it was found that not only the concentration of the system but also its composition, namely the proportion of both terpenes, determines the influence on lipid system. Moreover, terpinen-4-ol, but not eucalyptol, even in low concentrations, was of strong influence on membrane activity of total mixture. Additionally, it was suggested that terpinen-4-ol acts as penetration enhancer for eucalyptol into the model membrane system. Highlights • Eucalyptol and terpinen-4-ol change elasticity of model Botrytis cinerea membrane. • Both concentration and composition of terpene mixture define its properties. • Terpnene-4-ol enhances penetration of eucalyptol into model plant pathogen membrane. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the protective effects of Terpinen-4-ol (TER) on dextran sulfate sodium (DSS)-induced experimental colitis and clarify the possible mechanisms. In vivo, an acute colitis model was used to confirm the anti-inflammatory activity and the possible mechanisms of TER in C57BL/6 and NLRP3−/− mice. In vitro, we performed further study, using RAW264.7 cells and Caco-2 cells, to confirm the molecular mechanisms of TER on inflammatory response. In C57BL/6 mice, TER alleviated DSS-induced disease activity index (DAI), colon length shortening, colonic pathological damage, and myeloperoxidase (MPO) activities. The production of pro-inflammatory mediators was significantly decreased by TER. Furthermore, TER inhibited NF-κB and NLRP3 inflammasome activation. Surprisingly, TER reduced the plasmatic lipopolysaccharide (LPS) concentration and re-balanced Escherichia coli (E. coli) and Lactobacillus levels. In addition, TER prevented the impairment of colon epithelium barrier by regulating the expression of zonula occludens-1 and occludin. In vitro, the results showed that TER significantly suppressed NLRP3 inflammasome activation in LPS-stimulated RAW264.7 cells, as indicated by decreased expression of NLRP3 and caspase-1, and lowered interleukin-1β secretion. In contrast, mice deficient for NLRP3 were less sensitive to DSS-induced acute colitis, and TER treatment exerted little protective effect on DSS-induced intestinal inflammation in NLRP3−/− mice. The protective effect of TER may be largely attributed to its inhibition of NLRP3 inflammasome activation in colon. Taken together, our findings showed that TER might be a potential agent for the treatment of ulcerative colitis.

Biodegradable nanoparticles (NPs) have received considerable attention because of their possible use in the development of strategies for the topical delivery of oils and therapeutic drugs, particularly when drug penetration in dermis is desired. Zein is a prolamine and is a promising material for the design of drug delivery systems. In this study, NPs were prepared with zein and were used to encapsulate and release terpinen-4-ol, which is a therapeutic agent for the treatment of melanoma. The results show that the zein NPs are promising nanostructured systems for the prolonged delivery of T4OL with potential applications in anti-melanoma therapy.

The growing interest towards essential oils stems from their biological capabilities that include antibacterial and antioxidant effects. Such properties may be extremely useful in the reproductive field; nonetheless essential oils show toxic effects that can lead to cell disruption. The present study aimed to evaluate and compare the effects of tea tree oil (TTO) and its principal component terpinen-4-ol (TER) on the morpho-functional parameters of swine spermatozoa. Experimental samples were prepared by suspending 15 × 107 spermatozoa in 5 mL of medium with different concentrations of the above-mentioned compounds: from 0.2 to 2 mg/mL at an interval of 0.2 for TTO, while TER concentrations were adjusted according to its presence in TTO (41.5%). After 3 h incubation at 16 °C, samples were analyzed for pH, viability, acrosome status, and objective motility. The results highlighted a concentration-dependent effect of TTO with total motility as the most sensitive parameter. TER was better tolerated, and the most sensitive parameters were related to membrane integrity, suggesting a different pattern of interaction. The study confirms the importance of evaluating the effects of natural compounds on spermatozoa before exploiting their beneficial effects. Spermatozoa seem to be good candidates for preliminary toxicological screenings in the light of their peculiar properties.

Cassumunar ginger (Zingiber montanum (Koenig) Link ex Dietr.) is a native Thai herb with a high content and large variety of terpenoids in its essential oil. Improving the essential oil content and quality of cassumunar ginger is difficult for a breeder due to its clonally propagated nature. In this research, we describe the isolation and expression level of the monoterpene synthase gene that controls the key step of essential oil synthesis in this plant and evaluate the mechanical wounding that may influence the transcription level of the monoterpene synthase gene. To isolate the gene, the selected clones from DNA derived from young leaves were sequenced and analyzed and the monoterpene synthase gene from cassumunar ginger (ZMM1) was identified. The ZMM1 CDS containing 1 773 bp (KF500399) is predicted to encode a protein of 590 amino acids. The deduced amino acid sequence is 40-74% identical with known sequences of other angiosperm monoterpene synthases belonging to the isoprenoid biosynthesis C1 superfamily. A transcript of ZMM1 was detected almost exclusively in the leaves and was related to leaf wounding. The results of this research offer insight into the control of monoterpene synthesis in this plant. This finding can be applied to breeding programs or crop management of cassumunar ginger for better yield and quality of essential oil.

Melaleuca (Melaleuca alternifolia) essential oil (MEO), commonly known as tea tree oil, is popularly used in skincare products. In the current study, we investigated the biological activity of a commercially available MEO (with terpinen-4-ol as the major active component) in pre-inflamed human dermal fibroblasts, which were designed to simulate chronic inflammation. We analyzed the levels of seventeen biomarkers that are important in inflammation and tissue remodeling. Additionally, we studied the effect of MEO on genome-wide gene expression. MEO showed a robust antiproliferative activity against the cells. It also increased the levels of monocyte chemoattractant protein 1, an inflammatory chemokine and several tissue remodeling molecules such as epidermal growth factor receptor, matrix metalloproteinase 1 and tissue inhibitor of metalloproteinase-1 and -2. It was also noted that MEO diversely modulated global gene expression. Furthermore, Ingenuity Pathway Analysis showed that MEO affects many important signaling pathways that are closely related to metabolism, which suggests its potential modulation of metabolism. The results provide an important evidence of the biological activity of MEO in human dermal fibroblasts. They also suggest that MEO plays useful roles in tissue remodeling and metabolism; however, further research is needed to explore the mechanisms underlying these actions. [ABSTRACT FROM AUTHOR]

In the present study, 42 pure monoterpenes and volatile aromatic compounds were tested to evaluate their toxicities against adults of granary weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae) at laboratory condition. For the insecticidal activity tests, 10 and 20 µL/Petri dish concentrations for liquid compounds and 10 and 20 µg/Petri dish concentrations for solid compounds were used. The results show that majority of tested compounds were found to be toxic against to the adults of S. granarius and they showed various degrees of toxicity with range of 6-100% mortality. Among the compounds tested, oxygenated monoterpenes, linalool, carvacrol, terpinen-4-ol, limonene oxide, carvone, dihydrocarvone, fenchone, menthone and aromatic volatiles, p-anis aldehyde, benzyl acetate, cinnamyl aldehyde in the current study displayed complete mortality on the pest adults after 24h of exposure. In general, oxygenated monoterpenes and aromatic compounds exhibited high toxicity as compared with monoterpene hydrocarbons. Among the monoterpenes hydrocarbons, the highest toxic effects were shown by γ-terpinene, limonene and β-pinene. Our results showed that linalool, carvacrol, terpinen-4-ol, limonene oxide, carvone, dihydrocarvone, fenchone, menthone, p-anisaldehyde, benzyl acetate and cinnamyl aldehyde were the most toxic compounds against the adults of the pest. Therefore, these compounds can be used as natural insecticides against the S. garanarius adults. [ABSTRACT FROM AUTHOR]