Methyl Eugenol Research Articles

Rapid Identification and Quantification of Adulteration in Methyl Eugenol using Raman Spectroscopy Coupled with Multivariate Data Analysis.

Identification of adulterants in commercial samples of methyl eugenol is necessary because it is a botanical insecticide, a tephritid male attractant lure that is used to attract and kill invasive pests such as oriental fruit flies and melon flies on crops. In this study, Raman spectroscopy was used to qualitatively and quantitatively assess commercial methyl eugenol along with adulterants. For this purpose, commercial methyl eugenol was adulterated with different concentrations of xylene. The Raman spectral features of methyl eugenol and xylene in liquid formulations were examined, and Raman peaks were identified as associated with the methyl eugenol and adulterant. Principal component analysis (PCA) and partial least-squares regression analysis (PLSR) have been used to qualitatively and quantitatively analyze the Raman spectral features. PCA was applied to differentiate Raman spectral data for various concentrations of methyl eugenol and xylene. Additionally, PLSR has been used to develop a predictive model to observe a quantitative relationship between various concentrations of adulterated methyl eugenol and their Raman spectral data sets. The root-mean-square errors of calibration and prediction were calculated using this model, and the results were found to be 1.90 and 3.86, respectively. The goodness of fit of the PLSR model is found to be 0.99. The proposed approach showed excellent potential for the rapid, quantitative detection of adulterants in methyl eugenol, and it may be applied to the analysis of a range of pesticide products.

Composition of Arthropods in Conventional and Surjan Systems in the Special Region of Yogyakarta

Arthropods are the most abundant phylum found in plant ecosystems. The surjan planting system is sustainable agroecosystem engineering. The surjan system is one of the local cultural wisdom for dealing with pest and plant disease problems. In contrast to conventional systems, the majority of cultivation processes apply a monoculture farming system with massive use of pesticides and fertilizers. The research aims to determine the composition of arthropods from the application of surjan and conventional systems. The research was conducted in the Special Region of Yogyakarta in August 2022. The tools and materials used consisted of an inverter microscope, yellow trap, pitfall trap, pheromone trap, 70% alcohol, Taxofone, insect needles, vials and methyl eugenol. Each type of trap was repeated four times and designed diagonally. The collected arthropods were then observed using an inverter microscope. The identification results of Bactrocera sp and Atherigona sp are the dominant species found in the Bantul and Kulonprogo districts. The composition of arthropods in conventional land (Bantul Regency) is greater than in the surjan system (Kulonprogo Regency) based on population natural enemies. In contrast to the status of natural enemies, the surjan system has more natural enemies than conventional systems.

Effect of natural attractant essential oil from Ocimum gratisimum from Timor Island against fruit flies

Ocimum gratisimum, well-adapted to arid regions in East Nusa Tenggara, has essential oil that attracts fruit flies, pest important affecting crops like mango and jackfruit. This study aims to assess the impact of O. gratisimum essential oil on the diversity of fruit flies on these plants. The essential oil, source from leaves of O. gratisimum, was obtained from the Bioscience Laboratory of the University Nusa Cendana, East Nusa Tenggara, Kupang, Indonesia. It was applied to mango and jackfruit plants in Baumata Village, Taebenu District, Kupang Regency, East Nusa Tenggara. For experiment, total of 0.2 µL of O. gratisimum essential oil was carefully placed on a cotton swab, which was subsequently positioned within traps constructed using 1.5-L mineral bottles. The results of this study indicated that the essential oil extracted from O. gratisimum leaves had the capacity to attract Bacrtocera umbrosa and Bactrocera dorsalis flies when applied on mango plants. In case of jackfruit plants, the traps successfully lured B. umbrosa, B. dorsalis, and Bactrocera musae. This attraction contains methyl eugenol in the oil derived from O. gratisimum.

A comparison of vertical and horizontal trap orientations for attracting male Bactrocera spp. as fruit fly pest

Fruit flies, such as Bactrocera spp., are significant agricultural pests focusing on crop yields in Indonesia. One way of environmentally friendly control is the application of attractants to the trap. This study aims to ascertain the trap model that efficiently captures Bactrocera spp. This survey was conducted in Malang’s Dau Subdistrict between December 2022 to February 2023. The traps used were modified Steiner traps, namely plastic bottle traps with vertical and horizontal models. Any traps were baited with 0.125 milliliters of methyl eugenol, which was dripped on cotton and suspended inside the trap. To determine the effective trap model for capturing fruit flies, the study randomly installed vertical (3 pieces) and horizontal (3 pieces) traps in each citrus orchard. The findings within the Friedman testing analysis suggested that the attraction of fruit flies to vertical and horizontal trap models had significant differences. Horizontal traps had 58% effectiveness compared to vertical traps. The types of fruit flies in the vertical model are Bactrocera dorsalis, B. carambolae, and B. umbrosa. Meanwhile, in the horizontal model, B. umbrosa was absent. Modifying this trap model increases the ability as a potential fruit fly trap and a fruit fly pest monitoring tool.

An Antenna-Enriched Chemosensory Protein Plays Important Roles in the Perception of Host Plant Volatiles in Bactrocera dorsalis (Diptera: Tephritidae).

Olfaction plays indispensable roles in insect behavior such as host location, foraging, oviposition, and avoiding predators. Chemosensory proteins (CSPs) can discriminate the hydrophobic odorants and transfer them to the odorant receptors. Presently, CSPs have been identified in many insect species. However, their presence and functions remain unknown in Bactrocera dorsalis, a destructive and invasive insect pest in the fruit and vegetable industry. Here, we annotated eight CSP genes in the genome of B. dorsalis. The results of quantitative real-time polymerase chain reaction (RT-qPCR) showed that BdorCSP3 was highly expressed in the antennae. Molecular docking and in vitro binding assays showed that BdorCSP3 had a good binding ability to host volatiles methyl eugenol (ME, male-specific attractant) and β-caryophyllene (potential female attractant). Subsequently, CRISPR/Cas9 was used to generate BdorCSP3-/- mutants. Electroantennograms (EAGs) and behavioral assays revealed that male mutants significantly reduced the preference for ME, while female mutants lost their oviposition preference to β-caryophyllene. Our data indicated that BdorCSP3 played important roles in the perception of ME and β-caryophyllene. The results not only expanded our knowledge of the olfaction perception mechanism of insect CSPs but also provided a potential molecular target for the control of B. dorsalis.

Response of male Bactrocera zonata (Diptera: Tephritidae) to methyl eugenol: can they be desensitized?

Abstract The response of male peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae), to the parapheromone methyl eugenol (ME) was studied using two different bioassays. A laboratory assay was used to assess the short-distance response of males to ME, and a semi-field study, conducted in large screen-cages, was used to assess the attraction of released males to ME-baited traps. The ME response was studied in relation to several physiological parameters. Our findings show that the response of males to ME increased with both age and sexual maturation. Larval diet also influenced adult response to ME. The frequency of attraction to ME among males that had been raised on artificial larval-rearing diets was higher than that observed among males that had been raised on fruit. In addition, we found that solutions of ME (<0.5 %) and sucrose (a phagostimulant) were toxic to adult males. In contrast, ME volatiles were not toxic and exposure to the volatiles significantly reduced the males’ post-exposure response to the attractant. This effect extended for at least 4 weeks. The possibility of being able to reduce the attractive response of irradiated B. zonata males to ME volatiles opens the opportunity of using ME-baits in the field as a method to reduce wild males by attracting them to baited devices, and concomitantly release sterile flies to induce “sterility” on female wild flies.

Essential oil was extraction from Cinnamomum camphor peel using microwave as an aid and study of their inhibitory effect on Pseudocercospora psidii fungi

To apply the natural ingredients of plants in the field of food preservation, the essential oil of Cinnamomum camphor peel was isolated by salt-out pretreatment and microwave-assisted hydrodistillation. Using the single-factor mixed response surface approach, the extraction yield was optimized. A total of 14.98 mL/kg DW (dry weight: DW) was the greatest essential oil yield recorded. By using GC–MS analysis, a total of 29 compounds were found in the essential oil, with methyl eugenol (12.66 %) and safrole (10.36 %) being the two predominant compounds. However, the essential oil had a clear inhibitory effect on Pseudocercospora psidii at a concentration of 10 mg/mL. In conclusion, Cinnamomum camphora pericarp essential oil is anticipated to be a green natural pesticide that significantly inhibits pathogenic bacteria in crops.

Complementary use of visual and olfactory cues to assess capture of Bactrocera dorsalis (Hendel): Implementation and field verification via an IoT-based automatic monitoring system.

This study examined the effect of combining visual and olfactory cues to attract oriental fruit flies (OFFs). Six different colored light-emitting diodes (LEDs) served as a visual attractant and methyl eugenol served as olfactory bait to lure male flies. An internet of things (IoT)-based pest monitoring system, consisting of sensor nodes, a gateway, and automatic counting traps, was deployed in the field to automatically collect environmental data and pest counts. The results of the calibrated experiments indicated that green, yellow, or red LEDs exhibited better performance in attracting flies than white, purple, or blue LEDs or no LEDs. With an accurate combination of visual and olfactory cues, the proposed IoT-based pest monitoring system may be an effective tool in agricultural pest management, given its advantages for efficiently capturing OFFs in a labor and time saving manner, providing accurate information regarding increases in pest populations, and enabling long-term, real-time data collection.

Application of ZnO NPs, SiO2 NPs and Date Pollen Extract as Partial Substitutes to Nitrogen, Phosphorus, and Potassium Fertilizers for Sweet Basil Production.

The reduction in mineral fertilizer usage is crucial to the production of medicinal and aromatic products for safety and health purposes. Presently, nanotechnology and the utilization of natural extracts have been extensively studied due to their significant contribution. Ocimum basilicum is commonly employed for various medicinal and aromatic applications. Therefore, randomized complete block design field experiments containing 10 treatments were conducted during the 2021 and 2022 seasons to investigate the effect of nanoparticles (NPs) of ZnO (1.5 and 2.0 g/L) and SiO2 (100 and 150 mg/L) and date palm pollen extract (DPPE) at 10 and 20 g/L either alone or in combination with the ¾ or ½ NPK recommended dose (RD). The NPK RD was served as a control treatment on basil plant production in each season. The effectiveness of ZnO NPs, SiO2 NPs, and DPPE for the decrease in NPK utilization was evaluated. Meanwhile, the most effective treatment for vegetative traits (except for plant height), essential oil %, and yield was ½ NPK RD + 20 g/L DPPE + 2.0 g/L ZnO NPs. Such a treatment increased the branch number/plant, main stem diameter, relevant chlorophyll content, fresh weight/plant, dry weight/plant, essential oil %, and essential oil yield/plant by 21.00 and 9.94%, 58.70 and 40.00%, 20.69 and 15.83%, 68.83 and 58.28%, 48.70 and 56.16%, 45.71 and 35.53%, and 113.22 and 110.32% over the control in the two seasons, respectively. For total phenol and antioxidant activity, the most effective treatments were the ¾ NPK +1.5 g/L ZnO NPs and ½ NPK +2.0 g/L ZnO NPs, respectively. Simultaneously, essential oil composition (with their compound numbers identified (11-29 for control and ¾ NPK RD + 1.5 g/L ZnO NPs)) and the percentage of total compounds, monoterpene hydrocarbons, sesquiterpene hydrocarbons, and oxygenated hydrocarbons were varied among the used applications. The major observed compounds (>8%) estragole, methyl eugenol, linalool, cineole, and caryophyllene were found in different treatments. Thus, the findings of this study indicate the favorable utilization of ZnO NPs, SiO2 NPs, and DPPE in reducing the application of NPK, which may present a novel strategy and beneficial approach.

Attractant potential of Enterobacter cloacae and its metabolites to Bactrocera dorsalis (Hendel).

Bactrocera dorsalis (Hendel) has a wide host range. It has been the most important quarantine pest in many countries or regions. Currently, chemical control and bait trapping are mainly used in the monitoring, prevention, and control of B. dorsalis. However, chemical control will cause pollution of the environment and drug resistance of insects. Methyl eugenol, the main attractant currently used, can only attract males of B. dorsalis. This study focused on the attractant function and active substances of one key intestinal bacterium, Enterobacter cloacae, which was isolated from B. dorsalis. First, the attraction of the E. cloacae autoclaved supernatant to male and female adults of 0, 6, and15days post-emergence was confirmed using a Y-type olfactometer. Subsequently, through metabolome sequencing and bioassays, L-prolinamide was identified and confirmed as the most effective attractant for B. dorsalis. Finally, the synergistic effect of L-prolinamide with the sex attractant ME was validated through field experiments. This study confirmed the attraction effect of E. cloacae on B. dorsalis and also proved the attraction effect of L-prolinamide, the metabolite of E. cloacae, on B. dorsalis. This laid a theoretical foundation for the development of a new attractant and safe, green, and efficient prevention and control technology of B. dorsalis.

Research Status of Botanical Insecticide in Indonesia and Its Commercial Constraints

This article aims to review the status of botanical insecticide and its commercialization constraints in Indonesia. The method used was by tracking botanical insecticide papers published from 1993 to 2019. The collected data consisted of the plant source of botanical insecticide; intensively studied insect pests; and the number of commercial botanical insecticides and their active ingredients. The results found that Annona muricata, Azadirachta indica, Nicotiana tabacum, Carica papaya, and Cymbopogon nardus were the most common plants used for botanical insecticide. The most studied insect pests were: Spodoptera litura, Crocidolomia pavonana, Plutella xylostella, Sitophilus oryzae, and Aedes aegypti. Methyl eugenol was the most common commercialized active ingredient followed by azadirachtin. Citronella and geraniol were used only as mixtures. The constraint of commercializing botanical insecticide was from the companies. They are not interested in developing botanical insecticides since the prospect is not certain and the registration fee is more expensive than that of synthetic ones.

The Role of Lipids in Enhancing the Koku Perception of Pork Sausage.

This study was investigated the effect of adding fat to pork sausage on taste and aroma persistence. Sensory evaluation indicated that increasing fat content intensified umami and saltiness perception, enhancing the mouthfulness and flavor persistence, leading to Koku enhancing effect. Gas chromatography/mass spectrometry (GC/MS) analysis identified aroma compounds such as β-pinene, 3-carene, D-limonene, octanal, nonanal, caryophyllene, and methyl eugenol, which were consistently present regardless of fat content. These aroma compounds were less likely to be released as the fat content increased. Furthermore, the release of these aroma compounds from the sausage with addition of fat was larger than that without addition of fat in the presence of saline, indicating that the added fat retained these aroma compounds and released them in the presence of saline. This suggests that sausages with added fat release more aroma compounds during consumption, resulting in a more intense flavor and flavor persistence of Koku perception. These seven compounds detected in pork sausage were found to be easily retained by cholesterol and lecithin, likely due to differences in their log P values (octanol/water partition coefficients), which were greater than 3.

Resposta de moscas-de-frutas-cítricas (Bactrocera spp.) à aplicação de óleo de citronela como repelente de pragas

Abstract: The fruit fly is one of the major citrus pests. The study aimed to evaluate the repellency of citronella oil against Bactrocera spp. in citrus. The two experiments were carried out in a farmer’s citrus orchard in Junrejo, East Java, Indonesia from August to December 2022. In the first experiment, a randomized block design with five treatments and four replications was employed in the field to evaluate the potential repellency of citronella against Bactrocera spp. The treatments consisted of various mixtures of citronella and methyl eugenol. In the second experiment, the effect of one and two applications of 2 mL /L of citronella per week and synthetic pesticide on the population of Bactrocera spp. were compared. The results showed that citronella had a repellent capacity against Bactrocera spp. The number of pests trapped in citronella traps was lower than those captured in Methyl Eugenol traps only. The effectiveness of citronella as repellent for ten days. The one spraying per week of citronella was more efficient and effective in controlling Bactrocera spp. than other treatments. The use of citronella as a repellent could be integrated with the existing technologies to form an environmentally friendly package of fruit fly control approach.

The Effects of Nine Compounds on Aldehyde-Oxidase-Related Genes in Bactrocera dorsalis (Hendel).

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) (B. dorsalis) is an important agricultural, major invasive, and quarantine pest that can cause significant damage to the economic value of the fruit and vegetable industry. Male bait is one of the most effective methods of surveying, monitoring, and controlling B. dorsalis. In our study, we constructed cDNA libraries using total RNA extracted independently from the antennae, mouthparts, and thoracic legs of male and female adults and the ovipositors of female adults and screened out four aldehyde-oxidase-related genes (AOX-related), C58800, C66700, C67485, and C67698. Molecular docking predictions showed that eight compounds, including 3,4-dimethoxycinnamyl alcohol, 3,4-dimethoxy-cinnamaldehyde, deet, ethyl N-acetyl-N-butyl-β-alaninate, n-butyl butyrate, n-butyl butyrate, ethyl butyrate, methyl eugenol, and ethyl acetate, could combine with proteins encoded by the four B. dorsalis AOX-related genes. Furthermore, QPCR was performed to confirm that four compounds, including 3,4-dimethoxy cinnamic aldehyde, butyl levulinic acid ethyl ester (mosquito repellent), butyl butyrate, and methyl eugenol, induced significant changes in the AOX-related genes of B. dorsalis. These results provide useful information and guidance for the batch screening of potentially useful compounds and the search for effective attractants of B. dorsalis.

Historical and contemporary development of novel chemotype varieties with high essential oil of lemongrass in India: A review

Lemongrasses found in India encompass Cymbopogon flexuosus, C. citratus, C. khasianus, and C. pendulus. This fragrant perennial grass belongs to the Poaceae family and is indigenous to India as well as other tropical and subtropical regions in Southeast Asia and Africa. Pinpointing its precise place of origin is challenging due to its extensive history of cultivation and utilization across various cultures. It is believed to have originated in the maritime Southeast Asian region, encompassing countries like India, Sri Lanka, Indonesia, and Malaysia. Lemongrass thrives in these regions and has played a significant role in their culinary and medicinal traditions for many generations. Among these, Cymbopogon citratus, a tropical lemongrass variety, is native to multiple Asian regions, particularly Southeast Asia and South Asia. It is widely cultivated and employed in a range of global cuisines and traditional healing practices. Lemongrass finds extensive applications in the herbal, medicinal, cosmetic, pharmaceutical, and fragrance industries. Lemongrass oil is known for its diverse biological properties, which encompass antibacterial, immunomodulatory, and antioxidant effects. Not too long ago, India ranked as one of the world' leading exporters of lemongrass essential oil. Several prominent lemongrass cultivars have emerged, including GRL-1 (geraniol-rich), Krishna, Cauveri, Pragati, Praman, T-1, CIM Shikhar, Chirharit, CKP-25, SD-68, CIMAP Suwarna, and Krishnapriya. Among these, CIMAP Suwarna, Krishna, and CIM Shikhar stand out as the most widely favoured varieties across India developed at the CSIR-CIMAP in Lucknow, India. Indian universities and research institutions have also played a pivotal role in the development of novel lemongrass cultivars. Examples include Jor Lab L-2, OD-19, SD-68 (C. flexuosus), RRL-16 (C. pendulus), and CKP-25. Notably, there's Jor Lab L-9, a distinctive strain of C. khasianus known for its high methyl eugenol content. Furthermore, the germplasm for Malabar lemongrass (C. khasianus) is notable for its abundant herbage and elevated elemicin content, reaching up to 70%. The CSIR-NEIST in Jorhat and the CSIR-CIMAP, Lucknow have contributed to the development of new high geraniol-rich lemongrass cultivars, such as "Jor Lab L-15" (C. khasianus), GRL-1, and CIM Atal (C. flexuosus), respectively. b: citral, elemicin, geraniol, methyl eugenol content, vitamin A, Cymbopogon, flexuosus, Cymbopogon pendulus, Cymbopogon khasianus, Cymbopogon citratus, Lemongrass varieties Citral, Cymbopogon citratus, Cymbopogon flexuosus, Cymbopogon khasianus, Cymbopogon pendulus, Elemicin, Geraniol, Lemongrass varieties, Methyl eugenol content, Vitamin A

The species composition, richness and diversity studies of fruit flies captured from the orchard of Nagpur mandarin

The present experiment was conducted to study the diversity of fruit flies in Nagpur mandarin orchard from different agro-ecological zones of Vidarbha region of Maharashtra, India. The fruit flies samples were collected from 18 places falling under 9 agro-ecological zone using methyl eugenol traps. Out of the total collected catches of fruit flies from each zones, Bactrocera dorsalis was found to be the most prominent species followed by Bactrocera zonata. The Z. cucurbitae and B. correcta which occupied third and fourth rank in species composition, respectively. The species viz., Zeugodacus duplicatus and Zeugodacus gavisus recorded very less abundance at all locations. Shannons index of diversity was maximum in Morshi followed by Katol. Simpson index was more at Tiwasa and Achalpur locations which indicated minimum diversity in the population of fruit flies. Higher diversity of fruit flies were recorded in Morshi and Katol followed by Amravati.

Development by design of experiment and validation of a HPLC-UV method for simultaneous quantification of 1-nitro-2-phenylethane and methyleugenol: Application to nail permeation/retention studies

Aniba canelilla (Kunth) Mez is an aromatic tree from Amazon region whose essential oil presents 1-nitro-2-phenylethane (NP) and methyleugenol (ME) as major compounds. Several properties are attributed to Aniba canelilla essential oil (ACEO), such as antifungal. Onychomycoses are fungal nail infections that require novel therapeutic alternatives, especially topical ones. However, to ensure the success of topical therapy, the active compound should be able to penetrate/permeate the nail plate, which is challenging due to the highly keratinized composition of this structure. Thus, the aims of this article were to develop, validate and apply a high-performance liquid chromatography method (HPLC-UV) to quantify NP and ME in porcine hoof extract (PHE) and receptor fluid (RF) during in vitro permeation/retention studies in nail model, for which porcine hoof membranes were used. For method development, two Designs of Experiment (DoE) were adopted: 23 Full Factorial and Box-Behnken. Retention times of 5.65 and 7.49 min were achieved for NP and ME, respectively. The method was full validated for NP and ME quantification in receptor fluid, in accordance with the recommended parameters by ICH Q2(R1) Guideline. In addition, the method was full validated for NP and ME quantification in porcine hoof extract, considering the parameters and criteria of ICH M10 Guideline. In vitro permeation/retention studies were carried out in nail model, and promising results were obtained. NP reached the receptor fluid in the order of 441.1 ± 92.1 µg/cm2 at 72 h. The amount of NP and ME retained into porcine hoof membrane was 1272.6 ± 225.7 µg/cm2 and 84.7 ± 20.4 µg/cm2, respectively, at 72 h. Our findings open perspective to develop topical formulations containing ACEO as active compound aiming the management of onychomycosis.

Quality and bioactive compound accumulation in two holy basil cultivars as affected by microwave-assisted hot air drying at an industrial scale

Holy basil (Ocimum Tenuiflorum L.) contains several bioactive compounds useful to the pharmaceutical and food industries. Microwave drying (MD) is a powerful technique for rapid drying of food or plant materials while preserving bioactive compounds during the process. However, little is known about the optimal combination of MD power with hot air drying (HAD) that can preserve the quality and yet only consume reasonable energy when drying holy basils. For that purpose, the effects of drying methods using MD combined with HAD at 45°C were examined to prevent losses in quality, antioxidant activities, and volatile flavor compounds in two holy basil cultivars (green and red cultivars). Holy basil leaves were dried at different MD powers of 200, 400, and 600 W combined with HAD and compared with a traditional tray drying (TD) at 45°C. Drying using MD at 600 W with HAD displayed significantly high levels of color retention, chlorophyll, and carotenoid content in both cultivars. The green cultivar showed a greater accumulation of total phenolic compounds (TPC), terpenoids, and DPPH free radical scavenging at 400 W with HAD. However, the red cultivar had the highest TPC, flavonoid, and terpenoid content at 600 W with HAD. The accumulation of major volatile organic compounds (VOCs) was also affected, and treatment at 600 W exhibited the highest methyl eugenol and β-caryophyllene content in both cultivars. The use of the highest power of MD (600 W) with HAD for leaf drying reduced the effective drying time and energy consumption among both cultivars. Taking into consideration the dried quality of antioxidant accumulation and energy consumed for drying, we recommend using MD at 400 or 600 W with HAD for the green cultivar and 600 W for the red.

Jiawei guomin decoction regulates the degranulation of mast cells in atopic dermatitis mice via the HIS/PAR-2 pathway

Ethnopharmacological relevanceGuomin decoction (GMD) is a traditional Chinese medicine commonly used in clinical practice. It has traditionally been used to treat all allergic diseases. Currently, Jiawei Guomin Decoction (JWGMD) is used to treat sensitive skin after initial therapy. Although it has a significant clinical therapeutic effect, the exact role of mast cell degranulation in treating atopic dermatitis (AD) is still unclear. Aim of the studyGMD and JWGMD can both treat allergic diseases, while JWGMD focuses on skin allergies. This study aims to explore the potential effect of JWGMD on the degranulation of mast cells in an AD mouse model induced by 2,4-dinitrofluorobenzene (DNFB) and investigate the effectiveness of JWGMD in alleviating disease progression to further provide specific therapeutic targets for treating AD. Materials and methodsThe scratching times and skin lesions of model mice induced by DNFB were observed, and skin tissues were collected for subsequent measurement. Histopathological changes in the back skin of mice were observed by haematoxylin eosin (H&E) staining, Toluidine blue staining was used to detect the degranulation of mouse skin mast cells, and the relationship between the expression of histamine (HIS), mast cell tryptase (MCT) and mast cell degranulation was analysed by enzyme-linked immunosorbent assay (ELISA). The expression of protease-activated receptor-2 (PAR-2), histamine 1 receptor (H1R), H2R, H4R and MCT proteins in AD mice was detected by Western blot (WB). Immunofluorescence assay (IFA) further confirmed the localization of PAR-2, H1R, H2R, H4R, and MCT proteins in the skin. Quantitative real-time PCR (qPCR) was used to determine PAR-2, H1R, H2R and H4R mRNA levels in skin lesions to further clarify the mechanism by which JWGMD amplifies mast cell degranulation in AD. In addition, a reliable ultrahigh-performance liquid chromatography-quadrupole electrostatic field orbitrap mass spectrometry (UPLC-QE-MS) nontargeted metabolomics analysis was performed to analyse the differences in metabolite abundance between GMD and JWGMD, and these results were used to identify the active components in JWGMD that may have antipruritic and anti-inflammatory properties and inhibit mast cell degranulation. ResultsAfter intermittent stimulation with DNFB, the skin lesions showed extensive desquamation, dryness, scabbing, skin thickening, and slight bleeding. Both treatments alleviated this phenomenon and reduced the number of scratches, with JWGMD being the most effective. JWGMD can significantly reduce inflammatory cell infiltration, oedema, and some capillary neogenesis in mice and reduce the degranulation of mast cells. The ELISA results showed that JWGMD can increase the levels of MCT and HIS proteins. The WB and IFA results demonstrated that JWGMD reduced the expression levels of PAR-2, H1R, H4R, and MCT proteins in skin lesions, with protein localization mainly in the epidermal layer, while H2R protein levels were increased and mainly localized in the dermis. In addition, JWGMD downregulates the mRNA expression of PAR-2, H1R, H2R, and H4R. Interestingly, through UPLC-QE-MS nontargeted metabolomic analysis, we detected the anti-inflammatory and antiallergy active substances in JWGMD, such as methyl eugenol, dictamnine and sinapine. ConclusionsJWGMD may alleviate itching through methyl syringol, dictamnine, sinapine and other substances, and its mechanism may be related to inhibiting the HIS/PAR-2 pathway in AD model mice and further regulating the self-amplification of mast cell degranulation. JWGMD is a potential drug for treating AD. Therefore, it deserves continuous attention and research.

Methyl eugenol aromatherapy: a delivery system facilitating the simultaneous application of male annihilation and sterile insect technique against the peach fruit fly.

The peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae) is an economically important polyphagous, quarantine pest endemic to South and South-East Asia. The male annihilation technique (MAT) and the sterile insect technique (SIT) are environmentally benign techniques used to suppress fruit fly populations on an area-wide basis. The MAT and SIT are typically used sequentially to avoid killing released sterile males; however, MAT and SIT potentially could be used simultaneously and thereby increase the overall efficiency of control programmes. Mating competitiveness of sterile males against wild counterparts is critical for the success of the SIT. Feeding on a semiochemical, methyl eugenol (ME) has been reported to enhance the male mating performance of many Bactrocera spp., including B. zonata, but its use in SIT operational programmes is limited owing to the absence of a viable delivery system. In the present study, we demonstrated that ME aromatherapy, a practical method for large-scale delivery of ME olfactorily, enhances the mating success of treated B. zonata males. ME aromatherapy application to 5-day-old immature males for a duration of 5 h resulted in increased mating success of males tested when sexually mature, compared to untreated males. The ME-aromatized males also exhibited reduced attraction to ME-lure. A practical delivery system for applying ME by aromatherapy to mass-reared males was developed. ME-aromatherapy enhanced male mating success and suppressed their subsequent attraction to ME, thus enabling the application of MAT and SIT at the same time. © 2023 Society of Chemical Industry.