Preparation of protein-stabilized Litsea cubeba essential oil nano-emulsion by ultrasonication: Bioactivity, stability, in vitro digestion, and safety evaluation.

Litsea cubeba essential oil (LCEO) has garnered widespread attention due to its robust biological activity. However, challenges such as high volatility, limited water solubility, and low bioavailability impede its application. Nano-emulsion encapsulation technology offers an effective solution to these issues. In this study, we prepared litsea cubeba essential oil nano-emulsion (LCEO-NE) for the first time using whey protein (WP) as the emulsifier through an ultrasonic-assisted method, achieving high efficiency with minimal energy consumption. Transmission electron microscopy and dynamic light scattering analyses revealed that the nanoparticles were uniformly spherical, with a particle size of 183.5 ± 1.19 nm and a zeta potential of -35.5 ± 0.95 mV. Stability studies revealed that LCEO-NE exhibited excellent thermal and salt stability, maintaining its integrity for up to four weeks when stored at 4 °C and 25 °C. In vitro digestion assays confirmed the digestibility of LCEO-NE. Furthermore, evaluation of the DPPH, ABTS, and antimicrobial activities revealed that LCEO-NE displayed superior bacteriostatic and antioxidant properties compared to LCEO. Scanning electron microscopy elucidated that its bacteriostatic effect involved the disruption of bacterial microstructure. Hemocompatibility and cytotoxicity assays demonstrated the safety of LCEO-NE within the effective concentration range. This research supports the utilization of nanoparticles for encapsulating LCEO, thereby enhancing its stability and bioactivity, and consequently expanding its applications in the food and pharmaceutical industries.

Inclusion Complexes of Litsea cubeba (Lour.) Pers Essential Oil into ß-Cyclodextrin: Preparation, Physicochemical Characterization, Cytotoxicity and Antifungal Activity.

The uses of natural compounds, such as essential oils (EOs), are limited due to their instability to light, oxygen and temperature, factors that affect their application. Therefore, improving stability becomes necessary. The objective of this study was to prepare inclusion complexes of Litsea cubeba essential oil (LCEO) with ß-cyclodextrin (ß-CD) using physical mixing (PM), kneading (KN) and co-precipitation (CP) methods and to evaluate the efficiency of the complexes and their physicochemical properties using ATR-FTIR, FT-Raman, DSC and TG. The study also assessed cytotoxicity against human colorectal and cervical cancer cells and antifungal activity against Aspergillus flavus and Fusarium verticillioides. The complexation efficiency results presented significant evidence of LCEO:ß-CD inclusion complex formation, with KN (83%) and CP (73%) being the best methods used in this study. All tested LCEO:ß-CD inclusion complexes exhibited toxicity to HT-29 cells. Although the cytotoxic effect was less pronounced in HeLa tumor cells, LCEO-KN was more active against Hela than non-tumor cells. LCEO-KN and LCEO-CP inclusion complexes were efficient against both toxigenic fungi, A. flavus and F. verticillioides. Therefore, the molecular inclusion of LCEO into ß-CD was successful, as well as the preliminary biological results, evidencing that the ß-CD inclusion process may be a viable alternative to facilitate and increase future applications of this EO as therapeutic medication, food additive and natural antifungal agent.

Fabrication and characterization of pullulan/tapioca starch-based antibacterial films incorporated with Litsea cubeba essential oil for meat preservation.

Active packaging is a novel technology that utilizes active materials to interact with products and the environment, improving food shelf life. The purpose of this work was to fabricate a multifunctional film using Litsea cubeba essential oil (LC-EO) (1 %, 3 %, 5 %, and 7 %) as the active ingredient and pullulan(P)/tapioca starch (TS) as the carrier material. Adding essential oil improves the films properties, such as barrier ability, anti-oxidant, and antibacterial activity. However, tensile strength (TS) and elongation at break (EAB) were slightly reduced from 28.94 MPa to 11.29 MPa and 15.36 % to 12.19 %. The developed PTS3% films showed the best performance in mechanical properties, especially EAB (14.26 %), WVP (3.26 %) and OP (3.13 %), respectively. The inhibitory zone diameters in the agar-well diffusion test were 18.59 mm for Staphylococcus aureus and 17.32 mm for Escherichia coli. Further study was conducted to compare the preservation effects of film with low-density polyethylene bag (LDPE) on chilled beef. Remarkably, PTS3% film decreased the bacterial population in beef meat while maintaining the pH, color, texture, and TBARS levels within an acceptable range for ten days of storage at 4 °C rather than in a low-density polyethylene bag. The outcomes indicated the potential of PTS3% films in food packaging applications.

Non-Volatile Component and Antioxidant Activity: A Comparative Analysis between Litsea cubeba Branches and Leaves.

Litsea cubeba, which is found widely distributed across the Asian region, functions as both an economic tree and a medicinal plant with a rich historical background. Previous investigations into its chemical composition and biological activity have predominantly centered on volatile components, leaving the study of non-volatile components relatively unexplored. In this study, we employed UPLC-HRMS technology to analyze the non-volatile components of L. cubeba branches and leaves, which successfully resulted in identifying 72 constituents. Comparative analysis between branches and leaves unveiled alkaloids, organic acids, and flavonoids as the major components. However, noteworthy differences in the distribution of these components between branches and leaves were observed, with only eight shared constituents, indicating substantial chemical variations in different parts of L. cubeba. Particularly, 24 compounds were identified for the first time from this plant. The assessment of antioxidant activity using four methods (ABTS, DPPH, FRAP, and CUPRAC) demonstrated remarkable antioxidant capabilities in both branches and leaves, with slightly higher efficacy observed in branches. This suggests that L. cubeba may act as a potential natural antioxidant with applications in health and therapeutic interventions. In conclusion, the chemical composition and antioxidant activity of L. cubeba provides a scientific foundation for its development and utilization in medicine and health products, offering promising avenues for the rational exploitation of L. cubeba resources in the future.

Effects of Litsea cubeba Essential Oil-Chitosan/Corn Starch Composite Films on the Quality and Shelf-Life of Strawberry (Fragaria × ananassa).

In this work, we have developed a composite chitosan film incorporating the Litsea cubeba essential oil (LCEO) and starch with good physical properties, and investigated the effect of coating strawberries with this composite film. The best formula of the LCEO/chitosan/corn starch/glycerol (LCEO/CH/CS/gly) composite films is 0.25% LCEO, 2.75% CH, 0.40% corn starch, and 0.75% glycerol. Coating strawberries with CH/CS/gly film or LCEO/CH/CS/gly films resulted in significantly lower respiration intensity and a slower decay rate, much slower decreases in the firmness, and reductions in the sugar and ascorbic acid content of the fruit during storage (p < 0.05). The coatings also led to a much slower accumulation of malondialdehyde and anthocyanins (p < 0.05). The LCEO/CH/CS/gly film was generally more effective than the CH/CS/gly film; however, the effect was more obvious in the later stages of storage. Thus, coating strawberries with CH/CS/gly film or LCEO/CH/CS/gly film can be a viable method for extending the shelf-life of the fruit.

N-alkylamides from Litsea cubeba (Lour.) Pers. with potential anti-inflammatory activity.

Six amides, including a new N-alkylamide (1), four known N-alkylamides (2-5) and one nicotinamide (6) were isolated from Litsea cubeba (Lour.) Pers., which is a pioneer herb traditionally utilized in medicine. Their structures were elucidated on the basis of 1D and 2D NMR experiments and by comparison of their spectroscopic and physical data with the literature values. Cubebamide (1) is a new cinnamoyltyraminealkylamide and possessed obvious anti-inflammatory activity against NO production with IC50 values of 18.45 µM. Further in-depth pharmacophore-based virtual screening and molecular docking were carried out to reveal the binding mode of the active compound inside the 5-LOX enzyme. The results indicate that L. cubeba, and the isolated amides might be useful in the development of lead compounds for the prevention of inflammatory diseases.

Antifungal activity and mechanism of Litsea cubeba (Lour.) Persoon essential oil against the waxberry spoilage fungi Penicillium oxalicum and its potential application.

Litsea cubeba essential oil (LCEO) is a broad-spectrum bacteriostatic substance produced from the fruit of the Litsea tree that has been used for the treatment of various diseases in China for thousands of years. Here, the antifungal activities of LCEO against 10 different fungi (Naganishia diffluens, Fusarium sacchari, Cladosporium tenuissimum, Fusarium proliferatum, Fusarium verticillioides, Fusarium subglutinans, Mucor racemosus, Penicillium oxalicum, Penicillium chrysogenum, and Aspergillus niger) that cause rot to waxberries were assessed. The chemical components of LCEO and its modes of action against P. oxalicum were investigated. Citral (32.62 %) was characterized as the main component of LCEO by gas chromatography-mass spectrometry. LCEO exhibited excellent antifungal activities against all 10 fungi. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration of LCEO against P. oxalicum were 2.24 and 4.48 g/L, respectively. Furthermore, LCEO (MIC) compromised membrane permeability and integrity, caused leakage of the cell components, and increased production of malondialdehyde and reactive oxygen species. Scanning electron microscopy and transmission electron microscopy indicated that the morphology and ultrastructure of the LCEO-treated hyphal cell membrane and organelles were severely damaged. Meanwhile, LCEO increased the shelf life of waxberries from 1-2 to 5-6 d. LCEO is a potential ecologically friendly alternative to commercial fungicides to inhibit postharvest fungal contamination of waxberries during shipment and storage.

The Association between BZIP Transcription Factors and Flower Development in Litsea cubeba.

The basic leucine zipper (bZIP) family is one of the largest families of transcription factors among eukaryotic organisms. Members of the bZIP family play various roles in regulating the intricate process of flower development in plants. Litsea cubeba (Lour.) (family: Lauraceae) is an aromatic, dioecious plant used in China for a wide range of applications. However, no study to date has undertaken a comprehensive analysis of the bZIP gene family in L. cubeba. In this work, we identified 68 members of the bZIP gene family in L. cubeba and classified them into 12 subfamilies based on previous studies on Arabidopsis thaliana. Transcriptome data analysis revealed that multiple LcbZIP genes exhibit significantly high expression levels in the flowers of L. cubeba, while some also demonstrate distinct temporal specificity during L. cubeba flower development. In particular, some LcbZIP genes displayed specific and high expression levels during the stamen and pistil degradation process. Using differential gene expression analysis, weighted gene co-expression network analysis, and Gene Ontology enrichment analysis, we identified six candidate LcbZIP genes that potentially regulate stamen or pistil degradation during flower development. In summary, our findings provide a framework for future functional analysis of the LcbZIP gene family in L. cubeba and offer novel insights for investigating the mechanism underlying pistil and stamen degeneration in this plant.

Volatile constituents of the leaf and fruit essential oils of Litsea cubeba (Lour.) Pers. growing wild in Baoshan region, China.

The chemical composition of the essential oil from the fruits and leaves of Litsea cubeba (Lour.) Pers. (Lauraceae) growing wild in Baoshan region, Yunnan Province of China was investigated for the first time in 5.36% and 2.16% (w/w) yields, respectively, when analysed by GC and GC/MS. Ten and 25 components were identified in the fruit and leaf oils which constituted 99.15% and 99.4% of the oils. Of the fruit oil, the major components were neral (36.51%), geranial (44.23%), and citronella (8.77%). The major components of the leaf oil were linalool (67.37%), limonene (6.37%), ß-bisabolene (6.03%), neral (5.86%), and caryophyllene oxide (3.20%). The analysis of the essential oil obtained from Baoshan revealed a significant abundance of citral and linalool in the fruits and leaves, respectively. This was the first Litsea species to exhibit ß-bisabolene as the principal constituent.

Therapeutic potential of Litsea cubeba essential oil in modulating inflammation and the gut microbiome.

Inflammation, a sophisticated and delicately balanced physiological mechanism, is paramount to the host's immunological defense against pathogens. However, unfettered and excessive inflammation can be instrumental in engendering a plethora of chronic ailments and detrimental health repercussions, notably within the gastrointestinal tract. Lipopolysaccharides (LPS) from bacteria are potent endotoxins capable of instigating intestinal inflammation through the disruption of the intestinal epithelial barrier and the stimulation of a pro-inflammatory immune response. In this study, we sought to investigate the influence of Litsea cubeba essential oil (LCEO) on LPS-induced intestinal inflammation and associated changes in the gut microbiota. We investigated the therapeutic potential of LCEO for gut health, with particular emphasis on its gut protective properties, anti-inflammatory properties and modulation of the gut microbiome. LCEO exhibited protective effects on colonic tissue by protecting crypts and maintaining epithelial integrity, and anti-inflammatory properties by reducing TNF-α, IL-6, and IL-1ß levels in the liver and intestine. Citral, a major component of LCEO, showed robust binding to IL-1ß, IL-6, and TNF-α, exerting anti-inflammatory effects through hydrogen bonding interactions. Using community barplot and LEfSe analyses, we detected significant variation in microbial composition, identified discrete biomarkers, and highlighted the influence of essential oils on gut microbial communities. Our research suggests that LCEO may be a promising natural compound for ameliorating diarrhea and intestinal inflammation, with potential implications for modulating the gut microbiome. These observations provide invaluable insight into the potential therapeutic role of LCEO as a natural anti-inflammatory agent for treating intestinal inflammatory disorders, particularly in the setting of a dysregulated immune response and altered gut microbiota. Furthermore, our findings highlight the need to understand the complex interplay between the host, the gut microbiome and natural products in the context of inflammatory diseases.

Comparison of Chemical Compositions and Antioxidant Activity of Essential Oils from Litsea Cubeba, Cinnamon, Anise, and Eucalyptus.

The purpose of this study was to compare the antioxidant activity of litsea cubeba oil (LCO), cinnamon oil (CO), anise oil (AO), and eucalyptus oil (EUC) in vitro. The chemical compositions of the essential oils (EOs) were analyzed using gas chromatography-mass spectrometry (GC-MS). The antioxidant activity of the four EOs was evaluated through scavenging DPPH free radicals, chelating Fe2+, scavenging hydroxyl free radicals, and inhibiting yolk lipid peroxidation. The results showed that the major compounds found in LCO, CO, AO, and EUC are citral (64.29%), cinnamaldehyde (84.25%), anethole (78.51%), and 1,8-cineole (81.78%), respectively. The four EOs all had certain antioxidant activity. The ability to scavenge DPPH radical was ranked in the order of LCO > CO > AO > EUC. The hydroxyl radical scavenging ability was ranked in the order of EUC > CO > LCO > AO. The chelating Fe2+ capacity was ranked in the order of EUC > AO > CO > LCO. The yolk lipid peroxidation inhibition ability was ranked in the order of CO > AO > EUC > LCO. In different antioxidant activity assays, the antioxidant activity of the EOs was different. It was speculated that the total antioxidant activity of an EO may be the result of the joint action of different antioxidant capacities.

Inactivation of Salmonella using ultrasound in combination with Litsea cubeba essential oil nanoemulsion and its bactericidal application on cherry tomatoes.

The presence of Salmonella in nature poses a significant and unacceptable threat to the human public health domain. In this study, the antibacterial effect and mechanism of ultrasound (US) combined with Litsea cubeba essential oil nanoemulsion (LEON) on Salmonella. LEON + US treatment has a significant bactericidal effect on Salmonella. Reactive oxygen species (ROS), malondialdehyde (MDA) detection, N-phenyl-l-naphthylamine (NPN) uptake and nucleic acid release assays showed that LEON + US exacerbated cell membrane lipid peroxidation and increased the permeability of the cell membrane. The results of field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) showed that LEON + US treatment was able to alter cell morphology. It can be observed by flow cytometry (FCM) that LEON + US treatment can cause cell apoptosis. In addition, bacterial counts of cherry tomatoes treated with LEON (0.08 µL/mL) + US (345 W/cm2) for 9 min were reduced by 6.50 ± 0.20 log CFU/mL. This study demonstrates that LEON + US treatment can be an effective way to improve the safety of fruits and vegetables in the food industry.

Characterization, Thermal Stability and Antimicrobial Evaluation of the Inclusion Complex of Litsea cubeba Essential Oil in Large-Ring Cyclodextrins (CD9-CD22).

Food safety issues are becoming increasingly important as a result of contamination with foodborne pathogenic bacteria. Plant essential oil is a safe and non-toxic natural antibacterial agent that can be used to develop antimicrobial active packaging materials. However, most essential oils are volatile and require protection. In the present study, LCEO and LRCD were microencapsulated through coprecipitation. The complex was investigated using GC-MS, TGA, and FT-IR spectroscopy. According to the experimental results, it was found that LCEO entered the inner cavity of the LRCD molecule and formed a complex with LRCD. LCEO had a significant and broad-spectrum antimicrobial effect against all five microorganisms tested. At 50 °C, the microbial diameter of the essential oil and its microcapsules showed the least change, indicating that this essential oil has high antimicrobial activity. In research on microcapsule release, LRCD has proven to be a perfect wall material for controlling the delayed release of essential oil and extending the duration of antimicrobial activity. LRCD effectively extends antimicrobial duration by encasing LCEO, thus improving its heat stability and antimicrobial activity. The results presented here indicate that LCEO/LRCD microcapsules can be further utilized in the food packaging industry.

LcWRKY17, a WRKY Transcription Factor from Litsea cubeba, Effectively Promotes Monoterpene Synthesis.

The WRKY gene family is one of the most significant transcription factor (TF) families in higher plants and participates in many secondary metabolic processes in plants. Litsea cubeba (Lour.) Person is an important woody oil plant that is high in terpenoids. However, no studies have been conducted to investigate the WRKY TFs that regulate the synthesis of terpene in L. cubeba. This paper provides a comprehensive genomic analysis of the LcWRKYs. In the L. cubeba genome, 64 LcWRKY genes were discovered. According to a comparative phylogenetic study with Arabidopsis thaliana, these L. cubeba WRKYs were divided into three groups. Some LcWRKY genes may have arisen from gene duplication, but the majority of LcWRKY evolution has been driven by segmental duplication events. Based on transcriptome data, a consistent expression pattern of LcWRKY17 and terpene synthase LcTPS42 was found at different stages of L. cubeba fruit development. Furthermore, the function of LcWRKY17 was verified by subcellular localization and transient overexpression, and overexpression of LcWRKY17 promotes monoterpene synthesis. Meanwhile, dual-Luciferase and yeast one-hybrid (Y1H) experiments showed that the LcWRKY17 transcription factor binds to W-box motifs of LcTPS42 and enhances its transcription. In conclusion, this research provided a fundamental framework for future functional analysis of the WRKY gene families, as well as breeding improvement and the regulation of secondary metabolism in L. cubeba.

Antibacterial Activity and Possible Mechanism of Litsea cubeba Essential Oil Against Shigella sonnei and Its Application in Lettuce.

Shigella sonnei, the causative agents of bacillary dysentery, remains a significant threat to public health. Litsea cubeba essential oil (LC-EO), one of the natural essential oils, exhibited promising biological activities. In this study, the antibacterial effects and possible mechanisms of LC-EO on S. sonnei and its application in lettuce medium were investigated. The minimum inhibitory concentration (MIC) of LC-EO against S. sonnei ATCC 25931 and CMCC 51592 was 4 and 6 µL/mL, respectively. The LC-EO could inhibit the growth of S. sonnei, and decreased S. sonnei to undetectable levels with 4 µL/mL for 1 h in Luria-Bertani broth. The antibacterial mechanism indicated that after the treatment of LC-EO, the production of reactive oxygen species and the activity of superoxide dismutase were significantly elevated in S. sonnei cells, and eventually led to the lipid oxidation product, the malondialdehyde content that significantly increased. Moreover, LC-EO at 2 MIC could destroy 96.51% of bacterial cell membrane integrity, and made S. sonnei cells to appear wrinkled with a rough surface, so that the intracellular adenosine triphosphate leakage was about 0.352-0.030 µmol/L. Finally, the results of application evaluation indicated that the addition of LC-EO at 4 µL/mL in lettuce leaves and 6 µL/mL in lettuce juice could decrease the number of S. sonnei to undetectable levels without remarkable influence on the lettuce leaf sensory quality. In summary, LC-EO exerted strong antibacterial activity and has the potential to control S. sonnei in food industry.

First report of black patch disease caused by Phyllosticta capitalensis on Litsea cubeba in China.

Litsea cubeba, an economical important tree species originally from China, produces fruit from which essential oils are extracted and extensively used in the chemical industry (Zhang et al. 2020). In August 2021, a large-scale outbreak of black patch disease was first observed on the leaves of Litsea cubeba in Huaihua (27°33'N; 109°57'E), Hunan province, China (disease incidence 78%). A second outbreak in 2022, in the same area, lasted from June to August. Symptoms consisted of irregular lesions that initially appeared as small black patches near the lateral veins. These lesions grew along the lateral veins and formed feathery patches until almost the entire lateral veins of the leaves were infected by the pathogen. The infected plants grew poorly and eventually the leaves desiccated and the tree defoliated. To identify the causal agent, the pathogen was isolated from nine symptomatic leaves from three trees. Symptomatic leaves were washed with distilled water three times. Leaves were cut into small pieces (11 cm), surface sterilized with 75% ethanol for 10s and 0.1% HgCl2 for 3 min, and then washed 3 times in sterile distilled water. Surface disinfected leaf pieces were placed onto potato dextrose agar (PDA) medium with cephalothin (0.2 mg/ml) and incubated at 28°C for 4-8 days (about 16h light, 8h dark). Seven morphologically identical isolates were obtained, from which five were selected for further morphological examination and three for molecular identification and pathogenicity test. Strains from grayish white colonies with a granular surface and grayish black wavy edges; bottom of the colonies turned black over time. Conidia were hyaline and nearly elliptical, unicellular. The sizes of conidia ranged from 8.59 to 15.06 µm (n=50) in length and 3.57 to 6.36 µm (n=50) in width. These morphological characteristics are consistent with the description of Phyllosticta capitalensis (Guarnaccia et al. 2017, Wikee et al. 2013). To further confirm the identity of this pathogen, genomic DNA of three isolates (phy1, phy2 and phy3) were extracted to amplify the internal transcribed spacer (ITS) region, the 18S rDNA region, the transcription elongation factor (TEF), and actin (ACT) gene with ITS1/ITS4 (Cheng et al. 2019), NS1/NS8 (Zhan et al. 2014), EF1-728F/EF1-986R (Druzhinina et al. 2005) and ACT-512F/ACT-783R (Wikee et al. 2013) primers, respectively. Sequence similarity indicated that these isolates were highly homologous to Phyllosticta capitalensis. The ITS (Genbank No. OP863032, ON714650 and OP863033), 18S rDNA (Genbank No. OP863038, ON778575 and OP863039), TEF (Genbank No. OP905580, OP905581 and OP905582) and ACT (Genbank No. OP897308, OP897309 and OP897310) sequences of isolates Phy1, Phy2 and Phy3 shared up to 99%, 99%, 100% and 100% similarities with their counterparts (Genbank No. OP163688, MH051003, ON246258 and KY855652) in Phyllosticta capitalensis, respectively. To further confirm their identity, a neighbor-joining phylogenetic tree was generated using MEGA7. Based on morphological characteristics and sequence analysis, the three strains were identified as P. capitalensis. To fulfill Koch's postulates, conidial suspension (1×105 conidia per mL) collected from three isolates were independently inoculated on artificially wounded detached leaves and leaves on trees of Litsea cubeba. Leaves were inoculated with sterile distilled water as negative controls. The experiment was repeated three times. All pathogen-inoculated wounds exhibited necrotic lesions within 5 days on detached leaves and 10 days on the leaves growing on trees after inoculation, whereas no symptoms were observed on the controls. The pathogen was exclusively re-isolated from the infected leaves and showed identical morphological characteristics to those of the original pathogens. P. capitalensis is a destructive plant pathogen that has been shown to cause leaf spots or black patch symptoms on variety of host plants around the world (Wikee et al. 2013), including oil palm (Elaeis guineensis Jacq.), tea plant (Camellia sinensis), Rubus chingii and castor (Ricinus communis L.). To our knowledge, this is the first report of black patch disease of Litsea cubeba caused by P. capitalensis in China. This disease causes severe leaf abscission in fruit development stage of Litsea cubeba and leads to a large amount of fruit drop.

Dietary Litsea cubeba essential oil supplementation improves growth performance and intestinal health of weaned piglets.

This paper was to determine the effects of dietary Litsea cubeba essential oil (LEO) supplementation on growth performance, immune function, antioxidant level, intestinal morphology and microbial composition in weaned piglets. One hundred and ninety-two piglets (Duroc × [Large White × Landrace]) with 6.85 ± 0.22 kg mean body weight weaned at 21 d of age were randomly assigned to 4 treatment groups with 8 replicates and were fed with a basal diet (CON) or CON diet containing 100 (LLEO), 200 (MLEO) and 400 (HLEO) mg/kg LEO. The results revealed that HLEO supplementation (P < 0.05) increased the average daily gain on d 28 compared with CON. MLEO and HLEO supplementation decreased (P < 0.05) feed conversion ratio. LEO-containing diets had a lower (P < 0.05) diarrhea rate. Supplementation with HLEO increased (P < 0.05) total antioxidant capacity (T-AOC) both in the serum and liver. Meanwhile, the supplementation of MLEO and HLEO resulted in higher (P < 0.05) glutathione peroxidase (GPx) activities both in serum and liver. Supplementation of HLEO increased (P < 0.05) serum immunoglobulin A, immunoglobulin G and interleukin-10, whereas supplementation with MLEO and HLEO decreased (P < 0.05) tumor necrosis factor-α. Villus height in the duodenum or jejunum was increased (P < 0.05) in the HLEO group, and the villus height to crypt depth ratio in the jejunum was also improved (P < 0.05) in the MLEO group. The addition of LEO increased (P < 0.05) the richness and diversity of the microbial community in the cecum, which mainly increased the relative abundance of Oscillospiraceae _UCG-005, Faecalibacterium, Blautia and Coprococcus. Piglets supplemented with HLEO increased (P < 0.05) the concentration of short chain fatty acids (SCFA), including acetic acid in the cecum and propionic acid in the colon. In conclusion, these findings indicated that LEO supplementation improved growth performance and intestinal health in weaned piglets.

Preparation and application of cinnamon-Litsea cubeba compound essential oil microcapsules for peanut kernel postharvest storage.

This research developed a novel, efficient and safe antimildew for peanut kernel postharvest storage. The antimildew, cinnamon-Litsea cubeba compound essential oil (CLCEO) microcapsule (CLCEOM), was synthesized with CLCEO as core materials and ß-cyclodextrin as wall materials. Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry analyses indicated that major antifungal compounds of CLCEO were encapsulated in the cavity of ß-cyclodextrin. The inhibition zone experiment showed that CLCEOM retained antifungal effect on Aspergillus spp. strains even after storage for 2 months at 4 â„ƒ. Besides, CLCEOM reduced total number of fungal colonies, relative abundance of Aspergillus spp., and aflatoxin B1 content of peanut kernels, and had positive effect on slowing down the increase in acid value of peanut oil without causing any adverse effect on the viability and sensory properties during storage process. Overall, CLCEOM presented good preservative effects on peanut kernels, providing evidence for its potential use as antimildew for peanut storage.

LcERF134 increases the production of monoterpenes by activating the terpene biosynthesis pathway in Litsea cubeba.

Litsea cubeba, an aromatic species of the Lauraceae family, produces a diverse array of monoterpenes. The biosynthesis of monoterpenes is regulated by transcriptional factors (TFs), such as APETALA2/ethylene response factor (AP2/ERF). However, the regulatory mechanisms that control the AP2/ERF gene responsible for the biosynthesis of monoterpenes in L. cubeba have yet to be elucidated. Here, we identified an AP2/ERF gene, LcERF134, as an activator for the accumulation of citral and other monoterpenes. The expression level of LcERF134 was consistent with terpene synthase LcTPS42 in the pericarp. The transient overexpression of LcERF134 significantly increased monoterpene production in L. cubeba as well as the expression of rate-limiting genes involved in the monoterpene biosynthesis pathway. Furthermore, yeast one-hybrid, dual-luciferase and electrophoretic mobility shift assays demonstrated that LcERF134 activated the monoterpene biosynthesis pathway by directly binding to the GCC-box elements of the LcTPS42 and LcGPPS.SSU1 promoters. However, the overexpression of LcERF134 in tomatoes had no impact on the synthesis of monoterpenes, thus indicating that LcERF134 is a species-specific TF. Our research demonstrated that LcERF134 significantly increased the biosynthesis of monoterpenes by inducing the expression of LcTPS42 and LcGPPS.SSU1, thus offering insight into how to enhance the flavor of L. cubeba essential oil.

Preparation of Aliphatic Hydroxamic Acid from Litsea cubeba Kernel Oil and Its Application to Flotation of Fe(III)-Activated Wolframite.

Litsea cubeba is a characteristic woody oil resource in Hunan. As a solid waste of woody oil resources, Litsea cubeba kernels are rich in Litsea cubeba kernel oil with a carbon chain length of C10-12 fatty acid. In this work, aliphatic hydroxamic acids (AHAs) with carbon chain lengths of C10-12 were prepared from Litsea cubeba kernel oil via methylation and hydroximation reactions. The adsorption and hydrophobicity mechanism of AHA towards wolframite was explored by contact angle, zeta potential, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The flotation results demonstrated that AHA was a superior collector than the traditional collector such as benzoyl hydroxamic acid (BHA). Zeta potential and contact angle results have shown that AHA was adsorbed on the surface of the Fe(III)-activated wolframite in its anionic form, which significantly improved the surface hydrophobicity of wolframite. FTIR and XPS revealed that AHA was chemically adsorbed on the surface of Fe(III)-activated wolframite in the form of a five-member ring, which made the hydrophobic chain reach into the solution, come in contact with bubbles, and achieve flotation separation.