Search Results (38)

The rising prevalence of bacterial antibiotic resistance remains a significant challenge, while many existing antibacterial agents exhibit limited efficacy and notable adverse effects. Edible plants offer a promising avenue for developing novel antimicrobial drugs and preservatives. Etrog citron (Citrus medica L.) and its bioactive phytochemicals have demonstrated activity against various pathogenic microorganisms. However, the potential application of these compounds is hindered by factors such as poor solubility, limited bioavailability, and unclear mechanisms of action. This review consolidates key findings on the antimicrobial properties of extracts and essential oils derived from different parts of Citrus medica, emphasizing strategies for improving the delivery of these bioactive compounds. Full article

Parthenocarpy, the development of fruit without fertilization, is a significant trait in fingered citron (Citrus medica L. var. sarcodactylis Swingle). This study aims to elucidate the regulatory mechanisms underlying parthenocarpy through comparative transcriptome analysis and phytohormone profiling between fingered citron and its non-parthenocarpic counterpart, citron. A total of 66 differentially expressed hormone-related genes were identified, with the auxin pathway emerging as the most prominent in fingered citron. Protein–protein interaction analysis revealed a potential interaction between auxin and abscisic acid (ABA). Phytohormone content analysis indicated that fingered citron exhibited higher levels of indole-3-acetic acid (IAA) and lower levels of ABA compared to citron. A weighted gene co-expression network analysis (WGCNA) suggested that the interplay between auxin and ABA is crucial for triggering parthenocarpy. Virus-induced gene silencing (VIGS) experiments demonstrated that silencing CmsABI5 led to decreased ABA levels, while auxin levels remained unchanged, resulting in disrupted parthenocarpy and increased ethylene levels, indicating a secondary hormonal response. Additionally, gene expression changes associated with failed parthenocarpy showed down-regulation of SAUR50 and up-regulation of PP2C 56, linking these changes to ABA signaling. Our findings highlight the central regulatory role of auxin in parthenocarpy in fingered citron, with ABA acting as a critical modulator. The suppression of ABA alone disrupts parthenocarpy despite stable auxin levels, emphasizing the necessity of balanced hormone interactions. This research underscores the significant role of auxin, rather than gibberellin (GA), in regulating parthenocarpy in fingered citron, contributing valuable insights to the understanding of fruit development mechanisms. Full article

Buccal drug delivery offers a promising alternative for avoiding gastrointestinal degradation and first-pass metabolism. However, enhancing the buccal epithelial barrier’s permeability remains challenging. This study explores the effects of ethanolic extracts from Citrus medica var. Balady (CM), Citrus medica var. Calabria (CMC), and Origanum dayi (ORD) on buccal epithelium permeability in vitro using a TR146 cell-based model. The cell viability assay revealed that the extracts were non-toxic at the concentration range tested (<0.5% w/v). Surprisingly, none of the tested extracts significantly enhanced the buccal permeability of 40 kDa Fluorescein Isothiocyanate Dextran (FD40). However, the CMC and ORD extracts significantly reduced the epithelial permeability of FD40, mirroring the effects of hyaluronic acid (HA), a known barrier integrity enhancer. The total phenolic content (TPC) analysis suggested a potential link between the phenolic concentration and epithelial barrier reinforcement. The rapid colorimetric response method was applied to assess the interaction of these extracts with biological membranes. The results indicated that HA interacts with cellular membranes via lipid bilayer penetration, whereas the extracts likely influence the barrier integrity through alternative mechanisms, such as ligand–receptor interactions or extracellular matrix modulation. These findings highlight the potential of CMC and ORD extracts as natural agents to enhance buccal epithelial integrity. In conclusion, incorporating these extracts into formulations, such as hydrogels, could offer a cost-effective and biocompatible alternative to HA for improving buccal cavity health. Full article

Limoncella of Mattinata, a rare and ancient Mediterranean citrus fruit, was investigated by sequence analysis of the ribosomal internal transcribed spacer regions, which assigns it as a variety of Citrus medica L. Morphological, chemical, and biomolecular approaches, including light and electron microscopy, HPLC-ESI-MS/MS, and antioxidant and anti-inflammatory assays, were used to characterize the flavedo and albedo parts, usually rich in bioactive compounds. The morphological findings showed albedo and flavedo cellular structures as “reservoirs” of nutritional components. Both albedo and flavedo hydroalcoholic extracts were rich in polyphenols, but they were different in compounds and quantity. The flavedo is rich in p-coumaric acid and rutin, whereas the albedo contains high levels of hesperidin and quercitrin. Antioxidant, anti-inflammatory, and genoprotective effects for albedo and flavedo were found. The results confirmed the health properties of flavedo and highlighted that albedo is also a rich source of antioxidants. Moreover, this study valorizes Limoncella of Mattinata’s nutritional properties, cueing its crops’ repopulation. Full article

(1) Background: Insomnia is a neurological illness that poses a significant threat to both physical and mental health. It results in the activation of neuroglial cells, heightened neuroinflammation, oxidative stress, and disruptions in the Hypothalamic–Pituitary–Adrenal (HPA) axis. Ligusticum Chuanxiong (CX) and Finger citron (FC) are frequently utilized botanicals for addressing sleeplessness. Both herbs possess notable anti-inflammatory properties in their volatile oils. However, their effectiveness is hindered by the nasal mucosal irritation and instability they exhibit. (2) Methods: This study involved the preparation of a nanofiber composite system using carbon nanofiber (CNF) suspensions containing essential oils of Ligusticum chuanxiong–Finger citron (CXEO-FCEO-CNF). The effects and mechanisms of these essential oils in improving insomnia were investigated using an insomnia mouse model after encapsulation. (3) Results: The CXEO-FCEO-CNF had an average particle size of 103.19 ± 1.64 nm. The encapsulation rates of essential oils of Ligusticum chuanxiong (CXEO) and essential oils of Finger citron (FCEO) were 44.50% and 46.15%, respectively. This resulted in a considerable improvement in the stability of the essential oils over a period of 30 days. The essential oils effectively decreased the irritation of the nasal mucosa following encapsulation. Furthermore, CXEO-FCEO-CNF enhanced voluntary activity and sleep in mice with insomnia, notably boosted the activity of superoxide dismutase (SOD), reduced the concentration of lipoxidized malondialdehyde (MDA), decreased the levels of hormones associated with the HPA axis, and regulated the levels of neurotransmitters, resulting in a beneficial therapeutic outcome. CXEO-FCEO-CNF contains a total of 23 active ingredients, such as alpha-Asarone, (E)-methyl isoeugenol, and Senkyunolide. These ingredients primarily work by modulating the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling system to decrease oxidative stress and inflammatory reactions. (4) Conclusions: This study presented initial evidence that the combination of CXEO and FCEO in nanofiber formulations effectively reduces the nasal mucosal irritation and instability of essential oils. Furthermore, it demonstrated the potential anti-neuroinflammatory and therapeutic effects of these formulations in treating insomnia. Overall, this study provides a theoretical foundation for developing new essential oil formulations derived from herbs. Full article

Citrus medica L. is a traditional citrus fruit that is rich in bioactive compounds and has the potential to be used as a natural source of food additives. This study aims to evaluate the antioxidant capacity and characterize the phenolic compounds present in the peels (including flavedo and albedo), pulp, and seeds of citron. The results showed that, compared to the other parts, the pulp had a substantially higher Antioxidant Activity Coefficient (AAC) of 168.2. The albedo and the seeds had significantly lower AAC values, while the green and yellow flavedo showed noteworthy results. O-coumaric acid was the predominant phenolic acid in all of the citron fractions; it was found in the highest concentration in albedo (37.54 µg/g FW). Flavanones and flavanols were the primary flavonoids in the pulp, peel, and seeds, with total flavonoid concentration ranging from ~9 µg/g FW in seeds to 508 µg/g FW in the pulp. This research offers significant insights into the antioxidant properties of this ancient fruit, emphasizing its potential applications as a natural source of antioxidants to be used in different applications. Full article

Citrus bacterial canker disease, caused by Xanthomonas citri subsp. citri (Xcc), poses a significant global threat to the citrus industry. Lateral organ boundaries 1 (Lob1) is confirmed as a citrus susceptibility gene that induces pathogenesis by interaction with the PthA4 effector of Xcc. Citron C-05 (Citrus medica) is a Citrus genotype resistant to Xcc. However, there is little information available on the regulation of Lob1 in resistant genotypes, which is important for the breeding of citrus cultivars resistant to canker disease. This study aimed to identify upstream regulatory factors of Lob1 in Citron C-05 and to investigate its function in disease resistance. ‘Bingtang’ sweet orange (C. sinensis), a susceptible genotype, was utilized as the control. cDNA yeast libraries of Xcc-induced Citron C-05 and ‘Bingtang’ sweet orange were constructed. The capacities of ‘Bingtang’ and Citron C-05 were 1.896 × 10⁷ and 2.154 × 10⁷ CFU, respectively. The inserted fragments ranged from 500 to 2000 bp with a 100% recombination rate. The promoter of Lob1 was segmented into two pieces and the P1 fragment from both genotypes was used to construct a bait yeast (PAbAi-CsLob1-P1; PAbAi-CmLob1-P1). Through library screening with the bait yeast, upstream regulators interacting with the Lob1-P1 promoter were identified and then validated using Y1H and dual-luciferase tests. The expression analysis of the three transcript factors indicated that RMA3 was upregulated by inoculation with Xcc in the resistant Citron C-05, but not in the susceptible sweet orange. The overexpression of CsRMA3 in ‘Bingtang’ sweet orange led to reduced canker symptoms, with a significantly lower pathogen density in the leaves following Xcc inoculation. When CmRMA3 was silenced by virus-induced gene silencing (VIGS) in Citron C-05, typical canker symptoms appeared on the CmRMA3-silenced leaves at 15 days post-inoculation with Xcc. Further expression analyses revealed that the CmRMA3 transcription factor suppressed the expression of Lob1. These results suggest that RMA3 participates in the resistant reaction of Citron C-05 to Xcc infection, and such a response might be in relation to its suppression of the expression of the pathogenic gene Lob1. Full article

The main objective of this study is to analyze the drying kinetics of Citrus medica by using the freeze-drying method at various thicknesses (3, 5, and 7 mm) and cabin pressures (0.008, 0.010, and 0.012 mbar). Additionally, the study aims to evaluate the efficacy of an artificial neural network (ANN) in estimating crucial parameters like dimensionless mass loss ratio (MR), moisture content, and drying rate. Feedforward multilayer perceptron (MLP) neural network architecture was employed to model the freeze-drying process of Citrus medica. The ANN architecture was trained using a dataset covering various drying conditions and product characteristics. The training process, including hyperparameter optimization, is detailed and the performance of the ANN is evaluated using robust metrics such as RMSE and R². As a result of comparing the experimental MR with the predicted MR of the ANN modeling created by considering various product thicknesses and cabin pressures, the R² was found to be 0.998 and the RMSE was 0.010574. Additionally, color change, water activity, and effective moisture diffusivity were examined in this study. As a result of the experiments, the color change in freeze-dried Citrus medica fruits was between 6.9 ± 0.2 and 21.0 ± 0.6, water activity was between 0.4086 ± 0.0104 and 0.5925 ± 0.0064, effective moisture diffusivity was between 4.19 × ${10}^{-11}$ and 21.4 × ${10}^{-11}$, respectively. In freeze-drying experiments conducted at various cabin pressures, it was observed that increasing the slice thickness of Citrus medica fruit resulted in longer drying times, higher water activity, greater color changes, and increased effective moisture diffusivity. By applying the experimental data to mathematical models and an ANN, the optimal process conditions were determined. The results of this study indicate that ANNs can potentially be applied to characterize the freeze-drying process of Citrus medica. Full article

Regenerative endodontics (REP) is a new clinical modality aiming to regenerate damaged soft and hard dental tissues, allowing for root completion in young adults’ teeth. Effective disinfection is crucial for REP success, but commonly used antimicrobials often harm the niche dental pulp stem cells (DPSCs). To our knowledge, this is the first study to explore the biocompatibility and antimicrobial potential of pectin as a potential natural intracanal medicament for REPs. Low methoxyl commercial citrus pectin (LM) (pectin CU701, Herbstreith&Fox.de) was used in all experiments. The pectin’s antibacterial activity against single species biofilms (E. faecalis and F. nucleatum) was assessed using growth curves. The pectin’s antimicrobial effect against mature dual-species biofilm was also evaluated using confocal laser scanning microscopy (CLSM) after 30 min and 7 days of treatment. The DPSC biocompatibility with 2% and 4% w/v of the pectin coatings was evaluated using live/dead staining, LDH, and WST-1 assays. Pectin showed a concentration-dependent inhibitory effect against single-species biofilms (E. faecalis and F. nucleatum) but failed to disrupt dual-species biofilm. Pectin at 2% w/v concentration proved to be biocompatible with the HDPSCs. However, 4% w/v pectin reduced both the viability and proliferation of the DPSCs. Low concentration (2% w/v) pectin was biocompatible with the DPSCs and showed an antimicrobial effect against single-species biofilms. This suggests the potential for using pectin as an injectable hydrogel for clinical applications in regenerative endodontics. Full article

Citron (Citrus medica L. cv. Liscia-diamante), cultivated in the “Riviera dei Cedri” (southern Italy), is mainly utilized in the production of candied fruit and essential oils (EOs). Up to now, no information regarding the effect of storage temperatures on citron has been reported. Here, citron samples, after harvesting, were stored at different temperatures (5, 10 and 20 °C at 70% relative humidity) for two weeks, and the main postharvest quality parameters were evaluated. Moreover, EOs extracted from the stored samples were chemically characterized to reveal changes in the volatiles profile and antimicrobial activity. The EOs presented monoterpene hydrocarbons (87.1 to 96.3% of the total oil profile) as the most abundant compounds, followed by oxygenated metabolites ranging from 9.7 to 3.1% of the total pattern. Postharvest quality traits showed a good retention of green peel color during storage at 5 °C, while EOs from samples stored for 7 and 14 days at 10 and 20 °C, respectively, showed the highest antimicrobial activity against most assayed strains. The results indicated storage at 10 °C for 7 days as the most suitable for the preservation of the postharvest quality of the fruit and the antimicrobial activity of the extracted EOs. Full article

In this paper, liquid–liquid chromatography was introduced for the first time for the separation of fingered citron (Citrus medica L. var. sarcodactylis Swingle). The fingered citron cultivated in Jinhua is of significant industrial and medicinal value, with several major coumarin compounds detected in its extract. Therefore, further separation for higher purity was of necessity. A preparative liquid–liquid chromatographic method was developed by combining two elution modes (isocratic and step-gradient) with selection according to different polarities of the target sample. Five coumarin derivatives—5,7-dimethoxycoumarin (52.6 mg, 99.6%), phellopterin (4.9 mg, 97.1%), 5-prenyloxy-7-methoxycoumarin (6.7 mg, 98.7%), 6-hydroxy-7-methoxycoumarin (7.1 mg, 82.2%), and byakangelicol (10.5 mg, 90.1%)—with similar structures and properties were isolated on a large scale from 100 mg of petroleum ether (PE) extract and 100 mg of ethyl acetate (EA) extract in Jinhua fingered citron. The productivity was much improved. The anti-growth activity of the isolated coumarins was evaluated against three cancer cell lines (HeLa, A549, and MCF7) with an MTT assay. The coumarins demonstrated potential anti-tumor activity on the HeLa cell line, with 5,7-dimethoxycoumarin in particular exhibiting the best anti-growth activity (IC₅₀ = 10.57 ± 0.24 μM) by inhibiting proliferation. It inhibited colony formation and reduced the size of the tumor sphere in a concentration-dependent manner. The main mechanism was confirmed as inducing apoptosis. This work was informative for further studies aimed at exploring new natural-product-based antitumor agents. Full article

This study aimed to investigate selected bioactive components in three underutilized wild edible exotic fruits (Syzygium guineense Wild. DC, Ziziphus spina-christi L., and Citrus medica L.), using high-performance thin-layer chromatography and ultraviolet-visible spectrophotometry (HPTLC-UV-Vis), treated under three drying conditions. Ultrasound-assisted extraction was used to extract the target bioactive components under specified conditions, i.e., time of 15 min, temperature of 35 °C, methanol and water 75/25, v/v, and fruit powder-to-solvent ratio of 1:15, w/v. The mobile phase ratio for rutin, kaempferol, myricetin, and quercetin was toluene/ethylacetate/methanol/formic acid at 20:12:8:4, whereas, for phenolic acids, the ratio was 10:15:10:5, respectively. The HPTLC plates were scanned to identify and quantify selected compounds (phenolic acids, quercetin, rutin, myricetin, and kaempferol) at their maximum optimized absorption wavelengths. The contents of target bioactive components ranged from 0.64 ± 0.19 mg/100 g for rutin to 320.04 ± 7.10 mg/100 g for chlorogenic acid. Based on the results of this investigation, the phenol content of freeze-dried fruit was significantly (p ≤ 0.05) higher than other drying methods. The calculated average limit of detections and quantifications ranged from 0.37 to 75 ng/spot to 2.5 to 250 ng/spot, respectively. The average recoveries were 99.91 ± 5.65% for quercetin and 99.08 ± 5.96% for rutin. Overall, the validated HPTLC method was simple, selective, sensitive, and stable for the simultaneous identification and determination of phenolic acids and flavonoids. As a result, this study revealed that the contents of phenolic acids and flavonoids in selected exotic edible fruits can be used as effective antioxidants. Full article

Plant species are a reservoir of natural compounds that can potentially be used to treat different diseases. Citrus medica Linn. belonging to the Rutaceae family, has been used for centuries in medicine for its antioxidant, anti-inflammatory, antimicrobial, antiviral, and antihyperglycemic properties. These activities are ascribable not only to the presence of health-promoting macronutrients and micronutrients, such as carbohydrates, minerals, amino acids, and vitamins, but also to specialized metabolites, such as flavonoids (apigenin, hesperetin, hesperidin, naringin, naringenin, rutin, quercetin, and diosmin), coumarins (citropten, scoparone, and bergapten), terpenes (limonene, γ-terpinene, limonin, and nomilin), and phenolic acids (p-coumaric acid, trans-ferulic acid, and chlorogenic acid). In recent years, particular attention has been focused on the antioxidant, anti-inflammatory, antimicrobial activity, antidiabetic, anticancer, and neuroprotective activity of C. medica. However, although many studies have reported this species’ chemical and biological properties, the literature has never been analyzed via a systematic approach. For this reason, using PubMed and Scopus as databases, we performed a systematic review of C. medica’s chemical composition and biological properties to inspire new research approaches and increase its curative application. Full article

Citrus Medica limonum essential oil (LEO) has been reported to have antibacterial and anti-inflammatory activities, but its protective effect in the intestine remains unknown. In this study, we researched the protective effects of LEO in relation to intestinal inflammation induced by E. coli K99. The mice were pretreated with 300, 600, and 1200 mg/kg LEO and then stimulated with E. coli K99. The results showed that E. coli K99 caused immune organ responses, intestinal tissue injury, and inflammation. LEO pretreatment dose-dependently alleviated these changes by maintaining a low index in the thymus and spleen and producing a high content of immunoglobulin A, G, and M (IgA, IgG, and IgM) and low content of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). Intestinal integrity as a consequence of the LEO pretreatment may be related to the high mRNA expression of intestinal trefoil factor (ITF) and the low mRNA expression of transforming growth factor-β1 (TGF-β1). Conclusively, an LEO pretreatment can alleviate E. coli K99-induced diarrhea, immune organ response, and body inflammation in mice by reducing the levels of inflammatory cytokines and improving the levels of immunoglobulin, and the intestinal integrity remained highest when maintaining the high mRNA expression of ITF and keeping the mRNA expression of TGF-β1 low in the intestinal tissue. Full article

WRKY proteins are an important group of transcription factors (TFs) gene family and were identified primarily in plants. WRKY TFs play vital roles in modulating gene expression when plants face detrimental effects due to the environment. In the current study, we focused on using the mandarin citrus (Citrus reticulata) genome to understand the impact of the WRKY gene family on the extraction of alleles mining in mandarins. The mining of the C. reticulata genome identified 46 CrWRKY genes that were classified into three main groups (G1, G2, and G3) further with five subclasses (IIa, IIb, IIc, Iid, and IIe) in the G2 group, and all were presented on 29 scaffolds representing numerous segmental duplications of 100% events established. Multiple sequence analysis predicted the presence of the “WRKYGQK” domain and metal-chelating zinc-finger motif C₂H₂ in 45 genes, while the “WRKYGQK” domain was replaced with “WRKYGKK” only in CrWRKY20. The comparative relationship of CrWRKY with other plant species using dual synteny analysis revealed that the divergence between C. reticulata and C. grandis occurred after the evolutionary divergence of C. clementine, C. sinensis, C. medica, and C. ichangensis. The possible functions of the CrWRKY genes in mitigating environmental effects were predicted using cis-regulatory elements analysis and in silico RNAseq analysis, for the development of plants. These results provide a robust platform and absence of knowledge for the functional identification from key genes of CrWRKY genes in the mandarin for the possible use to improve key desirable agronomic and consumer-driven fruit quality traits in mandarins and related species. Full article