Study on the chemical composition variability of some processed bergamot (Citrus bergamia) essential oils

Comparison of two biological systems used for phototoxicity testing: Cellular and tissue

The OECD has approved two similar methods for testing the phototoxic potency of chemicals. The first method, OECD 432, is based on the cytotoxicity properties of materials to the mouse 3T3 (clone A31) cell line (fibroblasts) after exposure to light. The second method, OECD 498, is based on the same properties but using reconstructed human epidermis - EpiDerm (stratified keratinocytes). The aim of this study was to compare these two methods using statistical tests (specificity, sensitivity, negative predictive value, positive predictive value and accuracy) and non-statistical characteristics (e.g. price and experimental duration, amount of material, level of complications, cell type, irradiation dose). Both tests were performed according to the relevant guidelines using the same 11 control substances. Higher performance values were observed for OECD 432 in both phototoxic and non-phototoxic classifications. The accuracy of OECD 432 was 90.9%, while that of OECD 498 was 72.7%. OECD 432 was also shorter and less expensive. On the other hand, OECD 498 was less complicated, and used human cells with stratum corneum, which better reflects real skin. This method can also be used with oily substances that are poorly soluble in water. However, both methods are important for testing the phototoxic properties of materials, and can be used alone or in a tiered strategy.

Essential Oils: Chemistry and Pharmacological Activities

In this review, we provide an overview of the current understanding of the main mechanisms of pharmacological action of essential oils and their components in various biological systems. A brief introduction on essential oil chemistry is presented to better understand the relationship of chemical aspects with the bioactivity of these products. Next, the antioxidant, anti-inflammatory, antitumor, and antimicrobial activities are discussed. The mechanisms of action against various types of viruses are also addressed. The data show that the multiplicity of pharmacological properties of essential oils occurs due to the chemical diversity in their composition and their ability to interfere with biological processes at cellular and multicellular levels via interaction with various biological targets. Therefore, these natural products can be a promising source for the development of new drugs.

Can Essential Oils/Botanical Agents Smart-Nanoformulations Be the Winning Cards against Psoriasis?

Although psoriasis remains one of the most devastating inflammatory disorders due to its huge negative impact on patients’ quality of life, new “green” treatment approaches still need to be fully explored. The purpose of this review article is to focus on the utilization of different essential oils and active constituents of herbal botanical origin for the treatment of psoriasis that proved efficacious via both in vitro and in vivo models. The applications of nanotechnology-based formulations which displayed great potential in augmenting the permeation and delivery of these agents is also addressed. Numerous studies have been found which assessed the potential activity of natural botanical agents to overcome psoriasis. Nano-architecture delivery is applied in order to maximize the benefits of their activity, improve properties, and increase patient compliance. This field of natural innovative formulations can be a promising tool to optimize remediation of psoriasis while minimizing adverse effects.

Biobased polymer resources and essential oils: a green combination for antibacterial applications

To fight nosocomial infections, the excessive use of antibiotics has led to the emergence of multidrug-resistant microorganisms, which are now considered a relevant public health threat by the World Health Organization. To date, most antibacterial systems are based on the use of petro-sourced polymers, but the global supplies of these resources are depleting. Besides, silver NPs are widely accepted as the most active biocide against a wide range of bacterial strains but their toxicity is an issue. The growing interest in natural products has gained increasing interest in the last decade. Therefore, the design of functional antibacterial materials derived from biomass remains a significant challenge for the scientific community. Consequently, attention has shifted to naturally occurring substances such as essential oils (EOs), which are classified as Generally Recognized as Safe (GRAS). EOs can offer an alternative to the common antimicrobial agents as an inner solution or biocide agent to inhibit the resistance mechanism. Herein, this review not only aims at providing developments in the antibacterial modes of action of EOs against various bacterial strains and the recent advances in genomic and proteomic techniques for the elucidation of these mechanisms but also presents examples of biobased polymer resource-based EO materials and their antibacterial activities. Especially, we describe the antibacterial properties of biobased polymers, e.g. cellulose, starch, chitosan, PLA PHAs and proteins, associated with EOs (cinnamon (CEO), clove (CLEO), bergamot (BEO), ginger (GEO), lemongrass (LEO), caraway (CAEO), rosemary (REO), Eucalyptus globulus (EGEO), tea tree (TTEO), orange peel (OPEO) and apricot (Prunus armeniaca) kernel (AKEO) essential oils). Finally, we discuss the influence of EOs on the mechanical strength of bio-based materials.

Authentication of Citrus spp. Cold-Pressed Essential Oils by Their Oxygenated Heterocyclic Components

Citrus essential oils are routinely adulterated because of the lack of regulations or reliable authentication methods. Unfortunately, the relatively simple chemical makeup and the tremendous price variations among Citrus varieties encouraged the interspecies adulteration of citrus oils. In this study, a sensitive UPLC-MS/MS method for the quantitation of 14 coumarins and furanocoumarins is developed and validated. This method was applied to screen the essential oils of 12 different Citrus species. This study, to our knowledge, represents the most comprehensive investigation of coumarin and furanocoumarin profiles across commercial-scale Citrus oils to date. Results show that the lowest amount was detected in calamansi oil. Expressed oil of Italian bergamot showed the highest furanocoumarin content and the highest level of any individual furanocoumarin (bergamottin). Notable differences were observed in the coumarin and furanocoumarin levels among oils of different crop varieties and origins within the same species. Potential correlations were observed between bergapten and xanthotoxin which matches with known biosynthetic pathways. We found patterns in furanocoumarin profiles that line up with known variations among the Citrus ancestral taxa. However, contrary to the literature, we also detected xanthotoxin in sweet orange and members of the mandarin taxon. Using multivariate analysis, we were able to divide the Citrus oils into 5 main groups and correlate them to the coumarin compositions.

Inhalation Aromatherapy via Brain-Targeted Nasal Delivery: Natural Volatiles or Essential Oils on Mood Disorders

Mood disorders, also often referred to as affective disorders, are a group of psychiatric illnesses that severely impact mood and its related functions. The high medical expenditures have placed a significant financial burden on patients and their families. Aromatherapy is an alternative and complementary treatment that utilizes essential oils (EOs) or volatile oils (VOs) to achieve major therapeutic goals. In general, EOs are volatile chemicals that enter the body primarily through skin absorption and/or nasal inhalation. In addition, they can work through oral administration. Inhalation aromatherapy has shown unique advantages for treating mood disorders, especially depression, anxiety and mental disorders such as sleep disorder, which have been validated over the last decade through clinical and animal studies. Accumulating evidence has shown that EOs or VOs can bypass the blood-brain barrier to target brain tissue through the nasal-brain pathway. Subsequently, they act on the cerebral cortex, thalamus, and limbic system in the brain to improve symptoms of anxiety, depression and improve sleep quality. Here, we review the natural aromatic plants’ volatiles or essential oils used commonly as adjuncts to manage mood disorders and illustrate the mechanisms of inhalation aromatherapy, and mainly summarized the application of transnasal inhalation aromatherapy in depression, anxiety, and sleep disorders. We conclude that aromatherapy does not cause side-effects, which is vastly different from commonly used psychotropic drugs. Inhalation aromatherapy via brain-targeted nasal delivery offers potentially efficacious treatment for mental disorders and merits further study.

Formulation of Biscuits Fortified with a Flour Obtained from Bergamot By-Products (Citrus bergamia, Risso)

Bergamot belongs to the Rutaceae family and is a typical fruit grown principally in the province of Reggio Calabria (South Italy). Nowadays, its industrial use is mostly related to the extraction of the essential oil contained in the flavedo but also to a lesser extent the extraction of the juice (from the pulp), which is rich in antioxidants. However, the pressed pulp (known as Pastazzo) is either used for animal feed or is discarded. The aim of this research was to study the effect of bergamot Pastazzo flour in shortbread biscuits. Pastazzo flour partially replaced the 00 wheat flour in different percentages (2.5%, 5%, 10% and 15%). Simultaneously, a sample without the addition of pastazzo flour (control) was analyzed, thus obtaining five biscuit samples. Cooking was done in a ventilated oven at 180 °C. The baking time was different for the control and the enriched samples depending on when the desired color was reached. The control took 12 min, while the enriched samples reached the desired color in 8 min. All samples were subjected to physicochemical and antioxidant characterization, as well as total polyphenols and flavonoids. The use of pastazzo flour resulted in a slight increase in water activity and humidity values. pH values decreased for all the enriched samples compared to the control, but this was more relevant for the samples enriched with 10 and 15% of flour from by-products. Hardness varied from 1823 g (Control) to 2022 and 2818 g (respectively, for 2.5% and 15% bergamot Pastazzo flour in the recipe). Total phenol content varied from 0.14 mg GAE g−1 (Control) to 0.60 and 3.64 mg GAE g−1 (respectively, for 2.5% and 15% bergamot Pastazzo flour in the recipe). The obtained results demonstrated that the use of pastazzo flour had a positive influence on the antioxidant content, with values which increased as more pastazzo flour was added.

The Second Life of Citrus Fruit Waste: A Valuable Source of Bioactive Compounds

Citrus fruits (CF) are among the most widely cultivated fruit crops throughout the world and their production is constantly increasing along with consumers' demand. Therefore, huge amounts of waste are annually generated through CF processing, causing high costs for their disposal, as well as environmental and human health damage, if inappropriately performed. According to the most recent indications of an economic, environmental and pharmaceutical nature, CF processing residues must be transformed from a waste to be disposed to a valuable resource to be reused. Based on a circular economy model, CF residues (i.e., seeds, exhausted peel, pressed pulp, secondary juice and leaves) have increasingly been re-evaluated to also obtain, but not limited to, valuable compounds to be employed in the food, packaging, cosmetic and pharmaceutical industries. However, the use of CF by-products is still limited because of their underestimated nutritional and economic value, hence more awareness and knowledge are needed to overcome traditional approaches for their disposal. This review summarizes recent evidence on the pharmacological potential of CF waste to support the switch towards a more environmentally sustainable society.

Optical Investigation of Essential Oils Using Absorbance and Photoluminescence

Essential oils are complex mixtures of organic substances with large commercial importance in the pharmaceutical, food, fragrance, and cosmetic industries due to their organoleptic and biological properties. Also, these materials are also luminescent what has taken several studies about its potential uses for the detection and quality control of essential oils, imaging, and for the investigation of the synergies of their constituents. Concerning this, the present work is dedicated to studying the optical properties of selected essential oils: citronella (Cymbopogon winterianus), Japanese mint (Mentha arvensis), clove bud (Syzygium aromaticum), and bergamot (Citrus bergamia). We carried out a comparative study of the photoluminescence and the ultraviolet-visible optical absorption (abs-UV-Vis) of these essential oils with their typical constituents. To inspect the effects of the intermolecular interactions on the optical response of these systems, mixtures between the essential oils constituents following the expected average percent mass fraction were also studied. From these experiments, the main results were bathochromic effects in the abs-UV-Vis spectra; excimer formation in citral, isopulegol, isomenthone, eugenol, and eugenyl acetate; excimer emission enhancing and specific solvent effect in the essential oils photoluminescence spectra. These results contribute to the knowledge of essential oils' applications, especially in the evaluation of components' interactions through a simple abs-UV-Vis assay.

Bergamottin and 5-Geranyloxy-7-methoxycoumarin Cooperate in the Cytotoxic Effect of Citrus bergamia (Bergamot) Essential Oil in Human Neuroblastoma SH-SY5Y Cell Line

The plant kingdom has always been a treasure trove for valuable bioactive compounds, and Citrus fruits stand out among the others. Bergamottin (BRG) and 5-geranyloxy-7-methoxycoumarin (5-G-7-MOC) are two coumarins found in different Citrus species with well-acknowledged pharmacological properties. Previously, they have been claimed to be relevant in the anti-proliferative effects exerted by bergamot essential oil (BEO) in the SH-SY5Y human neuroblastoma cells. This study was designed to verify this assumption and to assess the mechanisms underlying the anti-proliferative effect of both compounds. Our results demonstrate that BRG and 5-G-7-MOC are able to reduce the proliferation of SH-SY5Y cells, inducing apoptosis and increasing cell population in sub-G0/G1 phase. Moreover, we demonstrated the pro-oxidant activity of the two coumarins that increased reactive oxygen species and impaired mitochondrial membrane potential. From a molecular point of view, BRG and 5-G-7-MOC were able to modulate apoptosis related factors at both protein and gene levels. Lastly, we evaluated the synergistic effect of their combination, finding that the highest synergy was observed at a concentration ratio similar to that occurring in the BEO, supporting our initial hypothesis. Taken together, our results deepen the knowledge regarding the effect of BRG and 5-G-7-MOC in SH-SY5Y cells, emphasizing the relevance of their cooperation in achieving this effect.

Development of a Novel Microwave Distillation Technique for the Isolation of Cannabis sativa L. Essential Oil and Gas Chromatography Analyses for the Comprehensive Characterization of Terpenes and Terpenoids, Including Their Enantio-Distribution

A microwave distillation method was optimized for the extraction and isolation of cannabis essential oil from fresh and dried hemp inflorescences. The developed method enabled us to obtain a distilled product rich in terpenes and terpenoid compounds, responsible of the typical and unique smell of the cannabis plant. The distillate from different hemp cultivars, including Kompolti, Futura 75, Carmagnola, Felina 32 and Finola were characterized by using a gas chromatograph equipped with both mass spectrometer and flame ionization detectors. In a single chromatographic run, the identity and absolute amounts of distilled compounds were determined. Peak assignment was established using a reliable approach based on the usage of two identification parameters, named reverse match, and linear retention index filter. Absolute quantification (mg g⁻¹) of the analytes was performed using an internal standard method applying the flame ionization detector (FID) response factors according to each chemical family. An enantio-GC-MS method was also developed in order to evaluate the enantiomeric distribution of chiral compounds, an analytical approach commonly utilized for establishing the authenticity of suspicious samples.

Antioxidant, Antimicrobial, and Other Biological Properties of Pompia Juice

Pompia is a Citrus species belonging to Sardinian endemic biodiversity. Health benefits were attributed to its flavedo rind extracts and essential oils while the juice qualities have never been investigated. In this paper, the antioxidant, antimicrobial, and other biological properties of Pompia juice were studied. A combined LCMS/electrochemical/biological approach was used to clarify a still debated phylogeny of this species and to explain the role of its juice phenolic compounds. A closer phylogenetic relationship with lemon and citron, rather than oranges was suggested. Sensors-based electrochemical measures, together with LCMS qualitative and quantitative analyses, revealed a high contribution of ascorbic acid and phenolics with low redox potential, isorhamnetin 3-O-rutinoside, diosmin, and diosmetin 6,8-diglucoside, to antioxidant capacity. The biological assays demonstrated a marked effect of low concentration of Pompia juice against reactive oxygen species (ROS) starting from 50 µg mL⁻¹, and a moderate capacity to reduce ROS damages on cell membrane. Treatments with Pompia juice also resulted in a significant reduction (20%) of the metabolic activity of SW48 colon cancer cells. Lastly, MIC, MBC, and MBIC antimicrobial assays demonstrated that Pompia and lemon juices have inhibitory and antibiofilm effects against the pathogenic bacteria Pseudomonas aeruginosa, Streptococcus aureus, and Enterococcus faecalis.

Mechanisms Underlying the Anti-Inflammatory Activity of Bergamot Essential Oil and Its Antinociceptive Effects

Renewed interest in natural products as potential source of drugs led us to investigate on both the anti-inflammatory and anti-nociceptive activity of Citrus bergamia Risso et Poiteau (bergamot) essential oil (BEO). Carrageenan-induced paw edema in rats was used as an experimental model of inflammation. Because of the toxicity of furocoumarins, we performed our study by using the BEO fraction deprived of these compounds (BEO-FF). Treatment with BEO-FF led to a significant inhibition of paw edema induced by a sub-plantar injection of carrageenan. Moreover, histological examination of BEO-FF-treated rat paw biopsies showed a reduction of pathological changes typical of edema. Pre-treatment with BEO-FF significantly reduced interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α levels in the paw homogenates, as well as nitrite/nitrate and prostaglandin E₂ (PGE₂) content in exudates. In addition, BEO-FF possesses antioxidant properties, as determined by cell-free assays. Furthermore, results of the writhing test showed that BEO-FF elicited a pronounced analgesic response, as demonstrated by a significant inhibition of constrictions in mice receiving acetic acid, with respect to control animals, whereas the results of the hot plate test suggested that the supra-spinal analgesia participates in the anti-nociceptive effect of BEO-FF. Our study indicates that BEO-FF exerts anti-inflammatory and anti-nociceptive effects, and suggests its potential role as an anti-edemigen and analgesic drug.

Essential Oils as Antiviral Agents. Potential of Essential Oils to Treat SARS-CoV-2 Infection: An In-Silico Investigation

Essential oils have shown promise as antiviral agents against several pathogenic viruses. In this work we hypothesized that essential oil components may interact with key protein targets of the 2019 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A molecular docking analysis was carried out using 171 essential oil components with SARS-CoV-2 main protease (SARS-CoV-2 Mpro), SARS-CoV-2 endoribonucleoase (SARS-CoV-2 Nsp15/NendoU), SARS-CoV-2 ADP-ribose-1″-phosphatase (SARS-CoV-2 ADRP), SARS-CoV-2 RNA-dependent RNA polymerase (SARS-CoV-2 RdRp), the binding domain of the SARS-CoV-2 spike protein (SARS-CoV-2 rS), and human angiotensin-converting enzyme (hACE2). The compound with the best normalized docking score to SARS-CoV-2 Mpro was the sesquiterpene hydrocarbon (E)-β-farnesene. The best docking ligands for SARS-CoV Nsp15/NendoU were (E,E)-α-farnesene, (E)-β-farnesene, and (E,E)-farnesol. (E,E)-Farnesol showed the most exothermic docking to SARS-CoV-2 ADRP. Unfortunately, the docking energies of (E,E)-α-farnesene, (E)-β-farnesene, and (E,E)-farnesol with SARS-CoV-2 targets were relatively weak compared to docking energies with other proteins and are, therefore, unlikely to interact with the virus targets. However, essential oil components may act synergistically, essential oils may potentiate other antiviral agents, or they may provide some relief of COVID-19 symptoms.

Inhibition of Neuromuscular Contractions of Human and Rat Colon by Bergamot Essential Oil and Linalool: Evidence to Support a Therapeutic Action

Bergamot essential oil (BEO) added to food and drink promotes a citrus flavour. Folklore suggests benefits on gastrointestinal functions but with little supporting evidence. BEO and major constituents (linalool, limonene, linalyl acetate) were therefore examined for any ability to influence neuromuscular contractions of human and rat colon. Circular muscle strips (macroscopically-normal human colon obtained following ethical approval at cancer surgery; Sprague-Dawley rats) were suspended in baths (Krebs solution; 37 °C; 5% CO₂ in O₂) for measurement of neuronally-mediated contractions (prevented by tetrodotoxin or atropine) evoked by electrical field stimulation (5 Hz, 0.5 ms pulse width, 10s/minute, maximally-effective voltage), or contractions evoked by KCl (submaximally-effective concentrations). BEO and each constituent concentration dependently inhibited neuronally-mediated and KCl-induced contractions. In human: apparent pIC₅₀ for BEO (volume/volume Krebs), respectively, 3.8 ± 0.3 and 4.4 ± 0.3; I_max 55.8% ± 4.2% and 37.5% ± 4.2%. For the constituents, the rank order of potency differed in human (linalool > limonene >> linalyl-acetate) and rat colon (linalyl-acetate > limonene = linalool), but rank order of efficacy was similar (linalool >> (BEO) = linalyl-acetate >> limonene). Thus, linalool had high efficacy but greater potency in human colon (I_max 76.8% ± 6.9%; pIC₅₀ 6.7 ± 0.2; n = 4) compared with rat colon (I_max 75.3% ± 1.9%; pIC₅₀ 5.8 ± 0.1; n = 4). The ability of BEO and linalool to inhibit human colon neuromuscular contractility provides a mechanism for use as complementary treatments of intestinal disorders.

Anxiolytic Terpenoids and Aromatherapy for Anxiety and Depression

In our society, anxiety and depression are serious health issues that affect a large proportion of the population. Unfortunately, drug therapies are not always effective and can lead to drug abuse, delay of therapeutic effect, dependence, and tolerance. Traditionally, aromatherapy has also been used for anxiety relief and mood improvement. The use of essential oils, in relieving anxiety and depression, does not have the disadvantages associated with currently used drug therapies. In-vivo studies on animal models have verified the anxiolytic effects of these essential oils and the interactions of their major components with central nervous system receptors. Therefore, it seems reasonable to argue that the modulation of glutamate and GABA neurotransmitter systems are likely to be the critical mechanisms responsible for the sedative, anxiolytic, and anticonvulsant proprieties of linalool and essential oils containing linalool in significant proportions. Popular anxiolytic essential oils are generally rich in terpenoid alcohols like linalool, geraniol and citronellol, and the monoterpene limonene (or citral). Therefore, other essential oils or formulations that contain these terpenoids as major components may serve as important aromatherapeutics for relief of anxiety.

Impact of essential oil from plants on migratory activity of Sitophilus granarius and Tenebrio molitor

Measures against pests should be performed in the context of integrated management of agricultural crops and complex control of pests. Therefore, use of ecologically safe approaches is the best option. Essential oils of plants can make an impact on the main metabolic, biochemical, physiological and behavioural functions of insects. We evaluated the effect of 18 essential oils and 18 dried plants on migratory activity of Sitophilus granarius (Linnaeus, 1758) and Tenebrio molitor Linnaeus, 1758 in conditions of laboratory experiment. Notable repellent activity against S. granarius was exhibited by Citrus sinensis and Picea abies. Repellent action against T. molitor was displayed by dried and cut leaves of Origanum vulgare and Eucalyptus globulus, and also essential oils from Juniperus communis, Р. abies, Pterocarpus santalinus, C. sinensis and C. aurantiifolia. Therefore, out of 18 studied essential oils, only two samples had a notable biological effect on migratory activity of S. granarius and five samples – on T. molitor. These data indicate a possibility of using essential oils or their main components as ecologically safe natural repellents against pests of stored wheat and products of its processing.

Solid-phase microextraction-gas chromatography and ultra-high performance liquid chromatography applied to the characterization of lemon wax, a waste product from citrus industry

A novel application of SPME-GC and UHPLC is presented for the elucidation of an unexplored citrus by-product, namely lemon wax. In view of the current environmental protection strategies, directed toward reuse and/or recovery of waste products, this study aimed to evaluate a possible utilization of a discarded fraction from citrus fruits processing. Headspace SPME coupled with GC-MS and GC-FID allowed determining a residual amount (162.25 mg kg^-1) of lemon volatiles, by means of accurate calibration of 38 terpenoids through linear regression analysis (R² = 0.99). SPME method development, was supported by statistical analysis, consisting of experimental design and multisample comparison, where parameters such as type of coating, temperature and time of fiber exposure, were manipulated towards optimization. The optimized method was validated, showing limits of quantification (LOQ) and of detection (LOD) in the ranges 0.24 - 2.65 ng g^-1 and 0.11 - 0.87 ng g^-1, respectively; recoveries ranged from 84.9% to 111.5%. After optimization and validation, the UHPLC-PDA method revealed the presence in lemon wax samples of six coumarins, the most abundant being bergamottin (964 mg kg^-1), followed, in decreasing amount, by citropten, 8-geranyloxypsoralen, biacangelicin, oxypeucedanin, 5-geranyloxy-7-methoxycoumarin; each analyte was calibrated by external standard methodology. Sensitivity (LOD, 31 - 112 ng g^-1; LOQ, 102-370 ng⋅ g^-1), accuracy (recovery, 81-94%), and precision (Retention time RSD, 0.03 - 0.09%; peak area RSD, 1.03-2.92%), were also measured.

Volatile Compounds in Citrus Essential Oils: A Comprehensive Review

The essential oil fraction obtained from the rind of Citrus spp. is rich in chemical compounds of interest for the food and perfume industries, and therefore has been extensively studied during the last decades. In this manuscript, we provide a comprehensive review of the volatile composition of this oil fraction and rind extracts for the 10 most studied Citrus species: C. sinensis (sweet orange), C. reticulata (mandarin), C. paradisi (grapefruit), C. grandis (pummelo), C. limon (lemon), C. medica (citron), C. aurantifolia (lime), C. aurantium (bitter orange), C. bergamia (bergamot orange), and C. junos (yuzu). Forty-nine volatile organic compounds have been reported in all 10 species, most of them terpenoid (90%), although about half of the volatile compounds identified in Citrus peel are non-terpenoid. Over 400 volatiles of different chemical nature have been exclusively described in only one of these species and some of them could be useful as species biomarkers. A hierarchical cluster analysis based on volatile composition arranges these Citrus species in three clusters which essentially mirrors those obtained with genetic information. The first cluster is comprised by C. reticulata, C. grandis, C. sinensis, C. paradisi and C. aurantium, and is mainly characterized by the presence of a larger abundance of non-terpenoid ester and aldehyde compounds than in the other species reviewed. The second cluster is comprised by C. junos, C. medica, C. aurantifolia, and C. bergamia, and is characterized by the prevalence of mono- and sesquiterpene hydrocarbons. Finally, C. limon shows a particular volatile profile with some sulfur monoterpenoids and non-terpenoid esters and aldehydes as part of its main differential peculiarities. A systematic description of the rind volatile composition in each of the species is provided together with a general comparison with those in leaves and blossoms. Additionally, the most widely used techniques for the extraction and analysis of volatile Citrus compounds are also described.

Antioxidant and Antisenescence Effects of Bergamot Juice

Aging is one of the main risk factor for the onset of cardiovascular diseases; one of the possible explanations could be linked to the age-associated overproduction of free radicals. This increase of oxidative stress can be overcome with a high intake of food antioxidants. In this context, a number of studies have been addressed to assess the antiaging potential of natural antioxidant compounds. Recently, it has been shown that the juice of bergamot (Citrus bergamia Risso et Poiteau), a fruit mostly produced in the Ionian coastal areas of Southern Italy (Calabria), is a valuable source of health-promoting constituents with, among other, antioxidant properties. In order to investigate the potential antiaging effects of this Mediterranean natural antioxidant source, bergamot juices of three different cultivars (“fantastico,” “femminello,” and “castagnaro”) were herein characterized by the mean of high-performance liquid chromatography-photodiode array-electrospray ionization-tandem mass spectrometry. Then, juices were investigated for the evaluation of total polyphenolic and flavonoid contents, cell-free model antioxidant activities, and in vitro antiaging properties on two different cellular models of induced myocardial senescence. The best performing juice was also assessed in vivo. The phytochemical profiles confirmed that juices were rich in flavonoids, both flavone and flavanone glycosides. In addition, two limonoid glycosides were also identified in all cultivars. Each cultivar showed different phenolic and flavonoid contents. In tube results showed the juice robust antioxidant activities that correlate with their phenolic and flavonoid contents. Moreover, for the first time, the ability of juice to counteract the chemical-induced senescence was here demonstrated in both cellular models. Lastly, the in vivo data obtained from mouse hearts evidenced an increase in transcription of genes involved in antiaging and antioxidant responses. The overall results suggest that bergamot juice exerts antioxidant and antisenescence effects, making it useful for nutraceutical purposes.

Anticancer Potential of Citrus Juices and Their Extracts: A Systematic Review of Both Preclinical and Clinical Studies

Background: During the last decades, a huge body of evidence has been accumulated suggesting that Citrus fruits and their juices might have a role in preventing many diseases including cancer.

Objective: To summarize the numerous evidences on the potential of Citrus juices and their extracts as anticancer agents.

Data sources: A systematic review of articles written in English using MEDLINE (1946-present), EMBASE (1974-present) and Web of Sciences (1970-present) was performed independently by two reviewers. Search terms included Citrus, Citrus aurantifolia, Citrus sinensis, Citrus paradisi, Citrus fruits, Citrus fruits extract, cancer, neoplasm, neoplasia, tumor, metastasis, carcinogenesis, proliferation. The last search was performed on March 16th, 2017.

Study selection: Study selection and systematic review were carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Prior to the beginning of the review, Authors defined a checklist for inclusion criteria, thus including articles which meet the following: (i) published on peer-reviewed scientific journals; (ii) Citrus juice used alone; (iii) extracts derived from Citrus juice; (iii) for preclinical studies, an exposure time to Citrus juices and their extracts more than 24 h. Reviews, meta-analyses, conference abstracts and book chapters were excluded.

Data extraction: Three reviewers independently performed the extraction of articles.

Data synthesis: 22 papers met our inclusion criteria and were eligible for inclusion in the final review. According to the kind of study, the selected ones were further divided in preclinical (n = 20) and observational (n = 2) studies.

Conclusion: The studies discussed in this review strongly corroborate the role of Citrus juices and their derivatives as potential resource against cancer.

Bergamot Essential Oil Attenuates Anxiety-Like Behaviour in Rats

Preclinical studies have recently highlighted that bergamot essential oil (BEO) is endowed with remarkable neurobiolological effects. BEO can affect synaptic transmission, modulate electroencephalographic activity and it showed neuroprotective and analgesic properties. The phytocomplex, along with other essential oils, is also widely used in aromatherapy to minimize symptoms of stress-induced anxiety and mild mood disorders. However, only limited preclinical evidences are actually available. This study examined the anxiolytic/sedative-like effects of BEO using an open field task (OFT), an elevated plus-maze task (EPM), and a forced swimming task (FST) in rats. This study further compared behavioural effects of BEO to those of the benzodiazepine diazepam. Analysis of data suggests that BEO induces anxiolytic-like/relaxant effects in animal behavioural tasks not superimposable to those of the DZP. The present observations provide further insight to the pharmacological profile of BEO and support its rational use in aromatherapy.

Effectiveness of Citrus Fruits on Helicobacter pylori

It is known that Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer, and gastric carcinoma. Due to the increased side effects of the treatment regimens and the development of antimicrobial resistance, a number of natural compounds have been tested as potential alternatives. In this review, we will examine the current knowledge on the effect of Citrus fruits and their derivatives against H. pylori, highlighting the remaining outstanding questions on the development of novel therapeutic strategies.

Anti-Inflammatory Activity of Citrus bergamia Derivatives: Where Do We Stand?

Inflammatory diseases affect a large portion of the worldwide population, and chronic inflammation is a major risk factor for several dangerous pathologies. To limit the side effects of both synthetic and biological anti-inflammatory drugs, the use of herbal medicines, nutraceuticals and food supplements has increased tremendously as alternative and/or complementary medicine to treat several pathologies, including inflammation. During the last decades, the biological properties of Citrus bergamia (bergamot) derivatives have obtained important scientific achievements, and it has been suggested their use in a context of a multitarget pharmacological strategy. Here, we present an overview of the anti-inflammatory properties of bergamot extracts that could represent the scientific basis for develop novel and alternative strategies to improve health status and attenuate inflammatory conditions.

Anti-infective potential of Citrus bergamia Risso et Poiteau (bergamot) derivatives: a systematic review

Infectious diseases remain among the leading causes of morbidity and mortality worldwide, mainly because of the increase of resistance to chemotherapeutic drugs. Nature is the major source of anti-infective drugs and could represent a font of medicines that may help overcome antibiotic resistance. Recently, the potential antimicrobial effect of certain plant extracts has attracted attention within the scientific community as alternatives to synthetic drugs. Here, we present a systematic review on the anti-infective properties of bergamot derivatives that highlight the activity of bergamot essential oil against bacteria, mycetes and larvae, as well as the anti-Helicobacter pylori effect of bergamot juice and the antimicrobial properties of extracts from bergamot peel. Findings presented herein could be used to develop novel and alternative preventive and therapeutic strategies aimed to overcome antibiotic resistance. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of bergamot essential oil and its extractive fractions on SH-SY5Y human neuroblastoma cell growth

Objectives

The goals were to investigate the mechanisms underlying the antiproliferative effects of bergamot essential oil (BEO) and to identify the compounds mainly responsible for its SH-SY5Y cells growth rate inhibition.

Methods

Five BEO extractive fractions (BEOs) differing in their chemical composition were used. Cell proliferation was determined by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and cell count assays. Trypan blue exclusion test and Annexin V/PI staining were performed to assess their cytotoxic activity. Genotoxicity was detected by comet assay. The cell cycle was checked cytofluorimetrically. Reactive oxygen species (ROS) and Δψm were measured fluorimetrically. Western blotting analyses for some apoptosis-related proteins were carried out.

Key findings

Treatment of SH-SY5Y cells with some types of BEOs decreased cell growth rate by a mechanism correlated to both apoptotic and necrotic cell death. Coloured BEOs act by increasing ROS generation, responsible for the drop in Δψm, and modulate p38 and extracellular signal-regulated kinases (ERK ½) mitogen-activated protein kinases, p53, Bcl-2 and Bax signalling pathways. Finally, we identify bergamottin and 5-geranyloxy-7-methoxycoumarin as the bioactive molecules that could play a pivotal role in the antiproliferative effects exerted by coloured BEOs.

Conclusions

Our study provides novel insights into the field of the antiproliferative effects of BEO, which could be exploited in the context of a multitarget pharmacological strategy.

Citrus bergamia essential oil: from basic research to clinical application

Citrus bergamia Risso et Poiteau, also known as "Bergamot," is a plant belonging to the Rutaceae family, defined as a hybrid of bitter orange and lemon. It is an endemic plant of the Calabria region (Italy). Bergamot fruit is primarily used for the extraction of its essential oil (bergamot essential oil: BEO), employed in perfume, cosmetics, food, and confections. The aim of this review was to collect recent data from the literature on C. bergamia essential oil and, through a critical analysis, focus on safety and the beneficial effects on human health. Clinical studies on the therapeutic applications of BEO exclusively focus on the field of aromatherapy, suggesting that its use can be useful for reducing anxiety and stress.

Assessment of dietary exposure to flavouring substances via consumption of flavoured teas. Part II: transfer rates of linalool and linalyl esters into Earl Grey tea infusions

The assessment of dietary exposure via the consumption of flavoured foods is a key element of the safety evaluation of flavouring substances. Linalyl acetate and linalool are the major flavouring substances in Earl Grey teas; the objective of this study was to determine their transfer rates from the tea leaves into the tea beverage upon preparation of a hot water infusion. Spiking experiments revealed a transfer rate of 66% for linalool. In contrast, the transfer rate for linalyl acetate was only 1.9%; in turn, the hydrolysis product linalool (17.0%) and a spectrum (19.9%) of degradation and rearrangement products (monoterpene alcohols, esters and hydrocarbons) were present in the tea beverage. The transfer rates were shown to be proportional to the length of the infusion. The impact of the hot water treatment on the enantiomeric compositions of linalyl acetate and linalool was determined, and structure-dependent experiments were performed by variation of the acyl and the alcohol moiety of the monoterpene ester. Comparative dietary exposure assessments demonstrated the need to take correction factors based on the experimentally determined transfer rates into account. Based on tea consumption data from the UK National Diet and Nutrition Survey (2000/2001), the exposure to linalyl acetate ranges from 0.2 mg day(-1) (average) to 1.8 mg day(-1) (high). The corresponding values for linalool are 4.2 mg day(-1) (average) and 46.6 mg day(-1) (high). The exposure of linalool via consumption of the tea beverage is approximately 26 times higher than that of linalyl acetate, although in the flavoured tea leaves the median content of linalyl acetate is approximately 1.8 times higher than that of linalool.

Anticancer activity of liposomal bergamot essential oil (BEO) on human neuroblastoma cells

Citrus extracts, particularly bergamot essential oil (BEO) and its fractions, have been found to exhibit anticancer efficacy. However, the poor water solubility, low stability and limited bioavailability have prevented the use of BEO in cancer therapy. To overcome such drawbacks, we formulated BEO liposomes that improved the water solubility of the phytocomponents and increased their anticancer activity in vitro against human SH-SY5Y neuroblastoma cells. The results warrant further investigation of BEO liposomes for in vivo applications.