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Characterization of Essential Oil from Citrus aurantium L. Flowers: Antimicrobial and Antioxidant Activities
Abstract
Citrus aurantium L. essential oil is commonly used as a flavouring agent. In the present study, the essential oil of fresh Citrus aurantium L. (CaEO) flowers cultivated in North East of Tunisia (Nabeul) was analyzed by GC-FID and GC-MS. 33 compounds were identified, representing 99% of the total oil. Limonene (27.5%) was the main component followed by E-nerolidol (17.5%), α-terpineol (14%), α-terpinyl acetate (11.7%) and E. E-farnesol (8%). The antimicrobial activity of the CaEO was evaluated against a panel of 13 bacteria and 8 fungal strains using agar diffusion and broth microdilution methods. Results have shown that the CaEO exhibited moderate to strong antimicrobial activity against the tested species. The investigation of the mode of action of the CaEO by the time-kill curve showed a drastic bactericidal effect after 5 min using a concentration of 624 μg/ml. The antioxidant activities of the CaEO were assayed by DPPH and beta carotene tests. Results showed that CaEO displayed an excellent DPPH scavenging ability with an IC50 of 1.8 μg/ml and a strong Beta-carotene bleaching inhibition after 120 min of incubation with an IC50 of 15.3 μg/ml. The results suggested that the CaEO possesses antimicrobial and antioxidant properties, and is therefore a potential source of active ingredients for food and pharmaceutical industry.
... Similarly, Rahimi et al. [44] reported a higher content of linalool and a lower content of linalyl acetate in Iranian flower EO, which also contained significant amounts of limonene. Hsouna et al. [45] and Ammar et al. [46] identified limonene (27.14% and 27.5%, respectively) and α-terpineol (14% in both studies) as the main constituents, which are in contrast to the lower limonene contents in our results. In addition, Okla et al. [43] identified geraniol, α-terpineol, linalool, and benzene acetaldhehyde as the major components for Iranian Neroli. ...
... Of the EOs tested, EO2 showed the strongest antimicrobial activity. Previous studies have found higher inhibition zones for the EOs of C. aurantium flowers than our findings [39,[44][45][46]. These differences can be attributed to the geographical origin of the flowers (Iran and Morocco) and the year of the collection of the plant material. ...
... The ratio between the MBC and MIC values indicated a strong bactericidal effect, especially for EO1 and EO3, which showed a ratio close to 1 for most strains, suggesting high efficacy in killing bacterial cells at the concentrations necessary for growth inhibition. EO2 also demonstrated significant efficacy, particularly against B. cereus and S. enterica, although with varying potency against different strains [39,[44][45][46]. This broad-spectrum bactericidal activity is consistent with previous studies demonstrating the efficacy of C. aurantium EOs against various bacterial strains. ...
Essential oils (EOs) from various medicinal and aromatic plants are known for their diverse biological activities, including their antimicrobial effects. Citrus aurantium EO is traditionally used for therapeutic benefits due to its high content of bioactive compounds. Therefore, this study focuses on its potential use as a food preservative by investigating the combined antibacterial properties of EOs from leaves (EO1), flowers (EO2), and small branches (EO3) of Citrus aurantium against six bacterial strains by the agar disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. The chemical compositions of the EOs were analysed by gas chromatography–mass spectrometry (GC-MS) and revealed the presence of numerous compounds responsible for their antimicrobial properties. The MIC values for the EOs were 3.12 mg/mL, 4.23 mg/mL, and 1.89 mg/mL, for EO1, EO2 and EO3, respectively, while the MBC values were 12.5 mg/mL, 6.25 mg/mL, and 6.25 mg/mL, respectively. A simplex centroid design was created to analyse the effect of the individual and combined EOs against E. coli. The combined EOs showed enhanced antibacterial activity compared to the individual oils, suggesting a synergistic effect (e.g., trial 9 with an MIC of 0.21 mg/mL), allowing the use of lower EO concentrations and reducing potential negative effects on food flavour and aroma. Additionally, the practical application of investigated EOs (at concentrations twice the MIC) was investigated in raw chicken meat stored at 4 °C for 21 days. The EOs, individually and in combination, effectively extended the shelf life of the meat by inhibiting bacterial growth (total bacterial count of less than 1 × 104 CFU/g in the treated samples compared to 7 × 107 CFU/g in the control on day 21 of storage). The study underlines the potential of C. aurantium EOs as natural preservatives that represent a sustainable and effective alternative to synthetic chemicals in food preservation.
... The plant's phytochemicals' close interaction with the target cell and subsequent solubilization of the cell membrane give rise to the plant's antibacterial characteristics. In a study conducted by Ben Hsouna et al. [24], it was discovered that Citrus aurantium contains the following monoterpenes: 27.5% limonene, 14% terpineol, 4.3% E-ocimene, and 2.4% delta-3-carene. Sesquiterpenes are said to make up 30.2% of the essential oil, with (E)-nerolidol having the highest concentration (17.5%). ...
... The essential oils of Citrus aurantium were investigated for their antibacterial activity against a panel of 13 bacterial strains using agar diffusion and broth microdilution procedures. According to the findings [24], the plant's essential oils exhibit a moderate-to-strong antibacterial activity. The antibacterial efficacy of Citrus aurantium essential oil against the two foodborne pathogens Escherichia coli and Salmonella enterica in apple juices was studied by Friedman et al. [25] in 2004. ...
... Preservative Potential Many fungi, including Aspergillus niger, Aspergillus flavus, Aspergillus nidulans, Aspergillus fumigants, Fusarium graminearum, Fusarium oxysporum, Fusarium culmorum, and Alternaria alternate, are known to be responsible for food spoilage [24]. Therefore, an agent that can inhibit the growth of these fungi will do well as a food preservative. ...
Citrus aurantium, commonly referred to as sour orange or bitter orange, holds significant importance both in biological and economic terms. Throughout history, humans have turned to nature in their pursuit of health and wellness. Among the plants that have historically played a role in enhancing fitness, Citrus
aurantium stands out. A diverse array of phytochemical constituents present in Citrus aurantium have been closely tied to its various biological activities, encompassing areas such as gastrointestinal disorders, insomnia, headaches, cancer treatment, antiseptic properties, antioxidant effects, and antispasmodic effects. Beyond its pharmacological relevance, Citrus aurantium also boasts numerous non-pharmacological applications that make it particularly intriguing. It serves as a food preservative agent, contributes to aromatherapy practices, acts
as a pesticide, provides raw materials for the pulp and paper industry, lends its aromatic qualities to the food processing and cosmetics sectors, and offers potential as an anti-aging agent. Despite its impressive array of properties, the utilization of Citrus aurantium and its derivatives has been linked to certain
unwanted side effects. While some studies have largely cleared the plant of safety concerns, others have cast doubt on its safety. This chapter delves into the complex aspects surrounding the safety of Citrus aurantium’s photochemistry and its derived products. Ultimately, the chapter advocates for the ongoing use of this plant, but with a careful awareness of its limitations to prevent any undesirable effects.
... [59] Additionally, C. aurantium leaf and flowers essential oils have displayed good antibacterial activity against six bacterial species namely, Micrococcus luteus, Enterococcus faecium, E. coli, S. enterica, Listeria monocytogenes and Pseudomonas aeruginosa. [60] Essential oil from Citrus aurantium L. (Neroli) has exhibited an antibacterial effect by inhibiting the growth of the following bacteria Bacillus subtilis, B. cereus, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Micrococcus luteus, Listeria monocytogenes, Salmonella enteritidis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia [22,61,62] further confirming its antimicrobial potency. In addition, studies elsewhere have touted the antimicrobial activity of bitter orange essential oil which inhibited the growth of Penicillium digitatum and Penicillium italicum. ...
... [55,86,87] Citrus aurantium L. essential oil has reportedly shown significant inhibition against the growth of Aspergillus Niger, A. flavus, A. nidulans, A. fusarium graminearum, F. oxyporum, C. albicans, and Alternaria alternate.- [61,62,88,89] C. reticulata essential oil also showed antifungal properties by inhibiting the growth of Aspergillus flavus and it was found to cause 40% growth inhibition [93] ( Table 2). The mandarin essential oils at the concentration of 0.1 ml/100 ml against the following plant pathogens: Alternaria alternata, Rhizoctonia solani, Curvularia lunata, Fusarium oxyporum and Helminthosporium oryzae. ...
... [179] It has also been noted that essential oil from C. aurantium demonstrated a significant insecticidal effect against four selected storage grain-insects, Cryptolestes ferrugineus, Liposcelis bostrychophila, tribolium castaneum and Sitophilus graniarum. [62] The C. aurantium fruit peels essential oil also showed a remarkable toxicity effect against the survival of Aphis punicae at LC 50 of 0.37 μL/mL and A. illinoisensis at 0.82 μL/mL in 48 hours period. [180] This finding provides hope for the effective management of these two pests affecting pomegranate and grapevine in an environmentally-friendly way. ...
Citrus essential oil (CEO) is obtained from the fruit of Genus Citrus, a flowering plant shrub in the family of the Rutaceae (Eremocitrus or Microcitrus) and extensively used in food, chemical industry, and traditional medicinal treatment owing to its pleasant aroma, antioxidant, and antiseptic properties. This review presents a botanical description, distribution, traditional uses, chemical composition, bioactive components, and the therapeutic uses as well as toxicological effects of the CEO. The objective was achieved via a comprehensive literature search of electronic databases such as Science Direct, PubMed, Web of Science, Wiley, ACS, Springer, Taylor and Francis, Google Scholar, SCOPUS, conference proceedings, thesis, and books until 2022 for publications. Citrus essential oils and their constituents are extracted and isolated either from the fruit peels, seeds, leaves, or flowers of the citrus plants. A comparative study of the sources of CEO confirmed its origin, ethnopharmacological and therapeutic uses. Over 2000 secondary metabolites have been isolated, with the main active constituents: being terpenes, monoterpenes, sesquiterpenes, and diterpenes. A comprehensive literature review revealed vast therapeutic benefits of CEO. Incomplete data report on in vitro and in vivo trials especially, on dosage, positive and negative control groups, intervention time, toxicity studies, phytochemical profiling, and clinical trials seem to be a knowledge gap.
... Ten microliters of cell suspension were added to each test well. MIC (%) values were assessed as the lowest LmEO concentration that inhibited the visible growth of each tested bacterium [5]. As an indicator of microorganism growth, 25 µL of thiazolyl blue tetrazolium bromide (0.5 mg/mL) (Sigma-Aldrich, Taufkirchen, Germany) was added to the wells and incubated for 30 min. ...
... The negative control showed no inhibitory effect against the tested bacteria. The microorganisms tested in the present study are among the most important human pathogens known to be opportunistic to humans and animals and to cause food contamination and spoilage [5]. The results obtained are of great importance, especially in the case of B. cereus and S. aureus, which are well known for their resistance to several phytochemicals, and food production, and for the production of several types of enterotoxins that cause gastroenteritis [25]. ...
... However, the synergistic effect of minor constituents should be taken into consideration in overall antimicrobial activity. In fact, both the synergistic effects and the chemical diversity of major and minor constituents present in the essential oils account for their overall biological activity [5]. ...
This study was directed towards the investigation of the chemical composition and antimicrobial properties of the essential oil of Tunisian halophyte Lobularia maritime (LmEO). The antibacterial effects against major food-borne pathogenic and food spoilage bacteria were tested using the well diffusion method, followed by the determination of the minimum inhibitory (MIC) and bactericidal (MBC) concentrations. The essential oil has shown strong antimicrobial activity against eight pathogenic strains, which was attributed mostly to predominant constituents of the essential oil: benzyl alcohol, linalool, terpien-4-ol and globulol, as well as to synergistic effects of its major and minor constituents. Considering strong antimicrobial effects of the tested essential oil, it was further
tested as a natural alternative to food preservatives, using minced beef meat as a model system. Minced beef meat was spiked with 0.019, 0.038, and 0.076% of the essential oil and stored during 14 days at 4 °C, monitoring its microbiological, physicochemical, and sensory properties. Chemical analyses revealed that meat treated with 0.076% of LmEO at underwent a significant decrease (p < 0.05) in primary and secondary lipid oxidation and reduced metmyoglobin accumulation compared with control samples. Furthermore, microflora proliferation in the meat model system spiked with 0.076% of LmEO was significantly (p < 0.05) reduced in comparison to control. In addition, two multivariate exploratory techniques, namely principal component analysis (PCA) and hierarchical
analysis (HCA), were applied to the obtained data sets to describe the relationship between the main characteristics of the meat samples with and without essential oil addition. The chemometric approach highlighted the relationships between meat quality parameters. Overall, results indicated that the essential oil of Lobularia maritima deserves to be considered as a natural preservative in the meat industry.
... The chemical composition of EO of sour orange (Citrus aurantium) was assessed in different plant parts during different seasons. Many studies were focused on EO extract from C. aurantium peels and Limonene was found to be the major component [10][11][12][13][14][15][16][17][18][19]. In contrast, other studies carried out on EO extract from C. aurantium flowers showed that Linalool and Linalyl acetate are the main components [13,14,20,21]. ...
... These values were typically low and concur with those reported in Tunisian and Serbian EO of C. aurantium [12,16]. In contrast, hydrosol and ethanol extracts from C. auriatium from Turkey have shown significant antioxidant activities [18]. Indeed, in this report [18], ethanol and hydrosol were used as solvents, while our study used EO as extracted by hydrodistillation. ...
... In contrast, hydrosol and ethanol extracts from C. auriatium from Turkey have shown significant antioxidant activities [18]. Indeed, in this report [18], ethanol and hydrosol were used as solvents, while our study used EO as extracted by hydrodistillation. Moreover, many of the antioxidant activities observed in C. aurantium have been assessed in EO extracted from different organs or byproducts of Citrus transformation industries. ...
Sour orange (Citrus aurantium L.), which belongs to the Rutaceae family, is used around the Mediterranean Sea for ornamental and agronomic purposes as a rootstock for the Citrus species. Peels and flowers, the most-used parts of Citrus aurantium L., have constituted a largely promising area of research for their many medicinal properties. However, the leaves of sour orange have not yet been studied extensively. The present study aimed at investigating the essential oil composition of sour orange leaves grown in Algeria and determining their antioxidant and anti-inflammatory properties. Essential oil composition of leaves harvested before flowering was determined by GC-MS. Total phenol content, antioxidant activities (DPPH) and elastase and collagenase inhibition were assessed. Forty-three volatile compounds were detected in essential oil from leaves with a yield of 0.57%. The major compounds were linalool, linalyl acetate and α-Terpineol. Results show that the total phenol content and antioxidant activity of essential oil are low, 3.48 ± 0.10 mg/g (Gallic Acid Equivalent/EO) and IC50 > 10,000 mg·L−1, respectively. In contrast, EO present an interesting level of elastase and collagenase inhibition. This result emphasizes the potential interest of the essential oil of sour orange mainly in relation to its anti-aging mechanism.
... The search for natural antibiotics has become fundamental for human health, and essential oils (EOs) represent an inexhaustible source of countless compounds with biological activity (Ben Akacha et al., 2022;Ben Hsouna, Boye, Akacha, et al., 2022;Ben Hsouna, Hfaiedh, Ben Slima, et al., 2022;Bouteraa et al., 2023). EOs play an important role in plants, acting as antibacterial, antiviral, antifungal, and insecticidal agents and protecting plants from predators and pests Ben Hsouna et al., 2013;Ben Hsouna et al., 2014;Castilho et al., 2012). They are used and valued in perfumes and cosmetic products (creams, soaps, etc.), sanitary products, dentistry, agriculture, and the food industry, as preservatives and additives (Abelan et al., 2022;Akacha et al., 2022). ...
... These results are in agreement with a study investigating the antibacterial activity of some terpene compounds from essential oils (α-terpineol, linalool, 1,8-cineole, and α-pinene), both individually and in combination, to determine their interactions at lower doses against pathogenic foods(Zengin & Baysal, 2014). Other studies have shown no antagonistic effect in these mixtures(Ben Hsouna et al., 2013Salas-Oropeza et al., 2021). ...
Pinene, α-terpineol, and 1,8-cineole are compounds naturally present in essential oils, although their amounts vary from oil to oil. Although several studies have reported their antibacterial and antioxidant effects, there are few reports on the synergistic or antagonistic effects of their combinations. The objective of this study was to investigate the combined antibacterial effect of these three compounds. To our knowledge, this is the first report on the prediction of their optimal combination using the mixture design approach. The experimental antibacterial activity of the α-pinene, α-terpineol, and 1,8-cineole mixtures depended on the proportion of each compound in the mixture and the target strain, with minimum inhibitory concentrations (MIC) ranging from 0.31 to 1.85 mg/mL. Using the increased simplex-centroid mixture design, the mixture containing 0.33% of each molecule proved to be the most effective against Bacillus cereus and had the lowest MIC values. In addition, α-pinene, α-terpineol, and 1,8-cineole showed significant antioxidant activity against 2,2-picryl-1-hydrazyl radical (DPPH), with IC 50 values of 24.53 ± 0.05, 65.63 ± 0.71, and 63.58 ± 0.01 μg/ mL, respectively. Statistical planning and the development of utility profiles of the substance mixtures can predict the optimal composition that will exhibit the highest
... Olejek eteryczny C. aurantium ma działanie hamujące wzrost licznych mikroorganizmów, m.in.: grzybów Aspergillus [15,16], Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Bacillus subtilis, Listaria monocytogenes czy Salmonella sp. [17,18]. ...
... Olejek eteryczny z Citrus aurantium wykazuje aktywność względem Aspergillus fumigatus, hamując jego wzrost całkowicie przy 10-procentowym dodatku olejku do podłoża [16], co odpowiada wynikom otrzymanym w prezentowanej pracy w odniesieniu do Aspergillus niger. Dawka powodująca działanie hamujące wzrost A. niger, jakie wykazał olejek eteryczny z gorzkiej pomarańczy C. aurantium, została określona na 1,25 mg/ml [48], co potwierdziły również wyniki badań innych autorów [17]. Różnice mogą wynikać z różnic gatunkowych pomiędzy grzybami użytymi w badaniach a grzybami wskazanymi przez innych autorów oraz z różnic w składzie badanych olejków eterycznych wynikających z różnych metod ekstrakcji czy sezonu uprawy cytrusów. ...
... Several methods use DPPH free radical to ascertain extract antioxidant potential (Ben Hsouna et al., 2013). LmPS DPPH scavenging activity was proportional to extract concentration. ...
... The antioxidant property of a compound may be correlated with its reducing effect, which is mainly associated with reductones, able to interrupt free radical chain (Ben Hsouna et al., 2013). ...
Abstract The aim of the present study was to investigate the extraction and the characterization of a novel heteropolysaccharide from Tunisian halophyte Lobularia maritima (LmPS). We were also interested in its antioxidant, anti‐inflammatory, and hepatoprotective effects on carbon tetrachloride (CCl4)‐induced liver injury in rats. LmPS physicochemical properties were evaluated by thin‐layer chromatography (TLC), high‐performance liquid chromatography (HPLC), thermogravimetric analysis (TGA), and UV absorption. According to TLC and HPLC results, LmPS was a heteropolysaccharide composed of glucose, galactose, and xylose. Its molecular weight was 130.62 kDa. This heteropolysaccharide was characterized by a significant antioxidant potential and was efficient against oxidative stress and CCL4‐induced hepatotoxicity in rat Wistar models (n = 8) treated with a single dose of LmPS 250 mg/kg of body weight. This was evidenced by a significant increase in serum marker enzymes specially aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH). The cytokines released after stimulation of rats with LmPS showed high anti‐inflammatory profiles with an increased rate of interleukine‐10 (IL‐10) with 0.03 pg/mL compared to animals treated only with CCl4. On the contrary, we noticed a decrease of the other cytokines (tumor necrosis factor α: TNF‐α, interleukine‐6: IL‐6, transforming growth factor beta 1: TGF‐β1) with average concentration values of
... These bacteria were selected because of the common diseases caused by them in the local population, such as foodborne illness, diarrhea, skin infections, urinary tract infections, respiratory system infections, vomiting, and fever (Kim et al., 1995;Hsouna et al., 2013;Son et al., 2023). The results showed that propolis oil was more active against gram-positive bacteria than gram-negative strains. ...
... Experimental studies have also shown that p-C has antioxidant potential for the brain and may act as a neuroprotective agent. This demonstrates the potential of p-C as a therapeutic development agent for important pathophysiological diseases through p-Cinduced oxidative stress [81,82]. The antimicrobial activity of p-C from the essential oils of these plants was also significant in the antimicrobial activity test of thyme, which showed greater antimicrobial activity than marjoram, which contains limonene, linalool, terpinene-4-ol, α-terpineol, and linalyl acetate [83]. ...
p-Cymene (p-C) [1-methyl-4-(1-methylethyl)-benzene] is a monoterpene found in a variety of plants and has several biological activities, including antioxidant, anti-inflammatory, antimicrobial, and anticancer properties. This paper explores the microbial fermentation pathways involved in the biosynthesis of p-C, with an emphasis on its potential as a therapeutic agent. Through microbial and biochemical processes, p-C can be produced using renewable precursors such as limonene and 1,8-cineole. Recent advances in fermentation technology have enhanced the efficiency of p-C production, highlighting its role in various industries. Additionally, this paper reviews the antimicrobial bioactivity of p-C, focusing on its ability to inhibit pathogens and modulate immune responses. The integration of microbial biosynthesis and fermentation methods offers a sustainable approach to producing p-C for applications in the perfume, cosmetics, food, and pharmaceutical sectors. Understanding these biosynthetic pathways is crucial for advancing the use of p-C as a bio-based chemical with therapeutic potential. In particular, p-C inhibits the expression of cytokine signal 3 in intestinal inflammation and modulates antioxidant and immunomodulatory systems to protect barrier cells and maintain the mucus layer.
... This shows how our test results are in alignment with previous data on antioxidant activity showing that some essential oils like Allium cepa L., Citrus aurantium, Myrtus communis, Coriandrum sativum L., and Eucalyptus oleosa revealed a clear antioxidant potential but displayed different ranges of efficacy [40,43]. Essential oils extracted from aerial parts of coriander, specifically the one cultivated in European countries, possessed the highest free radical scavenging capacity using the DPPH scavenging assay [44][45][46][47][48]. The findings of our study suggest that the essential oil from Jordanian coriander seeds in particular could be of interest in the potential prevention of lipid oxidation and binding to reactive oxygen species (ROS) in the human body, preventing oxidation damage or oxidative stress [48,49]. ...
Coriander (Coriandrum sativum L.) is a member of the Umbelliferae/Apiaceae family and one of the well-known essential oil-containing plants, in which the seeds are used in traditional medicine, and as flavoring in food preparation. Knowing the diverse chemical components of different parts of the plant, this work aims to investigate the antioxidant, the anti-inflammatory, and the immunostimulatory modulator effects of the Jordanian C. sativum’s seed extracted essential oil (JCEO). Coriander oil extract was prepared by hydro-distillation method using the Clevenger apparatus. Different concentrations of coriander oil were examined by using DPPH radical scavenging assay, MTT assay, pro-inflammatory cytokine (Tumor Necrosis Factor-TNF-alpha) production in RAW264.7 murine macrophages in addition, scratch-wound assessment, NO level examination, Th1/Th2 assay, phagocytosis assay, and fluorescence imaging using DAPI stain were conducted. JCEO had a potential metabolic enhancer effect at a concentration of 0.3 mg/mL on cell viability with anti-inflammatory activities via increasing cytokines like IL-10, IL-4, and limiting NO, INF-γ, and TNF-α release into cell supernatant. Antioxidant activity was seen significantly at higher concentrations of JCEO reaching 98.7% when using 100mg/mL and minimally reaching 50% at 12.5mg/mL of the essential oil. Treated macrophages were able to attain full scratch closure after 48-hrs at concentrations below 0.3mg/mL. The seed-extracted JCEO showed significant free radical scavenging activity even at lower dilutions. It also significantly induced an anti-inflammatory effect via an increase in the release of cytokines but reduced the LPS-induced NO and TNF-α production at 0.16–0.3mg/mL. In summary, coriander essential oil demonstrated antioxidant, anti-inflammatory, and immunostimulatory effects, showcasing its therapeutic potential at specific concentrations. The findings underscore its safety and metabolic enhancement properties, emphasizing its promising role in promoting cellular health.
... Utilizing EOs in conjunction with seed coating and priming technologies holds significant promise as a natural biostimulant, contributing substantially to the improvement of both biotic and abiotic stress resistance (Tavares et al. 2002;Lutts et al. 2016). Numerous studies have predominantly concentrated on exploring the antifungal, antibacterial, and insecticidal properties of plant EO (Ben Hsouna et al. 2013Hsouna et al. , 2019Belasli et al. 2020;Moumni et al. 2021;Ben Akacha et al. 2022;Kesraoui et al. 2022). Additionally, there is a growing interest in elucidating the role of EOs in conferring abiotic stress tolerance during the critical stages of germination and seedling growth (Biṅgöl and Battal 2017; Souri and Bakhtiarizade 2019;Ben-Jabeur et al. 2019). ...
Salt-induced stress poses a significant barrier to agricultural productivity by impeding crop growth. Presently, environmentalists are dedicated to safeguarding food security by enhancing agricultural yields in challenging environments. Biostimulants play a crucial role in mitigating abiotic stresses in crop production, and among these, plant essential oils (EOs) stand out as organic substances with diverse biological effects on living organisms. Among the natural promoters of plant growth, Rosmarinus officinalis L. essential oil (RoEO) has gained considerable attention. Although the manifold effects of essential oils (EOs) on plant growth have been extensively demonstrated, their impact on salt stress tolerance in durum wheat seedlings remains unexplored. This investigation was undertaken to evaluate the biostimulatory capabilities of RoEO on the durum wheat cultivar “Mahmoudi.” The effects of three RoEO concentrations (1, 2.5, and 5 ppm) on seed germination, growth establishment, and the induction of salt resistance under salinity conditions (150 mM NaCl) were tested. At 5 ppm, RoEO enhanced seedlings’ tolerance to salinity by improving growth and reducing membrane deterioration and oxidative stress-induced damage. The expression profile analyses of seven stress-related genes (TdNHX1, TdSOS1, TdSOD, TdCAT, TdGA20-ox1, TdNRT2.1, and TdGS) using RT-qPCR showed enhancement of several important genes in durum wheat seedlings treated with 5 ppm RoEO, even under control conditions, which may be related to salt stress tolerance. The results indicate that the application of RoEO suggests a possible alternative strategy to increase salt tolerance in durum wheat seedlings towards better growth quality, thus increasing ROS scavenging and activation of antioxidant defense.
... Investigations into the chemical composition of essential oils extracted from C. aurantium align with our findings, suggesting that the primary components of the oil of the peel are monoterpene hydrocarbons such as limonene [20,44]. A study conducted by Hsouna et al., reported that C. aurantium L. flower extract displayed superior DPPH scavenging activity, with an IC 50 of 1.85 µg/ml [45]. The EO of C. aurantium L. exhibited IC 50 values of 1040 µg/ ml, 1580 µg/ml, and 140 µg/ml in the DPPH assay, reducing antioxidant power, and H 2 O 2 scavenging respectively [46]. ...
Background
Bitter orange (Citrus aurantium) is a fruiting shrub native to tropical and subtropical countries around the world and cultivated in many regions due to its nutraceutical value. The current study investigated the metabolic profiling and enzyme inhibitory activities of volatile constituents derived from the C. aurantium peel cultivated in Egypt by three different extraction methods.
Methods
The volatile chemical constituents of the peel of C. aurantium were isolated using three methods; steam distillation (SD), hydrodistillation (HD), and microwave-assisted hydrodistillation (MAHD), and then were investigated by GC-MS. The antioxidant potential was evaluated by different assays such as DPPH, ABTS, FRAP, CUPRAC, and phosphomolybdenum and metal chelating potential. Moreover, the effect of enzyme inhibition of the three essential oils was tested using BChE, AChE, tyrosinase, glucosidase, as well as amylase assays.
Results
A total of six compounds were detected by GC/MS analysis. The major constituent obtained by all three extraction methods was limonene (98.86% by SD, 98.68% by HD, and 99.23% by MAHD). Differences in the composition of the compounds of the three oils were observed. The hydrodistillation technique has yielded the highest number of compounds, notably two oxygenated monoterpenes: linalool (0.12%) and α-terpineol acetate (0.1%).
Conclusion
In our study differences in the extraction methods of C. aurantium peel oils resulted in differences in the oils’ chemical composition. Citrus essential oils and their components showed potential antioxidant, anticholinesterase, antimelanogenesis, and antidiabetic activities. The presence of linalool and α-terpineol acetate may explain the superior activity observed for the oil isolated by HD in both radical scavenging and AChE inhibition assays, as well as in the enzyme inhibition assays.
... The essential oils derived from the plant have a wide range of applications, such as analgesic, anti-inflammatory, antibacterial, and antifungal (Caccioni et al., 1998;Giamperi et al., 2002;de Moraes Pultrini et al., 2006;Gruenwald et al., 2000;Abdi-Azar & Maleki, 2014;Azadi et al., 2013). In addition, its flavonoids have been linked to a variety of health benefits, including cancer prevention, blood sugar regulation, and cellular reinforcement (Hsouna et al., 2013). Fructus aurantii is another name for Citrus aurantium L., (Bouchard et al., 2005;Haaz et al., 2006). ...
In this intriguing study, orange peel and seed extracts were tested for their antibacterial effects against pathogens isolated from urinary tract infections and wound swabs. Ethanol and acetone extracts demonstrated potent antibacterial activity against Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabilis, Escherichia coli, and Staphylococcus epidermidis. The ethanol extract showed larger inhibition zones against P. mirabilis (27 mm) compared to acetone extract. There was a significant decrease in bacterial growth when acetone extract was used, with the largest inhibition observed E. coli (23 mm). The phytochemical analysis revealed the presence of tannins, flavonoids, terpenoids, steroids, alkaloids, and saponin in the extracts, except for acetone extract lacking terpenoids and saponin. This in vitro study demonstrates the significant antibacterial activity of Citrus aurantium peels and seeds against a range of common bacterial pathogens. These findings warrant further investigation to assess the potential real-world applications of these extracts, including toxicity testing and determination of optimal dosage.
... These differences arise due to the different genotype profiles, as proposed by Sarrou et al. [39]. Furthermore, this work highlights the fact that limonene is the dominant essential oil compound in the kumquat flowers, similar to sour orange (Citrus aurantium L.) [40,41] and Citron (Citrus medica L.) var. sarcodactylis [42]. ...
The volatiles of different aerial parts of three kumquat species (Fortunella margarita Swingle–Nagami, Fortunella japonica Swingle–Marumi, and Fortunella crassifolia Swingle–Meiwa) growing in Greece were analyzed via GC-MS and evaluated for their antimicrobial properties against nine human pathogenic microorganisms. A total number of 23 compounds were identified in the peel, 38 in the leaves, and 30 in the flowers of the examined species. Limonene was the dominant metabolite in the peels of all three species, germacrene-D was present in the leaves of Nagami and Marumi kumquats, while limonene was the most abundant in the flower of Marumi and Meiwa kumquat but with significant differences in the composition of the total fracture of the essential oil, since compounds with high antimicrobial activity were only present in the flower of Meiwa kumquat. The essential oils from the leaf and peel of the three kumquat species were either inactive or showed weak antimicrobial activity, respectively, against Gram-positive and Gram-negative bacterial strains and pathogenic fungi. Only the essential oil from the flower of F. crassifolia Swingle (Meiwa) showed a stronger effect (MIC values 3.5–7.48 mg/mL) against all the assayed microorganisms. Furthermore, through multivariate statistical analysis, we studied the relationships between the samples regarding their origin (species and plant part), as well as between the chemical composition of the corresponding essential oils and their antimicrobial activity. Considering its chemical profile and antimicrobial activity, the Greek Meiwa flowers’ essential oil seemed a promising essential oil for further exploitation in the food and/or medicinal industry.
... The highest activity was found in the case of Aspergillus ochraceus, the zone of inhibition was calculated as 17 ± 1 mm, where MIC and MFC were noted to be 110 mg/ml and 130 mg/ml respectively. (Hsouna et al., 2013) found that the antifungal potency of Citrus aurantium against the growth of, Fusarium, Alternaria alternata and Aspergillus. According to this research, Citrus aurantium essential oil inhibited the growth of Fusarium graminearum and Aspergillus flavus with a zone of inhibition of 22 mm and MIC value of 78 lg/ml respectively. ...
Objectives: Pakistan is among the top agricultural countries around the globe, but mycotoxin contamination causes a major commercial loss every year. The present study aimed to isolate the fungi and their mycotoxins present in contaminated feed of animals in the local market of Peshawar. Methodology: The antifungal activity of certain plant extracts was to be tested against pathogenic fungi. TLC method was used for mycotoxin analysis and it was found that Aflatoxin G1, G2, B1 and B2 were present in different amounts both qualitatively and quantitatively based on samples. Result: This study found the presence of contamination in all the tested feed samples. All ten samples were found positive for Aspergillus flavus. B1 toxin was found in high quantity in all ten samples, while G2 was found in a lower quantity as compared to other toxins such as G1, B1 and B2. The quantity of aflatoxin was from 48.6 to 284.7 ppb in 25 g of samples. In the case of antifungal potency, all plant extracts showed important antifungal potency against tested fungi. The MIC and MFC values noted ranged from 110 to 300 mg/ml and 100–300 mg/ml respectively. Citrus aurantium and Myrtus communis were absorbed to have antifungal potency against all test fungi. Citrus aurantium extracts were also found to inhibit the growth of Aspergillus flavus. Conclusion: According to the results of the present research, a variety of fungal strains and aflatoxins were present in animal feed in numerous parts of Peshawar, Pakistan and different plant extracts can be used in animal feed to reduce this type of contamination.
... The heat map is a very popular representation, especially in various sciences and among the graphical representations commonly used to determine the effect of phenomena including those organic [56,57]. The heat map draws attention to the quantitative values in a rectangular data matrix. ...
In this work, the chemical composition and antioxidant and antimicrobial activities of the essential oils (EOs) of six species—Laurus nobilis, Chamaemelum nobile, Citrus aurantium, Pistacia lentiscus, Cedrus atlantica, and Rosa damascena—have been studied. Phytochemical screening of these plants revealed the presence of primary metabolites, namely, lipids, proteins, reducing sugars, and polysaccharides, and also secondary metabolites such as tannins, flavonoids, and mucilages. The essential oils were extracted by hydrodistillation in a Clevenger-type apparatus. The yields are between 0.06 and 4.78% (mL/100 g). The analysis of the chemical composition carried out by GC-MS showed the presence of 30 to 35 compounds and represent between 99.97% and 100% of the total composition of EOs, with a variation in the chemical composition detected at the level of the majority compounds between these species. Indeed, in the EO of Laurus nobilis, 1,8-cineole (36.58%) is the major component. In Chamaemelum nobile EO, the most abundant compound is angelylangelate (41.79%). The EO of Citrus aurantium is rich in linalool (29.01%). The EO of Pistacia lentiscus is dominated by 3-methylpentylangelate (27.83%). The main compound of Cedrus atlantica is β-himachalene (40.19%), while the EO of Rosa damascenaa flowers is rich in n-nonadecane (44.89%). The analysis of the similarity between the EOs of the plants studied by ACH and ACP showed that the chemical composition of the EOs makes it possible to separate these plants into three groups: the first represented by Chamaemelum nobile, because it is rich in oxygenated monoterpenes, the second defined Cedrus atlantica and Rosa damascena, which are rich in sesquiterpenes, and the third gathers Pistacia lentiscus, Laurus nobilis and Citrus aurantium, which are composed of oxygenated sesquiterpenes and monoterpenes (these three species are very close). The study of the antioxidant activity showed that all the EOs tested have a high capacity for scavenging free radicals from DPPH. The EOs of Laurus nobilis and Pistacia lentiscus showed the highest activity, 76.84% and 71.53%, respectively, followed by Cedrus atlantica EO (62.38%) and Chamaemelum nobile (47.98%) then Citrus aurantium EO (14.70%). Antimicrobial activity EO was tested against eight bacterial strains and eight fungal strains; the results showed that EOs exhibit significant bactericidal and fungicidal activities against all the microorganisms tested, of which the MICs of the bacterial strains start with 5 mg/mL, while the MICs of the fungal strains are between 0.60 mg/mL and 5 mg/mL. Thus, these EOs rich in antimicrobial and antioxidant components can serve as a natural alternative; this confirms their use as additives in cosmetics.
... In a study examining the essential oil obtained from the blooms of Citrus aurantium L., 33 compounds were identified, and the main components were detailed to be limonene (27.5%), e-nerolidol (17.5%), α -terpineol (14%), α-terpinyl acetate (11.7%), and E. E-farnesol (8%). As a result of the study, it was stated that the essential oil has antioxidant and antimicrobial characteristics, so that it may be a potential resource of active ingredients for the food and pharmaceutical industry [51]. ...
... The antioxidative effect of essential oils was evaluated with DPPH inhibition activity as a reagent, with some modifications to the Kirby and Schmidt method [40]. A total of 50 mL of the sample solutions was blended with 500 mL of an alcoholic DPPH solution containing 4% (w/v) dichloromethane after the samples were dissolved in dichloromethane at 0.01-10 mg/mL. ...
The composition of volatile oils of the leaf and stem of Farfugium japonicum (L.) Kitamura were prepared by supercritical fluid extraction (SFE)-CO2. A total 47 and 40 compounds were identified by GC/MS analysis, respectively, and only 13 compounds coexisted. The main constituent types in the leaf oil included alcohols (34.1%), hydrocarbons (24.1%), terpenoids (16.2%), benzenes (7.5%), and fatty acids (4.9%). In the stem oil, the constituent types chiefly included benzenes (18.8%), ketones (13.9%), terpenoids (17.0%), fatty acids (8.8%), phenolics (8.7%), steroids (8.6%), hydrocarbons (8.0%), and esters (5.7%). The predominant volatile compounds in the stem were 2-(1-cyclopent-1-enyl-1-methylethyl) cyclopentanone (11.7%), 1,2,3,4,5,6,7,8-octahydro- 9,10-dimethyl-anthracene (8.4%), 5-heptylresorcinol (6.5%), and α-sitosterol (5.2%). Those in the leaf mainly included (E)-3-hexen-1-ol (13.7%) and (Z)-3-hexen-1-ol (14.0%). This demonstrated a significant difference in the composition of both oils. Further study showed that stem oils demonstrated the highest DPPH (1,1-diphenyl-2-pinylhydrazyl) and ·OH free radical scavenging capacities at IC50 values of 9.22 and 0.90 mg/mL, respectively. In addition, they demonstrated the strongest antibacterial capacity against the Gram-positive bacteria methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) at a minimum inhibitory concentration (MIC) of 0.16 mg/mL. This could be due to the SFE-CO2 extraction and the high accumulation of benzenes, terpenoids, and phenolics in the stem. In particular, the monoterpenes presented in terpenoids could play a special role in these findings.
... To confirm the literature hypotheses [35] in which EOs extracted from similar plants possessed antimicrobial activity, inhibition halo experiments were performed according to the modified Kirby and Bauer protocol [22]. Figure 1 shows the relationship between the widths of the bacterial growth inhibition halos of two model indicator strains (E. coli and S. aureus) and the amount of EO spotted on a plate containing rich agar medium. ...
Food waste is one of the main topics of various scientific studies of the last decade. In this regard, this work analyzed an essential oil (EO) extracted from the flavedo of Citrus aurantium ‘Crispifolia’ fruit. The analysis, performed by GC-MS, showed a chemically variegated chromatogram characterized by the presence of limonene (33.35%), but also by oxygenated monoterpenes such as β-linalool (7.69%), α-terpineol (7.06%), and geranyl acetate (10.12%). EO from the external part of the C. aurantium peel had several properties, including excellent antimicrobial and good antibiofilm activities. It also showed antioxidant activity in vitro and decreased the amount of cellular ROS, thus stimulating the catalytic activity of crucial enzymes involved in mitigating oxidative stress.
... Natural phenolic chemicals, especially flavanone glycosides, principally naringin, hesperidine, narirutin, and neohesperidine, are abundant in it, making it stand out as a particularly rich source [20]. Citrus flavonoids have been linked to a broad range of biological functions, involving antibacterial, anticancer, antidiabetic, and antioxidant actions [21]. Additionally, Lv et al. [22] looked at how orange-peel essential oil affected acute otitis media rats' oxidative stress. ...
A disorder identified as obesity includes having too much body fat. It is a medical ailment that increases the risk of several syndromes and other health issues. Around the world, 19.5% of the adult population is obese, which is a widespread condition. The current study seeks to explore the chemical constitutes, bioactive substances, antioxidant activity, and impacts on obesity problems in rats of orange by-products, peel, and pulp integration with chromium. While orange pulp has larger amounts of carbohydrates, minerals (Mg, Fe, and Zn), vitamins (E, B1, and B6), and bioactive substances than orange peel, the latter has higher levels of total protein, fiber, minerals (Na, K, Ca, and P), vitamins (A and C), total polyphenols, flavonoids, and carotenoids. In contrast to the control normal group, rats fed a diet-stimulated obesity diet (DIO) had a higher body weight (416.76%), blood leptin (142.84%), glucose (95.17%), and hyperlipidemia (cholesterol (219.77%), triglycerides (131.22%), and low-density lipoprotein cholesterol (341.59%). Because orange peel and pulp contain antihyperlipidemic and anti-diabetic substances that lower serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol and raise high-density lipoprotein cholesterol, consuming them alone or in combination with chromium partially reversed these negative changes and decreased the likelihood of atherogenesis. When orange peels and pulp were combined with chromium, there showed noticeable synergistic effects. These results lay a foundation for the use of food industry by-products, with or without chromium, in the early detection and treatment of obesity. Additionally, the current study suggests adding orange by-product powder and/or extracts to our everyday meals, beverages, dietary supplements, and pharmaceutical formulations.
... In general, Gram-negative bacteria exhibit higher resistance to EOs compared to Gram-positive bacteria. This resistance is conferred by hydrophilic lipopolysaccharides present in the outer membrane of these Gram-negative bacteria, which serve as barriers blocking the entry of the macromolecules and hydrophobic compounds of the EO into the cell membrane (Hyldgaard et al. 2012;Hsouna et al. 2013). Fisher and Phillips (2009) reported the uptake of Citrus EOs into the cell, leading to the formation of vacuoles and causing complete cell lysis in two Gram-positive bacteria, Enterococcus faecium and Enterococcus faecalis. ...
Essential oils (EOs) extracted from Citrus peels contain 85%–99% volatile components (a mixture of monoterpenes, sesquiterpenes, and their oxygenated derivatives) and 1%–15% non-volatile compounds. Citrus EOs have been long known for their antimicrobial properties, owing to which these EOs have a diverse range of applications. However, no studies have reported the applicability of Citrus EOs for the control of bacterial and yeast contaminants in the bioethanol industry. In this regard, the present review aimed to explore the feasibility of Citrus EOs in this industry. The Web of Science database was searched for reports that described the association of Citrus EOs with the most common microorganisms in the bioethanol industry to evaluate the efficacy of these EOs as antimicrobial agents in this context. The objective of the review was to suggest a novel antimicrobial that could replace sulfuric acid and antibiotics as the commonly used antimicrobial agents in the bioethanol industry. Citrus EOs exhibit antibacterial activity against Lactobacillus, which is the main bacterial genus that contaminates this fermentation process. The present report also confirms the selective action of these EOs on the contaminating yeasts and not/less on ethanol-producing yeast Saccharomyces cerevisiae, however further studies should be conducted to investigate the effects of Citrus EOs in yeast-bacterium co-culture.
... In recent years, herbal medicine has begun to be used to treat many dermatological disorders such as itching and even severe forms of cancer [20,21]. So, the essential oils of Abies koreana, Anthemis aciphylla, Anthemis nobilis, Citrus aurantium, Eucalyptus globules, Foeniculum vulgare, Mentha sp., Salvia sp. are used in the treatment of dermatological disorders [22][23][24][25][26][27][28][29] such as acne, fungal infection, or cancer. Also, EO from Afromomum danielli and Pogostemon elsholtzioides reduced blood pressure [30,31], EO from Salvia officinalis L., Citrus aurantifolia, Curcuma longa L. can improve hyperlipidemia [32][33][34], while EO from Lavandula angustifolia and Citrus aurantium reduce blood pressure and anxiety with acute coronary syndrome [35,36]. ...
This study evaluates the antimicrobial and antioxidant activities of five essential oils (EO): pine oil, thyme oil, sage oil, fennel oil, and eucalyptus essential oils. To identify the chemical composition of the essential oils, we used gas chromatography coupled to a mass spectrometer (GC-MS). EO are predominantly characterized by the presence of monoterpene hydrocarbons and oxygenated monoterpenes, except in the case of fennel essential oil which contains phenylpropanoids as its main components. The antimicrobial activity of the EO was highlighted on four standard microbial strains (two Gram-negative strains-Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853; one Gram-positive strain Staphylococcus aureus ATCC 25923, and one yeast strain-Candida albicans ATCC 10231). Antimicrobial activity was assessed by measuring the diameter of the inhibition zone, and by determining the values of the minimum inhibitory concentration (MIC) and minimum concentration of biofilm eradication (MCBE). Analyzing the diameter values of the inhibition zones we observed increased efficiency of thyme essential oil, which showed the highest values for all tested microbial species. The results of tests performed in a liquid confirm the high sensitivity of the standard strain Escherichia coli ATCC 25922 to the action of all essential oils, the lowest values of MIC being recorded for sage and thyme essential oils. For the most essential oils tested in this study, the MCBE values are close to the MIC values, except for the pine EO which seems to have stimulated the adhesion of the yeast strain at concentrations lower than 5%. The study highlights the antimicrobial activity of the tested essential oils on Gram-positive and Gram-negative strains.
... Teneva et al. (2019) studying C. aurantium bark essential oil verified forty-eight compounds, in which the majority were d-limonene (85.22%), β-myrcene (4.30%) and pinene (1.29%). The Hsouna et al. (2013) found nine compounds, of which limonene (39.74%), β-pinene (25.44%) and α-terpineol (7.30%) were the major compounds. Shen et al. (2017) found as major compounds linalool (64.6%), α-terpineol (7.61%), and (R)-limonene (6.15%) in C. aurantium flowers. ...
Essential oils are highly concentrated compounds extracted from plants that are frequently used for flavor and preservative properties due to its antimicrobial and antioxidant activity. Besides its large use, there is a lack of studies regarding its its safety as food ingredient. In this book chapter, we summarized the main essential oils used as food ingredient, describing its chemical composition, antioxidant activity and potential against food-borne pathogens, as well as studies reporting care in the safety of its use. In research using PubMed database with the keywords “essential oil”, “food”, and the list of oils Generally Recognized As Safe (GRAS) by Food and Drug Association (FDA), the four oils with the highest research numbers were Origanum spp. (461), Thymus vulgaris (138), Citrus aurantium (113), and Rosmarinus officinalis (109). Most of the information available regarding safety are related to oral toxicity tests in laboratory animals. Overall, the data confirms most of the oils listed in GRAS as safety, although some of them have no data available or have study describing toxicity. This chapter highlights essential oils potential as natural alternative for increasing food shelf-life through multiple pathways of action, although clinical and toxicological studies can be improved.KeywordsEssential oilFoodAntimicrobialAntifungalAntioxidantToxicity
Origanum
Thymus vulgaris
Rosmarinus officinalis
Citrus aurantium
... The minimum inhibitory concentrations (MICs) of 13 test microorganisms from distinct species and environments were determined as previously described [19,21]. We utilized 100 µL/well sterile 96-well microplates. ...
Thiamine (TA), also known as vitamin B1, is an essential amino acid derived from food sources for normal body function. TA is thought to have antioxidant, antimicrobial, and anti-inflammatory effects in addition to its nutritional benefits. The degree to which a number of microorganisms implicated in food rotting are sensitive to increasing concentrations of thiamine (TA), was examined. TA at increasing concentration was incubated with minced beef and then physicochemical and microbiological assessments were conducted. LPS-stimulated RAW264.7 cells were used to test TA’s anti inflammatory capabilities. Western blot analysis revealed the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Finally, the ability of TA to act as a natural preservative was evaluated.
... They are volatile chemicals emitted by plants to defend against viruses, bacteria, saccharomyces, molds, and protozoans [69] or to prevent decay and herbivore attacks. Phytoncides also exhibit other beneficial effects, such as anti-microbial, antibacterial [70], anti-fungal, anti-inflammatory, anti-stress, analgesic, and anti-spoilage activities, and they can be used as food preservatives [36,[71][72][73][74][75][76][77][78][79][80][81][82]. They also exhibit anti-mycoplasmal activity [83], anti-larvicidal activity against malaria [84,85] and dengue [86], anti-septic activity, and anthelminthic activity; in addition, they facilitate wound healing [87], can act as cholesterol inhibitors [88], can enhance sleep [89][90][91], and even enhance bacterial susceptibility to antibiotics [92,93]. ...
Chemical compounds from plants have been used as a medicinal source for various diseases. Aromachology is a unique field that studies the olfactory effects after inhaling aromatic compounds. Aromatherapy is a complementary treatment methodology involving the use of essential oils containing phytoncides and other volatile organic compounds for various physical and mental illnesses. Phytoncides possess an inherent medicinal property. Their health benefits range from treating stress, immunosuppression, blood pressure, respiratory diseases, anxiety, and pain to anti-microbial, anti-larvicidal, antiseptic , anti-cancer effects, etc. Recent advancements in aromatherapy include forest bathing or forest therapy. The inhalation of phytoncide-rich forest air has been proven to reduce stress-induced immunosuppression, normalize immune function and neuroendocrine hormone levels, and, thus, restore physiological and psychological health. The intricate mechanisms related to how aroma converts into olfactory signals and how the olfactory signals relieve physical and mental illness still pose enormous questions and are the subject of ongoing research. Aroma-therapy using the aroma of essential oils/phytoncides could be more innovative and attractive to patients. Moreover, with fewer side effects, this field might be recognized as a new field of complementary medicine in alleviating some forms of physical and mental distress. Essential oils are important assets in aromatherapy, cosmetics, and food preservatives. The use of essential oils as an aromatherapeutic agent is widespread. Detailed reports on the effects of EOs in aromatherapy and their pharmacological effects are required to uncover its complete biological mechanism. This review is about the evolution of research related to phytoncides containing EOs in treating various ailments and provides comprehensive details from complementary medicine.
... In addition, a higher concentration of limonene in CREO leads to a better synergistic effect than that of CAEO. Based on these observations, it indicated that limonene had an influence on the antibacterial potential of EOs. is is in agreement to previous reports [16,20,[35][36][37] but in contrast to some other studies [14,31,38]. e antibacterial mechanism of citrus EOs has been described by a previous study. ...
Citrus reticulata Blanco and Citrus aurantifolia are the edible plants which contain several biological properties including antibacterial activity. The aims of the present study were to determine the chemical compositions and evaluate antibacterial activities of citrus essential oils extracted from the fruit peels of C. reticulata (CREO) and C. aurantifolia (CAEO), alone and in combination with gentamicin, against a panel of clinically isolated methicillin-resistant S. aureus (MRSA) (n = 40) and methicillin-susceptible S. aureus (MSSA) (n = 45). Gas chromatography-mass spectrometry analysis revealed that 12 and 25 compounds were identified in CREO and CAEO with the most predominant compound of limonene (62.9–72.5%). The antibacterial activities were determined by agar disk diffusion and resazurin-based microdilution methods. The results found that almost all MRSA isolates were resistant to ciprofloxacin, erythromycin, and clindamycin, and some isolates were resistant to gentamicin. CREO and CAEO exhibited inhibitory effects toward clinical isolates (MIC: 1.0–32.0 and 8.0–32.0 mg/mL, respectively), with a similar trend to limonene (MIC: 1.0–32.0 mg/mL). However, the higher antibacterial effects were found in CREO and limonene when compared to CAEO (p < 0.01). In combination effect, the results showed the synergistic interaction of gentamicin with CREO and limonene on the MRSA and MSSA isolates (FIC indexes: 0.012–0.258 and 0.012–0.375), but that interaction of gentamicin with CAEO was observed only on MRSA (FIC index: 0.012–0.016). These findings demonstrated the potential of these citrus essential oils as natural antibacterial agents that may contribute to reduce the emerging of antimicrobial-resistant bacteria.
... Neroli EO is nowadays an iconic product in the fragrance industry, due to its olfactive profile (Floral, orange blossom, green, methyl-like, and honeyed) in demand in the perfume industry (Berger, 2007). Many biological studies have reported neurotonic properties (Duval, 2012) and antimicrobial, antioxidant (Ammar et al., 2012;Dosoky and Setzer, 2018;Hsouna et al., 2013;Sarrou et al., 2013), anticonvulsant (Azanchi et al., 2014), analgesic and anti-inflammatory activities (Khodabakhsh et al., 2015) for this EO. Currently, this EO (C. ...
Les matières naturelles aromatiques, telles que les huiles essentielles, que l’on retrouve sur le marché, ne sont pas toujours authentiques, bien que ces produits soient vendus comme étant 100% purs et naturels. Certains fournisseurs fraudent leurs produits afin de réduire les coûts de production, d’améliorer la qualité des huiles essentielles ou encore pour augmenter artificiellement les volumes de production. Les huiles essentielles sont adultérées en ajoutant des produits à moindre coût, incluant des matières naturelles moins chères et des molécules d’origine pétrochimique. Des méthodes d’authentification appropriées sont nécessaires pour contrôler la naturalité et la pureté des huiles essentielles. La détermination des ratios isotopiques stables et l’analyse énantiosélective de composés spécifiques, associées à la recherche de traces de précurseurs de synthèses, permettent d’authentifier de nombreuses huiles essentielles (gaulthérie, alliacées, néroli, menthe crépue, cannelle et cypriol). Le contrôle de ces produits naturels requiert l’établissement de banques de données, constituées d’échantillons parfaitement tracés pour l’authenticité de leurs origines. La méthodologie mise en place a permis de développer de nouveaux outils pertinents pour l’authentification, comprenant le développement de l’analyse isotopique de composés ciblés pour la mesure du δ18O et du δ34S, et d’identifier de nouvelles fraudes, comprenant les ajouts de composés enrichis en 14C et les molécules issues d’hémisynthèses.
... The minimum inhibition concentrations ranged between 0.16-10 mg/ml; the oil had the highest activity against Rhizopus stolonifera and the least activity to Pseudomonas spp. Table 2 shows the presence of compounds like myristicin, limonene, phytol, and methyl salicylate in abundance, all of which have been reported to show the antimicrobial property [16,[105][106][107][108]. The antimicrobial property of this oil should be expected because, according to Table 1, methyl salicylate an ester, limonene, a hydrocarbon both have antifungal and antibacterial properties. ...
Compounds useful for drugs, cosmetics, and food have been obtained directly or indirectly from living organisms over the years. However, there has been a renewed interest in getting useful compounds from living organisms, especially plants. Essential oils, interchangeably called volatile oils, are bioactive compounds found in minute quantities in some plants. Essential or volatile oils have been known for years to find usefulness in foods, drugs (antimicrobial, antifungal), and cosmetics. This review attempts to summarize information on the essential oil from Ficus species concerning their morphology, pharmacology, bioactivity, and application. This was achieved by gathering information on essential oils from different Ficus species. Essential oils from Ficus species are a good source of bioactive compounds for use in drug, food, and cosmetic industries. It is worthy to note that Nigerian Figs were characterized by the high presence of phytol and 6,10,14-trimethyl-2-pentadecanone, and these compounds are, therefore, seen as markers. Furthermore, this review presents numerous insights on how to best harness the different potentials of the essential oils and possibilities to be examined.
... Hydrodistillation is used to extract essential oils and bioactive compounds from C. aurantium flowers [70][71][72][73][74], peels [12,40,75], and leaves [28]. ...
Citrus genus is a prominent staple crop globally. Long-term breeding and much hybridization engendered a myriad of species, each characterized by a specific metabolism generating different secondary metabolites. Citrus aurantium L., commonly recognized as sour or bitter orange, can exceptionally be distinguished from other Citrus species by unique characteristics. It is a fruit with distinctive flavor, rich in nutrients and phytochemicals which possess different health benefits. This paper presents an overview of the most recent studies done on the matter. It intends to provide an in-depth understanding of the biological activities and medicinal uses of active constituents existing in C. aurantium. Every plant part is first discussed separately with regards to its content in active constituents. All extraction methods, their concepts and yields, used to recover these valuable molecules from their original plant matrix are thoroughly reported.
... Bitter orange originated from India, and its oil, peel, flowers, and leaves are classified as Generally Recognized As Safe (GRAS) food additives in Korea [8]. A previous study on the antibacterial activity of C. aurantium flowers confirmed their efficacy against all tested gram-positive and gram-negative bacterial species [9]. Another study also reported the antimicrobial activities of citrus extracts against the biofilms of Enterococcus faecalis [10]. ...
The halal food market is steadily increasing. The use of alcohol for any reason is strictly prohibited in halal foods; however, ethanol is widely used as a preservative for commercial rice cakes (tteok). The purpose of this study was to investigate the use of natural substances as alternative preservatives for rice cakes. Four different solutions were tested: distilled water (control), ethanol, grapefruit seed extract (GSE), and a mixture of citric extracts and organic acids (MCO). We investigated the total plate count (TPC), yeast and mold counts, color, texture profile assays (TPA), and sensory evaluation. Significant reductions of 3.65 log CFU were observed in TPC in rice cake treated with MCO solution after 28 days of storage. However, mold and yeast counts were only reduced by ethanol treatment. Among the physical texture properties analysis, hardness was maintained for the 28 days in all samples. The total color difference values (ΔE) revealed no significant color changes in any rice cake compared to the controls. The ethanol-treated rice cake scored the lowest for overall preference and desired hardness.
... These indicated that the EO from aerial parts of coriander possessed the highest free radical scavenging capacity using the DPPH • scavenging assay. These results are in line with results found in the literature, depicting IC 50 values ranging from 0.001 to 1.5 g L −1 , depending on the tested EO, including Allium cepa L., Citrus aurantium, Myrtus communis, and Eucalyptus oleosa EO [59][60][61][62]. So as to compare the antioxidant capacity of the EO to that of a well-known antioxidant standard, Trolox ® , the obtained results were also expressed in terms of TEAC. ...
The potential of essential oils (EO), distilled from two aromatic plants—clary sage (Salvia sclarea L.) and coriander (Coriandrum sativum L.)—in view of applications as natural therapeutic agents was evaluated in vitro. These two were cultivated on a trace element (TE)-polluted soil, as part of a phytomanagement approach, with the addition of a mycorrhizal inoculant, evaluated for its contribution regarding plant establishment, growth, and biomass production. The evaluation of EO as an antioxidant and anti-inflammatory, with considerations regarding the potential influence of the TE-pollution and of the mycorrhizal inoculation on the EO chemical compositions, were the key focuses. Besides, to overcome EO bioavailability and target accession issues, the encapsulation of EO in β-cyclodextrin (β-CD) was also assessed. Firstly, clary sage EO was characterized by high proportions of linalyl acetate (51–63%) and linalool (10–17%), coriander seeds EO by a high proportion of linalool (75–83%) and lesser relative amounts of γ-terpinene (6–9%) and α-pinene (3–5%) and coriander aerial parts EO by 2-decenal (38–51%) and linalool (22–39%). EO chemical compositions were unaffected by both soil pollution and mycorrhizal inoculation. Of the three tested EO, the one from aerial parts of coriander displayed the most significant biological effects, especially regarding anti-inflammatory potential. Furthermore, all tested EO exerted promising antioxidant effects (IC50 values ranging from 9 to 38 g L−1). However, EO encapsulation in β-CD did not show a significant improvement of EO biological properties in these experimental conditions. These findings suggest that marginal lands polluted by TE could be used for the production of EO displaying faithful chemical compositions and valuable biological activities, with a non-food perspective.
... This article is protected by copyright. All rights reserved antibacterial activity of bitter orange flower essential oil against foodborne and spoiling bacteria, due to the presence of high concentrations of monoterpene hydrocarbons and oxygenated monoterpenes (Hsouna et al., 2013). ...
In this research, hydrodistillation ultrasonic‐assisted green technique was applied to extract the essential oils from bitter orange peel. The effects of independent factors (volume/mass ratio (X1), ultrasonic time (X2) and hydrodistillation extraction time (X3)) on the quantitative, phenolic and antioxidant properties of essential oils were investigated. Linear and quadratic polynomial models with suitable ANOVA results (model p‐values <0.0003, R2 values of 0.84‐0.95, adjusted R2 values of 0.82‐0.90, predicted R2 values of 0.71‐0.75, and lack of fit p‐values >0.5) were used for fitting the responses. Two optimal extraction conditions for bitter orange peel essential oils were determined as follows: optimum responses (OR) with maximum essential oil volume (0.99 ml), maximum TPC (108.33 mg GAE/100 ml) and minimum IC50 (251.56 µl) could be achieved at X1: 6.00 ml/g, X2: 39.10 min and X3: 4.72 h, and optimum phenolic compounds (OP) with maximum TPC of 190.75 mg GAE/100 ml could be obtained at X1: 13.89 ml/gr, X2: 3.75 min and X3: 4.92 h. The most predicted values for optimum conditions were in good agreement with experimental data. The disk diffusion experiments showed high antimicrobial activities of the optimum essential oils against E. coli. The GC‐MS results proved limonene was the main compound in both optimum essential oils. These bitter orange peel essential oils with suitable antioxidant and antimicrobial activities, and healthy compositions, could be considered as dietary and pharmaceutical supplements.
This work is part of the study of the antibacterial and antioxidant activity of Algerian aromatic and medicinal plants. We conducted a study on a plant widely used by the local population, Citrus limon, an aromatic plant from the Ghardaïa region. Essential oils were extracted from Citrus limon (zest and leaves) using hydrodistillation, yielding 1.12% for the zest and 0.71% for the leaves. The essential oils were analyzed using GC/MS, identifying 35 constituents in the leaf oils, with 19.41% L-Limonene and 15.02% Nerol acetate, and 25 constituents in the zest oils, with 45.62% L-Limonene, 9.40 Beta-Pinene and 8.3% 3-Carene as major compounds. The antioxidant activity of the essential oils was evaluated using three methods. The first method was the DPPH free radical scavenging test, where the zest showed an IC50 of 135.678 mg/mL, higher than that of the leaf essential oil (IC50 of 34.238 mg/mL). The second method, potassium ferricyanide reduction (FRAP), showed that the essential oils of the leaves had an antioxidant activity of EC50 = 63.3773 mg/mL, and the zest showed EC50 = 200.875 mg/mL. The third method, ammonium phosphomolybdate, based on molybdate reduction (TAC), gave antioxidant activities for the leaves and zest, respectively, of EC50 = 1.5722 mg/mL and EC50 = 1.9604 mg/mL. The antibacterial activity was tested against six reference bacterial strains, with Klebsiella pneumoniae being the most sensitive to both essential oils, showing inhibition zones of 48 mm for the leaf oil and 40 mm for the zest oil. According to the obtained results, the essential oils appear to exhibit excellent antioxidant and antibacterial activity.
The genus Citrus of the Rutaceae family remains one of the beneficial fruit crops that produce high quantities of essential oils that have pharmaceutical, biological, and food preservative applications. Despite the numerous benefits of citrus essential oils (CEOs), there is a major challenge in choosing the most efficient extraction method(s) for large-scale production of quality CEOs to meet industrial, research, and domestic demands. This review provides a general overview of the listed citrus species, the chemical composition of their essential oils, medicinal uses, and the major methods of extraction of citrus essential oils from 10 selected citrus species. A meticulous, in-depth review of the various methods of CEOs extraction has been provided, along with their advantages, limitations, and novel modifications. This comprehensive literature review expounded on the current extraction methods for citrus essential oils and the various modifications developed to reduce the extraction time, excessive energy consumption, CO2 production, and quality, as well as to improve the extraction yield.
Gibberellic acid-stimulated Arabidopsis (GASA) proteins, also known as Snakin proteins, have emerged as key players in plant development and stress tolerance. The investigation of the role of TdGASA2 in host defense responses revealed dynamic expression patterns under different stress conditions. TdGASA2 expression showed a consistent increase after wounding, methyl jasmonate (MeJA), and ethylene (ETP) treatments, peaking after 12–24 hours for MeJA and ETP and after 1 hour for pathogen elicitor (PA) treatment. Optimal expression conditions were determined, and the protein was successfully purified with a molecular weight of approximately 10 kDa. In vitro experiments demonstrated the potent antimicrobial activity of TdGASA2 against a range of pathogens, surpassing the efficacy of kanamycin. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values confirmed its bactericidal and bacteriostatic activity against various bacteria. Time-kill assays also highlighted its efficacy against Listeria monocytogenes and Salmonella enterica, underscoring its potential as a therapeutic agent. Additionally, TdGASA2 exhibited superior DPPH radical-scavenging activity compared to ascorbic acid, indicating its potential as a natural antioxidant. In situ experiments revealed dose-dependent effects of TdGASA2 treatment on microbial growth in cheese, suggesting its efficacy as a preservative to extend shelf life and enhance food safety. These findings underscore TdGASA2's multifaceted potential in both antimicrobial and antioxidant applications, positioning it as a promising candidate for food preservation and health promotion.
Natural raw materials such as essential oils have received more and more attention in recent decades, whether in the food industry, as flavorings and preservatives, or as insecticides and insect repellents. They are, furthermore, very popular as fragrances in perfumes, cosmetics, and household products. In addition, aromatherapy is widely used to complement conventional medicine. This review summarizes investigations on the chemical composition and the most important biological impacts of essential oils and volatile compounds extracted from selected aromatic blossoms, including Lavandula angustifolia, Matricaria recutita, Rosa x damascena, Jasminum grandiflorum, Citrus x aurantium, Cananga odorata, and Michelia alba. The literature was collected from PubMed, Google Scholar, and Science Direct. Blossom essential oils discussed in this work are used in a wide variety of clinical issues. The application is consistently described as safe in studies and meta-analyses, although there are notes that using essential oils can also have side effects, especially dermatologically. However, it can be considered as confirmed that essential oils have positive influences on humans and can improve quality of life in patients with psychiatric disorders, critically ill patients, and patients in other exceptional situations. Although the positive effect of essential oils from blossoms has repeatedly been reported, evidence-based clinical investigations are still underrepresented, and the need for research is demanded.
Species belonging to the genus Citrus are produced and traded in large amounts around the world. In addition to the consumption of citrus fruits as food due to their high vitamin C content, their use in many areas has become widespread with the development of the plant-based products industry. In this study, the amount and structure of volatile components of leaves and flowers of 5 different citrus species (Citrus aurantium, Citrus limon, Citrus paradisi, Citrus reticulata, and Citrus sinensis) were determined using the solid phase micro extraction. Monoterpene hydrocarbons and their oxygenated derivatives were identified as the most abundant chemical component groups. Limonene was the dominant compound in Citrus limon flowers (36.5%), leaves (22.5%) and Citrus paradisi flowers (22.4%). Linalool, and sabinene were the other major components. Linalool was determined at 50.5% in flowers and 73.3% in leaves of Citrus aurantium. Moreover, sabinene had a high amount in Citrus sinensis flowers (19.7%), leaves (24.7%), and in Citrus paradisi (27.4%) leaves. Apart from these dominant components, γ-terpinene (13.9%) and p-cymene (25.4%) were detected in Citrus reticulata flowers and leaves in an important amount. It was seen that the leaves and flowers of Citrus species gathered from Hatay province were an important source of limonene and linalool compounds.
Citrus fruits, members of the Rutaceae family, have seen a surge in the popularity of their essential oils (EO) due to their versatile industrial applications. These EOs are primarily derived from citrus fruit peels, a practice that not only reduces waste generation but also minimizes environmental contamination. Citrus EO serves as a natural and cost-effective substitute for synthetic preservatives and flavoring agents, contributing to the pursuit of safe and wholesome food, a paramount goal in the food industry. The antimicrobial properties of key compounds such as D-limonene, linalool, α & β-pinene, sabinene, β-myrcene, α-terpineol, and other bioactive chemicals are well-documented. Moreover, these components exhibit antioxidative and potential anticancer attributes. Additionally, citrus EO-based films and coatings offer diverse applications in the realm of food packaging materials. This comprehensive review delves into a variety of extraction methods, component characterization, and recent applications of citrus essential oils across different food categories. As the demand for safe and natural food continues to grow, citrus essential oils employed as food preservatives hold a promising future. Nonetheless, further research is imperative to explore broader applications and ascertain potential allergenic and toxicological consequences, ensuring the continued advancement of this promising field.
Background
Antimicrobial resistance is imposing an alarming public health threat in regard to the irrational use of the currently available antibiotics and the lack of new antimicrobi-als.
Objective
The current study aims to comparatively investigate the antimicrobial potential and phytochemical compositions of citrus peel essential oils (EOs) and phenolic compounds (PCs) as an approach to combat life-threatening bacterial and fungal infections.
Methods
Citrus EOs and PCs were extracted from Citrus aurantifolia, Citrus reshni, Citrus lati-folia and Citrus paradisi peels and phytochemically characterized by GC-MS and HPLC, respec-tively. The antimicrobial potential of citrus peel EOs and PCs was tested against Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Escherichia coli O157:H7, Pseudomonas ae-ruginosa, Salmonella typhimurium and Candida albicans using disc diffusion and broth micro-dilution assays.
Results
The compositional analysis of citrus peel EOs revealed that limonene was the major volatile constituent, comprising 81.38%, 79.39%, 76.40% and 52.35% of grapefruit, mandarin, orange and lemon EOs, respectively. In addition, naringenin was the most abundant PC in grape-fruit, orange and mandarin peel methanolic extracts, whereas catechin was the major PC in lemon peel. Lemon EO displayed the highest inhibitory effects against the investigated Gram-positive and Gram-negative bacteria as well as Candida albicans. Moreover, mandarin PCs exhibited the highest antibacterial effects, while orange PCs displayed the highest anticandidal effects. Fur-thermore, Gram-positive bacteria displayed higher sensitivity to both citrus peel EOs and PCs.
Conclusion
Citrus peel extracts possess versatile bioactive compounds that can be utilized as promising antimicrobial candidates.
Other
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Monoterpenoids, a sub-class of terpenoids, are secondary metabolites frequently extracted from the essential oils of aromatic plants. Their antitumor properties including antiproliferative, apoptotic, antiangiogenic, and antimetastatic effects along with other biological activities have been the subject of extensive study due to their diverse characteristics. In recent years, numerous investigations have been conducted to understand its potential anticancer impacts, specifically focusing on antiproliferative and apoptotic mechanisms. Metastasis, a malignancy hallmark, can exert either protective or destructive influences on tumor cells. Despite this, the potential antimetastatic and antiangiogenic attributes of monoterpenoids need further exploration. This review focuses on specific monoterpenoids, examining their effects on metastasis and relevant signaling pathways. The monoterpenoids exhibit a high level of complexity as natural products that regulate metastatic proteins through various signaling pathways, including phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin, mitogen-activated protein kinase/extracellular signal-regulated kinase/jun N-terminal kinase, nuclear factor kappa B, vascular endothelial growth factor, and epithelial mesenchymal transition process. Additionally, this review delves into the biosynthesis and classification of monoterpenoids, their potential antitumor impacts on cell lines, the plant sources of monoterpenoids, and the current status of limited clinical trials investigating their efficacy against cancer. Moreover, monoterpenoids depict promising potential in preventing cancer metastasis, however, inadequate clinical trials limit their drug usage. State-of-the-art techniques and technologies are being employed to overcome the challenges of utilizing monoterpenoids as an anticancer agent.
Composion chimique et enantiomerique de l'huile essentielle de neroli bigarade ainsi que ses qualités pharmacologiques et médicinales
Bu çalışmada turunç çiçeği, karanfil tanesi ve portakal kabuğu yağları ve etanolik ekstraktlarının; lakerda örneklerinden izole edilen bakteriler üzerinde in vitro koşullarda antibakteriyel etkileri araştırılmıştır. Sonuçlara göre; esansiyel yağların etanolik ekstraktlara göre daha etkili olduğu belirlenmiştir. Turunç çiçeği ve karanfil tanesi esansiyel yağları; Pseudomonas fluorescens, Staphylococcus pasteuri, Staphylococcus equorum, Carnobacterium mobile, Carnobacterium maltaromaticum, Vibrio hibernica ve Vibrio rumoiensis bakterileri üzerinde güçlü etki göstermiştir. Esansiyel yağlar en yüksek inhibisyon etkisini, C. mobile üzerinde göstermiştir. Bu tür üzerinde turunç çiçeği %0,00977 ve karanfil tanesi %0,00488 konsantrasyon ile esansiyel yağlarının etkili olduğu bulunmuştur. Turunç çiçeği esansiyel yağının Staphylococcus pasteuri üzerinde %0,3125 konsantrasyon ile daha güçlü bir inhibisyon sağlanmıştır. En az etki %1,25 konsantrasyon ile karanfil esans yağında S. pasteuri bakterisine karşı tespit edilmiştir. Bu çalışmada turunç çiçeği ve karanfil tanesi esansiyel yağlarının, test edilen bakteriler üzerinde güçlü inhibisyon etkisi olduğu belirlenmiştir. Sonuç olarak, bulgular gıda güvenliğini sağlamak için lakerdalarda; turunç çiçeği ve karanfil tanesi esansiyel yağlarının kullanılabilirliğini desteklemektedir.
Special Issue of Antioxidants MDPI
Citrus is one of the main fruit crops cultivated in tropical and subtropical regions worldwide. Approximately half (40–47%) of the fruit mass is inedible and discarded as waste after processing, which causes pollution to the environment. Essential oils (EOs) are aromatic compounds found in significant quantities in oil sacs or oil glands present in the leaves, flowers, and fruit peels (mainly the flavedo part). Citrus EO is a complex mixture of ~400 compounds and has been found to be useful in aromatic infusions for personal health care, perfumes, pharmaceuticals, color enhancers in foods and beverages, and aromatherapy. The citrus EOs possess a pleasant scent, and impart relaxing, calming, mood-uplifting, and cheer-enhancing effects. In aromatherapy, it is applied either in message oils or in diffusion sprays for homes and vehicle sittings. The diffusion creates a fresh feeling and enhances relaxation from stress and anxiety and helps uplifting mood and boosting emotional and physical energy. This review presents a comprehensive outlook on the composition, properties, characterization, and mechanism of action of the citrus EOs in various health-related issues, with a focus on its antioxidant properties.
The physiological activity of the 50% ethanolic extract of Citrus aurantium flower before and after fermentation was investigated in this study. C. aurantium flowers grown in Taiwan were extracted using 100% methanol or 50% ethanol and then fermented by one of six microbes: four species of lactic acid bacteria (Bifidobacterium bifidum, Bifidobacterium lactis, Lactobacillus acidophilus, and Lactobacillus brevis) anaerobically cultivated in MRS broth and two species of mold (Aspergillus oryzae and Aspergillus niger) aerobically cultivated in potato dextrose broth. The 50% ethanolic extract of C. aurantium flowers exhibited higher tyrosinase inhibition (IC50: 200.8 ± 11.6 mg/L) and antioxidative activity than did a 100% methanolic extract (IC50: 274.1 ± 15.7 mg/L). The 50% ethanolic extract fermented by L. brevis (L. brevis–fermented extract) exhibited the highest yield (86.2% ± 1.2%) and physiological activity. The L. brevis–fermented extract exhibited over 5.2-, 13.5-, 12.5-, 3.17-, and 4.29-fold higher antityrosinase activity, antioxidative activity, antibacterial activity, total flavonoid content, and antiwrinkle activity than did the unfermented extract. The L. brevis–fermented extract can be considered safe because it exerted no toxic effect on CCD-966SK or HEMn cells at concentrations of 400 and 200 mg/L, respectively. The fermented extract (40 mg/L) inhibited melanin formation, reducing it to 50.8% ± 2.3%. Furthermore, the L. brevis–fermented extract exhibited excellent antiaging and antiwrinkle activity, as determined from MMP-1, MMP-2, elastase, and collagenase activity. The improvement in physiological characteristics, especially the considerable formation of neohesperidin, is mainly attributable to biosynthesis or biotransformation by L. brevis during fermentation. In conclusion, the 50% ethanolic extract of C. aurantium flowers fermented with L. brevis can be used in cosmetics applications aiming for skin-whitening or antiwrinkle properties.
In this work, seven Citrus aurantium essential oils (EOs) derived from flavedo of cultivars ‘Canaliculata’, ‘Consolei’, ‘Crispifolia’, ‘Fasciata’, ‘Foetifera’, ‘Listata’, and ‘Bizzaria’ were investigated. EOs were also combined in 1:1 (v/v) ratio to identify possible synergism or antagonism of actions. GC-MS analysis was done to investigate Eos’ phytochemical profiles. The antioxidant activity was studied by using a multi-target approach based on FRAP, DPPH, ABTS, and β-carotene bleaching tests. A great difference was observed in EOs’ phytochemical profiles. d-limonene (33.35–89.17%) was the main monoterpene hydrocarbon, and α-Pinene, β-myrcene, and β-linalool were identified in almost all samples. Among EOs, only C3 showed high quantitative and qualitative variability in its chemical composition. The chemical diversity of EOs was also demonstrated by PCA and HCA statistical analysis. Samples C2, C4, C5, C6, and C7 were statistically similar to each other, while C1 and C3 were characterized as having a different amount of other compounds and oxygenated monoterpenes, respectively, with respect to the other EOs mentioned. The global antioxidant score (GAS) revealed that among the tested EOs, C. aurantium ‘Fasciata’ EO had the highest antioxidant potential, with a GAS value of −0.47, whereas among combinations, the EO obtained by mixing ‘Canaliculata’ + ‘Bizzaria’ was the most active. Comparison by theoretical and real data on inhibitory concentration (IC50) and FRAP values did not reveal any significant effect of synergism or antagonism of actions to be valid in all biological applied tests. These findings, considered together, represent an important starting point to understand which compounds are responsible for the activities and their future possible industrial application.
Lemon, lime, orange, grapefruit, bergamot, mandarin and bitter orange species which have major characteristic specialities of Rutaceae family, have antimicrobial activities on pathogene microorganisms. Probiotic microorganisms have valuable effects on human body and inhibition of probiotics causes many diseases. In this present study, it was aimed to determine indicate probiotic resistance against natural antimicrobial agents (as essential oils) compare to pathogenes in previous studies. Analysis of essential oils (Eos) from were analyzed by GC-FID and GC/MS, analysis of Eos antimicrobial and antifungal activity from were analyzed by Microdilution test. Limonene (%95.29) and Linalool (%34.94) were found as major compounds of EOs respectively. All essential oils have antimicrobial activities on probiotic microorganisms.
This study was designed to examine the in vitro antimicrobial and antioxidant activities of the essential oil and various extracts (prepared by using solvents of varying polarity) of Salvia tomentosa (Miller). The essential oil was particularly found to possess strong antimicrobial activity while other non-polar extracts and subfractions showed moderate activities while polar extracts remained almost inactive. GC and GC/MS analyses of the oil resulted in the identification of 44 compounds, representing 97.7% of the oil; β-pinene (39.7%), α-pinene (10.9%) and camphor (9.7%) were the main components. The samples were also subjected to screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene-linoleic acid assays. In the first case, the free radical scavenging activity of aqueous methanol extract (MW) was superior to all other extracts (IC50=18.7 μg/ml). Polar extracts exhibited stronger activities than non-polar extracts. In the case of the linoleic acid system, oxidation of the linoleic acid was effectively inhibited by the polar subfraction of the MW extract, while the oil was less effective. The MW extract showed 90.6% inhibition, that is close to the synthetic antioxidant BHT.
Clove bud essential oil (CEO) and its major individual phenolic constituent eugenol were formulated as nanoparticles in water-based microemulsion systems. The oil titration method was used to incorporate different amounts of the oil and eugenol in the micellar solution of Tween-20. The Antioxidant and antimicrobial activities were evaluated using the DPPH* free radical scavenging assay and the agar disc dilution method, respectively. Results showed that microemulsion improved the evaluated activities of CEO and eugenol compared with the crude counterparts. Individual eugenol microemulsion was more effective than CEO microemulsion which contained only 61.7% eugenol among its constituents. The results of this study could have potential applications in water-based disinfectants, preservation and flavoring of food and in personal hygiene products. It may also have promising applications in the nutraceutical and functional beverage field.
The objective of this study was to evaluate the effect of distillation time (DT) (1.25, 2.5, 5, 10, 20, 40, 80, 160, 240, 360, 480 minutes) on yield, oil profile and antioxidant capacity of female Juniperus scopulorum trees. Analysis of the data revealed that essential oil yields reached a maximum of 0.77% at 240 minutes DT; the concentrations of alpha-thujene, alpha-pinene, camphene, myrcene and para-cymene decreased with longer DT; and the concentrations of cis-sabinene hydrate and linalool/trans-sabinene hydrate reached maximum at 40 minutes DT, whereas that of pregeijerene-B, delta-carene reached maximum at 240 minutes DT. The concentrations of alpha-terpinene, limonene, gamma-terpinene and 4-terpineol reached their maximum at 360 minutes DT, whereas terpinolene, alpha-eudesmol/ beta-eudesmol and 8-alpha acetoxyelemol reached maximum at 480 minutes DT. The yield of various essential oil constituents increased with increasing DT and reached maximum at 240 minutes or longer. The antioxidant capacity of J. scopulorum leaf essential oil increased with longer DT and was highest at 480 minutes DT. In conclusion, DT can be used as a tool to obtain an essential oil with differential composition and antioxidant activity. This paper can be used as a reference for comparing reports where different DTs were applied to extract essential oil from the leaves of female J. scopulorum.
A detailed analysis of Rosmarinus officinalis L. essential oil from Sardinia and Corsica (-pinene/verbenone/bornyl acetate chemotype) was carried out using GC–RI, GC–MS and 13C-NMR, on the bulk sample or after repeated chromatography. Fifty-eight compounds were identified. The antimicrobial activity of two Sardinian samples was investigated and both exhibited a moderate antibacterial activity. Gram-positive bacteria were more sensitive (MIC 2.5–4 mg/ml) than Gram-negative bacteria. Killing time experiments demonstrated that prolonged times (60 min) are needed to completely inactivate the bacterial inoculum. Copyright © 2001 John Wiley & Sons, Ltd.
The replacement of synthetic antioxidants by safe natural antioxidants fosters research on the screening of vegetables and food as sources of new antioxidants. Moreover, oxidative degeneration of cells is associated with neurodegenerative diseases such as Alzheimer's disease. On the basis of these considerations this work aimed to investigate the antioxidant properties [by using the diphenyl picryl hydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing ability of plasma assays, and the β-carotene bleaching test] and the anti-cholinesterase activity of Citrus aurantifolia peel and leaves from different areas of growth.
Methanol extracts of the peel and leaves demonstrated the strongest radical scavenging activity. A similar trend was observed with the reducing ability, with values from 112.1 to 146.0 µmol L(-1) Fe(II) g(-1) . The relationship between phenol and flavonoid contents and antioxidant activity was statistically investigated. Based on analysis by high-performance liquid chromatography, the most abundant flavonoids found in C. aurantifolia extracts were apigenin, rutin, quercetin, kaempferol and nobiletin. n-Hexane fractions of both peel and leaves showed a good acetylcholinesterase inhibitory activity with IC(50) values in the range 91.4-107.4 µg mL(-1) . Gas chromatography-mass spectrometry analysis revealed the presence of monoterpenes and sesquiterpenes as most common components.
The findings of this study suggest a potential use of C. aurantifolia peel and leaves for supplements for human health. Copyright © 2012 Society of Chemical Industry.
The compositions of essential oils isolated from nine samples of three Thymus species (Thymus algeriensis, Thymus pallescens and Thymus dréatensis) were analysed by GC and GC–MS, and a total of 114 components were identified. T. pallescens collected from various regions showed a great similarity in their compositions and were characterised by carvacrol (44.4–57.7%), p-cymene (10.3–17.3%) and γ-terpinene (10.8–14.2%) as the major components for four samples; only one sample was thymol-rich (49.3%) with a small amount of carvacrol (9.0%). On the other hand, T. algeriensis showed a chemical polymorphism, even for samples from the same location, and two new chemotypes for this species were proposed. Oxygen-containing monoterpenes were the predominant class (76.3%) in T. dreatensis oil, with linalool (30.4%), thymol (20.2%) and geraniol (19.6%) as the principal constituents. The oils were screened for their possible antioxidant activities by four complementary assays, namely DPPH free radical scavenging, hydroxyl radical scavenging, inhibition of lipid peroxidation and reducing power. The two new chemotypes of T. algeriensis exhibited strong hydroxyl radical scavenging (IC50 = 2.2–3.3 μg/ml), but were not or only slightly active against the other radicals and exhibited a weak reducing power. Despite their chemical similarity, T. pallescens oils sometimes produced significant differences in their antioxidant activities. The essential oils were also screened for their antimicrobial activity against five bacteria (three Gram-positive and two Gram-negative) and one yeast (Candida albicans). The tested essential oils showed antimicrobial activity against the microorganisms used, in particular against two important pathogens, C. albicans and Helicobacter pylori.
A novel, lipid-degrading bacterium (strain AHD-1) was isolated from soil regularly contaminated with washing-machine wastewater in Sfax, Tunisia. When this strain was grown in a medium containing 2% triacylglycerol, the hydrolysis products were found to be diacylglycerols, monoacylglycerols and free fatty acids. This strain was an aerobic, mesophilic, Gram-negative, motile, non-sporulating bacterium, capable of growing optimally at pH 7 and 27 degrees C. The predominant fatty acids were found to be C16:1omega7c (31%), C16:0 (28.1%), C18:1 omega7c (16.3%) and C17:0 (5.8%). Phylogenetic analysis of the 16S rRNA gene showed that this isolate is a new strain belonging to the genus Pseudomonas. Strain AHD-1 was found to be closely related to Pseudomonas azotoformans IAM 1603T, Pseudomonas gessardii CIP 105469T and Pseudomonas libanensis CIP 105460T with 99.7%, 99.56% and 99.54% of similarity, respectively.
Research into the mode of action of the essential oil of Melaleuca alternifolia (Tea tree oil) is briefly reviewed. Its mode of action is interpreted in terms of the membrane-toxicity of its monoterpenoid components and different approaches for determining cell membrane damage are discussed.
The MICs of rabeprazole sodium (RPZ), a newly developed benzimidazole proton pump inhibitor (PPI), against 133 clinicalHelicobacter pylori strains revealed a higher degree of activity than the another two PPIs, lansoprazole and omeprazole. Time-kill curve assays
of RPZ, when combined with amoxicillin, clarithromycin, or metronidazole, disclosed that synergistic effects were demonstrated
in combination with each antibiotic examined. Moreover, no apparent antagonistic effect appeared among all of the strains
tested.
A standardized mixture of Chinese herbs has recently been demonstrated to be an effective treatment for chronic atopic eczema in placebo controlled trials in the UK. Aqueous decoctions of this formulated mixture (PSE 222), the placebo mixture, and their component herbs were examined for antioxidant activity to determine whether antioxidant activity could account for the anti-eczema activity. Two measures of antioxidant activity were employed: the DPPH assay for non-specific hydrogen atom (or electron) donating activity and a superoxide scavenging assay. Antioxidant activity was detected in some components of both the active and placebo mixtures, but the formulated active mixture (PSE 222) was significantly more effective than the formulated placebo mixture. Further studies are needed to elucidate the in vivo significance of this result.
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The essential oil of Melaleuca alternifolia (tea tree) has broad-spectrum antimicrobial activity. The mechanisms of action of tea tree oil and three of its components, 1,8-cineole, terpinen-4-ol, and alpha-terpineol, against Staphylococcus aureus ATCC 9144 were investigated. Treatment with these agents at their MICs and two times their MICs, particularly treatment with terpinen-4-ol and alpha-terpineol, reduced the viability of S. aureus. None of the agents caused lysis, as determined by measurement of the optical density at 620 nm, although cells became disproportionately sensitive to subsequent autolysis. Loss of 260-nm-absorbing material occurred after treatment with concentrations equivalent to the MIC, particularly after treatment with 1,8-cineole and alpha-terpineol. S. aureus organisms treated with tea tree oil or its components at the MIC or two times the MIC showed a significant loss of tolerance to NaCl. When the agents were tested at one-half the MIC, only 1,8-cineole significantly reduced the tolerance of S. aureus to NaCl. Electron microscopy of terpinen-4-ol-treated cells showed the formation of mesosomes and the loss of cytoplasmic contents. The predisposition to lysis, the loss of 260-nm-absorbing material, the loss of tolerance to NaCl, and the altered morphology seen by electron microscopy all suggest that tea tree oil and its components compromise the cytoplasmic membrane.
The chemical composition of the essential oils of Achillea holosericea, Achillea taygetea, Achillea fraasii was determined by GC/MS analysis. Among the ninety-five assayed constituents, camphor, borneol and 1,8-cineol were found to be the major components. The in-vitro antimicrobial activity of these essential oils was evaluated against six bacteria indicating that the first is totally inactive, while the other two possess moderate to strong activities mainly against the Gram negative strains. The essential oil of A. fraasii was also active against the tested pathogenic fungi.
Citrus aurantium L. is commonly used as an alternative treatment for insomnia, anxiety and epilepsy. Essential oil from peel (EOP) and hydroethanolic (70% w/v) extract (HE) from leaves were obtained. Hexanic (HF), dichloromethanic (DF) and final aqueous (AF) fractions were obtained from HE by successive partitions. Swiss male mice (35-45 g) were treated orally with 0.5 or 1.0 g/kg of these preparations 30 min before the experiments for the evaluation of the sedative/hypnotic activity (sleeping time induced by sodium pentobarbital - SPB: 40 mg/kg, i.p.), anxiolytic activity (elevated plus maze--EPM) and anticonvulsant activity (induced by pentylenetetrazole--PTZ: 85 mg/kg, sc or by maximal electroshock--MES: 50 mA, 0.11 s, corneal). The results showed that EOP (0.5 g/kg) increased the latency period of tonic seizures in both convulsing experimental models. This effect was not dose-dependent. Treatment with 1.0 g/kg increased the sleeping time induced by barbiturates and the time spent in the open arms of the EPM. Specific tests indicated that the preparation, in both doses used, did not promote deficits in general activity or motor coordination. HF and DF fractions (1.0 g/kg) did not interfere in the epileptic seizures, but were able to enhance the sleeping time induced by barbiturates. The results obtained with EOP in the anxiety model, and with EOP, HF and DF in the sedation model, are in accord with the ethnopharmacological use of Citrus aurantium L., which could be useful in primary medical care, after toxicological investigation.
Polyphenols are the most abundant antioxidants in the diet and are widespread constituents of fruits, vegetables, cereals, dry legumes, chocolate, and beverages, such as tea, coffee, or wine. Experimental studies on animals or cultured human cell lines support a role of polyphenols in the prevention of cardiovascular diseases, cancers, neurodegenerative diseases, diabetes, or osteoporosis. However, it is very difficult to predict from these results the effects of polyphenol intake on disease prevention in humans. One of the reasons is that these studies have often been conducted at doses or concentrations far beyond those documented in humans. The few clinical studies on biomarkers of oxidative stress, cardiovascular disease risk factors, and tumor or bone resorption biomarkers have often led to contradictory results. Epidemiological studies have repeatedly shown an inverse association between the risk of myocardial infarction and the consumption of tea and wine or the intake level of some particular flavonoids, but no clear associations have been found between cancer risk and polyphenol consumption. More human studies are needed to provide clear evidence of their health protective effects and to better evaluate the risks possibly resulting from too high a polyphenol consumption.
Bacteriocin activity can be detected and assayed by a modification of the punchhole method.
Most food grade proteins derived from animal sources do not lend themselves to incorporation into certain formulated and synthesized food products without major preparative procedures. Animal proteins are, also, steadily increasing in cost and are becoming less available. In many cases oil-seed products extend, supplement, or replace more costly ingredients without detracting from the quality of the finished food. Oil-seed proteins may also be used to supplement or replace foods from other plant sources in order to enhance their nutritional value or alter their sensory characteristics.
Salvia fructicosa essential oil analyzed by gas chromatography/mass spectrometry showed high contents of 1,8-cineole, α- and β-thujone, and camphor, representing 47.48%, 11.93%, and 9.04% of the total oil, respectively. The essential oil and its isolated components thujone and 1,8-cineole exhibited antimicrobial activity against eight bacterial strains, while camphor was almost inactive against all of the bacteria tested. The essential oil was bactericidal at 1/4000 dilution, and dilutions up to 1/10000 caused considerable decrease in bacterial growth rates. The essential oil of S. fructicosa and the three main components exhibited cytotoxic activity against African Green Monkey kidney (Vero) cells and high levels of virucidal activity against herpes simplex virus 1, a ubiquitous human virus. Keywords: Salvia fructicosa; essential oil; antimicrobial activity; cytotoxicity; antiviral activity (herpes simplex virus); camphor; 1,8-cineole; thujone
Nutritional research on the health benefits of substances in plant foods has recently advanced to a new stage. The research frontier has moved from study of classical vitamin deficiency diseases to study of the thousands of phytochemicals that may have important physiological effects. Recent research suggests that citrus fruit consumers may be getting another health benefit from orange juice and other citrus products called limonoids, which appear to possess substantial anticancer activity. Limonoids are highly oxidized triterpenes present in Rutaceae and Maliaceae families. Several citrus limonoids have recently been subjected to anticancer screening utilizing laboratory animals and human breast cancer cells. The experimental results described that citrus limonoids may provide substantial anticancer actions. The compounds have been shown to be free of toxic effects in animal models, so potential exists for the use of limonoids against human cancer in either natural fruits, in citrus fortified with limonoids, or in purified forms of specific limonoids. Although the initial studies are very promising they have been conducted primarily with in vitro cell culture and animal models. Thus, research is needed to determine whether the limonoids may be useful in preventing or treating cancer in humans. Copyright © 2005 Society of Chemical Industry
The essential oil in traditional Chinese medicine (TCM) Herba Artemisiae Scopariae (HAC) grown in China was obtained by hydrodistillation and studied by GC and GC-MS. Twenty compounds were identified representing 96.6% of the essential oil, of which the most prominent were n-hexadecanoic acid (33.1%), caryophyllene oxide (19.1%) and spathulenol (9.9%). The antioxidant activity of the essential oil (25-400 µg/ml) of HAC was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing/antioxidant power (FRAP) assay. The essential oil of HAC exhibited a strong antioxidant activity, which possess a good potential for use in the food and pharmaceutical industry.
The antimicrobial properties of essential oils (EOs) have been recognised for centuries and, with growing demand from changes in legislation, consumer trends and increasing isolation of antibiotic resistant pathogens, alternatives to chemical-based bactericides need to be found. Citrus oils not only lend themselves to use in food but also are generally recognised as safe (GRAS) and have been found to be inhibitory both in direct oil and vapour form against a range of both Gram-positive and Gram-negative bacteria. This group of oils may provide the natural antimicrobials that the food industry requires to fulfil both its requirements and those of the consumer.
Antioxidants minimize oxidation of the lipid components in foods. There is an increasing interest in the use of natural and/or synthetic antioxidants in food preservation, but it is important to evaluate such compounds fully for both antioxidant and pro-oxidant properties. The properties of thymol, carvacrol, 6-gingerol, hydroxytyrosol and zingerone were characterized in detail. Thymol, carvacrol, 6-gingerol and hydroxytyrosol decreased peroxidation of phospholipid liposomes in the presence of iron(III) and ascorbate, but zingerone had only a weak inhibitory effect on the system. The compounds were good scavengers of peroxyl radicals (CCl3O2; calculated rate constants > 106m−1 sec−1) generated by pulse radiolysis. Thymol, carvacrol, 6-gingerol and zingerone were not able to accelerate DNA damage in the bleomycin-Fe(III) system. Hydroxytyrosol promoted deoxyribose damage in the deoxyribose assay and also promoted DNA damage in the bleomycin-Fe(III) system. This promotion was inhibited strongly in the deoxyribose assay by the addition of bovine serum albumin to the reaction mixtures. Our data suggest that thymol, carvacrol and 6-gingerol possess useful antioxidant properties and may become important in the search for ‘natural’ replacements for ‘synthetic’ antioxidant food additives.
The fate of antibiotics in the environment, and especially antibiotics used in animal husbandry, is subject to recent studies and the issue of this review. The assumed quantity of antibiotics excreted by animal husbandry adds up to thousands of tonnes per year. Administered medicines, their metabolites or degradation products reach the terrestrial and aquatic environment by the application of manure or slurry to areas used agriculturally, or by pasture-reared animals excreting directly on the land, followed by surface run-off, driftage or leaching in deeper layers of the earth. The scientific interest in antimicrobially active compounds in manure and soil, but also in surface and ground water, has increased during the last decade. On the one side, scientific interest has focused on the behaviour of antibiotics and their fate in the environment, on the other hand, their impact on environmental and other bacteria has become an issue of research. Analytical methods have now been developed appropriately and studies using these new techniques provide accurate data on concentrations of antimicrobial compounds and their residues in different organic matters. Some antibiotics seem to persist a long time in the environment, especially in soil, while others degrade very fast. Not only the fate of these pharmaceuticals but their origin as well is an object of scientific interest. Besides human input via wastewater and other effluents, livestock production has been recognised as a source of contamination. One main concern with regard to the excessive use of antibiotics in livestock production is the potential promotion of resistance and the resulting disadvantages in the therapeutic use of antimicrobials. Since the beginning of antibiotic therapy, more and more resistant bacterial strains have been isolated from environmental sources showing one or multiple resistance. There have been several attempts to use antibiotic resistance patterns in different bacteria as indicators for various sources of faecal pollution. This review gives an overview of the available data on the present use of veterinary antibiotics in agriculture, on the occurrence of antibiotic compounds and resistant bacteria in soil and water and demonstrates the need for further studies.
Chemical fungicides provide the primary means for controlling postharvest fungal decay of fruit and vegetables. Continuous use of fungicides has faced two major obstacles—increasing public concern regarding contamination of perishables with fungicidal residues, and proliferation of resistance in the pathogen populations. The ultimate aim of recent research in this area has been the development and evaluation of various alternative control strategies to reduce dependency on synthetic fungicides. Several non-chemical treatments have been proposed for fungal decay control. Although these approaches have been shown to reduce postharvest rots of fruit and vegetables, each has limitations that can affect their commercial applicability. When used as stand-alone treatments, none of the non-chemical control methods has been clearly shown to offer a consistently economic level of disease control that warrants acceptance as an alternative to synthetic fungicides. Recently, the exploitation of natural products to control decay and prolong storage life of perishables has received more and more attention. Biologically active natural products have the potential to replace synthetic fungicides. This review deals with exploitation of some natural products such as flavour compounds, acetic acid, jasmonates, glucosinolates, propolis, fusapyrone and deoxyfusapyrone, chitosan, essential oils and plant extracts for the management of fungal rotting of fruit and vegetables, thereby prolonging shelf life.
There are a few reports on the antimicrobial activity of essential oils or their major constituents towards Shigella sp. The antimicrobial effect of basil and thyme essential oil and its major constituents thymol, p-cymene, estragol, linalool, and carvacrol was determined using the agar well diffusion assay. Thyme essential oil and thymol and carvacrol showed inhibition of Shigella sp. in the agar well diffusion method. The potential of thyme essential oil, thymol and carvacrol at 0.5% and 1.0% v/v for decontamination of lettuce was evaluated. A decrease of the shigellae was observed after washing with 0.5% while at 1% Shigella numbers dropped below the detection limit. However, the antimicrobial effect on a subsequent lettuce sample in the same decontamination solution was significantly decreased. In addition, application of thyme essential oil or thymol or carvacrol for decontamination is hampered by sensoric properties of the lettuce (browning, strong odour).
The essential oil (EO) isolated by hydro-distillation from the peel of fully matured ripen fruits of Citrus reticulata Blanco were analyzed by GC and GC–MS. Thirty seven different components were identified constituting approximately ≥99% of the oil. The major components were limonene (46.7%), geranial (19.0%), neral (14.5%), geranyl acetate (3.9%), geraniol (3.5%), β-caryophyllene (2.6%), nerol (2.3%), neryl acetate (1.1%) etc. The antifungal activity of the oil was tested by poisoned food (PF) technique and the volatile activity (VA) assay against five plant pathogenic fungi viz Alternaria alternata (Aa), Rhizoctonia solani (Rs), Curvularia lunata (Cl), Fusarium oxysporum (Fo) and Helminthosporium oryzae (Ho). The oil showed better activity in VA assay. The Minimum inhibitory concentration (MIC) for Aa, Rs and Cl was 0.2 ml/100 ml whereas >0.2 ml/100 ml for Fo and Ho in PF technique. Fungal sporulation was also completely inhibited at 2 ml/100 ml of the oil except for Cl and Ho, which was only 0.5% (±0.5) and 0.25% (±0.25) respectively as compared to control.
About 100 pure components of essential oils have been tested for their antioxidant effectiveness. The main classes of compounds, namely monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons, oxygenated sesquiterpenes, benzene derivatives, and non isoprenoid components comprising alcohols, aldehydes, ketones, which are the most common constituents of essential oils, have been analysed. Two model systems for the antioxidant efficacy have been used; the first exploiting the thiobarbituric acid reactive species (TBARS) method using egg yolk as oxydable substrate, the second measuring the formation of hydroperoxydienes from linoleic acid in a micellar system, using in both cases 2,2′-azobis (2-amidinopropane) dihydrochloride (ABAP) as a radical initiator, and α-tocopherol as a reference compound. From a general point of view phenols were confirmed to possess the highest antioxidant activity. In particular some monoterpene hydrocarbons, namely, terpinolene, α- and γ-terpinene showed a significant protective action, whereas among the oxygenated components, beside the aforesaid phenols, allylic alcohols manifested an appreciable activity. Sesquiterpene hydrocarbons and non isoprenoid components subjected to this study showed a low, if any, antioxidant effect. The role of the different model systems and the relationship between structure and antioxidant effectiveness are discussed.
Antibacterial activity of 11 essential oil constituents against Escherichia coli, E. coli O157:H7, Salmonella typhimurium, Listeria monocytogenes, and Vibrio vulnificus was tested at 5, 10, 15, and 20% in 1% Tween 20 using a paper disk method. Eight constituents were then tested in liquid medium to determine minimum inhibitory and minimum bactericidal concentrations (MIC and MBC, respectively). V. vulnificus was most susceptible using disk assay. Carvacrol showed strong bactericidal activity against all tester strains, while limonene, nerolidol, and β-ionone were mostly inactive. Carvacrol was highly bactericidal against S. typhimurium and V. vulnificus in liquid medium (MBC 250 μg/mL). Citral and perillaldehyde had MBCs of 100 and 250 μg/mL against V. vulnificus. Terpineol and linalool were least potent against tester strains, with MBCs of 1000 μg/ mL. Citral, geraniol, and perillaldehyde at 500 μg/mL completely killed E. coli, E. coli O157:H7, and S. typhimurium, while citronellal at 250 μg/mL killed V. vulnificus. Therefore, these compounds could serve as potential antibacterial agents to inhibit pathogen growth in food.
Anti-Candida activity of essential oils has been widely studied and as a consequence they are being investigated as possible alternatives or complementary therapeutic agents for candidosis. We reviewed the most studied essential oils concerning chemical composition and in vitro/in vivo studies under the perspective of their possible clinical use.
The factors affecting oil yield and quality of essential oils from Dalmatian sage (Salvia officinalis L.) are analyzed. Distillations of oils from individual plants and GC analyses revealed the presence of three chemotypes with different proportions of alpha- and beta-thujone (alpha/beta 10:1, 1.5:1, and 1:10). Different accessions could also be classified as having high (39-44%), medium (22-28%), or low (9%) total thujone contents. Flowering parts of S. officinalis had higher oil contents (1.6 versus 1.1%) and beta-pinene levels (27 versus 10%) than leaves and lower thujone levels (16 versus 31%). Major seasonal changes were found in the composition of oil distilled from a flowering type of Dalmatian sage, but oil yields from healthy, established plants did not vary greatly. Total thujone levels were lowest (25%) around flowering in spring and summer, so autumn or winter was the best harvest time to obtain oils with high thujone levels.
Fragrances are common causes of allergic contact dermatitis. beta-Caryophyllene is a sesquiterpene that is used as a fragrance chemical. Analogous to the monoterpenes R-limonene and linalool, it can be expected to autoxidize when air exposed. The aim of the present study was to investigate the autoxidation of beta-caryophyllene and to evaluate the effect on the contact allergenic activity. beta-Caryophyllene started to oxidize immediately when air exposed and after 5 weeks almost 50% of the original compound was consumed. Caryophyllene oxide was found to be the major oxidation product. Hydroperoxides of beta-caryophyllene could not be detected in the oxidation mixture. Caryophyllene oxide was shown to be an allergen of moderate strength and beta-caryophyllene air exposed for 10 weeks showed a weak sensitizing capacity in the local lymph node assay. The study reveals that the allergenic activity of beta-caryophyllene is affected by autoxidation, but to a lesser extent when compared to R-limonene and linalool. The present findings support our results in clinical studies showing oxidized beta-caryophyllene to be a rather rare sensitizer compared to oxidized R-limonene and linalool.
Citrus reticulata Blanco var. Suavissima historical investigation
- X R Lin
- J R Xu
Lin, X. R.; Xu, J. R. Citrus reticulata Blanco var. Suavissima historical investiga