Chemotypic differentiation in indigenous populations of Foeniculum vulgare var. vulgare in Israel

Chemical and Genetic Variability of Istrian Foeniculum vulgare Wild Populations

Wild Foeniculum vulgare populations from the region of Istria have been subjected to a genetic and chemical study. Headspace-gas chromatography analysis of volatile secondary metabolites and PCR-RFLP analysis of the ribosomal DNA internal transcribed spacer region has been chosen to analyze the chemical and genetic traits of single plants, respectively. Large intrapopulation and interpopulation differences have been observed in both chemical profiles and restriction patterns of PCR products. The data from chemical and genetic analyses were pooled and used to assess allele frequencies of three putative genetic loci on individual populations. The pooled allele frequencies were used to determine interpopulation distances for phenogram reconstruction. The combined use of chemical and genetic datasets for genetic variation analysis proved to be a more comprehensive approach for such a study, compared to the use of single datasets, even using such relatively simple analytical tools.

Characterization of essential oil recovered from fennel horticultural wastes

Fennel crop has been traditionally used as spice in cooking and fragrances, and in folk medicine for its spectrum of useful properties. Mediterranean is the elective natural cultivation area for this plant with Italy being a leader producer. A limit of this production is due to the high amount of wastes derived still rich of phytochemicals, which are usually underused. Hence, the extraction and characterization of essential oil from residues of fennel horticultural market was investigated to understand the potential profit of their recycling. Forty-eight compounds resulted for fennel oil waste, analysed by GC-FID-MS, with the most abundant among components was anethole. Other constituents contributing to fennel flavour were the monoterpenes limonene and nerol. The exploitation of this oil as a good source of bioactive compounds was assessed by means of its antioxidant power measured with DPPH test.

Cytotoxicity of the Essential Oil of Fennel (Foeniculum vulgare) from Tajikistan

The essential oil of fennel (Foeniculum vulgare) is rich in lipophilic secondary metabolites, which can easily cross cell membranes by free diffusion. Several constituents of the oil carry reactive carbonyl groups in their ring structures. Carbonyl groups can react with amino groups of amino acid residues in proteins or in nucleotides of DNA to form Schiff's bases. Fennel essential oil is rich in anise aldehyde, which should interfere with molecular targets in cells. The aim of the present study was to investigate the chemical composition of the essential oil of fennel growing in Tajikistan. Gas chromatographic-mass spectrometric analysis revealed that the main components of F. vulgare oil were trans-anethole (36.8%); α-ethyl-p-methoxy-benzyl alcohol (9.1%); p-anisaldehyde (7.7%); carvone (4.9%); 1-phenyl-penta-2,4-diyne (4.8%) and fenchyl butanoate (4.2%). The oil exhibited moderate antioxidant activities. The potential cytotoxic activity was studied against HeLa (human cervical cancer), Caco-2 (human colorectal adenocarcinoma), MCF-7 (human breast adenocarcinoma), CCRF-CEM (human T lymphoblast leukaemia) and CEM/ADR5000 (adriamycin resistant leukaemia) cancer cell lines; IC₅₀ values were between 30-210 mg L^-1 and thus exhibited low cytotoxicity as compared to cytotoxic reference compounds.

Changes in Volatile Compounds during Aging of Sweet Fennel Fruits-Comparison of Hydrodistillation and Static Headspace Sampling Methods

Two extraction methods for subsequent gas chromatographic (GC) determination of volatiles from freshly harvested and aged fennel fruit samples ( Foeniculum vulgare Mill.,ssp. vulgare var. dulce) have been compared. Hydrodistillation followed by GC-FID and GC-MS analysis was used as a standard method for essential oil characterization, while static headspace followed by GC (SHS-GC-FID) was used as a comparative method for determination of volatile components. As the fennel fruit ages, there is a gradual loss of the volatile components as indicated by the lower yield of essential oil and lower content of volatiles, as indicated by the alternative SHS-GC-FID analysis. Slight differences observed for the main components ( trans-anethole, estragole, fenchone, and limonene) using the two methods are negligible, indicating that these volatiles did not undergo chemical transformation during the sample preparation procedures. A difference in anisaldehyde content was observed when the composition of the hydrodistilled essential oil was compared with the SHS-GC-FIDanalysis of volatiles and explanation for the variation of anisaldehyde content and the origin of other compounds was suggested. Comparison of the obtained results showed that limonene oxides, carvone and carveolare detectable in SHS-GC-FID analysis of the aged fennel fruits, while in hydrodistilled samples analyzed by GC-FID they were not present. Another observed difference was the appearance of products in significant amounts with higher retention times than trans-anethole, namely threo- and erythro-anethole β-hydroxymethylether and anethole glycol that are not detectable in the essential oil obtained by hydrodistillation. So, the relative abundance of the major components is comparable between these two methods for fennel seed up to 3 years from harvest and they can be used interchangeably depending on the purpose and amount of material. Furthermore, SHS-GC-FID can be used for assessment of maximum storage time and quality of fennel fruit suitable for human consumption.

Simultaneous Determination of Essential Oil Components and Fatty Acids in Fennel using Gas Chromatography with a Polar Capillary Column

Cultivated and wild growing samples of fennel ( Foeniculum vulgare Mill., Apiaceae) from R. Macedonia were studied for their volatiles and fatty acid composition. The main essential oil components isolated via hydrodistillation were: trans-anethole (>80%), estragole (<6%), limonene (<6%), anisaldehyde (<1%) and 0.5 % fenchone. An alternative method for characterization of both the non-polar volatile and non volatile fractions was developed using n-hexane and dichloromethane (3:1, v/v) in a Soxhlet extraction followed by transesterification. The obtained extracts were then characterized and the dominant fatty acid was 18:1 (petroselinic and oleic acid) 75.0–82.8 %, followed by 18:2 (linoleic acid) 10.8–16.2% and other fatty acids: palmitic (4.3–6.9%), stearic (1.2–1.7%) and myristic (0–2.9%). The results for the volatile fraction after Soxhlet extraction and transesterification did not significantly differ from results obtained after hydrodistillation, especially for the main components ( trans-anethole, estragole, fenchone and limonene), implying that the developed method can be used for simultaneous determination of volatiles and fatty acids.

Activities of Apiaceae essential oils against armyworm, Pseudaletia unipuncta (Lepidoptera: Noctuidae)

Essential oils (EOs) from four Apiaceae species and 11 pure compounds were evaluated for their antifeedant, growth inhibitory, and insecticidal activities against Pseudaletia unipuncta (Lepidoptera: Noctuidae) fourth-instar larvae. EOs from Foeniculum vulgare subsp. vulgare var. vulgare, Anethum graveolens , Petroselinum crispum , and Cuminum cyminum were characterized by gas-chromatography (GC) and mass spectrometry. Anti-insect activity varied according to plant specie/composition, type, and exposure period. EOs from P. crispum and A. graveolens fruits, trans-anethole and cuminaldehyde, exerted acute effects on larvae feeding and growth (FDI and GI > 70%). A. graveolens , C. cyminum , and F. vulgare EOs and some of their constituents were effective by fumigation (≥ 80%). Satisfactory contact toxicities (>70%) were observed for five compounds and all EOs, except F. vulgare EOs, when tested by the filter paper impregnation method. For the most active EOs/compounds, dose-dependent toxicity was determined and inverse relationships of LC50 with time were established.

Chemical composition, antimicrobial and antioxidant activities of anethole-rich oil from leaves of selected varieties of fennel [Foeniculum vulgare Mill. ssp. vulgare var. azoricum (Mill.) Thell]

The chemical composition and biological activity of the essential oils obtained from the leaves of two different cultivars of Florence fennel cropped under three different fertilization treatments (Control not fertilized; Mineral Fertilization; Compost from Municipal Solid Wastes) have been analyzed. All the oils were characterized by high anethole concentration and some showed also a good percentage of limonene. Thus, the leaves of Florence fennel, which are agricultural wastes, could be used for the recovery of anethole to be used for its flavoring and biomedical properties. The antimicrobial activity expressed by assays on the examined oils indicates an appreciable effect, generally higher on Gram-positive bacteria. The various samples of Florence fennel analyzed did not show any results with FRAP test. The DPPH test showed a weak capacity of the samples to catch the free radicals from the solution, attributable to their content in anethole.

Can estragole in fennel seed decoctions really be considered a danger for human health? A fennel safety update

Fennel (Foeniculum vulgare Mill.) mature fruit (commonly known as seeds) and essential oil of fennel are widely used as flavoring agents in food products such as liqueurs, bread, cheese, and an ingredient of cosmetics and pharmaceutical products. Moreover fennel infusions are the classical decoction for nursing babies to prevent flatulence and colic spasm. Traditionally in Europe and Mediterranean areas fennel is used as antispasmodic, diuretic, anti-inflammatory, analgesic, secretomotor, secretolytic, galactagogue, eye lotion, and antioxidant remedy and integrator. Topically, fennel powder is used as a poultice for snake bites. In Asian cultures fennel was ingested to speed the elimination of poisons. As one of the ancient Saxon people's nine sacred herbs, fennel was credited with the power to cure. Fennel was also valued as a magic herb: in the Middle Ages it was draped over doorways on Midsummer's Eve to protect the household from evil spirits. Recently because of estragole carcinogenicity, fennel has been charged to be dangerous for humans especially if used as decoction for babies. But this allegation do not consider the remedy is prepared as a matrix of substances, and recent researches confirm that pure estragole is inactivated by many substance contained in the decoction.

Antinociceptive activity of the monoterpene α-phellandrene in rodents: possible mechanisms of action

OBJECTIVES

The aim of this work was to investigate the antinociceptive property of α-phellandrene (α-PHE) in experimental nociception models and possible mechanisms involved.

METHODS

Mass spectrometry was used to evaluate the purity and molecular mass of α-PHE. Macrophages from mice peritoneal cavity were used in an MTT test. Rodents were used in tests of chemical and mechanical nociception. In the study of the mechanisms, the animals were treated with pharmacological tools and then submitted to the glutamate test.

KEY FINDINGS

α-PHE purity was 98.2% and molecular mass 136.1 Da. α-PHE did not show cytotoxicity. In the writhing and capsaicin tests, α-PHE promoted the antinociceptive effect in all evaluated doses (minimum dose 3.125 mg/kg). In the formalin test, α-PHE (50 mg/kg) was effective in inhibiting both phases. In the glutamate test, the monoterpene (12.5 mg/kg) decreased the nociceptive response. In carrageenan-induced hyperalgesia, α-PHE (50 mg/kg) decreased the hypernociception index. In the study of the mechanisms involved, pretreatment with naloxone reversed the α-PHE antinociceptive effect, the same occurred with glibenclamide, l-arginine, atropine and yohimbine. α-PHE did not show muscle relaxant activity or central depressant effects in open field and rota rod tests.

CONCLUSIONS

α-PHE has an antinociceptive effect and it possibly involves the glutamatergic, opioid, nitrergic, cholinergic and adrenergic systems.

Antimicrobial activities of essential oil and hexane extract of Florence fennel [Foeniculum vulgare var. azoricum (Mill.) Thell.] against foodborne microorganisms

The objective of this study was to determine the chemical compositions of the essential oil and hexane extract isolated from the inflorescence, leaf stems, and aerial parts of Florence fennel and the antimicrobial activities of the essential oil, hexane extract, and their major component, anethole, against a large variety of foodborne microorganisms. Gas chromatography and gas chromatography-mass spectrometry analysis showed that the essential oils obtained from inflorescence, leaf stems, and whole aerial parts contained (E)-anethole (59.28-71.69%), limonene (8.30-10.73%), apiole (trace to 9.23%), beta-fenchyl acetate (3.02-4.80%), and perillene (2.16-3.29%) as the main components. Likewise, the hexane extract of the plant sample exhibited a similar chemical composition, and it contained (E)-anethole (53.00%), limonene (27.16%), gamma-terpinene (4.09%), and perillene (3.78%). However, the hexane extract also contained less volatile components such as n-hexadecanoic acid (1.62%), methyl palmitate (1.17%), and linoleic acid (1.15%). The in vitro antimicrobial assays showed that the essential oil, anethole, and hexane extract were effective against most of the foodborne pathogenic, saprophytic, probiotic, and mycotoxigenic microorganisms tested. The results of the present study revealed that (E)-anethole, the main component of Florence fennel essential oil, is responsible for the antimicrobial activity and that the essential oils as well as the hexane extract can be used as a food preservative. This study is the first report showing the antimicrobial activities of essential oil and hexane extract of Florence fennel against probiotic bacteria.

Foeniculum vulgare Essential Oils: Chemical Composition, Antioxidant and Antimicrobial Activities

The essential oils from Foeniculum vulgare commercial aerial parts and fruits were isolated by hydrodistillation, with different distillation times (30 min, 1 h, 2 h and 3 h), and analyzed by GC and GC-MS. The antioxidant ability was estimated using four distinct methods. Antibacterial activity was determined by the agar diffusion method. Remarkable differences, and worrying from the quality and safety point of view, were detected in the essential oils. trans-Anethole (31-36%), α-pinene (14-20%) and limonene (11-13%) were the main components of the essentials oil isolated from F. vulgare dried aerial parts, whereas methyl chavicol (= estragole) (79-88%) was dominant in the fruit oils. With the DPPH method the plant oils showed better antioxidant activity than the fruits oils. With the TBARS method and at higher concentrations, fennel essential oils showed a pro-oxidant activity. None of the oils showed a hydroxyl radical scavenging capacity >50%, but they showed an ability to inhibit 5-lipoxygenase. The essential oils showed a very low antimicrobial activity. In general, the essential oils isolated during 2 h were as effective, from the biological activity point of view, as those isolated during 3 h.

Antioxidant activity and phenolic composition of wild, edible, and medicinal fennel from different Mediterranean countries

Fennel (Foeniculum vulgare Mill.) is a typical aromatic plant of the Mediterranean area, long used as a medicinal and spice herb. Fennel is also well-known for its essential oil, which has been extensively studied for many years owing to its commercial importance. In this work, the antioxidant activity and the total phenolic and flavonoid contents, as well as the quantitative determination of individual flavonoids and phenolic acids of wild, edible, and medicinal fennel from different Mediterranean countries, have been determined. The antioxidant activity was measured as the free radical (DPPH), hydroxyl radical, and superoxide anion scavenging activities. Wild fennel was found to exhibit a radical scavenging activity, as well as a total phenolic and total flavonoid content, higher than those of both medicinal and edible fennels.

Protective effect of Foeniculum vulgare essential oil and anethole in an experimental model of thrombosis

In a previous screening work, Foeniculum vulgare essential oil emerged from a pool of 24 essential oils for its antiplatelet properties and its ability to destabilize the retraction of the coagulum. In the present work the main component of the oil, anethole, tested in guinea pig plasma was as potent as fennel oil in inhibiting arachidonic acid-, collagen-, ADP- and U46619-induced aggregation (IC(50) from 4 to 147 microg ml(-1)). It also prevented thrombin-induced clot retraction at concentrations similar to fennel oil. The essential oil and anethole, tested in rat aorta with or without endothelium, displayed comparable NO-independent vasorelaxant activity at antiplatelet concentrations which have been proved to be free from cytotoxic effects in vitro. In vivo, both F. vulgare essential oil and anethole orally administered in a subacute treatment to mice (30 mg kg(-1)day(-1) for 5 days) showed significant antithrombotic activity preventing the paralysis induced by collagen-epinephrine intravenous injection (70% and 83% protection, respectively). At the antithrombotic dosage they were free from prohemorrhagic side effect at variance with acetylsalicylic acid used as reference drug. Furthermore, both F. vulgare essential oil and anethole (100 mg kg(-1) oral administration) provided significant protection toward ethanol induced gastric lesions in rats. In conclusion, these results demonstrate for F. vulgare essential oil, and its main component anethole, a safe antithrombotic activity that seems due to their broad spectrum antiplatelet activity, clot destabilizing effect and vasorelaxant action.

Determination of phenolic compounds in fennel by HPLC and HPLC-MS using a monolithic reversed-phase column

A reversed-phase high-performance liquid chromatography (HPLC) method for analyzing phenolic compounds in fennel (Foeniculum vulgare) has been developed. The use of a monolithic column with short dimensions in combination with optimized chromatographic conditions allows over 100 samples per day to be analyzed. Chromatographic parameters such as column temperature and injection volume, were found to be crucial in obtaining adequate selectivity and resolution, consequently allowing short run times. The method was validated for the major phenolic compounds present in fennel plant material: 3-O-caffeoylquinic acid (3-CQA), chlorogenic acid, 4-O-caffeoylquinic acid (4-CQA), eriocitrin, rutin, miquelianin, 1,3-O-dicaffeoylquinic acid (1,3-diCQA), 1,5-O-dicaffeoylquinic acid (1,5-diCQA), 1,4-O-dicaffeoylquinic acid (1,4-diCQA) and rosmarinic acid. The limits of detection (LOD) and the limits of quantitation (LOQ) ranged from 0.05 to 1.0 microg/mL and from 0.15 to 2.5 microg/mL, respectively. With some adaptation, the extraction procedure could be even less invasive, which is useful in screening work.

Study on the transfer of components of Aetheroleum carvi and Aetheroleum foeniculi oils

The transfer through a membrane of the main organic components and mineral elements of Carum carvi and Foeniculum vulgare volatile oils was studied. The transfer was studied from buffer solution pH 1.1 (stomach) and pH 6.5 (intestine) to pH 7.5 (plasma) in a Sartorius model. The transferred components were measured by GC-MS for volatile components and ICP-OES for inorganic elements. The main components (trans-anethole and fenchone from F. vulgare, carvone and D-limonene from C. carvi), as well as some mineral elements (Ca, Mg, S, Zn), transferred through the membrane.