Search

Potato plants and their tubers in Egypt are affected by one of the most renowned soil-borne pathogen, Ralstonia solanacearum, that caused brown rot in potato tubers and wilt in plants. There is no efficient therapeutic bactericide so; control of bacterial wilt is very rough. The study investigated three different concentrations of seven essential plant oils under in vitro and in vivo conditions as a result of their effects on Ralstonia solanacearum growth and their possibility use as potato seed pieces dressing for controlling bacterial wilt disease incidence. In vitro, anise oil at the three tested different concentrations (0.04, 0.07, and 0.14% vol/vol) was the most effective one inhibiting the growth of T4 and W9 isolates of Ralstonia solanacearum then pursued by thyme, lemongrass, and clove oils. On the other hand, rocket oil at the tested concentration was the least effective one followed by fennel oil. However, wheat germ oil was not completely effective. In vivo, experiment revealed that anise oil at the three concentrations significantly reduced disease incidence and severity in sponta and hermes potato cultivars and their effect was associated with increase of peroxidase, polyphenoloxidase, phenols and the foliar fresh weight of treated plants as well as the weight of tubers/plant followed by thyme and lemongrass oils compared to the infected untreated control. Morphological differences in bacterial cell structure have been observed using a transmission electron microscope (TEM). Anise oil at higher concentration caused of cell wall rupture and degraded cellular components.

The aim of this study was to investigate the influence of foliar application of Moringa oleifera leaf extracts (control, 2.5% and 5% aqueous MLE, 2.5% and 5% ethanolic MLE) and/or benzyladenine (control, 50, 100 and 200 ppm BA) on the growth, fruit and oil yield and its main components and chemical constituents of fennel (Foeniculum vulgare, Mill.) plants. The obtained results revealed that treated fennel plants with MLE and/or BA resulted in a significant increase in the vegetative growth, number of umbels/plant, fruit and oil yield per plant and feddan as well as total carbohydrates in fruits, chlorophyll a, b and carotenoids, nitrogen, phosphorus and potassium contents in leaves compared to untreated plants. Generally, the application of moringa leaf extracts was more effective than BA treatments. The individual treatment of aqueous MLE at 5% or BA at 100 ppm gave the best results of the previous mentioned characteristics followed by 5% ethanolic MLE or 50 ppm BA compared to the control and the rest of tested individual ones. The highest values of all studied parameters were obtained by using 5% aqueous or ethanolic MLE combined with 100 ppm BA. The increments were 91.1% and 85.3% in fruit yield/feddan, 52.5% and 46.3% in volatile oil percentage and 192.4% and 172.0% in oil yield/feddan, respectively over the control. The G.C. analysis of the volatile oil showed that the major component of volatile oil was methyl chavicol (estragole) with concentration range from 77.5% to 87.3%. The minor compounds were myrcene and limonene. The best treatment for decreasing the concentration of methyl chavicol (77.5%), which is undesirable component in fennel oil resulted from the combination of 5% aqueous MLE plus 100 ppm BA. Therefore, it could be recommended that spraying fennel plants with 5% aqueous MLE plus 100 ppm BA for obtaining higher vegetative growth, fruit and oil yield.

Fennel is one of the most significant medicinal and aromatic herbs. It is used as a culinary ingredient and has an essential role as a raw material in the pharmaceutical industry. Many researchers across the world are working to increase the active components in the essential oil of medicinal and aromatic plants under organic farming. Growth promoters are one of the most effective methods for stimulating secondary metabolite production under organic agriculture. The objectives of this study were to investigate how foliar sprays of yeast extract (Y) and/or chitosan-oligosaccharide (CHO) affected the growth and yield of organic fennel (Foeniculum vulgare spp. vulgare Mill.) and if these applications can stimulate the production of pharmaceutical active ingredients in fennel fruits. Fennel foliage was subjected to foliar spray of Y at concentrations of 0 (Y0), 2 (Y1), and 4 (Y2) g L−1, and CHO at concentrations of 0 (CHO0), 60 (CHO1), and 120 (CHO2) mg L−1 twice. The results revealed that both Y and CHO treatments promoted growth parameters and leaf pigments content. Total phenols and nutritional content (N, P, K, Ca, and Mg) in fennel fruits were also improved. Furthermore, Y and CHO treatments enhanced fruit and oil productivity. Foliar spraying with Y and/or CHO, as well as their combination, resulted in significant modification in main pharmacological active components in fennel essential oil. Treated plants with Y1 had the lowest proportion of estragole (24.61 %), an undesirable component in fennel oil, and the highest concentration of anethole (64.50 %), which improved the oil quality. While treated plants with CHO1 or CHO2 displayed an increase in estragole content by about 33.34 and 46.59 % compared with Y1-plants, respectively. These new findings demonstrated that applying Y2 or CHO at both levels not only increased fennel growth and yield, but also contributed to increasing estragole and decreasing anethole concentration, and both had a negative impact on essential oil quality. However, applying Y1 enhanced fennel productivity as well as essential oil quality.

This study assessed the effects of essential oil of Foeniculum vulgare Mill. (fennel oil) and of trans-anethole, the main component of fennel oil, on extracellular Ca2+-induced store-operated Ca2+ entry (SOCE) into vascular endothelial (EA) cells and their mechanisms of action. Components of fennel oil were analyzed by gas chromatography-mass spectrometry. Cytosolic Ca2+ concentration ([Ca2+]c) in EA cells was determined using Fura-2 fluorescence. In the presence of extracellular Ca2+, fennel oil significantly increased [Ca2+]c in EA cells; this increase was significantly inhibited by the Ca2+ channel blockers La3+ and nifedipine. In contrast, fennel oil induced [Ca2+]c was significantly lower in Ca2+-free solution, suggesting that fennel oil increases [Ca2+]c mainly by enhancing Ca2+ influx into EA cells. [Ca2+]c mobilization by trans-anethole was similar to that of fennel oil. Moreover, SOCE was suppressed by fennel oil and trans-anethole. SOCE was also attenuated by lanthanum (La3+), a non-selective cation channel (NSC) blocker; 2-aminoethoxydiphenyl borane (2-APB), an inositol 1,4,5-triphosphate (IP3) receptor inhibitor and SOCE blocker; and U73122, an inhibitor of phospholipase C (PLC). Further, SOCE was more strongly inhibited by La3+ plus fennel oil or trans-anethole than by La3+ alone. These findings suggest that fennel oil and trans-anethole significantly inhibit SOCE-induced [Ca2+]c increase in vascular endothelial cells and that these reactions may be mediated by NSC, IP3-dependent Ca2+ mobilization, and PLC activation.

The effect of enzyme pre-treatment on extraction yield and quality of volatile oil of fennel seeds were evaluated using various enzymes viz., Celluclast, Pectinex, Viscozyme and Protease. Scanning Electron Microscopic (SEM) studies were conducted to visualize the effect of these enzymes on fennel seed cell walls. The quality of the oil was further evaluated using Gas Chromatography Mass spectroscopy (GC–MS). The enzyme pre-treatment resulted in an increase in yield of oil in the range of 11–22.5% as compared to the control sample. Scanning electron microscopic studies revealed a marked difference between the structures of fennel seeds treated with enzymes than the non-treated seeds. GC–MS studies revealed that the flavor composition of the fennel oil remains unchanged even after pre-treatment. From an economic perspective, the results of the present study could be used effectively in the spice industry to increase the extraction yield of volatile oil from fennel seeds.

Functional dyspepsia (FD), a functional gastrointestinal disorder, is characterized by persistent or recurrent postprandial upper abdominal discomfort and epigastric pain. The high prevalence of FD and associated healthcare costs suggests that treatment of this condition by methods other than prescribed medicines, such as natural products, could be beneficial. Delayed gastric emptying and impaired gastric accommodation play important roles in the development of FD. Anethole (1-methoxy-4-((E)-propenyl)-benzene), a major component of essential fennel oil, has been used as a flavoring, in alcoholic beverage production and in pharmaceutical formulations for many years. In this study, we examined the effects of anethole on delayed gastric emptying and impaired gastric accommodation in rodents. Oral administration of anethole improved clonidine-induced delayed gastric emptying but did not affect normal gastric emptying in mice. Fennel oil and Anchu-san (a Japanese herbal medicine containing anethole) also restored delayed gastric emptying. Furthermore, oral administration of anethole stimulated gastric accommodation in rats. These results suggest that anethole could be beneficial for the treatment of FD.

With the addition of fennel (FEN) oil, a biodegradable film based on polylactic acids (PLA) and polyhydroxybutyrate (PHB) was developed to possess antimicrobial ability. Barrier property and mechanical property tests were performed on three films, including PLA-PHB film, PLA-PHB film integrated with FEN oil (PLA-PHB-FEN) and ethanol vinyl alcohol (EVOH) film, whereby oxygen transmission rate (OTR), water vapor permeation (WVP), tensile strength and elongation at break were gathered. In addition, active properties including releasing, antibacterial and antioxidant abilities were measured. The profile showed that the mechanical properties of PLA-PHB film were comparable to those of EVOH film, except for the oxygen barrier ability. The FEN oil released from PLA-PHB-FEN film significantly inhibited the growth of E.coli and Staphylococcus by 1.2 and 1.3 Log CFU/g, respectively. PLA-PHB-FEN film showed the potential to be compatible with oily food as the maximum release (38.82 μg/mL) of FEN oil took place in fat simulants (65% ethanol). Afterward, the three films were used on the preservation of oysters for empirical tests. The results showed that the abundance of both aerobic and anaerobic bacteria were reduced by 1 Log CFU/g in the packaging of PLA-PHB-FEN film, which was supported by pH value and TVB-N level of oysters. Texture profile analysis and free amino acids quantification were also conducted. The data suggested that the PLA-PHB-FEN film could prolong the shelf-life on oysters for 2–3 days while maintaining their quality compared to EVOH film. This study provides insight into biodegradable packaging by which synthetic packaging could be substituted.

The use of crude fennel seed oil in a diesel engine, whose combustion chamber was thermally insulated, with diesel fuel at specific rates was investigated in the present study. A single-cylinder air cooled diesel engine was used as the test engine. Plasma spray method (coated with Cr3C2 in a thickness of 300 µm) was used as the coating method. Since the atomisation and vaporisation of fennel oil are highly affected by the physical properties of the fuel, a preheating process of 100 °C was applied. Crude fennel oil mixed with diesel fuel at 30% and 50% by volume. It was shown that a preheating process of 100 °C provided a proper fuel flow and reduced the viscosity of the funnel oil and additionally, the coating process decreased carbon monoxide (CO), smoke, and hydrocarbon (HC) emissions but increased nitrogen oxides (NOx), thermal efficiency, and exhaust gas temperature (EGT).

Fennel ( Foeniculum vulgare Mill.) is cultivated for its seeds and foliage, which contain essential oil. We hypothesized that the collection of fennel seed oil at different time points during the distillation process may result in fennel oil with distinct composition and bioactivity. We collected essential oil from fennel seed at ten different distillation times, DT (at 2, 7, 15, 30, 45, 75, 105, 135, 165, and 195 min). Estragole (42.8–84.4% of the total oil) was the main constituent throughout the distillation. (−)-α-Pinene (0.12–0.84%) and ( R )-(+)-limonene (6.3–33.5%) were relatively high at initial DT and dropped significantly after the first DT. (−)-Fenchone (0.5–4.1%) showed a near linear decrease until approximately the 165 min DT. If high (−)-α-pinene and ( R )-(+)-limonene oil is desirable, then the oil fraction needs to be captured early in the distillation, at 2 min. Oil with highest estragole concentration may be obtained by collecting the oil eluted between 30 and 45 min. DT had an effect on the oil antioxidant activity; the oil from the control (195 min distillation time) had the highest antioxidant capacity (481 μmol Trolox equivalents/g), whereas the oil fraction sampled at 45 min DT had the lowest capacity (148 μmol Trolox equivalents/g). This study demonstrated an effective method for obtaining fennel seed oil fractions with differential composition and antioxidant capacity.

Aim To screen the antimicrobial activities of some plant essential oils against clinical isolates of C. albicans causing vulvovaginal candidiasis (VVC) and to investigate the antifungal effect of the most active one against planktonic and sessile cells compared to fluconazole. Methods Screening of biofilm production by C. albicans causing VVC was performed by tissue culture plate method. The antifungal susceptibility of fluconazole was performed by disk diffusion method. Antifungal activities of nine essential oils were screened against strong biofilm-producer, fluconazole-resistant or dose-dependently susceptible clinical isolates and Candida albicans ATCC 10,231 by well diffusion method. Determination of the minimum inhibitory concentration (MIC) of fennel essential oil and fluconazole against planktonic and sessile cells were performed by microdilution methods. Determination of the combined antimicrobial activity of fennel oil and fluconazole was evaluated by checkerboard microdilution assay. Results From 19 C. albicans strains, 10/19 showed strong ability to form biofilms. None of the tested clinical isolates was sensitive to fluconazole. Fennel oil had significantly higher antifungal activities against tested C. albicans compared with other tested oils (P = 0.000). The MICs of fennel oil for planktonic cells ranged from 0.78% to 6.25% with MIC50 of 3.12% and MIC90 of 6.25%, while concentrations ranging between 6.25% and 25% resulted in 50% biofilm reduction. Synergy or addition between fennel oil and fluconazole were detected against 7/11 strains, while no antagonism was detected. Conclusion Fennel oil alone or in combination with fluconazole could provide a promising approach to the management of VVC caused by drug-resistant strains.