Fenchone Ameliorates Constipation-Predominant Irritable Bowel Syndrome via Modulation of SCF/c-Kit Pathway and Gut Microbiota

In this study we sought to elucidate the therapeutic effects of fenchone on constipation-predominant irritable bowel syndrome (IBS-C) and the underlying mechanisms. An IBS-C model was established in rats by administration of ice water by gavage for 14 days. Fenchone increased the reduced body weight, number of fecal pellets, fecal moisture, and intestinal transit rate, and decreased the enhanced visceral hypersensitivity in the rat model of IBS-C. In addition, fenchone increased the serum content of excitatory neurotransmitters and decreased the serum content of inhibitory neurotransmitters in the IBS-C rat model. Meanwhile, western blot and immunofluorescence experiments indicated that fenchone increased the expressions of SCF and c-Kit. Furthermore, compared with the IBS-C model group, fenchone increased the relative abundance of Lactobacillus, Blautia, Allobaculum, Subdoligranulum, and Ruminococcaceae_UCG-008, and reduced the relative abundance of Bacteroides, Enterococcus, Alistipes, and Escherichia-Shigella on the genus level. Overall, fenchone ameliorates IBS-C via modulation of the SCF/c-Kit pathway and gut microbiota, and could therefore serve as a novel drug candidate against IBS-C.

Combination of fenchone and sodium hyaluronate ameliorated constipation-predominant irritable bowel syndrome and underlying mechanisms

We sought to explore the protective effect of the combination of fenchone (FE) and sodium hyaluronate (SH) on ice water-induced IBS-C rats and the potential mechanism. The neurotransmitter levels, including substance P (SP), motilin (MTL), 5-hydroxytryptamine (5-HT), and vasoactive intestinal peptide (VIP), were determined by ELISA methods. The stem cell factors (SCF)/c-Kit signaling pathway-related protein and mRNA levels were determined by western blot and reverse transcription quantitative polymerase chain reaction (RT-qPCR) analyses, respectively. The expressions of tight ZO-1, Occludin, and Claudin-1 were also measured by western blot assay and immunofluorescence staining. The 16S rRNA gene sequence was used to measure the composition of gut microbiota. The co-administration of FE and SH improved the body weight, number of fecal pellets, fecal moisture, abdominal with drawal reflex score, and gastrointestinal transit rate in IBS-C rats. The unique efficacy of combination depended on the regulation of balance between excitatory and inhibitory neurotransmitters, enhancement of intestinal barrier function, and activation of SCF/c-Kit pathway. The gut microbiota structure was also restored. The ability of FE combined with SH to regulate SCF/c-Kit signaling pathway, enhance intestinal barrier function, and modulate gut microbiota contributes to their efficacy in managing IBS-C in rats.

Fenchone, a monoterpene: Toxicity and diuretic profiling in rats

Fenchone is a monoterpene present in the essential oils of various plants, including Foeniculum vulgare and Peumus boldus. Previous studies confirmed the anti-inflammatory, antioxidant, wound-healing, antidiarrheal, antifungal, antinociceptive, and bronchodilator activities of fenchone. Owing to various pharmacological activities of Fenchone, the current research was designed to evaluate its diuretic activity along with toxicity profiling. For evaluating acute toxicity, OECD guideline 425 was followed in which a single dose of 2000 mg/kg was orally administered to rats. For evaluating the diuretic potential in rats, three doses of Fenchone (100, 200, and 400 mg/kg) were assayed in comparison to furosemide (15 mg/kg) as the standard drug, followed by measurements of urinary volume, urinary electrolytes, uric acid, and urinary creatinine in saline-loaded rats for 8 h. The acute toxicity study showed a significant increase in hemoglobin (Hb), red blood cells (RBCs), alkaline phosphatase (ALP), and alkaline transaminase (ALT) along with a significant decrease in serum triglycerides, cholesterol, and uric acid levels when compared with the control group. The oxidative stress parameter, superoxide dismutase (SOD), was increased in the heart and spleen. Nitrite (NO) and glutathione were significantly increased in the kidney. The acute diuretic effect of Fenchone (400 mg/kg) significantly increased the urinary output, electrolytes (Na⁺, K⁺, and Ca⁺⁺), urinary creatinine, and urinary uric acid in a dose-dependent manner. The Na⁺/K⁺ ratio was remarkably higher in the treatment group than that of the control group. The diuretic index, saluretic index, and Lipschitz value were also calculated from electrolyte concentration and urinary volume measurements, and the values were significantly increased in rats administered with fenchone at 400 mg/kg dose. The current study concluded that fenchone is safe and has remarkable diuretic action.

Antibacterial, Anticandidal, and Antibiofilm Potential of Fenchone: In Vitro, Molecular Docking and In Silico/ADMET Study

The aim of the present study is to investigate the effective antimicrobial and antibiofilm properties of fenchone, a biologically active bicyclic monoterpene, against infections caused by bacteria and Candida spp. The interactions between fenchone and three distinct proteins from Escherichia coli (β-ketoacyl acyl carrier protein synthase), Candida albicans (1, 3-β−D-glucan synthase), and Pseudomonas aeruginosa (Anthranilate-CoA ligase) were predicted using molecular docking and in silico/ADMET methods. Further, to validate the in-silico prediction, the antibacterial and antifungal potential of fenchone was evaluated against E. coli, P. aeruginosa, and C. albicans by determining minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC), and minimum fungicidal concentration (MFC). The lowest MIC/MBC values of fenchone against E. coli and P. aeruginosa obtained was 8.3 ± 3.6/25 ± 0.0 and 266.6 ± 115.4/533.3 ± 230.9 mg/mL, respectively, whereas the MIC/MFC value for C. albicans was found to be 41.6 ± 14.4/83.3 ± 28.8 mg/mL. It was observed that fenchone has a significant effect on antimicrobial activity (p < 0.05). Our findings demonstrated that fenchone at 1 mg/mL significantly reduced the production of biofilm (p < 0.001) in E. coli, P. aeruginosa, and C. albicans by 70.03, 64.72, and 61.71%, respectively, in a dose-dependent manner when compared to control. Based on these results, it has been suggested that the essential oil from plants can be a great source of pharmaceutical ingredients for developing new antimicrobial drugs.

Ureas derived from camphor and fenchone reveal enantiomeric preference of human soluble epoxide hydrolase

The soluble epoxide hydrolase (sEH) is a potential target to treat cardiovascular, renal and neuronal diseases. A series of sEH inhibitors containing naturally occurring lipophilic groups (originating from camphor and fenchone) were developed. Inhibitory potency ranging from 0.7 nM to 6.47 μM was obtained. It was discovered that ureas derived from L-camphor were more active against sEH (2.3-fold average) than the corresponding analogues derived from D-camphor indicating enantiomeric preference of sEH. Ureas derived from fenchone possess lower activity against sEH (ca. 80-fold on average) than their camphor-derived analogs due to the specific structure of the lipophilic fragment and show less enantiomeric preference (1.75-fold on average). Moreover, fenchone-derived ureas show no consistency in enantiomeric preference. Endo/exo-form of compound L-3a derived from L-camphor is 4-fold more potent than the corresponding analogue prepared from D-camphor (IC50 = 0.7 nM vs. 2.8 nM) making it the most promising sEH inhibitor among the tested series.

Foeniculum vulgare Miller, a New Chemotype from Montenegro

Previous studies relating to prolonged and fractionated distillation procedures highlighted essential oils' (EOs) chemical composition to be significantly dependent on the extraction duration and harvesting time. As a continuation, a hydrodistillation procedure was applied to ripe fruit material of fennel, Foeniculum vulgare Miller (Apiaceae), collected from three localities in Montenegro (Podgorica, Nikšić, and Kotor) to furnish a total of 12 EOs. Liquid and vapor phases of the samples were analyzed by Gas Chromatography/Mass Spectrometry and Headspace-Gas Chromatography/Mass Spectrometry techniques, and 18 compounds have been identified. Although both quantitative and qualitative differences between the samples were notable, the phenylpropanoids anethole (ANE) and estragole and the monoterpenoids α-terpineol (TER) and fenchone (FEN) could be singled out as the most abundant constituents. The EOs from Podgorica belong to the most common ANE-rich chemotype, while the predominance of the monoterpenoid fraction is characteristic of the samples from Nikšić and Kotor. The latter is particularly rich in TER (up to 56.5%), with significant amounts of FEN and ANE. This chemical profile could represent a new chemotype of fennel EO. Vapor phases contained mainly monoterpenoids, with increased amounts of FEN and TER, while the number of phenylpropanoids was significantly decreased.

Monoterpene Enrichments Have Positive Impacts on Soil Bacterial Communities and the Potential of Application in Bioremediation

We study here how soil bacterial communities of different ecosystems respond to disturbances caused by enrichments with monoterpenes that are common essential oil constituents. We used fenchone, 1,8-cineol and α-pinene, and soils from phrygana, a typical Mediterranean-type ecosystem where aromatic plants abound, and from another five ecosystem types, focusing on culturable bacteria. Patterns of response were common to all ecosystems, but responses themselves were not always as pronounced in phrygana as in the other ecosystems, suggesting that these enrichments are less of a disturbance there. More specifically, soil respiration and abundance of the bacterial communities increased, becoming from below two up to 16 times as high as in control soils (for both attributes) and remained at high levels as long as these compounds were present. Bacteria that can utilize these three compounds as substrates of growth became dominant members of the bacterial communities in the enriched soils. All changes were readily reversible once monoterpene addition stopped. Bacteria with the ability to utilize these monoterpenes as carbon sources were found in soils from all ecosystems, 15 strains in total, suggesting a rather universal presence; of these, six could also utilize the organic pollutants toluene or p-xylene. These results suggest also potential novel applications of monoterpenes in combating soil pollution.

Experimental and Theoretical Investigation of the 3sp(d) Rydberg States of Fenchone by Polarized Laser Resonance-Enhanced-Multiphoton-Ionization and Fourier Transform VUV Absorption Spectroscopy

The VUV absorption spectrum of fenchone is re-examined using synchrotron radiation Fourier transform spectrometry, revealing new vibrational structure. Picosecond laser (2+1) resonance enhanced multiphoton ionization (REMPI) spectroscopy complements this, providing an alternative view of the 3spd Rydberg excitation region. These spectra display broadly similar appearance, with minor differences that are largely explained by referring to calculated one- and two-photon electronic excitation cross-sections. Both show good agreement with Franck-Condon simulations of the relevant vibrational structures. Parent ion REMPI ionization yields with both femtosecond and picosecond excitation laser pulses are studied as a function of laser polarization and intensity, the latter providing insight into the relative two-photon excitation and one-photon ionization rates. The experimental circular-linear dichroism observed in the parent ion yields varies strongly between the 3s and 3p Rydberg states, in good overall agreement with the calculated two-photon excitation circular-linear dichroism, while corroborating other evidence that the 3pz sub-state plays no more than a very minor role in the (2+1) REMPI spectrum. Vibrationally resolved photoelectron spectra are recorded with picosecond pulse duration (2+1) REMPI at selected intermediate vibrational excitations. The 3s intermediate state displays a very strong Δv=0 propensity on ionization, but the 3p intermediate evidences more complex vibronic dynamics, and we infer some 3p→3s internal conversion prior to ionization.

Using photoelectron elliptical dichroism (PEELD) to determine real-time variation of enantiomeric excess

In this work, the photoionization of chiral molecules by an elliptically polarized, high repetition rate, femtosecond laser is probed. The resulting 3D photoelectron angular distribution shows a strong forward-backward asymmetry, which is highly dependent not only on the molecular structure but also on the ellipticity of the laser pulse. By continuously varying the laser ellipticity, we can observe molecular and enantiomer changes in real time at a previously unseen speed and precision. The technique allows enantiomeric excess of a pure compound to be measured with a 5% precision within 3 s, and a 10-min acquisition yields a precision of 0.4%. The isomers camphor and fenchone can be easily distinguished, unlike with conventional mass spectrometry. Preliminary results for the pharmaceutically interesting ibuprofen are also given, showing the capability of photoionization as a means of distinguishing larger molecular systems.