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

Evaluation of (-)-Fenchone antimicrobial activity against oral Candida albicans and toxicological parameters: an in silico, in vitro and ex vivo study

Candida albicans is the primary species causing oral candidiasis. Its increasing drug resistance drives the search for more effective antifungal agents. Therefore, we assessed toxicological parameters and the antimicrobial activity and mechanisms of action of the monoterpene (-)-fenchone against oral C. albicans. We conducted an in silico study using PASS online and AdmetSAR, followed by evaluation of antifungal activity through Minimum Inhibitory Concentration (MIC), Minimum Fungicidal Concentration (MFC), association study with miconazole, and assays with sorbitol and ergosterol. Inhibition of biofilm formation and disruption of preformed biofilm were considered. Toxicity was also assessed through hemolysis assay. The in silico study revealed a higher likelihood of the compound being active for antifungal activity, as well as promising pharmacokinetic and toxicity characteristics. Subsequently, (-)-fenchone exhibited predominantly fungicidal activity (MIC90 = 8 μg/mL; MFC = 16 μg/mL), including against miconazole-resistant C. albicans isolates. The substance does not appear to act by damaging the fungal cell wall or plasma membrane, and exhibited synergy with miconazole. There was activity in inhibiting biofilm formation but not in disrupting preformed biofilm. Finally, the product exerted low hemolytic activity at more than MIC×10. Based on these results, (-)-fenchone may represent a promising therapeutic alternative for oral candidiasis.

Phytoconstituents of Citrus limon (Lemon) as Potential Inhibitors Against Multi Targets of SARS-CoV-2 by Use of Molecular Modelling and In Vitro Determination Approaches

In the present work, phytoconstituents from Citrus limon are computationally tested against SARS-CoV-2 target protein such as Mpro - (5R82.pdb), Spike - (6YZ5.pdb) &RdRp - (7BTF.pdb) for COVID-19. Docking was done by glide model, QikProp was performed by in silico ADMET screening & Prime MM-GB/SA modules were used to define binding energy. When compared with approved COVID-19 drugs such as Remdesivir, Ritonavir, Lopinavir, and Hydroxychloroquine, plant-based constituents such as Quercetin, Rutoside, Naringin, Eriocitrin, and Hesperidin. bind with significant G-scores to the active SARS-CoV-2 place. The constituents Rutoside and Eriocitrin were studied in each MD simulation in 100 ns against 3 proteins 5R82.pdb, 6YZ5.pdb and 7BTF.pdb.We performed an assay with significant natural compounds from contacts and in silico results (Rutin, Eriocitrin, Naringin, Hesperidin) using 3CL protease assay kit (B.11529 Omicron variant). This kit contained 3CL inhibitor GC376 as Control. The IC50 value of the test compound was found to be Rutin -17.50 μM, Eriocitrin-37.91 μM, Naringin-39.58 μM, Hesperidine-140.20 μM, the standard inhibitory concentration of GC376 was 38.64 μM. The phytoconstituents showed important interactions with SARS-CoV-2 targets, and potential modifications could be beneficial for future development.

Biological Potential and Essential Oil Profile of Two Wild Apiaceae Species from Algeria (Daucus carota L. and Foeniculum vulgare Mill.): Larvicidal and Antibacterial Effects

Infectious diseases, including vector-borne and antibiotic-resistant infections, present significant global health challenges, necessitating the exploration of natural alternatives for disease control. In this study, we investigated the essential oil (EO) profile as well as larvicidal and antibacterial properties of two wild Apiaceae species used in Algeria: Daucus carota L. (DCEO) and Foeniculum vulgare Mill. (FVEO). EO was extracted from the aerial parts by steam distillation and analyzed using Gas Chromatography Mass Spectrometry (GC/MS). Major constituents identified in DCEO were geranyl acetate (50.07%) and elemicin (10.77%), while FVEO contained estragole (24.93%), fenchone (20.20%), and α-phellandrene (17.96%). Both EOs were highly effective towards Culex pipiens larvae, with low LC50 values of 30.6 ± 1.06 ppm for DCEO and 34.7 ± 1.06 ppm for FVEO, indicating their potential as bioinsecticides due to their bioactivity and bioavailability. Additionally, the two Eos demonstrated moderate antibacterial efficacy against gram-positive bacteria, Staphylococcus aureus ATCC 25923 and Staphylococcus aureus MRSA ATCC 43300, respectively, with DCEO showing MIC values of 10 and 20 mg/mL, respectively, and FVEO exhibiting MIC values > 20 mg/mL. However, both EOs showed limited effectiveness against gram-negative bacteria, Escherichia coli ATCC 25922 and Klebsiella pneumonia ATCC 700603. These results highlight the potential applications of DCEO and FVEO as natural bioinsecticides and antibacterial agents, offering promising avenues for further research and development in pest control and food preservation.

Exploring the Volatile Composition and Antibacterial Activity of Edible Flower Hydrosols with Insights into Their Spontaneous Emissions and Essential Oil Chemistry

In the circular economy framework, hydrosols, by-products of the essential oil industry, are gaining attention for their potential in waste reduction and resource reuse. This study analyzed hydrosols from six edible flowers, investigating their chemical composition (VOC-Hyd) and antibacterial properties alongside volatile organic compounds of fresh flowers (VOC-Fs) and essential oils (EOs). Antirrhinum majus exhibited ketones as major VOC-Fs (62.6%) and VOC-Hyd (41.4%), while apocarotenoids dominated its EOs (68.0%). Begonia cucullata showed alkanes (33.7%) and aldehydes (25.7%) as primary VOC-Fs, while alkanes were prevalent in both extracts (65.6% and 91.7% in VOC-Hyd and in EOs, respectively). Calandula officinalis had monoterpenoids in VOC-Fs and VOC-Hyd (89.3% and 49.7%, respectively), while its EOs were rich in sesquiterpenoids (59.7%). Dahlia hortensis displayed monoterpenoid richness in both VOC-Fs and extracts. Monocots species' VOC-Fs (Polianthes tuberosa, Tulbaghia cominsii) were esters-rich, replaced by monoterpenoids in VOC-Hyd. P. tuberosa EO maintained ester richness, while T. cominsii EOs contained a significant percentage of sulfur compounds (38.1%). Antibacterial assays indicated comparable minimum inhibitory concentration profiles across VOC-Hyd: B. calcullata and P. tuberosa against Staphylococcus aureus and Salmonella enterica ser. typhimurium, T. cominsii against Escherichia coli and S. enterica, A. majus and C. officinalis against S. aureus, and D. hortensis against S. enterica.

Inhibitory effect of natural compounds on quorum sensing system in Pseudomonas aeruginosa: a helpful promise for managing biofilm community

Pseudomonas aeruginosa biofilm is a community of bacteria that adhere to live or non-living surfaces and are encapsulated by an extracellular polymeric substance. Unlike individual planktonic cells, biofilms possess a notable inherent resistance to sanitizers and antibiotics. Overcoming this resistance is a substantial barrier in the medical and food industries. Hence, while antibiotics are ineffective in eradicating P. aeruginosa biofilm, scientists have explored alternate strategies, including the utilization of natural compounds as a novel treatment option. To this end, curcumin, carvacrol, thymol, eugenol, cinnamaldehyde, coumarin, catechin, terpinene-4-ol, linalool, pinene, linoleic acid, saponin, and geraniol are the major natural compounds extensively utilized for the management of the P. aeruginosa biofilm community. Noteworthy, the exact interaction of natural compounds and the biofilm of this bacterium is not elucidated yet; however, the interference with the quorum sensing system and the inhibition of autoinducer production in P. aeruginosa are the main possible mechanisms. Noteworthy, the use of different drug platforms can overcome some drawbacks of natural compounds, such as insolubility in water, limited oral bioavailability, fast metabolism, and degradation. Additionally, drug platforms can deliver different antibiofilm agents simultaneously, which enhances the antibiofilm potential of natural compounds. This article explores many facets of utilizing natural compounds to inhibit and eradicate P. aeruginosa biofilms. It also examines the techniques and protocols employed to enhance the effectiveness of these compounds.

Fenchone and camphor: Main natural compounds from Lavandula stoechas L., expediting multiple in vitro biological activities

Lavandula stoechas, a Mediterranean plant, renowned in traditional medicine for its health benefits, is also arousing strong interest associated with its essential oils (EOs) with promising therapeutic properties. The aim of this study was to analyze the chemical composition of the plant, as well as to study its major activities, including antioxidant, anti-diabetic, dermatoprotective, anti-inflammatory, and antibacterial effects, focusing on its major molecules. Using the GC-MS method, the main compounds identified in L. stoechas EO (LSEO) were fenchone (31.81 %) and camphor (29.60 %), followed by terpineol (13.14 %) and menthone (8.96 %). To assess their antioxidant activity, three in vitro methods were used (DPPH, FRAP, and ABTS). The results revealed that LSEO exhibited the best antiradical property (54 ± 62 μg/mL) according to the DPPH test, while fenchone demonstrated the highest antioxidant capacity (87 ± 92 μg/mL) in the FRAP test, and camphor displayed the highest antioxidant capacity (96 ± 32 μg/mL) in the ABTS test. However, these results were lower than those obtained by Trolox used as a reference. In addition, study also explored the anti-diabetic potential of LSEO and its major compounds by evaluating their inhibitory activity towards two digestive enzymes, α-glucosidase and α-amylase. Camphor (76.92 ± 2.43 μg/mL) and fenchone (69.03 ± 2.31 μg/mL) exhibited the best inhibitory activities for α-amylase and α-glucosidase assays, respectively. Interestingly, all elements of the study exerted activities superior to those of acarbose, regardless of the test performed. In contrast, the evaluation of the dermatoprotective potential was carried out in vitro by targeting two enzymes involved in cutaneous processes, tyrosinase and elastase. In this light, fenchone (53.14 ± 3.06 μg/mL) and camphor (48.39 ± 1.92 μg/mL) were the most active against tyrosinase and elastase, respectively. It should be noted that the effect of both molecules, as well as that of LSEO, ranged between 53.14 ± 3.06 and 97.45 ± 5.22 μg/mL, which was significantly lower than the standard, quercetin (IC50 of 246.90 ± 2 0.54 μg/mL) against tyrosinase. Furthermore, the anti-inflammatory potential of these elements has been studied by evaluating their ability to inhibit lipooxygenase (LOX), a class of enzymes involved in the inflammatory process in the human body. As a result, the LSEO demonstrated a remarkable effect with an IC50 of 6.34 ± 1.29 μg/mL, which was almost comparable to the standard, quercetin (IC50 = 3.93 ± 0.45 μg/mL). Concerning the antibacterial potential, we carried out a quantitative analysis of the various products tested, revealing a bactericidal activity of the LSEO against the strain L. monocytogenes ATCC 13932 at a minimum effective concentration (MIC = CMB = 0.25). Overall, LSEOs offer significant potential as a source of natural antioxidants, and antidiabetic and anti-inflammatory agents, as well as dermatoprotective and antibacterial compounds. Its major molecules, fenchone and camphor, showed promising activity in these areas of study, making it a valuable candidate for future research and development in the field of natural medicine.