Phytochemical analysis and biological evaluation of essential oils and extracts from Heracleum pastinacifolium subsp. incanum (Boiss. & A.Huet) P.H.Davis, an endemic plant from Turkey.

Essential oil content of and phenolic compounds flower-fruit, root, and aerial parts of Heracleum pastinacifolium subsp. incanum were analysed by GC/MS and LC/MS methods, respectively. Antidiabetic, anticholinesterase, and antioxidant activities of flower-fruit, root, aerial parts methanol extracts were evaluated. Apiole (35.0%), myristicine (72.2%), and myristicine (15.1%) were found as major compounds of fruit-flower mixture, root, aerial part essential oils, respectively. Hesperidin was found the highest amount in aerial part and flower-fruit extracts with 8904.2621 ng/mL and 11558.3634 ng/mL values, respectively. Fruit-flower extract showed the highest activity against α-glucosidase (24%). Root extract demonstrating the highest activity (18%) against AChE enzyme. Flowers-fruits mixture methanol extract had a higher % inhibition value on ABTS·+ and DPPH•. Flowers-fruits mixture methanol extract was rich in total phenol, total tannin, and protein content. All the extracts were determined as genetoxically safe according to the results of Ames/Salmonella, Escherichia coli WP2 and Allium cepa assays.

Enzyme-Based Antiviral Potential of Cinnamomum verum J. Presl. Essential Oil and Its Major Component (E)-Cinnamaldehyde.

In the present study, Cinnamomum verum J. Presl. bark essential oil and its main component cinnamaldehyde was evaluated in vitro for neuraminidase (NA), transmembrane serine protease (TMPRSS2), and angiotensin converting enzyme 2 (ACE2) inhibitory activities. The chemical composition of C. verum essential oil was confirmed by both gas chromatography-mass spectrometry (GC/MS), and gas chromatography-flame ionization detection (GC-FID), where 75.9% (E)-cinnamaldehyde was the major component. The ACE2, NA, and TMPRSS2 enzyme inhibitions of C. verum bark essential oil at 20 µg/mL concentration, and (E)-cinnamaldehyde (5 µg/mL) were calculated and compared in the range of 54.2-89.9%. Molecular docking results supported that (E)-cinnam-aldehyde was specific to ACE2 with 89.9% inhibition. Our findings suggest further in vivo studies to confirm the effective and safe use of the essential oil as well as the (E)-cinnamaldehyde.

Biological Activities and Chemical Compositions of Prangos platychlaena Boiss. Essential Oil and Fractions, Multivariate Statistical Analyses.

In this research, essential oil was obtained from the aerial parts of Prangos platychlaena Boiss. by hydrodistillation using a Clevenger-type apparatus, separated into fractions having different polarities by column chromatography. Both essential oil and the fractions were analyzed by GC-FID and GC/MS simultaneously. Nona-3,5-diyne-2-yl acetate (46%) and 3,5-nonadiyne (13.5%) were found to be the main constituents of the essential oil. While the main components of the n-hexane fraction were characterized as 3,5-nonadiyne (45.6%) and germacrene B (16.4%), the major components of the methanol fraction were found to be nona-3,5-diyne-2-yl acetate (59.6%) and 3,5-nonadiyne-2-ol (25.9%). In addition, principal multivariate statistical analyses were performed with principal component analyses and Venn diagram calculations, utilizing chemical compositions of the essential oil and the fractions. Furthermore, in vitro anti-inflammatory activities of the essential oil and the fractions were evaluated to correlate the chemical composition with the biological activity, and to the best of our knowledge, this study was performed for the first time in this aspect. LOX inhibitions of the essential oil, n-hexane, and methanol fractions were determined to be 70.98 ± 1.7, 67.10 ± 2.5, and 50.11 ± 4.8%, respectively. Preliminary initial findings of this study will be extended in the future with new biological assays.

Chemical profile, in vitro pharmacological activity and Satureja cuneifolia Ten. evaluation of essential oil based on distillation time.

The medicinal plant Satureja cuneifolia Ten. was widely utilized as spice, tea and traditional medicine. The objective of the current study was to examine the chemical composition and in vitro biological activities (LOX, MMP-1, and MMP-12 enzyme inhibition activity and cytotoxicity on A549 cell line) of Satureja cuneifolia extracts and essential oils. The essential oils of the flowering aerial parts were hydro-distilled at four different distillation times (5, 30, 60, and 180 min) using the Clevenger apparatus. The total essential oil and four fragments were compared in terms of the major component, yield, and distillation time. Volatile compounds of the infusion were extracted by using HS-SPME. Ethanolic extract had the strongest inhibition activity on the LOX enzyme (84.50%), while the essential oils exhibited more cytotoxic activity on the A549 cell line than the extracts. The oils and the infusion were analyzed using GC-MS and the primary chemicals identified by LC-MS/MS.

Exploring Astrodaucus orientalis (L.) Drude: Phytochemical Analysis and its Biological Potential Against Alzheimer's and Diabetes.

In current study antioxidant, antidiabetic, antimicrobial, anticholinesterase, and human carbonic anhydrase I, and II (hCA I and II) isoenzymes inhibition activities of Astrodaucus orientalis different parts were investigated. Achetylcholinesterse (AChE) and butyrylcholinesterse (BChE) inhibitory activities of octyl acetate were determined via molecular docking. Quantitative assessment of specific secondary metabolites was conducted using LC-MS/MS. An examination of chemical composition of essential oils was carried out by GC-MS/MS. A thorough exploration of plant's anatomical characteristics was undertaken. The highest phenolics level and DPPH antioxidant capacity were seen in root and fruit. Fruit essential oil demonstrated the highest AChE inhibition (44.13±3.61 %), while root dichloromethane sub-extract had the best inhibition towards BChE (86.13±2.58 %). Cytosolic hCA I, and II isoenzymes were influentially inhibited by root oil with 1.974 and 2.207 µM IC50 values, respectively. The most effective extracts were found to be root all extract/sub-extracts (except water) against C. tropicalis and C. krusei strains with MIC value 160>µg/mL. Sabinene (29.4 %), α-pinene (20.2 %); octyl acetate (54.3 %); myrcene (28.0 %); octyl octanoate (71.3 %) were found principal components of aerial parts, roots, flowers, and fruits, respectively. Flower essential oil, fruit dicloromethane and ethyl acetate exhibited potent α-glucosidase inhibitory activity with 900, 40, and 937 µg/mL IC50 values, respectively.

Essential Oil Composition of Capsella bursa-pastoris (L.) Medik. Aerial Parts.

Objectives: Capsella Medik. belongs to Brassicaceae family and is represented by 4 species in Türkiye. Among them, Capsella bursa-pastoris (L.) Medik. is a cosmopolite species and grows naturally throughout Türkiye. There have been a few studies on the essential oil composition of different parts of the plant, and, as far as we are concerned, the essential oil composition of the plant growing in Türkiye has not been studied previously. Thus, in this study, we isolated and analyzed the essential oil composition of the aerial parts of C. bursa-pastoris growing naturally in Ankara, Türkiye. Materials and Methods: Plant material was collected from Ankara University, Tandogan Campus, and essential oil of the aerial parts was obtained from hydrodistillation using a Clevenger-type apparatus for 3 h and analyzed by gas chromatography (GC)-flame ionization detection and GC-mass spectrometry simultaneously. Results: The essential oil yield was determined to be 0.2%, and 90.2% of the essential oil composition was identified, corresponding to 21 components. The major components of the oil were determined to be nonacosane (19.6%), phytol (19.3%), pentacosane (13.5%), heptacosane (9.9%), and hexadecanoic acid (9.9%). Conclusion: Phytol was found to be the main component of the essential oil of leaves and aerial parts (16.34% and 13.14, respectively) in a literature study consistent with the results of our study. The essential oil content of other parts of the species, along with species collected from different localities, would be an important contribution to the species and the genus and should be performed in the future.

Microbial Transformation of Hesperidin and Biological Evaluation.

The main aim of the study was the biotransformation evaluation of hesperidin for functionalization by 25 different nonhuman pathogenic microorganisms. As a result, four metabolites were identified and characterized. The structure of pinocembrin and naringenin from the microbial transformation of hesperidin was determined initially with LC/MS-MS. The metabolites eriodictyol and hesperetin were isolated, and their molecular structure was determined by NMR and MS. Pinocembrin, eriodictyol, and naringenin were characterized as new hesperidin microbial transformation metabolites, to the best of our knowledge. In order to evaluate the bioactivity, in vitro 5-lipoxygenase (5-LOX) enzyme inhibition, antioxidant, antimicrobial, and acute toxicity evaluations using the brine shrimp assay of hesperidin and its metabolites were performed comparatively. According to antioxidant and anti-inflammatory activity results, hesperetin metabolite was more active than naringenin and hesperidin. The antimicrobial activity of hesperetin and naringenin against the human pathogenic Staphylococcus aureus strain was relatively higher when compared with the substrate hesperidin. In line with this result, biofilm activity of hesperetin and naringenin against S. aureus with combination studies using biofilm formation methods was carried out. The checkerboard combination method was utilized for biofilm layering, also for the first time in the present study. As an initial result, it was observed that hesperidin and naringenin exerted a synergistic activity with a fractional inhibitory concentration index (FICI) value of 1.063. Considering the bioactivity of hesperidin, hesperetin, and naringenin used as substrates are relatively nontoxic. The microbial and enzymatic biotransformation of natural products such as hesperetin and its new bioactive metabolites still have pharmacological potential, which needs further experimentation at the molecular level..

Essential Oil Composition of Fruits of Eight Ferulago Species Growing in Türkiye and Multivariate Statistical Analyses.

In this study, the composition of the volatile oils obtained from the fruits of 8 Ferulago species (Ferulago cassia Boiss., F. isaurica Pesmen, F. humilis Boiss., F. macrosciadia Boiss. & Balansa, F. setifolia K.Koch, F. silaifolia (Boiss.) Boiss., F. syriaca Boiss., F. trojana Akalin & Pimenov) growing naturally in Türkiye were examined by means of GC/MS and GC-FID and α-pinene was determined to be present in the fruits of four species along with other monoterpenes as major components. Principal Component Analyses (PCA) and Hierarchical Cluster Analysis (HCA) was performed, utilizing ten major components in the eight essential oils. Also, a Venn diagram was used to demonstrate chemotaxonomical variations in the composition of the essential oils of eight Ferulago species.

Antioxidant Activity and Chemical Composition of Geranium Oil and Its Synergistic Potential against Pneumococci with Various Antibiotic Combinations.

The essential oil of Pelargonium graveolens L. is valuable for its therapeutic benefits, so this study aimed to determine the synergistic effect of the combination of the essential oil of this plant with antibiotics instead of the extracts prepared with various solvents. In addition, the second goal of this study was to determine whether the essential oil combined with various antibiotics increased the overall killing activity in mouse macrophage cells with the aim of introducing an immunotherapeutic approach to the infection treatments used today. Herein, the volatile profile of Geranium oil (G.O) was analyzed using GC/MS. The current study sought to assess the synergistic characteristics of several antibiotic combinations using G.O against pneumococci, as well as the oil's antioxidant and antimicrobial activities. The major components of the oil were citronellol, geraniol, and isomenthone. In the combinations of G.O and antibiotics, the synergism of the Streptococcus pneumoniae to antibiotics advanced. When the time-kill data were evaluated, G.O + antibiotic combinations quickly diminished the viable cell count of S. pneumoniae from the 6th h. In this study, the combined use of existing antibiotics used in infection treatments with G.O could improve antibiotic effectiveness and thus prevent bacteria from developing antibiotic resistance.

Comparative In Vitro and In Silico Enzyme Inhibitory Screening of Rosa x damascena and Pelargonium graveolens Essential Oils and Geraniol.

The present work aims to evaluate Rosa x damascena Herrm. and Pelargonium graveolens L'Hér. essential oils, and the major constituent geraniol for their in vitro and in silico inhibitory activities against 5-lipoxygenase (5-LOX), cyclooxygenase (COX), acetyl cholinesterase (AChE), butyryl cholinesterase (BuChE), and angiotensin converting enzyme (ACE2) enzymes. Geraniol most potently inhibited the ACE2 relative to other enzymes. R. damascena essential oil moderately inhibited the cancer cell lines with no toxic effects on healthy HEK 293 cells. P. graveolens essential oil inhibited a number of cancer cell lines including A549, MCF7, PC3, and HEK 293 that are reported here for the first time. The molecular docking of geraniol with the target enzymes revealed that it binds to the active sites similar to that of known drugs. Geraniol carries the potential for further drug development due to its drug-like binding mode for the target enzymes. Our work confirms that these essential oils possess similar biological activities due to their similar phytochemistry in terms of the major constituents of the plants. The promising biological activities reported in this work further warrant the inclusion of in vivo studies to establish safe use of the target essential oils and their constituents.

Phytochemical screening, biological evaluation, anatomical, and morphological investigation of Ferula tingitana L. (Apiaceae).

Ferula tingitana L. is a high perennial plant and its leaf is an alternate arrangement and yellow, and its flowers are unisexual like other Apiaceae. It has been used as a spice and for various medicinal purposes in the Mediterranean region. The paper reports antidiabetic, antimicrobial, anticholinesterase, antioxidant, and genotoxic activities of leaves, flowers, stems, and fruits methanol extracts of F. tingitana. Also, quantitative determination of some secondary metabolites was also analyzed by LC-MS/MS. Moreover, chemical composition of essential oils was analyzed. Consequently, anatomical, and morphological properties of plant were investigated. Germacrene D (23.6%), 1,3,5-trimethylbenzene (18.4%), and α-pinene (50.0%) were found as the main compounds in flower, leaf, and stem oils, respectively. The cortex in stem, pedicel, and fruit is characterized by angular collenchyma cells and a distinct cambium layer. 6 compounds (quinic acid, fumaric acid, keracyanin chloride, cyanidin-3-O-glucoside, chlorogenic acid, hesperidin) were observed in samples. Leaf extract showed anticholinesterase activity. Leaf and flower extracts showed the highest % inhibition value on ABTS·+ and DPPH•. Leaf extract has the strongest antioxidant effect because it is rich in total phenolic contents. All extracts of F. tingitana were found generally effective against C. albicans. Stem extract was found effective against E. coli and flower extract was found more effective against S. enterica and C. albicans. Bacterial genotoxicity results showed that extracts did not have genotoxic activity on tester strains S. typhimurium and E. coli WP2uvrA. Thus, it revealed that extracts were genotoxic-ally safe at applied concentrations up to 3 mg/plate.

In Vitro Anti-Inflammatory and Anticancer Evaluation of Mentha spicata L. and Matricaria chamomilla L. Essential Oils.

Spearmint, Mentha spicata L., and the German chamomile, Matricaria chamomilla L., preparations are used against inflammatory conditions traditionally and in modern medicinal applications. This present study aimed to evaluate pharma-grade essential oils for their in vitro anti-inflammatory and anticancer effects using COX-1, COX-2, and 5-LOX enzyme assays, as well as their apoptosis potential through the caspase pathway. In addition, the (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) (MTT) assay was applied to evaluate the in vitro cytotoxic effects using HEK293/A549, MCF7, and PC3 cell lines. Major components of M. spicata essential oil were confirmed both by gas chromatography (GC)-flame ionization detector (FID) and GC/mass spectrometry (MS) as 72.8% carvone, 12.6% limonene, 2.2% 1,8-cineole, 1.3% myrcene, and 1% trans-dihydrocarvone. The major components of M. chamomilla essential oil were also confirmed as 47.9% α-bisabolol oxide A, 16.8% α-bisabolol, 13.8%, (Z)-ß-farnesene, 5.8% α-bisabolol oxide, and 4.7% α-bisabolene oxide A. The IC50 values for M. chamomilla essential oil on A549, MCF7, PC3, and HEK293 cells were calculated as 208.54 ± 1.39, 315.44 ± 1.17, 197.52 ± 0.98, and 638.79 ± 1.15 µg/mL, respectively, whereas the IC50 values for M. spicata essential oil on A549, MCF7, and PC3 cells were 672.13 ± 2.57, 708.27 ± 2.05, and 206.49 ± 1.48 µg/mL, respectively. For M. spicata essential oil, no cytotoxic effects on healthy HEK293 cells were observed at the tested concentrations. The essential oils increased the apoptotic activity, where all results were statistically significant. According to the anti-inflammatory evaluation, both M. chamomilla and M. spicata oils showed selective COX-2 inhibitions, where the SI values were calculated as 0.30 and 0.67, respectively. Overall, both M. spicata and M. chamomilla essential oils showed selective inhibition on the COX-2 enzyme and apoptosis against the selected cancer cell lines for the first time, to the best of our knowledge, with this specific dual mode of action. The initial results encourage further detailed in vivo experimental evaluations.

Contributions of Chemical Content and Biological Activity to Plant Taxonomy Based on the Four Allium L. Taxa (Sect. Cupanioscordum - Amaryllidaceae).

Garlic and onions are used as food and for medicinal purposes worldwide. Allium L. species are rich in bioactive organosulphur compounds that exhibit many biological activities like anticancer, antimicrobial, antihypertensive, antidiabetic activities. In this study, macro- and micromorphological characteristics of four Allium taxa were examined and the results suggested that A. callimischon subsp. haemostictum was the outgroup to sect. Cupanioscordum. Also, for the genus Allium, which is a taxonomically difficult genus, the hypothesis that chemical content and bioactivity can also be used taxonomically in addition to micro and macromorphological characters has been questioned. The bulb extract was analyzed to determine their volatile compositions and anticancer activities against human breast cancer, human cervical cancer, and rat glioma cells for the first time in the literature. To detect the volatiles, the Head Space-Solid Phase Micro Extraction method was used followed by Gas Chromatography-Mass Spectrometry. The main compounds were found as dimethyl disulfide that (36.9 %, 63.8 %, 81.9 %, 12.2 %) and methyl (methylthio)-methyl disulfide (10.8 %, 6.9 %, 14.9 %, 60.0 %) for A. peroninianum, A. hirtovaginatum and A. callidyction, respectively. Additionally, methyl-trans-propenyl disulfide is detected for A. peroniniaum (36 %). As a result, all extracts have shown significant efficacy against MCF-7 cells depending on applied concentrations. The treatment of MCF-7 cells for 24 h with 10, 50, 200, or 400 µg/mL ethanolic bulb extract of four Allium species resulted in DNA synthesis inhibition. Survival rates for A. peroninianum was 51.3 %, 49.7 %, 42.2 %, 42.0 %, for A. callimischon subsp. haemostictum 62.5 %, 63.0 %, 23.2 %, 22 %, for A. hirtovaginatum 52.9 %, 42.2 %, 42.4 %, 39.9 %, for A. callidyction 51.8 %, 43.2 %, 39.1 %, 31.3 %, for cisplatin 59.6 %, 59.9 %, 50,9 %, 48.2 %, respectively. Moreover, taxonomic evaluation according to biochemical compounds and bioactivities is almost in agreement with that made according to micro and macromorphological characters.

Essential Oils of Ferulago glareosa Kandemir&Hedge Roots and Aerial Parts: PCA and HCA Analyses.

Ferulago glareosa Kandemir & Hedge. is an endemic species of the family Apiaceae for Turkey and has interesting morphological characteristics compared to the other members of the genus Ferulago Koch. In this study we investigated the essential oil compositions of the roots and aerial parts of F. glareosa for the first time and compared them with essential oil compositions of the roots and aerial parts of other species of the genus. In our study, major components of the essential oil of the roots were determined to be 2,3,6-trimethylbenzaldehyde (32.2 %), falcarinol (23.7 %), hexadecanoic acid (9.5 %) and 2,5-dimethoxy-p-cymene (5.9 %); and major components of the essential oil of the aerial parts were found to be α-pinene (33.7 %), p-cymene (14.8 %), γ-terpinene (13.2 %), (Z)-ß-ocimene (12.4 %) and terpinolene (8.2 %). The essential oil compositions of F. glareosa root compare with essential oils components in the literature differ varies greatly. Hierarchical Cluster Analysis (HCA) was performed with Minitab software, utilizing 8 major components in the published 20 literatures, as well as in this study. Principal Component Analyses (PCA) were used in order to demonstrate chemotaxonomical variations in the composition of the essential oils of Ferulago species.

Enhanced Bioactivity of Rosemary, Sage, Lavender, and Chamomile Essential Oils by Fractionation, Combination, and Emulsification.

This study aimed to increase the bioactivity of essential oils by fractionation, combination, and emulsification. In this regard, pharmaceutical quality Rosmarinus officinalis L. (rosemary), Salvia sclarea L. (clary sage), Lavandula latifolia Medik. (spike lavender), and Matricaria chamomilla L. (chamomile) essential oils were fractionated by vacuum-column chromatography. The main components of the essential oils were verified, and their fractions were characterized by thin layer chromatography, gas chromatography-flame ionization detector, and gas chromatography/mass spectrometry. Besides, oil-in-water (O/W) emulsions of essential oils and diethyl ether fractions were obtained by the self-emulsification method, followed by droplet size, polydispersity index, and zeta potential value measurements. The in vitro antibacterial effects of the emulsions and binary combinations (10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, v:v) against Staphylococcus aureus were determined by microdilution. In addition, the in vitro anti-biofilm, antioxidant, and anti-inflammatory effects of emulsion formulations were evaluated. According to the experimental results, fractionation and emulsification enhanced essential oil in vitro antibacterial, anti-inflammatory, and antioxidant effects due to increased solubility and nano-sized droplets. Among 22 different emulsion combinations, 1584 test concentrations resulted in 21 cases of synergistic effects. The mechanism of the increase in biological activities was hypothesized to be higher solubility and stability of the essential oil fractions. Food and pharmaceutical industries may benefit from the procedure proposed in this study.

Chemical Profile and Cytotoxicity Evaluation of Aerial Parts of Marrubium vulgare L. From Different Locations in Turkey.

Marrubium vulgare L. (Lamiaceae) is used for respiratory and gastrointestinal system disorders in folk medicine. According to European Pharmacopoeia criteria, standardization of the plant is defined by its marrubiin content. In present study, phenolics, marrubiin and essential oil compositions of M. vulgare from different locations in Turkey were analyzed quantitatively by UPLC, GC and GC/MS. Besides, their cytotoxic potentials were evaluated. In the samples, forsythoside B (77-400 mg/100 g dw), arenarioside (forsythoside F) (0-241 mg/100 g dw), verbascoside (acteoside) (171-416 mg/100 g dw) and apigenin-7-O-glucoside (0-17 mg/100 g dw) were determined in different ranges. Marrubiin contents (0.58-1.46 %) of some samples were two times higher than European Pharmacopoeia standards (0.7 %). ß-Caryophyllene (7.24-20.34 %), (Z)-ß-farnesene (1.58-34.85 %), germacrene D (9.8-13.37 %), bicyclogermacrene (1.71-8.63 %) and ß-bisabolene (0-16.68 %) were detected as major compounds in essential oils. The sample from the west of Aegean Region showed cytotoxicity against human neuroblastoma (SH-SY5Y) cell lines (IC50 : 59.80 µg/mL) although it has no effect on non-cancerous NIH-3T3cell lines. This is the first report on phenolic profiles of M. vulgare populations from Turkey. Their potential as marrubiin source for pharmaceutical industry should be considered.

In Vitro and In Silico Evaluation of ACE2 and LOX Inhibitory Activity of Origanum Essential Oils and Carvacrol.

Origanum spp. are used both for culinary purposes and for their biological activities. In this study, commercial Origanum majorana, Origanum minutiflorum, Origanum vulgare, and Origanum onites essential oils and their prominent constituent carvacrol were evaluated for their in vitro and in silico angiotensin-converting enzyme 2 and lipoxygenase enzyme inhibitory potentials. The essential oils were analysed by gas chromatography-flame ionisation detection and gas chromatography-mass spectrometry, where carvacrol was identified as the major component (62 - 81%), confirming the quality. In vitro enzyme inhibition assays were conducted both with the essential oils (20 µg/mL) and with carvacrol (5 µg/mL). The comparative values of angiotensin-converting enzyme 2 percent inhibition for O. majorana, O. minutiflorum, O. vulgare, and O. onites essential oils were determined as 85.5, 79.1, 74.3, and 42.8%, respectively. As a result of the enzyme assays, carvacrol showed 90.7% in vitro angiotensin-converting enzyme 2 inhibitory activity. The in vitro lipoxygenase inhibition of the essential oils (in the same order) was 89.4, 78.9, 81.1, and 73.5%, respectively, where carvacrol showed 74.8% inhibition. In addition, protein-ligand docking and interaction profiling was used to gain structural and mechanistic insights into the angiotensin-converting enzyme 2 and lipoxygenase inhibitory potentials of major Origanum essential oil constituents. The in silico findings agreed with the significant enzyme inhibition activity observed in vitro. Further in vivo studies are suggested to confirm the safety and efficacy of the oils.

Binary Synergistic Combinations of Lavender and Fennel Essential Oils with Amoxicillin.

Microbial resistance is an important problem in modern healthcare systems. In addition to drug resistance, the side effects of current antibiotic applications are also known issues. In this present study, binary combinations of amoxicillin with European Pharmacopoeia quality lavender (Lavandula angustifolia) and fennel (Foeniculum vulgare) essential oils were evaluated against human pathogenic microbial strains. The checkerboard method was used to quantify the efficacy of the essential oils in combination with amoxicillin. As an initial result, remarkable in vitro antimicrobial activity was observed at relatively low amoxicillin concentrations using different oil combinations against Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 14579, Escherichia coli NRRL B-3008, Salmonella typhi (clinical isolate), respectively. Fractional inhibitory concentrations were calculated and interpreted in terms of addition, synergy, antagonism, or indifferent. A synergistic interaction with the combination F. vulgare essential oil and amoxicillin (fractional inhibitory concentration index = 8.05 × 10-4) was observed against the pathogens E. faecalis and Escherichia coli. Both essential oils together and in combination with amoxicillin showed a synergistic effect with possible future applications.

Effect of Extraction Time on Origanum onites L. Infusions and Essential Oils - Biological Evaluation, Statistical Principal Component and Hierarchial Cluster Analyses.

Origanum onites L. of Lamiaceae, is used as a culinary spice and herbal tea; also for its antioxidant, antimicrobial effects among other activities and effects. This research aims to examine the in vitro antimicrobial and antioxidant activities of the infusions and the essential oils (EOs) obtained using different conditions from the aerial parts of the processed and raw of O. onites herbal material. The EOs from O. onites were distilled at different times and characterized both by GC-FID and GC/MS systems. The resulting main compounds were identified as carvacrol (65.5-91 %), linalool (0.3-17.9 %), γ-terpinene (2.8-4.6 %), and thymol (0.5-1.5 %), respectively. In addition, Origanum infusions were prepared at four different time intervals, where the volatile compounds of the infusions were analysed using the HS-SPME-GC/MS system. Statistical Principal Component (PCA) and Hierarchical Cluster Analyses (HCA) tools were used to demonstrate the composition variations on different times for O. onites infusion and EO samples.

ACE2 and LOX Enzyme Inhibitions of Different Lavender Essential Oils and Major Components Linalool and Camphor.

In this present study, Lavandula angustifolia, Lavandula stoechas, and Lavandula × heterophylla essential oils and their main compounds linalool and camphor were evaluated in vitro for lipoxygenase enzyme (LOX) and for angiotensin converting enzyme 2 (ACE2) inhibition potential. The chemical compositions of L. angustifolia, L. stoechas, and L. heterophylla essential oils were confirmed both by gas chromatography-mass spectrometry and gas chromatography-flame ionization detection, where 22.4, 0.9, and 30.6% linalool and 17.8, 54.7, and 15% camphor were identified for each oil among other components, respectively. Enzyme inhibitory activity studies were performed at 20 µg/mL for the tested essential oils, whereas for linalool and camphor concentrations, 5 µg/mL was used. The ACE2 inhibitions of L. angustifolia, L. stoechas, and L. heterophylla essential oils were 25.4, 34.1, and 27.1%, while the LOX inhibitions were observed as 79, 49.1, and 86.7%, respectively. In addition, linalool and camphor showed remarkable ACE2 inhibition with 77.1 and 85.1%, whereas the LOX inhibition was observed at 92 and 67.2%, respectively. In conclusion of the initial findings, further detailed in vivo studies are needed to confirm the safe use.