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.

Novel Sprayable Thermosensitive Benzydamine Hydrogels for Topical Application: Development, Characterization, and In Vitro Biological Activities.

Benzydamine hydrochloride (BZD) having analgesic, anesthetic, and anti-inflammatory effects is used orally or topically in the treatment of disorders such as joint inflammation and muscle pain. Within the scope of this study, sprayable thermosensitive BZD hydrogels were developed using thermoresponsive poloxamers to avoid systemic side effects and to provide better compliance for topical administration. Also, hydroxypropyl methyl cellulose (HPMC) was employed to improve the mechanical strength and bioadhesive properties of the hydrogel. The addition of BZD generally decreased the viscosity of the formulations (p < 0.05), while increasing the gelation temperature (p < 0.05). The formulations that did not have any clogs or leaks in the nozzle of the bottle during the spraying process were considered lead formulations. To spray the formulations easily, it was found that the viscosity at RT should be less than 200 mPa·s, and their gelation temperature should be between 26 and 34°C. Increasing HPMC and poloxamer improved bioadhesion. The amount of HPMC and poloxamers did not cause a significant change in the release characteristics of the formulations (p > 0.05); the release profiles of BZD from the formulations were similar according to model-independent kinetic (f2 > 50). HPMC and poloxamers had important roles in the accumulation of BZD in the skin. In vitro biological activity studies demonstrated that the formulations presented their anti-inflammatory activity with TNF-α inhibition but did not have any effect on the inhibition of COX enzymes as expected. As a result, thermosensitive hydrogels containing BZD might be an appropriate alternative, providing an advantage in terms of easier application compared to conventional gels.

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.

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.

In Vitro Antiviral Evaluations of Coldmix®: An Essential Oil Blend against SARS-CoV-2.

Coldmix® is a commercially available Eucalyptus aetheroleum and, Abies aetheroleum blend for medicinal applications. In this present study, the in vitro antiviral potential of Coldmix®, and its major constituents 1,8-cineole and α-pinene were evaluated by using the in vitro ACE2 enzyme inhibition assay as well as the direct contact test against SARS-CoV-2. The observed ACE2 enzyme inhibitory activity of Coldmix®, 1,8-cineole, and α-pinene were 72%, 88%, and 80%, respectively; whereas in the direct contact test in the vapor phase, the destruction of the virus was 79.9% within 5 min and 93.2% in the 30th min, respectively. In a similar Coldmix® vapor phase setup using the in vitro cytotoxicity cell assay, E6 VERO healthy cells were experimentally not affected by toxicity. According to the promising initial antiviral results of Coldmix® and the individually tested constituents, detailed further in vivo evaluation using different virus classes is suggested.

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.

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.

Novel benzofurane-pyrazole derivatives with anti-inflammatory, cyclooxygenase inhibitory and cytotoxicity evaluation.

Novel benzofurane-pyrazolone hybrids have been synthesized for evaluating their anti-inflammatory and cytotoxic properties. 4-(2-chloroacetyl)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one were reacted with α-hydroxy aldehyde or α-hydroxy ketone derivatives to obtain nine novel pyrazolone derivatives. Structures were successfully elucidated by 1H NMR, 13C NMR, IR and HRMS. Enzyme inhibitory activity was measured on cyclooxygenases (COXs) as considered to address anti-inflammatory activity. Compound 2 showed the highest activity on both COX-1 and COX-2 subtypes with 12.0 µM and 8.0 µM IC50, respectively. This activity was found close to indomethacin COX-2 inhibition measured as 7.4 µM IC50. Rest of the compounds (1, 3-9) showed 10.4-28.1 µM IC50 on COX-2 and 17.0-35.6 µM IC50 on COX-1 (Compound 1 has no activity on COX-1). Tested compounds (1-9) showed activity on NO production. Only compound was the 4, which showed a low inhibition on IL-6 levels. Cell viability was up to 60% at 100 µM for all compounds (1-9) on RAW 264.7 and NIH3T3 cell lines, thus compounds were reported to be noncytotoxic.

Novel cyanothiouracil and cyanothiocytosine derivatives as concentration-dependent selective inhibitors of U87MG glioblastomas: Adenosine receptor binding and potent PDE4 inhibition.

Thiouracil and thiocytosine are important heterocyclic pharmacophores having pharmacological diversity. Antitumor and antiviral activity is commonly associated with thiouracil and thiocytosine derivatives, which are well known fragments for adenosine receptor affinity with many associated pharmacological properties. In this respect, 33 novel compounds have been synthesized in two groups: 24 thiouracil derivatives (4a-x) and 9 thiocytosine derivatives (5a-i). Antitumor activity of all the compounds was determined in the U87 MG glioblastoma cell line. Compound 5e showed an anti-proliferative IC50 of 1.56 µM, which is slightly higher activity than cisplatin (1.67 µM). The 11 most active compounds showed no signficant binding to adenosine A1, A2A or A2B receptors at 1 µM. Brain tumors express high amounts of phosphodiesterases. Compounds were tested for PDE4 inhibition, and 5e and 5f showed the best potency (5e: 3.42 µM; 5f: 0.97 µM). Remakably, those compounds were also the most active against U87MG. However, the compounds lacked a cytotoxic effect on the HEK293 healthy cell line, which encourages further investigation.

Synthesis, antioxidant and antimicrobial properties of novel pyridyl-carbonyl thiazoles as dendrodoine analogs.

Marine compound dendrodoine was first obtained from tunicate species ( Dendrodo grossularia ). It has a five-membered ring, namely, it is a heterocycle thiadiazole, which is found rarely in natural sources . Following its biological activities, novel analogs have been investigated recently. Synthesis of the analogs for this study is realized with uncommon thiazole closure, including methylene-carbonyl condensation. Structures are elucidated by NMR ( 1 , 13 C) and HRMS spectrums. As an alkaloid derivative, antioxidant properties were evaluated with DPPH and FRAP assays and antimicrobial effect with microdilution method. Among the series, 3bc-3cf showed higher antioxidant activity than those having 3 or 4-pyridyl substituents. There is lesser activity for 2-pyridyl activity for 2-pyridyl containing group, which may be a result of intramolecular interactions. No activity was observed against gram-negative bacteria at 250 µg/mL. 3ae and 3ce showed activity at 64 µg/mL against S. aureus and 3ae showed activity at 16 µg/mL against S. epidermidis gram-positive bacteria. Chloramphenicol showed activity against all microorganisms at 8-16 µg/mL. Sixteen original dendrodoine analogs have been defined by close/higher activity compared to dendrodoine analogs and Trolox.

Studies on non-steroidal inhibitors of aromatase enzyme; 4-(aryl/heteroaryl)-2-(pyrimidin-2-yl)thiazole derivatives.

Steroidal and non-steroidal aromatase inhibitors target the suppression of estrogen biosynthesis in the treatment of breast cancer. Researchers have increasingly focused on developing non-steroidal derivatives for their potential clinical use avoiding steroidal side-effects. Non-steroidal derivatives generally have planar aromatic structures attached to the azole ring system. One part of this ring system comprises functional groups that inhibit aromatization through the coordination of the haem group of the aromatase enzyme. Replacement of the triazole ring system and development of aromatic/cyclic structures of the side chain can increase selectivity over aromatase enzyme inhibition. In this study, 4-(aryl/heteroaryl)-2-(pyrimidin-2-yl)thiazole derivatives were synthesized and physical analyses and structural determination studies were performed. The IC50 values were determined by a fluorescence-based aromatase inhibition assay and compound 1 (4-(2-hydroxyphenyl)-2-(pyrimidine-2-yl)thiazole) were found potent inhibitor of enzyme (IC50:0.42 nM). Then, their antiproliferative activity over MCF-7 and HEK-293 cell lines was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Compounds 1, 7, 8, 13, 15, 18, 21 were active against MCF-7 breast cancer cells. Lastly, a series of docking experiments were undertaken to analyze the crystal structure of human placental aromatase and identify the possible interactions between the most active structure and the active site.