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

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.

Treating COVID-19 with Medicinal Plants: Is It Even Conceivable? A Comprehensive Review

In 2020, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) challenged the world with a global outbreak that led to millions of deaths worldwide. Coronavirus disease 2019 (COVID-19) is the symptomatic manifestation of this virus, which can range from flu-like symptoms to utter clinical complications and even death. Since there was no clear medicine that could tackle this infection or lower its complications with minimal adverse effects on the patients' health, the world health organization (WHO) developed awareness programs to lower the infection rate and limit the fast spread of this virus. Although vaccines have been developed as preventative tools, people still prefer going back to traditional herbal medicine, which provides remarkable health benefits that can either prevent the viral infection or limit the progression of severe symptoms through different mechanistic pathways with relatively insignificant side effects. This comprehensive review provides scientific evidence elucidating the effect of 10 different plants against SARS-CoV-2, paving the way for further studies to reconsider plant-based extracts, rich in bioactive compounds, into more advanced clinical assessments in order to identify their impact on patients suffering from COVID-19.

In Vitro and In Silico Evaluation of the Antimicrobial and Antioxidant Potential of Thymus pulegioides Essential Oil

The study was designed to analyze and evaluate the antioxidant and antibacterial properties of the essential oils of Thymus pulegioides L. grown in Western Romania. Thymus pulegioides L. essential oil (TPEO) was extracted by steam distillation (0.71% v/w) using a Craveiro-type apparatus. GC-MS investigation of the TPEO identified 39 different compounds, representing 98.46% of total oil. Findings revealed that thymol (22.89%) is the main compound of TPEO, followed by para-cymene (14.57%), thymol methyl ether (11.19%), isothymol methyl ether (10.45%), and beta-bisabolene (9.53%). The oil exhibits good antibacterial effects; C. parapsilosis, C. albicans, S. pyogenes, and S. aureus were the most sensitive strains. The antioxidant activity of TPEO was evaluated by peroxide and thiobarbituric acid value, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), [2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium] (ABTS) radical scavenging assay, and beta-carotene/linoleic acid bleaching testing. The antioxidative data recorded reveal, for the first time, that TPEO inhibits primary and secondary oxidation products, in some particular conditions, better than butylated hydroxyanisole (BHA) with significant statistical difference (p < 0.05). Moreover, TPEO antioxidant capabilities in DPPH and ABTS assays outperformed alpha-tocopherol (p < 0.001) and delta-tocopherol (p < 0.001). Molecular docking analysis revealed that one potential target correlated with the TPEO antimicrobial activity was d-alanine-d-alanine ligase (DDl). The best scoring ligand, linalyl anthranilate, shared highly similar binding patterns with the DDl native inhibitor. Furthermore, molecular docking analysis also showed that the main constituents of TPEO are good candidates for xanthine oxidase and lipoxygenase inhibition, making the essential oil a valuable source for protein-targeted antioxidant compounds. Consequently, TPEO may represent a new potential source of antioxidant and antibacterial agents with applicability in the food and pharmaceutic industries.

Phytochemical Characterization and Biological Evaluation of Origanum vulgare L. Essential Oil Formulated as Polymeric Micelles Drug Delivery Systems

This study presents phytochemical characterization and biological evaluation of Origanum vulgare L. essential oil (OEO) formulated as polymeric micelles drug delivery systems as a possible non-invasive approach for the management of skin tags. GC-MS analysis of Romanian OEO revealed the identification and quantification of 43 volatile compounds (thymol and carvacrol being the main ones). The antioxidant activity was shown by four consecrated methods: CUPRAC, ABTS, ORAC and DPPH. OEO was incorporated by micellar solubilization into a binary hydrogel based on a Pluronic F 127/L 31 block-copolymers mixture. The pH, consistency, spreadability, particle size, polydispersity index and zeta potential of the OEO-loaded poloxamer-based binary hydrogel (OEO-PbH) were investigated. OEO-PbH was skin compatible in terms of pH and exhibited adequate spreadability and consistency. The minimal inhibitory concentrations of the tested OEO were similar to those obtained for the formulation, lower (2.5 µg/mL) for yeast and higher (40-80 µg/mL) for Gram-negative bacilli. As keratinocytes are among main components of skin tags, an in vitro evaluation was conducted in order to see the effect of the formulation against HaCaT human keratinocytes. OEO-PbH decreased HaCaT cells migration and proliferation and elicited a cytotoxic and pro-apoptotic effect in a dose- and time-dependent manner. No harmful effect on the viability of dendritic cells (DCs) was detected following the incubation with different concentrations (0-200 µg/mL) of the 5% formulation. Treatment in inflammatory DCs (+LPS) indicated a decrease in cytokine production of IL-6, TNF-α and IL-23 but no significant effect on IL-10 in any of the tested concentrations.

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.

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.