Herbicide Potential of Selected Essential Oils From Plants of Lamiaceae and Asteraceae Families

Essential oils from Monarda fistulosa L., Satureja pilosa Vel., Origanum vulgare subsp. hirtum Ietswaart. (Greek oregano), Micromeria dalmatica Benth., Thymus longedentatus (Degen & Urum.) Ronniger, and Artemisa campestris L. were evaluated as inhibitors of seed germination in target plants Lolium perenne L. and Trifolium pratense L. using in vitro assays. The essential oils were applied on the seeds as aqueous solutions at concentrations ranging from 0.5–3.0 µL/mL. Complete inhibition was established at a concentration of 1.5 µL/mL with the most effective essential oils. Oregano oil was evaluated for its inhibitory activity on seed germination under field conditions; the essential oil was applied as an aqueous solution at concentrations of 3, 5, and 10 µL/mL on superabsorbent Terawet. The mass obtained was mixed with the seeds of the target plants and planted in a field. After 1 month, the results were evaluated based on the weight of the aerial parts of the plants from control and experimental areas. At the highest concentration studied, the weight of the plants was 77% lower in the experimental areas than in the controls. The chemical composition of the essential oils was analyzed using gas chromatography–mass spectrometry. The results showed that carvacrol-rich essential oils had a strong inhibitory effect on seed germination. The inclusion of the essential oil on a superabsorbent was a good way to preserve its herbicidal activity under field conditions as this prevented its rapid evaporation.

The Development of the New Approaches to the Standardization of the Monarda fistulosa L. Herbs

In the present paper are discussed the results of the study on the development of the new approaches to the standardization of the Monarda fistulosa L. herbs. From the herb of the Monarda fistulosa L. there were isolated for the first time isorhoifolin (apigenin-7-O-rutinoside) and linarin (acacetin-7-O-rutinoside) chemical structures of which there were elucidated by means of 1H-NMR-, 13C-NMR-, UV-spectroscopy, mass spectrometry and results of chemical transformations. It was determined, that the isolated flavonoids cause the spectral characteristics in the UV spectra of the water-ethanolic extracts from the Monarda fistulosa L. herbs. It was substantiated the expediency of the estimation of the total flavonoids in the herbs of Monarda fistulosa L. calculated on isorhoifolin. As results there was development the method of the quantitative determination of the total flavonoids in the herbs of Monarda fistulosa L. by the using of the differential spectrophotometry at an analytical wavelength of 394 nm. It was determined that the content of the total of flavonoids in the raw materials of the studied plant varies from 4.23±0.08% to 7.68±0.12%.

Chemical Composition and Nematicidal Properties of Sixteen Essential Oils—A Review

Essential oils (EOs) can be a large source of new food-safe and healthy nematicidal products, due to their strong activity on crop pathogens and pests, including phytoparasitic nematodes, as well as to their low environmental persistence. This review summarizes the results from our 10-year studies on chemical features and nematicidal properties of 16 EOs with different botanical origins and compositions, i.e., the EOs from Artemisia herba-alba Asso (Asteraceae), Cinnamomum camphora (L.) J. Presl. and Cinnamomum verum J. Presl. (Lauraceae), Citrus aurantium L., Cinnamomum. sinensis L. Osbeck and Ruta graveolens L. (Rutaceae), Eucalyptus citriodora Hook, Eucalyptus globulus Labill. and Syzygium aromaticum (L.) Marry et Perry (Myrtaceae), Mentha piperita L., Monarda didyma L., Monarda. fistulosa L., Rosmarinus officinalis L. and Thymus satureioides Cosson (Lamiaceae), Pelargonium asperum Ehrh ex Willd (Geraniaceae) and Schinus molle L. (Anacardiaceae). All these EOs were chemically characterized and tested in vitro and/or in vivo for their activity against the phytoparasitic species Meloidogyne incognita Kofoid et White (Chitw.), Pratylenchus vulnus Allen et Jensen and Xiphinema index Thorne et Allen. Toxicity bioassays were conducted by exposing 2nd stage juveniles (J2) of M. incognita, mixed-age specimens of P. vulnus and adult females of X. index to 2–100 μg mL−1 concentrations of EOs or EO’s major constituents for 4–96 h and checking mortality effect after a further 24–72 h permanence in water. Egg hatchability bioassays consisted in exposing (24–48 h) M. incognita egg masses to 500–1000 mg mL−1 EO solutions followed by a 5-week hatching test in water. The in vivo experiments were undertaken in sandy soil strongly infested by M. incognita and treated with different doses of EOs, applied either in water solution or by fumigation. The effects of the treatments on nematode infestation on tomato and in soil were checked at the end of each experiment. Structure-activity relationships, as suggested by the different chemical compositions of tested EOs, were also highlighted. In agreement with literature data, our studies indicated that most of the tested EOs are highly suitable for the formulation of new safe nematicides, though still retarded by the lack of efficient stabilization processes and standardized EOs’ components and extraction techniques.

Scientific evidence for efficiency of medicinal plants in otorhinolaryngology

Objectives to provide scientific evidence for rational use of herbal medicines in otorhinolaryngological practice. Material and methods. The study included the following plants: Eucalyptus viminalis leaves, Monarda fistulosa herbs, Melissa officinalis herbs, Echinacea purpurea herbs, Calendula officinalis flowers, rhizomes of Rhodiola rosea, rhizomes of Eleutherococcus senticosus, Glycyrrhiza glabra roots, Macleaya microcarpa herbs, Macleaya cordata herbs, Plantago major leaves, Origanum vulgare herbs, Thymus serpyllum herbs. Phenylpropanoids, flavonoids, euglobals, monoterpene phenols, phenylpropanoids, terpenoids of essential oils, saponins and alkaloids were isolated from the medicinal plants and studied with thin-layer chromatography, spectrophotometry, NMR spectroscopy, mass spectrometry, and various chemical transformations. Results. It was scientifically proved that medicinal plants containing such biologically active compounds as phenylpropanoids, flavonoids, euglobals, terpenoid and phenolic components of essential oils, saponins, carotenoids, alkaloids and polysaccharides are useful for otorhinolaryngology. The active substances of the mentioned chemical groups in combination can provide antimicrobial, antifungal, antiviral, anti-inflammatory, regenerating, antihistamine, adaptogenic and immunomodulatory effects. Conclusion. The expediency of using medicinal herbal preparations containing euglobals, monoterpene phenols, flavonoids, phenylpropanoids, terpenoids of essential oils, saponins, alkaloids and polysaccharides in otorhinolaryngological practice was scientifically justified.

Thymoquinone: Biosynthesis, Biological Activities and Therapeutic Potential from Natural and Synthetic Sources

Thymoquinone (TQ; 2-isopropyl-5-methyl-1,4-benzoquinone) is a secondary metabolite found in abundance in very few plant species including Nigella sativa L., Monarda fistulosa L. and Satureja montana L. It is found in crystalline triclinic form in a range of organs in these plants. TQ has been synthetically prepared from thymol (2-isopropyl-5-methylphenol); commercially it is synthesized by modification of thymol and carvacrol (5-isopropyl-2-methylphenol). TQ has substantial therapeutic potential because of its anti-cancer, hepato-protective, anti-inflammatory, antioxidant, antimicrobial and cardio-protective activities in cell culture systems and animal models. In this article, we have reviewed recent studies on the natural and synthetic sources of TQ, its biosynthetic pathway and its modes of action in human and experimental models, as well as its commercial preparation. We also compiled the medicinal effects of TQ. The biological activities of TQ support the potential of this plant secondary metabolite as a drug with a wide range of therapeutic applications. To substantiate the benefits and pharmaceutical properties of TQ, further well-designed clinical research is required. © 2021 Friends Science Publishers

Polyphenols and Pharmacological Screening of a Monarda fistulosa L. dry Extract Based on a Hydrodistilled Residue By-Product

This study aimed to determine the composition and content of polyphenols in the dry extract obtained from the hydrodistilled residue by-product of the wild bergamot (Monarda fistulosa L., Lamiaceae Martinov family) herb (MFDE) and to evaluate its safety and pharmacological properties. The total phenolic content (TPC) in the MFDE was 120.64 mg GAE/g. The high-performance liquid chromatography (HPLC) analysis showed the presence of a plethora of phenolic compounds, including hydroxycinnamic acids and flavone derivatives in the MFDE, with rosmarinic acid and luteolin-7-O-glucoside being the main components. With an IC50 value of 0.285 mg/mL, it was found to be a strong DPPH radical scavenger. The acute toxicity study results indicate that the oral administration of MFDE to rats at the doses of 500–5,000 mg/kg did not produce any side effects or death in animals which indicates its safety. The results of the in vivo assay showed that the MFDE dose-dependently inhibited paw oedema and significantly reduced the number of writings in mice induced by the acetic acid injection suggesting its potent anti-inflammatory and analgesic activities, respectively. The conducted studies revealed that M. fistulosa hydrodistilled residue by-product could be regarded as a new natural source of polyphenols with valuable pharmacological properties.

Chromatographic Profiles of the main Secondary Metabolites in the Monarda fistulosa L. Aerial Part

Two different methods of chromatographic analysis have been used in this study for the phytochemical evaluation of main secondary metabolites in the aerial part of bee balm (Monarda fistulosa L.) as the non-officinal medicinal plant of the Lamiaceae Martinov family. The high performance thin layer chromatography (HPTLC) fingerprinting method was developed for the qualitative analyses of phenolic and non-polar compounds in the bee balm herb after its maceration in the solvents of different polarity. Such polyphenols as rosmarinic, caffeic and chlorogenic acids were authentically identified in the methanol extract of herb using HPTLC. Aromatic monoterpenoid thymol was identified by the HPTLC method in the extracts obtained with non-polar solvents (toluene, methylene chloride, and chloroform). 38 volatile compounds were determined in the methylene chloride extract of M. fistulosa herb by gas chromatography mass spectrometry (GC/MS); it was taken into account only components with the content more than 0.2 %. The GC/MS analysis showed that thymol (23.73 %), followed by carvacrol (10.09 %), p-cymene (9.74 %), and thymoquinone (8.52 %) were the major constituent of methylene chloride extract. Used chromatographic techniques may be recommended for the reliable phytochemical authentication of the M. fistulosa herb.

Is the Antimicrobial Activity of Hydrolates Lower than That of Essential Oils?

Among the top five human infections requiring medical treatment is dermatitis. Treatment of bacterial and fungal skin infections is usually based on antibiotic therapy, which is often ineffective due to the involvement of antibiotic-resistant microbial strains. The aim of this study was to compare the antimicrobial activity of essential oils (EOs) and hydrolates (Hys) extracted from six aromatic plants grown in Italy (Lavandula angustifolia, Lavandula intermedia, Origanum hirtum, Satureja montana, Monarda didyma, and Monarda fistulosa) towards fungal (Candida albicans, Candida parapsilosis, Candida glabrata and Candida tropicalis; Trichophyton soudanense, Trichophyton tonsurans, Trichophyton rubrum, Trichophyton violaceum and Microsporum canis) and bacterial strains (Staphylococcus aureus MRSA, Staphylococcus aureus MSSA, Streptococcus pyogenes, E. faecalis, Enterococcus faecalis VRE, and Enterococcus faecium) potentially pathogenic for human skin. The composition and antimicrobial activity of EOs and Hys were evaluated using the Gas-chromatography mass spectrometry and micro dilution-broth test, respectively. The volatiles’ conversion factors (CFs) were calculated to compare the activity of Hys with that of the corresponding EOs. Data show that, although the minimum inhibitory concentration values of EOs are lower than the corresponding Hys, the volatiles contained in Hys are more effective at inhibiting microbial growth because they are active at lower concentrations.