Nanovesicles loaded with origanum onites and satureja thymbra essential oils and their activity against food-borne pathogens and spoilage microorganisms

Food poisoning is a common cause of illness and death in developing countries. Essential oils (EOs) could be effective and safe natural preservatives to prevent and control bacterial contamination of foods. However, their high sensitivity and strong flavor limit their application and biological effectiveness. The aim of this study was firstly the chemical analysis and the antimicrobial evaluation of the EOs of Origanum onites L. and Satureja thymbra L. obtained from Symi island (Greece), and, secondly, the formulation of propylene glycol-nanovesicles loaded with these EOs to improve their antimicrobial properties. The EOs were analyzed by GC-MS and their chemical contents are presented herein. Different nanovesicles were formulated with small average sizes, high homogeneity, and optimal ζ-potential. Microscopic observation confirmed their small and spherical shape. Antibacterial and antifungal activities of the formulated EOs were evaluated against food-borne pathogens and spoilage microorganisms compared to pure EOs. Propylene glycol-nanovesicles loaded with O. onites EO were found to be the most active formulation against all tested strains. Additionally, in vitro studies on the HaCaT cell line showed that nanovesicles encapsulated with EOs had no toxic effect. The present study revealed that both EOs can be used as alternative sanitizers and preservatives in the food industry, and that their formulation in nanovesicles can provide a suitable approach as food-grade delivery system

Phytochemical investigation of the fern asplenium ceterach (Aspleniaceae)

The fern Asplenium ceterach L. (syn. Ceterach Officinarum Willd.) is used in lOcal traditiOnal medicine against kidney stOnes, gallstOnes, tO facilitate diuresis and tO treat benign prOstatic hyperplasia. The aim Of this study was first tO investigate the chemical cOmpOsitiOn Of this fern and then tO study the chemical prOfile Of the herbal preparatiOns used in lOcal medicine due tO its diuretic prOperties. In tOtal, nine secOndary metabOlites frOm the methanOl extract Of the aerial parts have been isOlated; three flavOnOids, namely kaempherOl-3-O-β-D-gentiObiOside (1), quercetin-3-O-β-D-glucurOnide (2), quercetin-3-O-β-DgentiObiOside (3), three phenOlic acids, i.e. Caffeic acid (4), chlOrOgenic acid (5) and p-cOumarOyl-4-O-β-D-glucOside (6), as well as three phenOls, 4-vinylphenOl- 1-O-β-D-glucOpyranOside (7), 3-(1-O-β-D-glucOpyranOsyl-4-hydrOxyphenyl)-prOpiOnic acid (8), and 4-β-O-D-glucOsyl-3,4-dihydrOxybenzyl alcOhOl (9). MOreOver, the cyclOhexane residue has been submitted tO GC-MS and NMR analyses and revealed the presence Of ethyl esters Of palmitic, linOleic and α- linOlenic acids. Finally, based On NMR, TLC and HPLC analyses, it was evident that the chemical fingerprints Of all herbal preparatiOns were quite similar, with chlOrOgenic acid being the main cOmpOund and caffeic acid present Only in traces. © 2018 Natural Product Incorporation. All rights reserved

Phytochemical study of Stachys candida Bory & Chaubard (Lamiaceae)

Phytochemical analysis of the aerial parts of Stachys candida Bory & Chaubard, growing wild in Greece led to the isolation of eleven bioactive secondary metabolites. Nine flavones, one of them methylated, one phenylethanoid glycoside and one phenolic acid were isolated from the methanol extract of this plant. The structure elucidation of the isolated compounds was achieved on the basis of NMR spectroscopy (1D and 2D spectra). The phytochemical profile was appeared to be similar with other Greek endemic Stachys species, while a strong difference was the absence of iridoids. Importantly, the chemotaxonomic significance of the isolated compounds has extensively been described. © 2020 Elsevier Lt

The genus Genista L.: A rich source of bioactive flavonoids

The genus Genista L. (family Fabaceae, subfamily Papilionoideae), with its cosmopolitan distribution, has attracted the human interest since ancient times, as it is used in folk medicine and mainly in the Mediterranean area for the treatment of respiratory diseases, rheumatic disorders, diabetes and ulcer, while it is also well known for its yellow pigment. The chemical composition of the Genista species revealed the presence of more than 108 flavonoids. Isoflavones, belonging to the group of phytoestrogens, are important secondary metabolites of the genus. The extracts of the Genista species may act as important source of bioactive phytochemicals for the treatment of many human ailments, mainly inflammation and pain, estrogen related pathology, hyperglycaemia, cancer and microbial infections. Therefore, the present review summarizes and discusses the flavonoid derivatives from the genus Genista, together with their structural features and pharmacological properties, aiming to highlight the recent advances in current knowledge on Genista species as a source of bioactive flavonoids. © 2020 Elsevier Lt

Phytochemistry and evidence-based traditional uses of the genus achillea l.: An update (2011–2021)

Knowledge within the field of phytochemistry research has accelerated at a tremendous speed. The excess of literature reports featuring plants of high ethnopharmacological importance, in combination with our interest in the Asteraceae family and traditional medicine, led us to acknowl-edge the value of the Achillea L. genus. In a broad context, the various Achillea species are used around the globe for the prevention and treatment of different diseases, including gastrointestinal problems, haemorrhages, pneumonia, rheumatic pains, diuresis, inflammation, infections, and wounds, as well as menstrual and gynaecologic abnormalities. The present review aims to provide and summarize the recent literature (2011–2021) on the phytochemistry of the Achillea genus. In parallel, this study attempts to bridge the reports on the traditional uses with modern pharmacological data. Research articles that focused on secondary metabolites, traditional uses and pharmacological activities were collected from various scientific databases such as Pubmed, ScienceDirect, Reaxys and Google Scholar. This study revealed the presence of 141 phytochemicals, while 24 traditionally used Achillea spp. were discussed in comparison to current data with an experimental basis. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

The Effect of Successive Harvesting on The Volatile Constituents of Two Essential Oils of Cultivated Populations of Sea Fennel (Crithmum maritimum L.) in Greece

Crithmum maritimum L. (Apiaceae), known as Sea fennel, is a perennial plant, growing wild mainly on maritime rocks along with the Mediterranean countries, Pacific and Atlantic coasts. Traditionally, various parts of this plant have been used as a tonic, antiscorbutic, carminative, vermifuge and diuretic. Over the last years, the essential oil (EO) of sea fennel is widely used in the food and cosmetic industry. In the present study, the EOs of the aerial parts obtained from cultivated populations of two consecutive years (2016; 2017; Larissa-Central Greece) were analyzed by GC/MS. The main compounds of the EO derived from the cultivar of 2016 were sabinene (17.6 %), γ-terpinene (17.5 %), p-cymene (16.7 %), β-phellandrene (15.5 %), thymol methyl ether (9.3 %), terpinen-4-ol (4.8 %) and dillapiole (2.0 %). Though, the sample of 2017 included β-phellandrene (30.9 %), γ-terpinene (19.6 %), sabinene (15.8 %), thymol methyl ether (7.6 %), terpinen-4-ol (4.8 %) and dillapiole (0.1 %). A comparison was made between the two samples, as well as with the previous literature data. This is the first study deals with the chemical analysis of EOs from Greek cultivated C. maritimum. Our data revealed the presence of monoterpene hydrocarbons as the major constituents in both EOs and confirmed the presence of dillapiole in the Greek EOs of the specific plant. © 2021 Har Krishan Bhalla & Sons

NMR-based chemical profiling, isolation and evaluation of the cytotoxic potential of the diterpenoid siderol from cultivated sideritis euboea heldr

Diterpenes are characteristic compounds from the genus Sideritis L., possessing an array of biological activities. Siderol is the main constituent of the ent-kaurene diterpenes in Sideritis species. In order to isolate the specific compound and evaluate for the first time its cytotoxic activity, we explored the dichloromethane extract of cultivated Sideritis euboea Heldr. To track the specific natural bioactive agent, we applied NMR spectroscopy to the crude plant extract, since NMR can serve as a powerful and rapid tool both to navigate the targeted isolation process of bioactive constituents, and to also reveal the identity of bioactive components. Along these lines, from the rapid 1D 1H NMR spectrum of the total crude plant extract, we were able to determine the characteristic proton NMR signals of siderol. Furthermore, with the same NMR spectrum, we were able to categorize several secondary metabolites into chemical groups as a control of the isolation process. Therefore, this non-polar extract was explored, for the first time, revealing eleven compounds—one fatty acid ester; 2-(p-hydroxyphenyl)ethylstearate (1), three phytosterols; β-sitosterol (2), stigmasterol (3), and campesterol (4); one triterpenoid; ursolic acid (5), four diterpenoids; siderol (6), eubol (7), eubotriol (8), 7-epicandicandiol (9) and two flavonoids; xanthomicrol (10) and penduletin (11). The main isolated constituent was siderol. The antiproliferative potential of siderol was evaluated, using the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay, on three human cancer cell lines DLD1, HeLa, and A549, where the IC50 values were estimated at 26.4 ± 3.7, 44.7 ± 7.2, and 46.0 ± 4.9 µM, respectively. The most potent activity was recorded in the human colon cancer cell line DLD1, where siderol exhibited the lowest IC50. Our study unveiled the beneficial potential of siderol as a remarkable cytotoxic agent and the significant contribution of NMR spectroscopy towards the isolation and identification of this potent anticancer agent. © 2020 by the authors

Traditional uses, phytochemistry, and pharmacology of elegia species: A review

In South Africa, plants belonging to the Restionaceae family possess an ecological dom-inance. As a result, they have been the subject of numerous morphological, anatomical, and evo-lutionary studies. However, few studies have focused on their phytochemical profile and their potential pharmacological activities. The genus Elegia L. is the second largest of this family compris-ing 52 species, which are mainly used as materials for thatching. Limited studies on the chemical constituents of Elegia species and their importance as medicinal plants have been undertaken. This review provides constructive and extensive information about the botanical characterization, distribu-tion, traditional uses, phytochemistry and pharmacology of the genus Elegia. A comprehensive search of previously published literature was performed for studies on this genus, using databases with different key search words. This survey documented 52 Elegia species summarizing their previous taxonomic classification. In addition, 14 species were found to be studied for their phytochemical profile, revealing 14 chemical compounds. Concerning their biological activities, only one species (E. tectorum (L.f.) Moline and H.P.Linder) is reported for its anti-wrinkle activity. Moreover, two species are locally used for thatching and as materials for brooms. The present review highlights the Elegia genus as an important source of bioactive phytochemicals with flavonol glycosides being the main metabolites and reveals the uncharted territory of this genus for new research studies. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Cultivation strategy to improve chemical profile and anti-oxidant activity of Sideritis perfoliata L. subsp. perfoliata

Due to the remarkable medicinal properties of Sideritis spp, the commercial demand for the plant is continuously on the rise both in the European and in the global market. Cultivation of Sideritis species have been occurred to successfully meet the need for mass production of high-quality plant material. The present study was undertaken in order to investigate the impact of different cultivation practices (conventional versus organic cultivation; full versus deficit irrigation) in the yield and phytochemical profile of S. perfoliata L. subsp. perfoliata from Cyprus, under two harvestings for biomass production. Deficit irrigation decreased plant growth, but increased dry matter content. The content of chlorophylls and the nitrogen and potassium content decreased in organically grown plants. Both organic cultivation and/or deficit irrigation increased total phenolics, flavonoids, vitamin C and antioxidants. Essential oil yield increased under deficit irrigation at the 2nd harvest, while essential oil composition fluctuated among the treatments. Infusions of each plant material were prepared according to the European Medicines Agency (EMA) monograph. Based on their NMR spectra, the deficit-irrigated plants from conventional cultivation were the most rich in secondary metabolites and chosen for further chemical analysis. Six iridoids such as three flavonoids, two phenylethanoid glucosides and one phenolic acid have been isolated indicating new knowledge on the effects of cultivation practices on plant secondary metabolisms with putative industrial applications and interest. © 2019 Elsevier B.V