Extracts from medicinal plants are widely used in the treatment and prevention of different diseases. Micromeria frivaldszkyana is a Balkan endemic species with reported antioxidant and antimicrobial characteristics; however, its phytochemical composition is not well defined. Here, we examined the metabolome of M. frivaldszkyana by chromatography–mass spectrometry (GC-MS), ultra-performance liquid chromatography–mass spectrometry (UPLC-MS-MS), and inductively coupled plasma mass spectrometry (ICP-MS). Amino acids, organic acids, sugars, and sugar alcohols were the primary metabolites with the highest levels in the plant extract. Detailed analysis of the sugar content identified high levels of sucrose, glucose, mannose, and fructose. Lipids are primary plant metabolites, and the analysis revealed triacylglycerols as the most abundant lipid group. Potassium (K), magnesium (Mg), zinc (Zn), and calcium (Ca) were the elements with the highest content. The results showed linarin, 3-caffeoil-quinic acid, and rosmarinic acid, as well as a number of polyphenols, as the most abundant secondary metabolites. Among the flavonoids and polyphenols with a high presence were eupatorin, kaempferol, and apigenin—compounds widely known for their bioactive properties. Further, the acute toxicity and potential anti-inflammatory activity of the methanolic extract were evaluated in Wistar rats. No toxic effects were registered after a single oral application of the extract in doses of between 200 and 5000 mg/kg bw. A fourteen-day pre-treatment with methanolic extract of M. frivaldszkyana in doses of 250, 400, and 500 mg/kg bw induced anti-inflammatory activity in the 1st, 2nd, and 3rd hours after carrageenan injection in a model of rat paw edema. This effect was also present in the 4th hour only in the group treated with a dose of 500 mg/kg. In conclusion, M. frivaldszkyana extract is particularly rich in linarin, rosmarinic acid, and flavonoids (eupatorin, kaempferol, and apigenin). Its methanolic extract induced no toxicity in male Wistar rats after oral application in doses of up to 5000 mg/kg bw. Additionally, treatment with the methanolic extract for 14 days revealed anti-inflammatory potential in a model of rat paw edema on the 1st, 2nd, and 3rd hours after the carrageenan injection. These results show the anti-inflammatory potential of the plant, which might be considered for further exploration and eventual application as a phytotherapeutic agent.

The genus Marrubium (Lamiaceae) is widely used in traditional medicine. While some representatives of the genus have been well investigated, the biological activity of others remains largely unknown. The aim of the current study was to assess the in vitro antioxidant potential and the effect on the reactivity of isolated rat gastric smooth muscles (SM) of aqueous extracts of Marrubium friwaldskyanum inflorescences, stems and leaves, and Marrubium peregrinum as a whole herb. The antioxidant activity was analyzed through multiple spectrophotometric and fluorometric assays. The effect on SM reactivity was determined by the treatment of excised gastric muscles of 10 male Whistar rats with the plant extracts alone or successive to 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide, ketanserin, verapamil, and acetylcholine. According to the obtained results, the M. friwaldskyanum leaf extract exhibited the greatest antioxidant potential, followed by the M. peregrinum one. The SM reactivity analysis revealed that the treatment with all four extracts induced a dose-dependent contractile response with predominant cholinergic character. However, activation of serotoninergic and/or dopaminergic pathways was also observed. Furthermore, when applied after verapamil, the extracts showed a SM relaxant effect. The discovered biological activity will serve as a basis for future analyses through which the therapeutic effect of the plants will be investigated.

Centaurea thracica (Janka) Hayek is a plant common in southern Bulgaria. The inflorescences were collected during June and September 2021, while their seeds were obtained in September 2021. The chemical and lipid composition of the inflorescences during the vegetation process of the plant were established. A significant decrease in total proteins (from 8.7 to 7.4%), glyceride oils (2.0–1.7%), and ash (4.5–4.2%) content was observed, while the amount of carbohydrates (72.3–77.2%) and fibers (28.7–35.8%) increased. During the vegetation of the plant, the content of oleic and linoleic acids increased up to 2–3 times, while the level of palmitic acid decreased. The lipids from the seeds were rich in oleic (53.0%) and palmitic (36.2%) acids. The tocopherol content in the oils of the inflorescences during vegetation increased from 58 to 110 mg/kg, and the content in the oil from the seeds was 260 mg/kg. The phospholipid content decreased during vegetation, and differences were observed in the composition between the inflorescences and the seeds. The high content of oleic acid, linoleic acid, tocopherols, and phospholipids determine the nutritional and biological value of the oils isolated from Centaurea thracica, and contribute to their potential use in various directions.

Background/Objectives: People in the developed world tend to consume food that is rich in calories but lacks sufficient nutrients such as essential minerals, vitamins, and other health-promoting metabolites. At the same time, hunger and malnutrition are still problems in other countries. Therefore, various forms of micronutrient deficiencies and diseases caused by unbalanced nutrition are global issues. Methods: In order to elucidate the beneficial potential of alternative food sources, we employed state-of-the-art UHPLC-MS and ICP-MS technologies to perform comprehensive metabolome and metallome analyses of five edible European plants, some of which are known as underutilized crops: Achillea millefolium, Agastache rugosa, Cercis siliquastrum, Crithmum maritimum, and Mespilus germanica. Results: This study reveals valuable nutritional properties such as high levels of essential amino acids, sugars, organic acids, health-promoting secondary metabolites, and essential microelements that are important for human diet. The analyzed samples indicate that A. millefolium, C. siliquastrum, and M. germanica could be marked as a viable source of beneficial flavonoids. In turn, both leaves and fruits of A. rugosa had elevated abundances of organic acids, along with A. millefolium and C. siliquastrum. Similar results were observed for amino acids. Conclusions: Taken as a whole, the fruits of C. siliquastrum could be described as the best source for most of the identified compounds. The M. germanica samples were rich in mineral contents, with indications that they can supply 26% of the recommended daily intake per 100 g for K, 16% for Mg, 26% for Fe, 63% for Mn, and 89% for B. The leaves of C. maritimum and A. millefolium are also a good source of K and Mn. Interestingly, the sampled leaves of C. maritimum contained a very high amount of B, representing more than three times the reference nutrient value for 100 g of plant material. In conclusion, these underutilized species can be used to diversify the European food systems by enriching our diets with essential nutrients and health-promoting metabolites.

The aim of the current study is to determine the nutritional value and the content of the biologically active components in kidney vetch (Anthyllis vulneraria L.). It is established that the dry biomass contains substantial amounts of proteins and carbohydrates, primarily dietary fiber, while the total oil content is relatively low (below 3.0%). The isolated glyceride oil represents the complete lipid fraction derived from all plant parts (leaves, stems, and flowers). The glyceride oil of A. vulneraria is notable for its high levels of biologically active constituents, particularly sterols, tocopherols, and phospholipids. Palmitic (30.3%) and oleic (11.5%) acids dominate the fatty acid profile; β-sitosterol, α-tocotrienol, and α-tocopherol are the major sterol and tocopherol components, respectively. On the other hand, phosphatidylinositol, together with phosphatidic acids, prevails within the phospholipid fraction. Based on the obtained fatty acid composition, several important ratios were calculated—unsaturated fatty acids (UFA)/saturated fatty acids (SFA), saturated fatty acids/monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA)/saturated fatty acids, and n-6/n-3, providing an integrated assessment of the lipid quality. The PUFA/SFA value (0.24) suggests relatively high oxidative stability. In contrast, the n-6/n-3 ratio (0.86) shows a balanced distribution of essential fatty acids, which is associated with favorable nutritional properties.

Five species of the genus Equisetum distributed in Bulgaria were studied: four species from the subgenus Equisetum (Equisetum arvense, E. telmateia, E. sylvaticum, and E. palustre) and one from the subgenus Hippochaete (E. ramosissimum). The anatomical, taxonomic, and phylogenetic characteristics of the selected species were established. In species belonging to the subgenus Equisetum, the endodermis was arranged in the form of a continuous ring, while in the representatives of the subgenus Hippochaete, a two-layered endodermis surrounding each vascular bundle was observed. The results from the DNA barcoding supported the taxonomic treatment of the studied species. The chemical and lipid compositions of the plants were also investigated. The Equisetum species had a similar chemical composition and a high content of sterols and phospholipids. In the glyceride oils, palmitic acid predominated, ranging from 69.5% to 78.7%. β-sitosterol was the main component in the sterol fraction, while the tocopherol content was found to be remarkably low in two of the samples (37.6–82.8 mg/kg), with α-tocopherol being predominant. In the phospholipid fraction, the major classes were phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, and phosphatidic acids. The chemical composition of the studied species and their high biologically active lipid constituents suggested that they were suitable for application in various directions.