GC-MS metabolic profiling and free radical scavenging activity of Micromeria dalmatica

Metabolite profile of acetone exudate and methanolic extract from aerial parts of Micromeria dalmatica Benth were analyzed by GC/MS. Palmitic and linolenic acids, hentriacontane, amyrin, quercetagetin 3,6,7-trimethyl ether, sucrose were identified among the main components in the acetone exudate. In the methanolic extract more than 100 chromatographic peaks were detected including alkanes, fatty alcohols, fatty acids, organic acids, phenolic acids, saccharides, polyoles, phytosterols and other. Most of the compounds were reported for the first time for the species. Hydromethanolic extract of M. dalmatica was studied for in vitro antioxidant 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity. The inhibitory concentration (IC50) of extract was calculated to be 21.36 μg/mL. The received result shows high antioxidant potential of Micromeria dalmatica extract which provide scientific support for the use of the plant as herbs and spices

GC/MS Based Metabolite Profiling and Antioxidant Activity of Balkan and Bulgarian Endemic Plants

Balkan and Bulgarian endemic plants Viola rhodopaea Becker (Violaceae), Veronica rhodopaea (Velen.) Degen ex Stoj. & Stefanov (Plantaginaceae), Silene roemeri Friv. (Caryophyllaceae), Jasione bulgarica Stoj. & Stef and Campanula lanata Friv. (Campanulaceae) were examined. Metabolite profiles of methanolic extracts of studied species were analyzed by GC/MS and HPTLC. Total flavonoid and phenol contents were determined by aluminum chloride (AlCl3) and Folin-Ciocalteu’s reagent, respectively. Antioxidant potential of the extracts was assayed by DPPH test. Fatty acids and alcohols, phenolic and organic acids, flavonoid aglycones and glycosides, sterols and carbohydrates were identified. Jasione bulgarica and Viola rhodopaea extracts were determined to have the highest flavonoid and phenol content. Significant radical scavenging activity was estimated for the extracts of J. bulgarica, Veronica rhodopaea and Viola rhodopaea. The present information of chemical composition and antiradical potential of studied species are reported for the first  time

Morphometric studies of Sideritis scardica Grsb. and S. syriaca L. in their natural populations in Bulgaria

 The paper aimed at studying the morphometric variation in eight natural populations of two rare Sideritis species occurring in Bulgaria. Thirteen measured traits and four ratios were used to reveal the degree and distribution of variation. Most traits exhibited moderate to high variation and the most differentiating one was the length of the acumen. Cluster analysis and Principal component analysis revealed that the two taxa, S. scardica and S. syriaca are well distinguished but the population Chervenata stena, classified as S. scardica differed significantly from the remaining ones of the same species. Results of the morphometric study indicate the necessity of further studies for revealing the taxonomic relationships among the taxa

The neuroprotective effects of astaxanthin: therapeutic targets and clinical perspective

As the leading causes of human disability and mortality, neurological diseases affect millions of people worldwide and are on the rise. Although the general roles of several signaling pathways in the pathogenesis of neurodegenerative disorders have so far been identified, the exact pathophysiology of neuronal disorders and their effective treatments have not yet been precisely elucidated. This requires multi-target treatments, which should simultaneously attenuate neuronal inflammation, oxidative stress, and apoptosis. In this regard, astaxanthin (AST) has gained growing interest as a multi-target pharmacological agent against neurological disorders including Parkinson’s disease (PD), Alzheimer’s disease (AD), brain and spinal cord injuries, neuropathic pain (NP), aging, depression, and autism. The present review highlights the neuroprotective effects of AST mainly based on its anti-inflammatory, antioxidative, and anti-apoptotic properties that underlies its pharmacological mechanisms of action to tackle neurodegeneration. The need to develop novel AST delivery systems, including nanoformulations, targeted therapy, and beyond, is also consideredS

Composition of the essential oil of the Balkan endemic Thymus longedentatus (Degen & Urum.) Ronniger

The genus Thymus comprises more than 250 species of perennial herbaceous or fruticose plants, classified into 8 sections. A total of 66 species with numerous subspecies and varieties are listed in the Flora Europaea. All species are considered important medicinal and aromatic plants. Twenty species grow spontaneously in Bulgaria. Thymus longedentatus is distributed only in the eastern part of the Balkan Peninsula (Bulgaria, Greece and Turkey), inhabiting sunny rocky habitats, mainly on limestone. Samples of this taxon were collected in the region of the Eastern Rhodopes. The essential oils were extracted from dried plant material by hydrodistillation using a Clevenger-type system and analyzed by gas chromatography coupled with mass spectrometry. The essential oils were characterized by a lemon-like odor due to the prevalence of citral isomers: neral (27.5%) and geranial (30.2%). Additionally, eucalyptol (7.8%), trans-β-ocimene (7.5%), germacrene D (4.4%) and β-myrcene (3.7%) were among other more abundant constituents of the oil. The remaining compounds were present in smaller percentage. Twenty-eight compounds comprising 98.2% of the total GC-areas detected were identified in the oil

Essential oil composition of the Balkan endemic Thymus longedentatus (Degen & Urum.) Ronniger

The chemical composition of essential oil obtained from the aerial parts of the Balkan endemic species Thymus longedentatuswas studied by GC-MS. Twenty eight compounds, consisting 98.2% of the total components were detected in amounts exceeding 0.1%. The oil was characterized by relatively high concencentration of oxygentated monoterpenes (78.7%), among which citral isomers neral (27.5%) and geranial (30.3%) were the principal ones. In addition, 1,8-cineole (7.8%), trans-β-ocimene (7.5%), and β-myrcene (3.7%) were detected in significant ammounts. Germacrene D (4.4%) was found to be the main sesquiterpene in the essential oil

DNA Barcoding Study of Representative Thymus Species in Bulgaria

We present a study on the taxonomy of eleven Thymus species, belonging to two sections and occurring naturally in Bulgaria. Four DNA barcoding markers—matK, rbcL, trnH-psbA and ITS—were applied to discriminate the species and to reveal their phylogenetic relationships. The results showed that rbcL has the lowest discriminating power regarding the studied species, while the other markers yielded results fitting better to the existing taxonomic schemes based on morphological traits. However, even in the case of better performing markers, the results were not straightforward—morphologically distinct species belonging to different sections were grouped together, and closely related species appeared genetically distinct. The results are typical for taxonomically complex groups, such as the genus Thymus, characterized in Bulgaria with great diversity, high percentage of endemism and still requiring a full and comprehensive taxonomic study. The results are discussed in the light of unresolved taxonomic problems and application of DNA barcoding methods

Genetic diversity in high-mountain Thymus species in Bulgaria revealed by ISSR genetic markers

High mountain populations of the plant species possess particular interest from both evolutionary and conservation points of view. The mode of distribution, limited gene flow and severe environmental conditions act as evolutionary forces shaping the level and distribution of genetic diversity within and among populations. The paper reports results of a study on four populations of Thymus praecox aggr., including the taxa T. vandasii and T. jankae. Two populations are located in Rila Mts (Belmeken dam and Yastrebets), one – in Pirin (Vihren hut) and one – in the Rhodopes (Perelik hut).  Eleven inter simple sequence repeat (ISSR) markers were applied to document the genetic diversity within and among populations. The level and distribution of the diversity correspond to the values reported in other studies on the species of the genus Thymus and other species with similar life-history characteristics. The populations from Rila and Pirin were genetically closer to each other, while the population from the Rhodopes was the most differentiated. The results are discussed in the light of the conservation and sustainable use of the species resources. 

Sideritis elica, a New Species of Lamiaceae from Bulgaria, Revealed by Morphology and Molecular Phylogeny

Sideritis elica, from the Rhodope Mountains, is described as a species new to science. Results of a detailed morphological analysis were combined with the data of molecular analyses using DNA barcoding as an efficient tool for the genetic, taxonomic identification of plants. The combination of morphological features distinguishes the new species well: Its first three uppermost leaf pairs are significantly shorter and wider, the branchiness of the stems is much more frequent, the whole plant is much more lanate, and it looks almost white, as opposed to the other closed species of section Empedoclia, which look grayish green. The molecular analysis, based on the rbcL and trnH-psbA regions, supports the morphological data about the divergence of Sideritis scardica and Sideritis elica. The studied populations of the two taxa were found to be genetically distant (up to 6.8% polymorphism for trnH-psbA) with distinct population-specific nucleotide patterns, while no polymorphism in the DNA barcodes was detected within the Sideritis elica population. The results confirm the existence of a new species called Sideritis elica, which occurs in the nature reserve Chervenata Stena, located in the northern part of the Central Rhodope Mountains. There were only 12 individuals found in the locality, which underlines the necessity of conservation measures