Essential oil compositions of subspecies of Scutellaria brevibracteata Stapf from Turkey

Evaluating Antibiofilm, Cytotoxic and Apoptotic Activities of Scutellaria brevibracteata subsp. brevibracteata Essential Oil

Essential oils have many important biological properties, including antibacterial and antibiofilm activities. These unique properties make, essential oils good alternatives to synthetic chemical drugs, which have many side effects. In this study, we aimed to determine the chemical composition and biological activity of the essential oil obtained from Scutellaria brevibracteata subsp. brevibracteata. Specifically, its antibiofilm activity against Pseudomonas aeruginosa PAO1 and Staphylococcus aureus ATCC 29213 biofilms using XTT assay. Cytotoxic and apoptotic properties of the essential oil were investigated in human lung cancer cells (A540 and H1299) using MTT assay, Annexin V-FITC and propidium iodide staining and q-PCR. Thirty-two different compounds were identified from the essential oil, of which elemol (20.42 %), γ-eudesmol (20.12 %) and β-eudesmol (14.85 %) were the main components. The essential oil was more effective against P. aeruginosa PAO1 biofilm (79 %) than S. aureus ATCC 29213 biofilm (27 %). The specific activity of the essential oil against P. aeruginosa biofilm may be related to its high terpene contents. In addition, the essential oil showed high cytotoxic activity towards A549 (IC50 9.09 μg/ml) and H1299 (IC50 55.04 μg/ml) cell lines, inducing apoptosis in these cancer cells. These results demonstrate the antibiofilm and anticancer activities of S. brevibracteata subsp. brevibracteata essential oil.

In Vitro Cultures of Scutellaria brevibracteata subsp. subvelutina as a Source of Bioactive Phenolic Metabolites

Some of the more than 350 Scutellaria species, such as S. baicalensis and S. lateriflora, have been used in traditional medicine and today play an important role in official phytotherapy. Other species have been less investigated, and their therapeutic potential is unknown. This is one of the few studies on Scutellaria brevibracteata subsp. subvelutina, and the first research of this species' in vitro cultures. The aim of this study was to establish an in vitro culture and analyse its phytochemical profile and biological activity. In the methanolic extracts from biomass cultured on six solid Murashige and Skoog (MS) medium variants supplemented with different combinations of 6-benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) in the range 0.5-3 mg/L analysed by HPLC, the presence of specific flavonoids (baicalein, baicalin, wogonin, wogonoside, scutellarin, chrysin), phenylpropanoid glycosides (verbascoside, isoverbascoside), and phenolic acids (p-hydroxybenzoic, caffeic, ferulic, m-coumaric acids) was confirmed. The dominant metabolites were wogonoside and verbascoside with the highest content of 346 and 457 mg/100 g DW, respectively. Thus, the extract with the highest content of bioactive metabolites was selected for further research and subjected to evaluation of antioxidant and antimicrobial potential. The extract exhibited good free radical scavenging activity (IC50 = 0.92 ± 0.01 mg/mL) and moderate reducing power and chelating activity. The brine shrimp lethality bioassay proved its lack of biotoxicity. Antimicrobial activity was tested against sixteen strains of Gram-positive and Gram-negative bacteria and fungi. The strongest growth inhibitory activity was observed against Trichophyton tonsurans.

A Background Search on the Potential Role of Scutellaria and Its Essential Oils

Scutellaria (Lamiaceae), which contains over 350 species, usually known as skullcaps, is found throughout Europe, the United States, and East Asia. In traditional Chinese medicine, several species are used to wipe out heat-evil and remove surface ills (TCM). The current study examines the ethnopharmacology, biological activity, and chemical substances associated with Scutellaria species. More than 295 chemicals, including flavonoids and diterpenes, have been identified. Scutellaria and its active principles have been shown in studies to have a wide range of pharmacological activities, including antioxidant, antimicrobial, antifeedant, phytotoxic, acaricidal toxicity, antibacterial, anti-inflammatory, and antianalgesic activities. Currently, effective monomeric compounds or active components from Scutellaria have been evaluated for pharmacological action in vivo and in vitro. More data facilitates applications and exploitation of novel medication development.

A novel study approach on Scutellaria altissima L. cultivated at the Ghirardi Botanic Garden (Lombardy, Italy)

Within an Open Science project, research was carried out to describe to the public of the Ghirardi Botanic Garden (BS, Lombardy, Italy) the invisible features of plants. This work is dedicated to Scutellaria altissima L. (Lamiaceae). Micromorphological, histochemical and phytochemical investigations were conducted on the vegetative and reproductive organs to correlate the structures involved in the emission of substances and their unique productivity. This work reports volatile organic compound (VOC) profiles of leaves and flowers and the composition of essential oil (EO) obtained from aerial parts of plants cultivated in Italy that have never been described before. Three morphotypes of glandular trichomes were observed: peltate, short-stalked capitate and long-stalked capitate. Peltate trichomes were the main producers of terpenes, short-stalked capitates of polysaccharides and long-stalked capitates of terpenes and polyphenols. The leaf VOC profile showed heterogeneous composition, with non-terpene derivatives as the major chemical class (71.04%), while monoterpene hydrocarbons represented almost the totality of the flower (99.73%). The leaf presented a higher number of total (37 versus 11) and exclusive (33 versus 7) compounds. (Z)-3-Hexenol acetate was most abundant in the leaf and (E)-β-ocimene in the flower. Four common compounds were detected: β-pinene, β-caryophyllene, γ-muurolene and germacrene-D. The EO contaied 21 compounds, dominated by β-caryophyllene, linalool and hexahydrofarnesyl acetone. This research allowed us to correlate morphotypes of the secretory structures with the production of secondary metabolites, with the aim of providing the public of the Ghirardi Botanic Garden with a dedicated iconographic approach, which accounts for olfactory perception linked to S. altissima.

Plant Natural Sources of the Endocannabinoid (E)-β-Caryophyllene: A Systematic Quantitative Analysis of Published Literature

(E)-β-caryophyllene (BCP) is a natural sesquiterpene hydrocarbon present in hundreds of plant species. BCP possesses several important pharmacological activities, ranging from pain treatment to neurological and metabolic disorders. These are mainly due to its ability to interact with the cannabinoid receptor 2 (CB2) and the complete lack of interaction with the brain CB1. A systematic analysis of plant species with essential oils containing a BCP percentage > 10% provided almost 300 entries with species belonging to 51 families. The essential oils were found to be extracted from 13 plant parts and samples originated from 56 countries worldwide. Statistical analyses included the evaluation of variability in BCP% and yield% as well as the statistical linkage between families, plant parts and countries of origin by cluster analysis. Identified species were also grouped according to their presence in the Belfrit list. The survey evidences the importance of essential oil yield evaluation in support of the chemical analysis. The results provide a comprehensive picture of the species with the highest BCP and yield percentages.

Scutellaria brevibracteata subsp. subvelutina (Rech.f.) Greuter & Burdet: morphological and phytochemical characterization

A micromorphological and phytochemical survey was performed on Scutellaria brevibracteata subsp. subvelutina cultivated in Italy. The indumentum of the vegetative and reproductive organs was investigated: peltate, short-, medium- and long-stalked capitates were described. Histochemistry evidenced similar results for peltates and long-stalked capitates, differences for short and medium capitates. For the first time, this work reported the characterization of volatile organic compounds from leaves and flowers, along with the first analysis of the essential oil obtained from the aerial parts of Italian samples. The floral profile resulted more complex than the foliar one, due to the higher number of the total compounds (40 vs 27) and of the exclusive constituents (24 vs 11). 16 common compounds were detected, with β-caryophyllene as the most abundant. The essential oil was characterized by 23 compounds, with β-caryophyllene dominating. The peltates, the medium and the long-stalked capitates resulted the producers of the investigated compounds.