Chemical composition and biological activity of essential oil of Teucrium scordium L. subsp. scordioides (Schreb.) Arcang. (Lamiaceae) from Sardinia Island (Italy)

The aim of this study is to demonstrate the antifungal, anti-inflammatory and anti-migratory potential of the essential oil of Teucrium scordium subsp. scordioides (Schreb.) Arcang, a plant widely used in traditional medicine in Sardinia. The oil was rich in germacrene D (25.1%), δ-cadinene (12.9%) and alloaromadendrene (11.3%). The yeast Cryptococcus neoformans and the dermatophytes Trichophyton rubrum, T. mentagrophytes var. interdigitale and Epidermophyton floccosum were the most susceptible fungi to the action of the oil. In lipopolysaccharide (LPS)-stimulated macrophages, the oil was able to decrease nitric oxide production by ca. 30% at 1.25 μL/mL, without affecting cell viability. In the scratch wound assay, it allowed for ca. 36% of wound closure after 18 h, thus showing anti-migratory properties. Overall, this study highlights the potential of this species to mitigate fungal infections associated with an inflammatory response. Furthermore, we also reported for the first time its anti-migratory capacity, thus suggesting anticancer properties.

Genotoxic and cytotoxic properties of two medical plants (Teucrium arduini L.and Teucrium flavum L.) in relation to their polyphenolic contents

A large number of species belonging to the genus Teucrium are used in pharmacy and traditional medicine for the treatment of different diseases. This study aimed to evaluate the polyphenolic composition as well as genotoxic and cytotoxic effects of methanolic extracts from T. arduini and T. flavum, two native species found in Montenegro. We determined the total phenolic and flavonoid contents of these plants using spectrophotometric methods; the qualitative content of polyphenolic compounds was investigated by high-performance liquid chromatography (HPLC). Genotoxicity in cultured human lymphocytes was measured in the cytokinesis-block micronucleus assay (CBMN) and comet assay in the range between 125 and 1000 μg/mL. Cytotoxicity was assessed by the MTT viability assay in normal human MRC-5 fibroblasts and MDA-MB-231 breast carcinoma cells. The content of total phenolics and flavonoids in T. arduini extract was higher than in T. flavum (200.35 mg GA/g vs. 171.08 mg GA/g; 96.32 mg RU/g vs. 78.14 mg RU/g). The polyphenolic composition of both extracts was qualitatively similar and eight phenol compounds were identified. The most commonly present phenol was caffeic acid and among four flavonoids, the most common was quercetin. Both plant extracts were genotoxic in both the CBMN and comet assays at concentrations of 250, 500 and 1000 μg/mL. After 72 h of exposure, the extracts of T. arduini and T. flavum were found to induce cytotoxicity in MRC-5 fibroblasts but not in MDA-MB-231 breast cancer cells. The results suggest that the constituents of both plant species are genotoxic and cytotoxic, therefore these extracts warrant additional evaluation to be safely applied in humans.

Complete chloroplast genomes of medicinally important Teucrium species and comparative analyses with related species from Lamiaceae

Teucrium is one of the most economically and ecologically important genera in the Lamiaceae family; however, it is currently the least well understood at the plastome level. In the current study, we sequenced the complete chloroplast (cp) genomes of T. stocksianum subsp. stenophyllum R.A.King (TSS), T. stocksianum subsp. stocksianum Boiss. (TS) and T. mascatense Boiss. (TM) through next-generation sequencing and compared them with the cp genomes of related species in Lamiaceae (Ajuga reptans L., Caryopteris mongholica Bunge, Lamium album L., Lamium galeobdolon (L.) Crantz, and Stachys byzantina K.Koch). The results revealed that the TSS, TS and TM cp genomes have sizes of 150,087, 150,076 and 150,499 bp, respectively. Similarly, the large single-copy (LSC) regions of TSS, TS and TM had sizes of 81,707, 81,682 and 82,075 bp, respectively. The gene contents and orders of these genomes were similar to those of other angiosperm species. However, various differences were observed at the inverted repeat (IR) junctions, and the extent of the IR expansion into ψrps19 was 58 bp, 23 bp and 61 bp in TSS, TS and TM, respectively. Similarly, in all genomes, the pbsA gene was present in the LSC at varying distances from the JLA (IRa-LSC) junction. Furthermore, 89, 72, and 92 repeats were identified in the TSS, TM and TS cp genomes, respectively. The highest number of simple sequence repeats was found in TSS (128), followed by TS (127) and TM (121). Pairwise alignments of the TSS cp genome with related cp genomes showed a high degree of synteny. However, relatively lower sequence identity was observed when various coding regions were compared to those of related cp genomes. The average pairwise divergence among the complete cp genomes showed that TSS was more divergent from TM (0.018) than from TS (0.006). The current study provides valuable genomic insight into the genus Teucrium and its subspecies that may be applied to a more comprehensive study.

Leaf extracts from Teucrium ramosissimum protect against DNA damage in human lymphoblast cell K562 and enhance antioxidant, antigenotoxic and antiproliferative activity

The in vitro antioxidant, antigenotoxic and antiproliferative activities of Teucrium ramosissimum extracts were investigated. The antioxidant activities of the tested extracts were evaluated through three chemical assays: The Cupric reducing antioxidant capacity, the reducing power and the ferric reducing antioxidant power. TR1 fraction from methanol extract showed the best antioxidant activity evaluated by the CUPRAC, RP and FRAP assays with TEAC values of 4.04, 1.77 and 1.48μM respectively compared to control. Yet, TR2 fraction exhibited the lowest antioxidant effect with a TEAC values of 1.97, 0.408 and 0.35μM respectively. All the tested extracts were also found to be effective in protecting plasmid DNA against the strand breakage induced by hydroxyl radicals. Furthermore, the effects of T. ramosissimum extracts on cell proliferation were also examined. The cytotoxic study revealed that methanol extract significantly inhibited the proliferation of K562 cells (IC50=150μg/mL). The antigenotoxic properties of these extracts were investigated by assessing the induction and inhibition of the genotoxicity induced by the direct-acting mutagen, hydrogen peroxide (H2O2), using an eukaryotic system; the "Comet assay." The results showed that all the extracts inhibited the genotoxicity induced by H2O2, and particularly TR2 fraction (96.99%) and methanol extract (96.64%). The present study has demonstrated that T. ramosissimum extract possess potent antioxidant, antiproliferative and antigenotoxic activities, which could be derived from compounds such as flavonoids and polyphenols.

neo-Clerodane diterpenoids from the aerial parts of Teucrium fruticans cultivated in China

Seven neo-clerodane diterpenes, teufruintins A-G (1-7), together with eight known compounds (8-15) were isolated from the CHCl3-soluble fraction of the aerial parts of Teucrium fruticans cultivated in China. The chemical structures of the isolated compounds were elucidated using different spectroscopic methods. All of the isolated diterpenes were evaluated for their cytotoxic activities on three human cancer cell lines, and for their ability to inhibit LPS-induced nitric oxide production in RAW 264.7 macrophages. None of the compounds displayed cytotoxic activities on the cancer cell lines, and only 15 showed weak NO inhibitory activity.

Effects of Teucrium polium spp. capitatum flavonoids on the lipid and carbohydrate metabolism in rats

CONTEXT

The main objective of the study was to investigate the biochemical mechanism of the antidiabetic activities of the dry extracts of Teucrium polium L. ssp. capitatum (L.) Arcangeli (Lamiaceae), from Republic of Macedonia, traditionally used to treat diabetes.

MATERIALS AND METHODS

Aerial parts of the plant were extracted in alcohol and freeze- or spray-dried, analyzed by high performance liquid chromatography (HPLC) and examined for insulinotropic effect in INS-1E cells in vitro. Their effect on blood glucose, lipids and carbohydrate-related enzymes was tested in normo- and streptozotocin hyperglycemic rats.

RESULTS AND DISCUSSION

HPLC analyses revealed several flavonoids: luteolin, apigenin, cirsiliol, diosmetin, cirsimaritin and cirsilineol as both free aglycons and glycosides. The extract and mixture of commercial flavonoids showed a distinct insulinotropic effect on INS-1E cells at 500 µg/ml. Intragastric (i.g.) administration of identical doses of the extract (125 mg/kg) in both normo- and hyperglycemic rats was more efficient in lowering the blood glucose than intraperitoneal injection (35% vs. 24% reduction) with highest effect (50% reduction) 8 h after administration. After 10 days of treatment, the magnitude of the effect was comparable to i.g. administration of 2.5 mg/kg of glibenclamide (38% reduction). No effect was seen on blood lipid profiles. In OGTT (oral glucose tolerance test), the extract lowered blood glucose levels by ~35%. The treatment reduced hepatic glycogen and tended to normalize the activity of gluconeogenic enzymes.

CONCLUSION

The results demonstrate that examined plant extracts contain flavonoids with insulinotropic and antihyperglycemic effects.

Chemical and genetic differentiation of Corsican subspecies of Teucrium flavum L

Corsica Island exhibited the particularity to display Teucrium flavum subsp. glaucum and subsp. flavum on the same territory with the same bioclimatic conditions. For the first time, volatile components extracted from aerial parts and genetic diversity of both Corsican T. flavum L. subspecies have been investigated through (i) the characterization of the chemical composition of essential oils and (ii) the study of three polymorphic genetic markers. Chemical analysis were performed using combination of capillary GC/RI, GC-MS after fractionation on column chromatography and the definition of the genetic structure were carried out using two chlororoplast markers (RPL32-TRNL and TRNL-F) and ribosomal nuclear markers (ITS region). According to statistical analysis, both subspecies were clearly distinguished by the chemical and genetic studies. Chemical compositions of oils from both subspecies were qualitatively similar but they differed by the normalized% abundances of their major components; oils from subsp. flavum were dominated by large amounts of hydrocarbon monoterpenes while oils obtained from subsp. glaucum were characterized by higher amounts of oxygenated compounds. The genetic analysis divided T. flavum L. populations in two groups, the first displayed subsp. glaucum populations and the latter group exhibited subsp. flavum populations. The presence of two groups is weakly consistent with chemical differentiation. These data suggest that the differences in the volatile composition of the two T. flavum subspecies depends more on the genetic background and less on environmental factors.

Anti-inflammatory and antiulcerogenic activities of leaf extracts and sesquiterpene from Teucrium ramosissimum (Lamiaceae)

Teucrium ramosissimum (Lamiaceae) is a native and endemic medicinal plant from South of Tunisia traditionally used for the treatment of many diseases. The anti-inflammatory and antiulcerogenic activities of sesquiterpene (β-eudesmol), chloroform, and ethyl acetate leaf extracts from T. ramosissimum were assayed. Macrophage phagocytic activity and lymphocyte proliferation in the absence and presence of mitogens (lipopolysaccharide [LPS] or lectin) were investigated. Depending on the concentrations, the extracts affect macrophage functions by modulating their lysosomal enzyme activity and nitric oxide (NO) release. For lymphocyte proliferation assay, tested extracts enhance significantly cell proliferation either with or without mitogen stimulation. These results suggest that leaf extracts from T. ramosissimum contain potent components such as flavonoids that may be potentially useful for modulating immune cell functions in physiological and pathological conditions. Antiulcerogenic activity was examined on rat ethanol-induced ulcerogenic model. Compared with control (cimetidine), leaf extracts from T. ramosissimum exert different protective effects against ethanol-induced ulcerogenesis.

Sesquiterpenoids from Teucrium ramosissimum

An antiplasmodial bioguided investigation of the EtOAc extract of the aerial parts of Teucrium ramosissimum led to isolation and identification of three sesquiterpenoids, teucmosin, 4alpha-hydroxy-homalomenol C, 1beta,4beta,7alpha-trihydroxy-8,9-eudesmene and two trinorsesquiterpenoids, 4beta-hydroxy-11,12,13-trinor-5-eudesmen-1,7-dione and 1beta,4beta-dihydroxy-11,12,13-trinor-8,9-eudesmen-7-one together with five known sesquiterpenoids, oplopanone, homalomenol C, oxo-T-cadinol, 1beta,4beta,6beta-trihydroxyeudesmane, 1beta,4beta,7alpha-trihydroxyeudesmane and four flavonoids, 5-hydroxy-7,4'-dimethoxyflavone, salvigenin, genkwanin and cirsimaritin. The structures and the relative stereochemistry were elucidated by extensive spectroscopic studies including 1D and 2D NMR and mass spectrometry (MS). Homalomenol C, 4beta-hydroxy-11,12,13-trinor-5-eudesmen-1,7-dione, oxo-T-cadinol and 1beta,4beta,6beta-trihydroxyeudesmane displayed a significant in vitro antiplasmodial activity against Plasmodium falciparum with IC(50) values ranging from 1.2 to 5.0 microg/ml. Furthermore, no cytotoxicity was observed upon the human diploid lung cell line MRC-5 for these compounds.

Pharmacological properties of the methanol extract from Mentha suaveolens Ehrh

The present study analyses the pharmacological activity in in vivo and in vitro models of the methanol extract obtained from the leaves and steams of Menta suaveolens Ehrh. This extract lacked toxicity, but exhibited a central nervous system depressant action; an analgesic effect in models of chemical and mechanical stimulation suggesting the induction of a peripheral analgesic response. The extract also exhibited an antiinflammatory action inhibiting the rat paw oedema induced by carrageenin. Moreover, the in vitro studies showed a significant diminution in the contractile effects induced by histamine, serotonin and acetylcholine.