[Anti-microbial activity of Rosmarinus officinalis and Zingiber officinale extracts on the species of the genus Candida and on Streptococcus pneumonia]. / Activité antimicrobienne des extraits de Rosmarinus officinalis et Zingiber officinale sur les espèces du genre Candida et sur Streptococcus pneumoniae.

OBJECTIVE: Identifying plant extracts that could be used as new treatments for candidiasis and Streptococcus pneumoniae infections. METHODS: In this work, we tested the activity of the ethanolic and methanolic extracts of Rosmarinus officinalis and Zingiber officinale on Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei and Streptococcus pneumoniae. The anti-microbial activity was first tested in vitro, then in vivo on mice and rats. RESULTS: The results showed that the methanolic extract of Rosmarinus officinalis and the ethanolic extract of Zingiber officinale were the most active on all the tested micro-organisms. The most sensitive species were Candida albicans, Candida krusei and Streptococcus pneumoniae. The in vivo anti-microbial activity reported that the ethanolic extract of Zingiber officinale was the most active on the three species. On the contrary, Candida glabrata and Candida tropicalis were more sensitive to the methanolic extract of Rosmarinus officinalis, but these species were considered as the most resistant yeasts. CONCLUSION: The ethanolic extract of Zingiber officinale was more active than fluconazole and amoxicillin on Candida albicans, Candida krusei and Streptococcus pneumoniae, so, it could be considered for treating infections by these species. Similarly, the methanolic extract of Rosmarinus officinalis could be effective for treating candidiasis by Candida glabrata and Candida tropicalis.

Trace elements in Labrador Tea (Rhododendron groenlandicum): How predominant sources to the plants impact the chemical composition of hot water extracts.

Labrador Tea (Rhododendron groenlandicum) has been an important food and medicinal plant to First Nations communities in North America for millenia, but little is known of its geochemical properties. Using plants from 10 sites in 4 provinces, including pristine and industrial regions, and employing the metal-free, ultraclean SWAMP laboratory facilities and procedures, we provide an estimate of the natural abundance of trace elements in the leaves, and the extent of their release during hot water extraction. Elements decrease in abundance in the order Mn > Al > Fe > Zn > Cu > Ni > V > Pb > La > Mo > Y > La > Tl > Cd > Th > Ag. The greatest concentrations of conservative, lithophile elements such as Al, La, Th and Y, are found in samples collected on lands reclaimed from open pit bitumen mines in northern Alberta, reflecting elevated inputs of atmospheric dusts. In contrast, micronutrients such as Cu and Zn are remarkably uniform which suggests that these are supplied almost exclusively by plant uptake via roots. Deionized, reverse osmosis water is more effective in removing some elements (e.g. Al, La, Y, Fe, Zn, Cd) whereas others are more readily extracted using groundwater (e.g. Cu, Ni, Pb); V behaves independently of water composition. In both types of water, the elements most readily extracted are plant micronutrients (Mn, Ni, Cu, and Zn) whereas those supplied primarily by dust exhibit much lower yields; Al shows behaviour intermediate between these two extremes. While element concentrations in the infusions increase with increasing concentrations in the leaves, the abundance of potentially toxic chalcophile elements such as Cd, Pb, Sb and Tl in the infusions are extremely low (ng/l). Plants from British Columbia, Ontario and Quebec provide evidence of atmospheric Pb contamination, yielding greater ratios of Pb/La compared to the samples from Alberta where crustal values are found. Given that this plant is common and found across the northern half of the continent, it shows great promise as a tool for biomonitoring of air quality. For consumers, Labrador Tea may represent an important dietary source of Mn.

Two new taraxerane-type triterpenes from Ledum palustre L.

Two new compounds, namely 6α-hydroxy-14-taraxerene-3,16,21-trione and 6α,26-dihydroxy-14-taraxerene-3,16,21-trione were isolated from the Ledum palustre L. Their chemical structures were confirmed after a combined analysis of IR, HR-ESI-TOFMS, 1D-NMR, and 2D-NMR. The compounds were evaluated for cell growth inhibitory activity against two cancer cell lines.

Chemical variability of Rhododendron tomentosum (Ledum palustre) essential oils and their pro-apoptotic effect on lymphocytes and rheumatoid arthritis synoviocytes.

Rhododendron tomentosum (Ledum palustre) is an aromatic plant traditionally used for alleviating rheumatic complaints which makes it a potential candidate for a natural drug in rheumatoid arthritis (RA) treatment. However, the effects of plants' volatiles on apoptosis of synovial fibroblasts and infiltrating leucocytes of RA synovia, have not been reported. Volatile fraction of R. tomentosum is chemically variable and chemotypes of the plants need to be defined if the oil is to be used for therapeutic purposes. In the presented work, cluster analysis of literature data enabled to define 10 chemotypes of the plant. The volatile fractions of known composition were then tested for bioactivity using a RA-specific in vitro models. Essential oils of two wild types (γ-terpineol and palustrol/ledol type) and one in vitro chemotype (ledene oxide type) were obtained by hydrodistillation and their bioactivity was tested in two in vitro models: I - peripheral blood lymphocytes of healthy volunteers and II - synoviocytes and immune cells isolated from synovia of RA patients. The influence of oils on blood lymphocytes' proliferation and apoptosis rates of synovia-derived cells was determined by flow cytometry. Dose-dependent inhibitory effect of the serial dilutions of R. tomentosum oils on proliferation rates of blood lymphocytes was found. At 1:400 dilutions, all the tested oils increased the number of necrotic cells in synovial fibroblasts from RA synovia. Additionally, increased proportions of late apoptotic cells were observed in leucocyte populations subjected to oils at 1:400 dilution.

Co-administration of a Rhododendron tomentosum extract does not affect mercury tissue concentrations and excretion rate in methylmercury-treated adult male rats.

OBJECTIVES: Consumption of fish/seafood is clearly linked to higher mercury levels in human tissue samples. However, correlations between methylmercury (MeHg) intakes calculated from dietary surveys and mercury body burdens are usually weak and can vary across populations. Different factors may affect MeHg absorption, distribution, metabolism and excretion, including co-exposures to phytochemicals and antibiotics, which were shown to affect mercury body burdens in rodents. Based on the observation that rat pups developmentally exposed to MeHg and a Rhododendron tomentosum extract (Labrador Tea) presented significantly higher blood mercury levels at weaning compared to pups exposed to MeHg alone, the modulation of MeHg toxicokinetics by Labrador Tea was further investigated in adult rats. RESULTS: Total mercury levels were quantified in the blood, liver, kidney and feces of adult male rats exposed to MeHg (1.2 mg/kg bodyweight/day, for 3 weeks) administered either alone or in combination with Labrador Tea (100 mg/kg bodyweight/day) or with an antibiotics cocktail (to inhibit MeHg demethylation by gut bacteria). While the reduced fecal excretion and higher blood mercury levels expected from antibiotics-treated rats were observed, mercury levels in samples from Labrador Tea-treated rats were not significantly different from those measured in samples from rats exposed to MeHg alone.

A novel proof of concept for capturing the diversity of endophytic fungi preserved in herbarium specimens.

Herbarium specimens represent important records of morphological and genetic diversity of plants that inform questions relevant to global change, including species distributions, phenology and functional traits. It is increasingly appreciated that plant microbiomes can influence these aspects of plant biology, but little is known regarding the historic distribution of microbes associated with plants collected in the pre-molecular age. If microbiomes can be observed reliably in herbarium specimens, researchers will gain a new lens with which to examine microbial ecology, evolution, species interactions. Here, we describe a method for accessing historical plant microbiomes from preserved herbarium specimens, providing a proof of concept using two plant taxa from the imperiled boreal biome (Andromeda polifolia and Ledum palustre subsp. groenlandicum, Ericaceae). We focus on fungal endophytes, which occur within symptomless plant tissues such as leaves. Through a three-part approach (i.e. culturing, cloning and next-generation amplicon sequencing via the Illumina MiSeq platform, with extensive controls), we examined endophyte communities in dried, pressed leaves that had been processed as regular herbarium specimens and stored at room temperature in a herbarium for four years. We retrieved only one endophyte in culture, but cloning and especially the MiSeq analysis revealed a rich community of foliar endophytes. The phylogenetic distribution and diversity of endophyte assemblages, especially among the Ascomycota, resemble endophyte communities from fresh plants collected in the boreal biome. We could distinguish communities of endophytes in each plant species and differentiate likely endophytes from fungi that could be surface contaminants. Taxa found by cloning were observed in the larger MiSeq dataset, but species richness was greater when subsets of the same tissues were evaluated with the MiSeq approach. Our findings provide a proof of concept for capturing endophyte DNA from herbarium specimens, supporting the importance of herbarium records as roadmaps for understanding the dynamics of plant-associated microbial biodiversity in the Anthropocene.This article is part of the theme issue 'Biological collections for understanding biodiversity in the Anthropocene'.

Simultaneous Determination of Aesculin, Aesculetin, Fraxetin, Fraxin and Polydatin in Beagle Dog Plasma by UPLC-ESI-MS/MS and Its Application in a Pharmacokinetic Study after Oral Administration Extracts of Ledum palustre L.

A rapid, simple and sensitive ultra-performance liquid chromatography-electrospray-ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed and validated for the simultaneous determination of aesculin, aesculetin, fraxetin, fraxin and polydatin in beagle dog plasma for the first time. Plasma samples were pretreated by protein precipitation with methanol. Chromatographic separation was performed on an Acquity UPLC HSS T3 C18 column (2.1 mm × 100 mm, 1.8 µm) with gradient elution at a flow rate of 0.4 mL/min, using a mobile phase consisting of 0.1% formic acid (A) and acetonitrile (B). The analytes and IS were detected by multiple reaction monitoring (MRM) via negative ion mode with ion transitions of m/z 339.1⁻m/z 176.8 for aesculin, m/z 176.8⁻m/z 88.9 for aesculetin, m/z 206.8⁻m/z 192.1 for fraxetin, m/z 369.1⁻m/z 206.9 for fraxin, m/z 389.1⁻m/z 227.0 for polydatin and m/z 415.2⁻m/z 295.1 for puerarin. This method was validated according to the FDA guidelines and the results met the requirements of analysis. The calibration curves of analytes were linear with correlation coefficients more than 0.9980. The intra- and inter-day precisions were less than 15% and the accuracy was within ±15%. The maximum plasma concentration (Cmax) of aesculin, aesculetin, fraxetin, fraxin and polydatin was 46.75 ± 7.46, 209.9 ± 57.65, 369.7 ± 48.87, 67.04 ± 12.09 and 47.14 ± 12.04 ng/mL, respectively. The time to reach the maximum plasma concentration (Tmax) was 1.32 ± 0.38 h for aesculin, 1.03 ± 0.27 h for aesculetin, 0.94 ± 0.23 h for fraxetin, 0.83 ± 0.18 h for fraxin and 1.15 ± 0.15 h for polydatin. The results indicated that the absorption of aesculin might be slow in beagle dog plasma. This method was successfully applied for pharmacokinetics in beagle dog plasma after oral administration of the extracts of Ledum palustre L. at a dosage of 0.27 g/kg.

Investigation of the enhancement effect of the natural transdermal permeation enhancers from Ledum palustre L. var. angustum N. Busch: Mechanistic insight based on interaction among drug, enhancers and skin.

It has been reported that natural transdermal permeation enhancers (TPEs) are superior in safety compared with synthetic TPEs. The essential oil (EO) of Ledum palustre L. var. angustum N. Busch had a strong enhancement effect on drug skin permeation based on previous studies. However, their enhancement mechanisms and safety were still unclear. The composition of the EO was determined using GC-MS. By using donepezil (DNP) as a model drug, the enhancement effect of the constituents of the EO and the EO were evaluated by in vitro skin permeation test. Confocal laser scanning microscopy (CLSM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and molecular docking were used to investigate the interaction among drug, enhancers and skin. Skin retention amount, apparent partition coefficient (K') and molecular simulation were used to reflect the effect of the enhancers on drug partition into skin. The skin irritation potential was evaluated using in vivo skin erythema analysis. The results showed that the main constituents of the EO were sabinene (SA), 4-terpineol (TE), p-cymene (CY) and cuminaldehyde (CU). CU was the main active constituent of the EO, which facilitated skin permeation of DNP. CU improved the skin permeation of DNP by increasing the mobility of the stratum corneum (SC) intercellular lipids, decreasing the interaction between DNP and the SC intercellular lipids, and improving the partition of DNP into the SC layer. Besides the superior enhancement effect, CU also showed a lower skin irritation potential compared with the EO. This work gave us some enlightenment that the effectiveness and safety of the natural transdermal permeation enhancers could be improved by understanding their composition and the enhancement mechanisms.

New 1,3-benzodioxin-4-ones from Synnemapestaloides ericacearum sp. nov., a biosynthetic link to remarkable compounds within the Xylariales.

Surveys of foliar endophytes from the Acadian forest region over the past three decades have identified numerous phylogenetically diverse fungi producing natural products toxic to forest pests and diseases. The life histories of some conifer endophytes can be restricted to plant foliage or may include saprotrophic phases on other plants tissues or even alternate hosts. Considering the potentially broad host preferences of conifer endophytes we explored fungi isolated from understory species and their metabolites as part of an ongoing investigation of fungal biodiversity from the Acadian forest. We report a hitherto unidentified Xylariomycetidae species isolated from symptomatic Labrador tea (Rhododendron groenlandicum) leaves and mountain laurel (Kalmia latifolia) collected in coastal southern New Brunswick, Canada. Morphological and phylogenetic evidence demonstrated the unknown species was a novel Synnemapestaloides (Sporocadaceae) species, described here as Syn. ericacearum. A preliminary screening assay indicated that the culture filtrate extract of the new species was potently antifungal towards the biotrophic pathogen Microbotryum violaceum, warranting an investigation of its natural products. Two natural products possessing a rare 1,3-benzodioxin-4-one scaffold, synnemadoxins A-B (1-2), and their postulated precursor, synnemadiacid A (3), were characterized as new structures and assessed for antimicrobial activity. All isolated compounds elicited in vitro inhibitory antifungal activity towards M. violaceum at 2.3 µg mL-1 and moderate antibiotic activity. Further, the characterization of synnemadoxins A-B provided a perspective on the biosynthesis of some related 1,3-benzodioxin-4-ones produced by other fungi within the Xylariales.

Therapeutic effect of Northern Labrador tea extracts for acute myeloid leukemia.

Acute myeloid leukemia (AML) is an aggressive hematological malignancy that is one of the more common pediatric malignancies in addition to occurring with high incidence in the aging population. Unfortunately, these patient groups are quite sensitive to toxicity from chemotherapy. Northern Labrador tea, or Rhododendron tomentosum Harmaja (a.k.a. Ledum palustre subsp. decumbens) or "tundra tea," is a noteworthy medicinal plant used by indigenous peoples in Alaska, Canada, and Greenland to treat a diversity of ailments. However, laboratory investigations of Northern Labrador tea, and other Labrador tea family members, as botanical sources for anticancer compounds have been limited. Utilizing an AML cell line in both in vitro and in vivo studies, as well as in vitro studies using primary human AML patient samples, this study demonstrated for the first time that Northern Labrador tea extracts can exert anti-AML activity and that this may be attributed to ursolic acid as a constituent component. Therefore, this medicinal herb holds the potential to serve as a source for further drug discovery efforts to isolate novel anti-AML compounds.

Ecological responses to forest age, habitat, and host vary by mycorrhizal type in boreal peatlands.

Despite covering vast areas of boreal North America, the ecological factors structuring mycorrhizal fungal communities in peatland forests are relatively poorly understood. To assess how these communities vary by age (younger vs. mature), habitat (fen vs. bog), and host (conifer trees vs. ericaceous shrub), we sampled the roots of two canopy trees (Larix laricina and Picea mariana) and an ericaceous shrub (Ledum groenlandicum) at four sites in northern Minnesota, USA. To characterize the specific influence of host co-occurrence on mycorrhizal fungal community structure, we also conducted a greenhouse bioassay using the same three hosts. Root samples were assessed using Illumina-based high-throughput sequencing (HTS) of the ITS1 rRNA gene region. As expected, we found that the relative abundance of ectomycorrhizal fungi was high on both Larix and Picea, whereas ericoid mycorrhizal fungi had high relative abundance only on Ledum. Ericoid mycorrhizal fungal richness was significantly higher in mature forests, in bogs, and on Ledum hosts, while ectomycorrhizal fungal richness did not differ significantly across any of these three variables. In terms of community composition, ericoid mycorrhizal fungi were more strongly influenced by host while ectomycorrhizal fungi were more influenced by habitat. In the greenhouse bioassay, the presence of Ledum had consistently stronger effects on the composition of ectomycorrhizal, ericoid, and ericoid-ectomycorrhizal fungal communities than either Larix or Picea. Collectively, these results suggest that partitioning HTS-based datasets by mycorrhizal type in boreal peatland forests is important, as their responses to rapidly changing environmental conditions are not likely to be uniform.

Interspecific differences in foliar 1 PAHs load between Scots pine, birch, and wild rosemary from three polish peat bogs.

Pine needles are one of the most commonly used bioindicators of polycyclic aromatic hydrocarbons (PAHs) in the environment. Therefore, the main objective of the current research was the assessment of PAHs accumulation potential of Scots pine (Pinus sylvestris L.) needles in comparison to wild rosemary (Rhododendron tomentosum Harmaja) and birch (Betula spp.) leaves. Our study was carried out on three peat bogs subjected to different degree of anthropopression, which gave us also the opportunity to identify local emission sources. Pine needles had the lowest accumulation potential from all the studied species. The highest accumulation potential, and hence carcinogenic potential, was observed for wild rosemary leaves. As far as emission sources are concerned, the most pronounced influence on atmospheric PAHs loads had traditional charcoal production, resulting in great influx of heavy PAHs. Observed seasonal changes in PAHs concentrations followed the pattern of winter increase, caused mainly by heating season, and summer decrease, caused mainly by volatilization of light PAHs.

Rhododendron groenlandicum (Labrador tea), an antidiabetic plant from the traditional pharmacopoeia of the Canadian Eastern James Bay Cree, improves renal integrity in the diet-induced obese mouse model.

Content Our team has identified Labrador tea [Rhododendron groenlandicum L. (Ericaceae)] as a potential antidiabetic plant from the traditional pharmacopoeia of the Eastern James Bay Cree. In a previous in vivo study, the plant extract was tested in a high-fat diet (HFD)-induced obese model using C57BL/6 mice and it improved glycaemia, insulinaemia and glucose tolerance. Objective In the present study, we assessed the plant's potential renoprotective effects. Materials and methods Rhododendron groenlandicum was administered at 250 mg/kg/d to mice fed HFD for 8 weeks to induce obesity and mild diabetes. Histological (periodic acid-Schiff (PAS), Masson and Oil Red O staining), immunohistochemical (IHC) and biochemical parameters were assessed to evaluate the renoprotective potential of R. groenlandicum treatment for an additional 8 weeks. Results Microalbuminuria and renal fibrosis were developed in HFD-fed mice. Meanwhile, there was a tendency for R. groenlandicum to improve microalbuminuria, with the values of albumin-creatinine ratio (ACR) reducing from 0.69 to 0.53. Renal fibrosis value was originally 4.85 arbitrary units (AU) in HFD-fed mice, dropped to 3.27 AU after receiving R. groenlandicum treatment. Rhododendron groenlandicum reduced renal steatosis by nearly one-half, whereas the expression of Bcl-2-modifying factor (BMF) diminished from 13.96 AU to 9.43 AU. Discussion and conclusions Taken altogether, the results suggest that R. groenlandicum treatment can improve renal function impaired by HFD.

Labrador tea (Rhododendron groenlandicum) attenuates insulin resistance in a diet-induced obesity mouse model.

PURPOSE: Using a diet-induced obesity (DIO) mouse model, we investigated the antidiabetic effect of Labrador tea [Rhododendron groenlandicum (Oeder) Kron and Judd], a beverage and medicinal tea used by the Cree Nations of northern Quebec. METHODS: C57BL6 mice were divided into five groups and given standard chow (~4 % of lipids) or high-fat diet (~35 % of lipids) for 8 weeks until they became obese and insulin resistant. Treatment began by adding the plant extract at three doses (125, 250 and 500 mg/kg) to the high-fat diet for another 8 weeks. At the end of the study, insulin-sensitive tissues (liver, skeletal muscle, adipose tissue) were collected to investigate the plant's molecular mechanisms. RESULTS: Labrador tea significantly reduced blood glucose (13 %), the response to an oral glucose tolerance test (18.2 %) and plasma insulin (65 %) while preventing hepatic steatosis (42 % reduction in hepatic triglyceride levels) in DIO mice. It stimulated insulin-dependent Akt pathway (55 %) and increased the expression of GLUT4 (53 %) in skeletal muscle. In the liver, Labrador tea stimulated the insulin-dependent Akt and the insulin-independent AMP-activated protein kinase pathways. The improvement in hepatic steatosis observed in DIO-treated mice was associated with a reduction in inflammation (through the IKK α/ß) and a decrease in the hepatic content of SREBP-1 (39 %). CONCLUSIONS: Labrador tea exerts potential antidiabetic action by improving insulin sensitivity and mitigating high-fat diet-induced obesity and hyperglycemia. They validate the safety and efficacy of this plant, a promising candidate for culturally relevant complementary treatment in Cree diabetics.

A combination of (+)-catechin and (-)-epicatechin underlies the in vitro adipogenic action of Labrador tea (Rhododendron groenlandicum), an antidiabetic medicinal plant of the Eastern James Bay Cree pharmacopeia.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhododendron groenlandicum (Oeder) Kron & Judd (Labrador tea) was identified as an antidiabetic plant through an ethnobotanical study carried out with the close collaboration of Cree nations of northern Quebec in Canada. OBJECTIVES: In a previous study the plant showed glitazone-like activity in a 3T3-L1 adipogenesis bioassay. The current study sought to identify the active compounds responsible for this potential antidiabetic activity using bioassay guided fractionation based upon an in vitro assay that measures the increase of triglycerides content in 3T3-L1 adipocyte. MATERIALS AND METHODS: Isolation and identification of the crude extract's active constituents was carried out. The 80% ethanol extract was fractionated using silica gel column chromatography. Preparative HPLC was then used to isolate the constituents. The identity of the isolated compounds was confirmed by UV and mass spectrometry. RESULTS: Nine chemically distinct fractions were obtained and the adipogenic activity was found in fraction 5 (RGE-5). Quercetins, (+)-catechin and (-)-epicatechin were detected and isolated from this fraction. While (+)-catechin and (-)-epicatechin stimulated adipogenesis (238±26% and 187±21% relative to vehicle control respectively) at concentrations equivalent to their concentrations in the active fraction RGE-5, none afforded biological activity similar to RGE-5 or the plant's crude extract when used alone. When cells were incubated with a mixture of the two compounds, the adipogenic activity was close to that of the crude extract (280.7±27.8 vs 311± 30%). CONCLUSION: Results demonstrate that the mixture of (+)-catechin and (-)-epicatechin is responsible for the adipogenic activity of Labrador tea. This brings further evidence for the antidiabetic potential of R. groenlandicum and provides new opportunities to profile active principles in biological fluids or in traditional preparations.

Wild Sicilian rosemary: phytochemical and morphological screening and antioxidant activity evaluation of extracts and essential oils.

To identify the best biotypes, an extensive survey of Sicilian wild rosemary was carried out by collecting 57 samples from various sites, followed by taxonomic characterization from an agronomic perspective. All the biotypes collected were classified as Rosmarinus officinalis L. A cluster analysis based on the morphological characteristics of the plants allowed the division of the biotypes into seven main groups, although the characteristics examined were found to be highly similar and not area-dependent. Moreover, all samples were analyzed for their phytochemical content, applying an extraction protocol to obtain the nonvolatile components and hydrodistillation to collect the essential oils for the volatile components. The extracts were characterized by LC-UV-DAD/ESI-MS, and the essential oils by GC-FID and GC/MS analyses. In the nonvolatile fractions, 18 components were identified, namely, 13 flavones, two organic acids, and three diterpenes. In the volatile fractions, a total of 82 components were found, with as predominant components α-pinene and camphene among the monoterpene hydrocarbons and 1,8-cineole, camphor, borneol, and verbenone among the oxygenated monoterpenes. Cluster analyses were carried out on both phytochemical profiles, allowing the separation of the rosemary samples into different chemical groups. Finally, the total phenol content and the antioxidant activity of the essential oils and extracts were determined with the Folin-Ciocalteu (FC) colorimetric assay, the UV radiation-induced peroxidation in liposomal membranes (UV-IP test), and the scavenging activity of the superoxide radical (O$\rm{{_{2}^{{^\cdot} -}}}$). The present study confirmed that the essential oils and organic extracts of the Sicilian rosemary samples analyzed showed a considerable antioxidant/free radical-scavenging activity.

Labrador tea--the aromatic beverage and spice: a review of origin, processing and safety.

Labrador tea is a name for the dried leaves of Rhododendron groenlandicum, R. tomentosum or R. neoglandulosum (family Ericaceae, previously genus Ledum) as well as for the beverage native to North America, which is made from them. The above species are rich in the essential oil, which gives a conifer aroma to the tisane. Labrador tea is a valuable source of ascorbic acid, with tonic, improving digestion and relaxing activity. However, this beverage should not be drunk more than once daily because of the ledol and grayanotoxin toxicity. The common recipe for making Labrador tea is to add one teaspoonful of dried leaves to one cup of boiling water and to brew for 5 min. It is often sweetened or enriched with other flavors. Additionally, Labrador tea dried leaves are used to spice meat, soups, sauces, salads, beer, cakes and other dishes. In agriculture, its insecticidal properties can be useful for controlling pests.