SPME as a green sample-preparation technique for the monitoring of phytocannabinoids and endocannabinoids in complex matrices.

The endocannabinoid system (ECS), particularly its signaling pathways and ligands, has garnered considerable interest in recent years. Along with clinical work investigating the ECS' functions, including its role in the development of neurological and inflammatory conditions, much research has focused on developing analytical protocols enabling the precise monitoring of the levels and metabolism of the most potent ECS ligands: exogenous phytocannabinoids (PCs) and endogenous cannabinoids (endocannabinoids, ECs). Solid-phase microextraction (SPME) is an advanced, non-exhaustive sample-preparation technique that facilitates the precise and efficient isolation of trace amounts of analytes, thus making it appealing for the analysis of PCs and ECs in complex matrices of plant and animal/human origin. In this paper, we review recent forensic medicine and toxicological studies wherein SPME has been applied to monitor levels of PCs and ECs in complex matrices, determine their effects on organism physiology, and assess their role in the development of several diseases.

Evaluation of the Content of Micro- and Macroelements in Raspberries Depending on the Species, Cultivar Variety, and Geographical Environment.

The study aimed to analyse the macro- and micro-nutrient content in fruits of Rubus species (R. idaeus, R. occidentalis, R. chamaemorus, and R. chingii) and their varieties or hybrids from different regions. Flame atomic absorption spectrometry with deuterium background correction was used to measure concentrations of nine essential elements (K, Mg, Ca, Na, Mn, Fe, Cr, Zn, and Cu) and two heavy metals (Pb, Cd). Chemometric analysis compared the elemental profiles. Results confirmed raspberries as a rich source of macroelements (K, Mg) and microelements (Zn, Cu, Mn, Cr). The 'Bristol' cultivar consistently had the highest Fe content regardless of origin. Cr presence was observed in black raspberries for the first time. Previously observed relationships like K-Na antagonism and Cr/Zn, Fe/Zn synergism were found in raspberry fruits. Factor and cluster analyses demonstrated species and geographical diversity among Polish raspberry samples and clear separation of R. chingii from China. Raspberry fruits, due to the rich complex of polyphenols, are classified as superfoods, and the content of bioelements determined in them guarantees coverage of the daily requirement for macro- and microelements (RDA depending on the element: 5.6-204% for R. idaeus, 8.8-469, 4% for R. occidentalis, and 1.4-67.2% for R. chamaemorus), finally confirming this opinion.

Chemical Composition, Antioxidant and Anti-Enzymatic Activity of Golden Root (Rhodiola rosea L.) Commercial Samples.

The aim of the study was to compare the chemical composition of the water and hydromethanolic extracts of R. rosea commercial samples in relation to their biological activity. For this purpose, the HPLC method was used for the determination of eleven phenolic compounds and AAS/AES was used for determination of five essential elements. Moreover, the contents of total phenolic, total flavonoid, total phenolic acids, and L(+)-ascorbic acid were determined. The antioxidant activity was assessed by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS radical scavenging activity, ferric-reducing/antioxidant power (FRAP), and cupric-reducing antioxidant capacity (CUPRAC) assays, while the inhibitory activity against AChE and BChE enzymes was determined using Ellman's method. The results showed that the hydromethanolic extracts of R. rosea were richer in phenolic compounds and showed higher antioxidant and neurobiological activity than the water extracts. However, the water extracts gave higher contents of determined elements. Among the individual phenolic compounds gallic acid (2.33 mg/g DW) and sinapic acid (386.44 µg/g DW) had the highest concentrations in the hydromethanolic and water extracts, respectively. Moreover, the most extracts were observed to be more efficient on BChE. Moreover, the correlation analysis indicated a high positive relationship between chemical composition and biological activity in both extracts of R. rosea.

Trace Elements in Medicinal Plants Traditionally Used in the Treatment of Diabetes-Do They Have a Role in the Claimed Therapeutic Effect?

Background: Medicinal plants are often used in the treatment of diabetes mellitus, although knowledge about their mode of action and the substances responsible for their antidiabetic potential is limited. It is well known that some trace elements play a role in glucose metabolism and insulin action. Thus, a particular trace elements profile could be associated with the antidiabetic properties observed for some medicinal plants. Methods: Infusions (n = 102) prepared from commercial herbal products (n = 34) containing medicinal plants indicated for the treatment of diabetes (n = 16 different plant species) and infusions (n = 60) prepared from commercial herbal products (n = 20) containing medicinal plants without such an indication (n = 7 different plant species) were analyzed by ICP-MS for their trace elements content. Results: In both groups, results varied significantly between different medicinal plants and also between different origins (brands) of the same medicinal plant. Significant differences (p < 0.05) between the two groups were found for nine elements, including four trace elements related to glucose metabolism (Mn, B, V, and Se), but with lower median contents in the group of medicinal plants for diabetes. Conclusions: Except for some particular species (e.g., Myrtilli folium) in which the trace element Mn may play a role in its antidiabetic effect, globally, a direct association between the claimed antidiabetic properties and a specific trace element profile of the studied medicinal plants was not evident.

Quality assessment of Coffea arabica commercial samples.

A simple and reliable HPLC method was developed and validated for the quality consistency evaluation of Coffea arabica commercial samples through establishing chromatographic fingerprint and simultaneous determination of bioactive constituents. In the HPLC fingerprint, thirteen common peaks were selected to assess the similarities of coffee samples of different geographical origin. A similarity analysis showed values from 0.434 to 0.950 for the analyzed samples, while quantitation of selected bioactive compounds revealed the highest content of caffeine and the lowest of p-coumaric acid and theobromine in coffee samples. Since phenolic compounds and alkaloids are commonly recognized as natural antioxidants, the antioxidant activity of coffee extracts was also evaluated. The correlation analysis and principal component analysis indicated that the combination of HPLC fingerprint and quantitative analysis can be readily utilized as a quality assessment tool for coffee and other plant products.

Essential elements in synovial fluid samples obtained from patients living in Northern Poland.

Many people after 50 year of life suffer pains caused by osteoarthritis (OA), which make their life difficult and painful. There is a probable association of OA with the concentration of certain elements in body fluids. Therefore the aim of the study was to relate the level of essential elements in synovial fluids of patients with OA with the treatment using antiarthritic drugs. Thus, flame-atomic absorption spectrometry was used to determine the concentrations of Fe, Zn, Cu, Mn, Na, K, Ca and Mg in 74 samples of synovial fluids taken from 36 patients. Prior to analysis, the samples of synovial fluids were centrifuged and obtained supernatants were digested by microwave technique. It was found that the level of investigated essential elements was differentiated in patients suffering with OA. High correlation between Zn and K, Na and K, as well as Cu and Mn were revealed. Based on cluster analysis, synovial fluids of patients treated with Diprophos, Euflexxa and Synocrom, can be found almost in all clusters. ANOVA has shown that there is a significant difference between Na level in synovial fluids of patients treated with antirheumatic drugs, and those who were not treated. For the patients treated with Euflexxa, similar relations for Ca and K exist. Principal component analysis has shown that essential elements responsible for variability within studied samples, are Ca, Mg, Cu, Mn and Fe. However, there were no statistically significant relations between the studied macro- and microelements, and treatment using specific preparations.

Chemical Composition of Selected Commercial Herbal Remedies in Relation to Geographical Origin and Inter-Species Diversity.

Infusions prepared from medicinal herbs that are rich in flavonoids are very popular herbal remedies in societies of Eastern Europe. Therefore, the content of essential elements together with total flavonoids was analyzed in 65 commercially available samples of herbal drugs originating from Ukraine, Romania, and Belarus. The results showed that metallic elements (in mg kg-1 d.w.) have occurred in the following order: Fe > Mn > Zn > Cu, both for total and water-extractable species. Total flavonoids were determined in the range from 10.0 to 191.8 mg g-1 d.w. Several significant correlations have been found between the analytes, especially among water-extractable Fe with other metals, and total flavonoids and Fe, Zn, and Mn. Analysis of variance has revealed significant differences among studied samples due to their origin from different countries, especially between Belarussian samples and others. Differences owing to belonging to various plant species were also found, as it was noticed in the case of Polygoni aviculare herba in comparison with other botanical plant species. Moreover, multivariate statistical techniques, such as cluster analysis (CA) and principal component analysis (PCA) were used to gather herbal drugs based on similarity of chemical composition. CA grouped the samples into clusters with similar level of elements and total flavonoid contents, and PCA has indicated Hyperici herba, Tiliae flores, and Crataegi fructus as herbal remedies with close concentration of studied elements and flavonoids.

An Approach Based on HPLC-Fingerprint and Chemometrics to Quality Consistency Evaluation of Matricaria chamomilla L. Commercial Samples.

Chamomile has been used as an herbal medication since ancient times and is still popular because it contains various bioactive phytochemicals that could provide therapeutic effects. In this study, a simple and reliable HPLC method was developed to evaluate the quality consistency of nineteen chamomile samples through establishing a chromatographic fingerprint, quantification of phenolic compounds and determination of antioxidant activity. For fingerprint analysis, 12 peaks were selected as the common peaks to evaluate the similarities of commercial samples of chamomile obtained from different manufacturers. A similarity analysis was performed to assess the similarity/dissimilarity of chamomile samples where values varied from 0.868 to 0.990 what indicating that samples from different manufacturers were consistent. Additionally, simultaneous quantification of five phenolic acids (gallic, caffeic, syringic, p-coumaric, ferulic) and four flavonoids (rutin, myricetin, quercetin and keampferol) was performed to interpret the quality consistency. In quantitative analysis, the nine individual phenolic compounds showed good regression (r > 0.9975). Inter- and intra-day precisions for all analyzed compounds expressed as relative standard deviation (CV) ranged from 0.05% to 3.12%. Since flavonoids and other polyphenols are commonly recognized as natural antioxidants, the antioxidant activity of chamomile samples was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing/antioxidant power (FRAP) assay. Correlation analysis was used to assess the relationship between antioxidant activity and phenolic composition, and multivariate analysis (PCA and HCA) were applied to distinguish chamomile samples. Results shown in the study indicate high similarity of chamomile samples among them, widely spread in the market and commonly used by people as infusions or teas, as well as that there were no statistically significant differences among them, which in turn is a proof of high quality of commercially available samples of chamomile. The study indicated that the combination of chromatographic fingerprint and quantitative analysis can be readily utilized as a quality consistency method for chamomile and related medicinal preparations. Moreover, the applied strategy seems to be the most promising for the assessment of the investigated plant material.

ELECTROCHEMICAL FINGERPRINT STUDIES OF SELECTED MEDICINAL PLANTS RICH IN FLAVONOIDS.

The combination of a size-exclusion column (SEC) with electrochemical (voltammetric) detection at a boron-doped diamond electrode (BDDE) was applied for studying the correlations between electroactive Cu and Fe species with phenolic groups of flavonoids. For comparison with electrochemical results, SEC-HPLC-DAD detection was used. The studied plant material comprised of: Betula verrucosa Ehrh., Equisetun arvense L., Polygonum aviculare L., Viola tricolor L., Crataegus oxyacantha L., Sambucus nigra L. and Helichrysum arenarium (L.) Moench. Based upon the results, high negative correlation was found for the chromatographic peak currents at 45 min with the sum of Cu and Fe for the aqueous extracts of Sambucus, Crataegus and Betula species, and for the peak currents at 65 min of the aqueous extracts of Sambucus, Crataegus, Helichrysum and Betula botanical species. This behavior confirms that it is mainly the flavonoids with easily oxidizable phenolic groups which are strongly influenced by the presence of Cu and Fe. Moreover, the electrochemical profiles obtained thanks to the use of HPLC hyphenated with voltammetric detection can be potentially applied for fingerprint studies of the plant materials used in medicine.

Phytate, inorganic and total phosphorus and their relations to selected trace and major elements in herbal teas.

Phytate phosphorus in 59 samples of herbal teas was determined within the range of 2.44-36.90 microg/mL. Extraction yield was statistically higher in extracts from the leaves than that found in extracts from other plant organs. Average total level of trace elements determined in medicinal herbs follows the order: Fe > Mn > Zn > Cu, for major elements the order is: Ca > Mg > Na > K. Correlation analysis revealed that relations of phytate P to other phosphorus forms and metals were statistically insignificant. However, there were several characteristic relations of inorganic phosphorus to water-extractable K, Zn and total Zn. Furthermore, positive relations were found between total and water-extractable fractions of metals. Principal component analysis grouped the samples into separate clusters. It was also found that inorganic P, as well as water-extractable Zn and Na, had a huge impact on differentiation of the studied plant material.

Methods for extraction and determination of phenolic acids in medicinal plants: a review.

Phenolic acids constitute a group of potentially immunostimulating compounds. They occur in all medicinal plants and are widely used in phytotherapy and foods of plant origin. In recent years, phenolic acids have attracted much interest owing to their biological functions. This paper reviews the extraction and determination methods of phenolic acids in medicinal plants over the last 10 years. Although Soxhlet extraction and ultrasonic assisted extraction (UAE) are commonly used for the extraction of phenolic acids from plant materials, alternative techniques such as supercritical fluid extraction (SFE), and accelerated solvent extraction (ASE) can also be used. After extraction, phenolic acids are determined usually by liquid chromatography (LC) owing to the recent developments in this technique, especially when it is coupled with mass spectrometry (MS). Also detection systems are discussed, including UV-Vis, diode array, electrochemical and fluorimetric. Other popular techniques for the analysis of this group of secondary metabolites are gas chromatography coupled with mass spectrometry (GC-MS) and capillary electrophoresis (CE).

Water-extractable magnesium, manganese and copper in leaves and herbs of medicinal plants.

Since herbal teas, infusions and decoctions prepared from medicinal plants are popular remedies, it remains a topical question whether these herbal drugs can be treated as sources of essential elements for humans, who often use them in their everyday diet. Therefore, total and water-extractable contents of Mg, Mn and Cu were determined in 41 leaves originating from four botanical species of Plantago lanceolata, Arctostaphyllos uva-ursi, Rubus fruticosus and Betula sp., as well as in 33 samples of herbs represented by three species of Urtica dioica, Hypericum perforatum and Achillea millefolium. The highest level was determined in the case of Mg (in a range from 2.0 to 7.0 mg/g of dry mass [d.m.]), followed by Mn (from 50.0 to 1300.0 mg/kg d.m.), and lowest of all, Cu (from 3.5 to 19.5 mg/kg d.m.). Student's t-test showed that a statistically significant difference exists between samples originating from different plant species regarding the total content and water-extractable forms of Mg, Mn and Cu. By analysis of the relations between elements, it was observed that total level of Cu correlated with total levels of Mg and Mn, which indicates a synergistic interaction between the essential elements under study. With regard to Dietary Reference Intakes (DRIs), the leaves of Rubus fruticosus contained the highest amounts of a water-extractable bioavailable form of Mn, which guarantees from 160 to 200% of the daily requirement of Mn for women and men, respectively. On the other hand, the extract obtained from Urticae folium gave water-extractable Mg in the amount of 76 mg/500 mL, which constitutes about 20% of daily requirement. The plant material richest in water-extractable Cu was Hyperici herba, containing 154.5 microg/500 mL, or 17% of DRI for both sexes.

Water extractable forms of nitrogen, phosphorus and iron in fruits and seeds of medicinal plants.

Water extractable nitrate nitrogen, phosphate phosphorus and iron(II) in relation to the total amount of these essential elements were analyzed in fruits and seeds of medicinal plants. Water extraction was chosen to simulate in the analytical procedure the way plant samples are prepared and used by people. The total amounts of nitrogen, phosphorus and phosphate phosphorus were determined in the range of concentration of mg/g of dry plant weight, however, the total and extractable iron and nitrate nitrogen in mg/kg of dry weight. The nitrate nitrogen appeared to be crucial factor in the differentiation of plant samples and its level is characterized by very wide range of concentrations, from 10.15 mg/kg to 1377.03 mg/kg of dry plant weight; however, it didn't exceed the Acceptable Daily Intake (ADI). Statistically significant correlation between N and P, N and Fe, P-PO4 and P, P-PO4 and N was found, probably caused by their co-participation in metabolism of medicinal plant's fruits. Thanks to results of PCA, the fruits of medicinal plants can be differentiated by the concentration of nitrogen and phosphorus and their water extractable fractions. PCA grouped analyzed samples into three clusters with similar concentration of elements, which depended on the plant species, and in some cases also on the place of cultivation in distant regions of the country.

The application of artificial neural networks for the selection of key thermoanalytical parameters in medicinal plants analysis.

In the present study three thermoanalytical methods: differential thermal analysis (DTA), thermogravimetric analysis (TGA), and derivative thermogravimetric analysis (DTG) were used to investigate the thermal behavior of medicinal plant raw materials. In order to describe DTA curve, designation of the onset T(i), and peak T(p), temperatures was required. In TGA the mass losses Delta(m), and in DTG the temperature range of peak DeltaT, peak temperature T(p), and peak height h, were recorded. All parameters were read for three stages of the thermal decomposition of plant samples which resulted in obtaining eighteen thermal variables for each sample. Some similarities in the course of thermal decomposition of the same plant organs were recognized, but complexity of the obtained data made it very difficult to determine if they could differentiate between medicinal plant materials and which of them encode the most valuable information about the studied herbals. In order to confirm the existence of any relations between the chemical composition of medicinal plants and their thermal decomposition and to find out which thermoanalytical variables or decomposition stages can be considered as the most significant in terms of their evaluation, it was decided to apply fully connected feed-forward artificial neural networks (ANN). Two different training algorithms were used to address the problem: back-propagation of error and conjugate gradient descent. To verify the results two-dimensional (2-D) Kohonen self-organizing feature maps (SOFMs) were employed. Two alternative datasets of thirteen key variables discriminating plant samples have been proposed.

Thermoanalytical, chemical and principal component analysis of plant drugs.

Thermal decomposition and elemental content of commercial raw plant materials used in medicine-roots, rhizomes and bark originating from different medicinal plant species were analyzed. The thermal decomposition was performed using the derivatograph. The content of non-metallic (N, P, S, Cl, I and B) and metallic (Ca, Mg, Fe, Mn, Cu and Zn) elements was determined by spectrophotometric techniques after previous mineralization of samples. In order to obtain more clear classification of the analyzed plant materials principal component analysis (PCA) was applied. Interpretation of PCA results for three databases (thermoanalytical, non-metals and metals data sets) allows the statement that samples of roots, rhizomes and bark from the same plant species in majority of cases are characterized by similar elemental composition and similar course of their thermal decomposition. In this way the differences in general chemical composition of medicinal plants raw materials can be determined.

Speciation of Mg, Mn and Zn in extracts of medicinal plants.

Aqueous extracts of birch leaves ( folium Betulae), peppermint leaves ( folium Menthae), sage leaves ( folium Salviae), valerian roots ( radix Valerianae), and dandelion roots ( radix Taraxaci) are analysed for the three essential elements magnesium, manganese and zinc. Ultrafiltration reveals that 60-100% of these metals are present as low molecular weight species (<5000 Da). Further characterisation of the low molecular weight fraction is done by using size exclusion chromatography and different detectors, namely element specific AAS detection, diode array UV-VIS detection and electrochemical detection. The similarities and differences of the plant extracts are well reflected by the respective chromatograms, and typical plant constituents can be identified by their spectral and electrochemical properties (e.g. flavonoids in Betula). Mg and Mn species are selectively detected by AAS in closely neighbouring chromatographic regions for all five samples. However, there are significant differences between the samples investigated. In all cases a good correlation exists between detection of these metals (Mg, Mn) and pulsed amperometric detection (PAD), which is selective for carbohydrates. The respective molecular weight of carbohydrate species is in the range of approximately 300-600 Da. The distribution of zinc species (detectable only in the Betula extract) is totally different from that of Mg and Mn species. For zinc, many more species are detected, and there is no correlation to carbohydrates; instead (poly)phenols are involved in zinc complexation.