HPLC-DAD and HPLC-ESI-MS analyses of Tiliae flos and its preparations.

In the present study extensive HPLC-DAD, HPLC-ESI-MS and NMR analyses were undertaken in the aqueous preparations (decoctions, infusions) and tinctures of Tilia platyphyllos Scop inflorescences. The aim of this work was to examine in depth the qualitative and quantitative profile of the investigated preparations, which find until today wide applications in pharmaceutical and cosmetic industry, and to propose a validated method for their quality control. An HPLC-DAD-ESI-MS method was developed and optimised for the quantitative determination of the constituents. Marker constituents of Tiliae flos are the flavonoids, while the volatile content is also used for the quality control. However, the analyses of the non-volatile fraction gave complex chromatographic fingerprints containing simple phenolics and low molecular weight procyanidins. The use of different HPLC columns permitted a good separation of the constituents and enabled their quantitation, while HPLC-MS analyses permitted the detection of procyanidin oligomers. Overall, 31 constituents were detected and identified. Extensive preparative chromatographic investigations and 2D-NMR analyses allowed the characterisation of procyanidins as epicatechin derivatives. Finally, the HPLC method was validated and complied with ICH guidelines. This is the first report of detailed analysis of the chemical composition of Tiliae flos.

Combined HPLC-DAD-MS, HPLC-MS(n) and NMR spectroscopy for quality control of plant extracts: the case of a commercial blend sold as dietary supplement.

The efficiency of 1D and 2D NMR spectroscopy along with HPLC-DAD-MS analyses in characterising the content of a dietary supplement is demonstrated. Experiments directly performed on a lyophilised sample of a commercial product gave details on the quality control of the product. The lack of the marker constituents of some of the declared plant species (Crataegus oxyacantha, Olea europea, Capsella bursa-pastoris and Fumaria officinalis) and the presence of banned adulterants, responsible for the strong antihypertensive effect of the supplement were established. The analyses proved the presence of indole alkaloids belonging to the group of Rauwolfia sp., such as ajmaline, reserpine and yohimbine. Quantitative HPLC analysis showed that the content of reserpine in the product was in the therapeutic range and therefore responsible for the collapses of the patients.

Uric acid induces caspase-1 activation, IL-1ß secretion and P2X7 receptor dependent proliferation in primary human lymphocytes.

BACKGROUND: Urate through Nacht Domain, Leucine-Rich Repeat, and pyrin domain-containing protein 3 (NALP3) dependent caspase-1 activation stimulates macrophages to secrete inteleukin-1ß (IL-1ß). Purinergic receptor P2X7 plays a role in the urate induced NALP3 activation. Urate also enhances adaptive immunity indirectly through its effect on antigen presenting cells. In this study, the direct effect of urate on primary human lymphocytes was evaluated. METHODS: Lymphocytes were cultured with or without monosodium urate crystals in the presence or not of a P2X7 inhibitor. Caspase-1 activity was assessed colorimetrically in cell lysates and IL-1ß was measured in supernatants with ELISA. Whole lymphocyte viability and proliferation, as well as T-cell proliferation were assessed by means of 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay and of flow cytometry respectively. RESULTS: Urate induced caspase-1 activation and IL-1ß release by lymphocytes. It also induced proliferation of whole lymphocytes and T-cells as well. P2X7 inhibitor abrogated lymphocyte proliferation. CONCLUSIONS: Urate, a well defined danger signal, stimulates directly human lymphocytes in a P2X7 dependent way. The subsequent IL-1ß secretion could enhance inflammation, whereas expansion of lymphocyte clones could facilitate a subsequent adaptive immune response.

Analysis of the essential oil of Origanum dubium growing wild in Cyprus. Investigation of its antioxidant capacity and antimicrobial activity.

The volatile composition of Origanum dubium in two different maturation stages has been studied. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus, and their analyses were performed by GC and GC-MS. Identification of the components was made by comparison of mass spectra and retention indices with literature records and by co-chromatography with authentic compounds. Carvacrol was shown to be the main constituent. The essential oils were evaluated for antimicrobial activity and proved to be active against all tested microorganisms. Furthermore, their potential antioxidant activity was investigated and found to be significant in scavenging O2-. The samples were further evaluated for inhibition of soybean lipoxygenase LOX and showed high inhibitory activity.

Effect of nitrogen concentration of the nutrient solution on the volatile constituents of leaves of Salvia fruticosa Mill. in solution culture.

Essential oils from hydroponically cultivated Salvia fruticosa were analyzed by GC-MS techniques. Three different levels of nitrogen (100, 150, and 200 mg/L) were used in the nutrient solution for the cultivation, using the nutrient film technique. A total of 79 compounds were identified, and qualitative and quantitative differences have been observed between the samples collected at full bloom (flowering stage) and at the end of the seed formation stage. 1,8-Cineole, beta-caryophyllene, and viridiflorol were the predominant constituents in most cases. 13-epi-Manool was identified by using GC parameters and mass spectrum fragmentation pattern, whereas labd-7,13-dien-15-ol, a labdane type diterpene, was identified for the first time in the genus Salvia, using GC parameters and an authentic sample. The results obtained from GC-MS analyses were submitted to chemometric analysis.