Thomas Pacher

University of Veterinary Medicine in Vienna, Wien, Vienna, Austria

Are you Thomas Pacher?

Claim your profile

Publications (4)8.61 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study focuses on development of phytochemical methods for quality assessment of two West-African Cochlospermum species (Cochlospermum planchonii and Cochlospermum tinctorium) traditionally used for malaria treatment in Burkina Faso. Antimalarial activity of preparations from dried rhizomes (decoction) was tested against the chloroquine-sensitive Plasmodium strain 3D7 using the histidine-rich protein II (HRP2) drug susceptibility assay and compared with extract preparations using organic solvents of different polarity. Two main apocarotenoids were isolated from rhizomes of C. planchonii and unambiguously identified as dihydrocochloxanthine and cochloxanthine by spectroscopic methods. Comparative HPLC analyses of thirty-nine (39) samples from markets and from collections in natural habitats of both species showed a high variability in the accumulation of cochloxanthines and related carotenoids which were proven to be characteristic for rhizomes of both species and generally absent in leaves. Furthermore, content of total phenolics and antioxidant activities (DPPH and FRAP) as well as haemolytic activity of various extracts was tested. The HPLC method presented here was validated and provides a good separation of both compounds including 10 minor carotenoids. Extracts from both species and pure cochloxanthine offered pronounced antioxidant activities and weak haemolytic activity while, in contrast, dihydrocochloxanthine had a strong haemolytic effect at the highest concentration analysed. However, cochloxanthine as well as dihydrocochloxanthine showed erythroprotective effects against the haemolytic activity of the reference saponin. Moderate antiplasmodial activity between 16 and 63μg/ml were observed with all tested extracts, and lower IC50 values were obtained with pure dihydrocochloxanthine (IC50=6.9μg/ml), cochloxanthine (IC50=6.8μg/ml), the DCM fraction (IC50=2.4μg/ml) and the ethyl acetate fraction (IC50=11.5μg/ml) derived from a methanolic extract of C. planchonii. This study shows a major variability of carotenoid content and antiplasmodial activity of both C. planchonii and C. tinctorium. The high haemolytic activity of dihydrocochloxanthine (at 100μg/ml) should be considered as a selection criterion for choosing species phenotypes for treatment.
    Phytochemistry 09/2015; DOI:10.1016/j.phytochem.2015.09.006 · 2.55 Impact Factor
  • Source
    Loi Huynh · Thomas Pacher · Hung Tran · Johannes Novak ·
    [Show abstract] [Hide abstract]
    ABSTRACT: The volatile compounds from roots, stems, and leaves of Valeriana hardwickii and Valeriana officinalis were obtained by microdistillation and analyzed by gas chromatography–flame ionization detector (GC–FID) and gas chromatography–mass spectometry (GC–MS). In V. hardwickii, sixty-two, thirty-one, and thirty-one components were identified representing 90, 90, and 92% of total oil in the roots, stems, and leaves, respectively. The major compounds in the root oil were camphene (12.9%), bornyl acetate (17.6%), and maaliol (10.6%), while borneol (6.2%), trans-anethole (32.7%), and maaliol (6.3%) were the dominant components in the stem oil and camphene (12.6%), bornyl acetate (15.0%), and hexahydrofarnesyl acetone (9.2%) were the principal components in the leaf oil. In V. officinalis, bornyl acetate (7.8%), δ-elemene (9.3%), and valerenal (14.7%) were the dominant components in the roots among fifty-four compounds identified which accounted for 80% of the total oil. In contrast to V. hardwickii, the stems and roots of V. officinalis contained very small amounts of essential oil and consequently, only a few compounds were identified in the leaves and none could be detected in the stems.
    Journal of Essential Oil Research 10/2013; 25(5):409-414. DOI:10.1080/10412905.2013.828325 · 0.79 Impact Factor

  • Planta Medica 07/2012; 78(11). DOI:10.1055/s-0032-1321151 · 2.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cannabinoids derived from Cannabis sativa demonstrate neuroprotective properties in various cellular and animal models. Mitochondrial impairment and consecutive oxidative stress appear to be major molecular mechanisms of neurodegeneration. Therefore we studied some major cannabinoids, i.e. delta-9-tetrahydrocannabinolic acid (THCA), delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in mice mesencephalic cultures for their protective capacities against 1-methyl-4-phenyl pyridinium (MPP(+)) toxicity. MPP(+) is an established model compound in the research of parkinsonism that acts as a complex I inhibitor of the mitochondrial respiratory chain, resulting in excessive radical formation and cell degeneration. MPP(+) (10 μM) was administered for 48 h at the 9th DIV with or without concomitant cannabinoid treatment at concentrations ranging from 0.01 to 10 μM. All cannabinoids exhibited in vitro antioxidative action ranging from 669 ± 11.1 (THC), 16 ± 3.2 (THCA) to 356 ± 29.5 (CBD) μg Trolox (a vitamin E derivative)/mg substance in the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay. Cannabinoids were without effect on the morphology of dopaminergic cells stained by tyrosine hydroxylase (TH) immunoreaction. THC caused a dose-dependent increase of cell count up to 17.3% at 10 μM, whereas CBD only had an effect at highest concentrations (decrease of cell count by 10.1-20% at concentrations of 0.01-10 μM). It influenced the viability of the TH immunoreactive neurons significantly, whereas THCA exerts no influence on dopaminergic cell count. Exposure of cultures to 10 μM of MPP(+) for 48 h significantly decreased the number of TH immunoreactive neurons by 44.7%, and shrunken cell bodies and reduced neurite lengths could be observed. Concomitant treatment of cultures with cannabinoids rescued dopaminergic cells. Compared to MPP(+) treated cultures, THC counteracted toxic effects in a dose-dependent manner. THCA and CBD treatment at a concentration of 10 μM lead to significantly increased cell counts to 123% and 117%, respectively. Even though no significant preservation or recovery of neurite outgrowth to control values could be observed, our data show that cannabinoids THC and THCA protect dopaminergic neurons against MPP(+) induced cell death.
    Phytomedicine: international journal of phytotherapy and phytopharmacology 05/2012; 19(8-9):819-24. DOI:10.1016/j.phymed.2012.04.002 · 3.13 Impact Factor