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The in vitro antiplasmodial activities of 14 plant species traditionally used in Central America for the treatment of malaria or fever were evaluated. Lipophilic extracts of Piper hispidum, Siparuna andina, S. pauciflora, S. tonduziana, and Xylopia cf. frutescens, proved to be active against both a chloroquine-sensitive and a resistant strain of Plasmodium falciparum. IC50 values ranged between 3.0 microg/ml and 21.9 microg/ml; however, moderate cytotoxicity of active extracts was observed. Bioactivity-guided fractionation of Piper hispidum yielded 2',4, 6'-trihydroxy-4'-methoxydihydrochalcone (asebogenin) as an active compound. [ABSTRACT FROM AUTHOR]

Some Dorema species are used in Persian traditional medicine. In the present study the total extract from the roots of Dorema hyrcanum Koso-Pol. was investigated for its in-vitro (pLDH assay) and in-vivo (Peters' 4-days suppressive test) antiplasmodial effects and assessed for cytotoxicity against the normal cell line MDBK (MTT test). The IC50 values for a chloroquine- sensitive (3D7) and a chloroquine- resistant (K1) strain of Plasmodium falciparum were 28.64 and 9.79 µg/mL, respectively. The inhibition percentage of the rodent parasite, Plasmodium berghei, on day 4 in mice was 77.9% and IC50 value on Madin-Darby bovine kidney cells (MDBK cells) was 59.84 µg/mL. The total extract was subjected to a bioassay-guided fractionation protocol based on the in-vivo model which resulted in the isolation of an acetophenon (compound 1), one new sesquiterpenoid; naghibione (compound 2) and two known sesquiterpenoid derivatives (compounds 3, 4). Their structures were elucidated by spectroscopic analysis, including 1D and 2D NMR experiments and ESI-MS. All compounds were evaluated for in-vivo antiplasmodial effect and the results revealed that naghibione showed good suppression activity, inhibiting 68.1 % of the parasite growth.

Background: Gypsophila trichotoma Wend. (Caryophyllaceae) is a medicinal plant which is protected in Bulgaria by the Biodiversity Law. Previous studies have showed the presence of triterpene saponins, sterols, flavonoids, triterpens, etc., Objective: Gypsogenic acid, isolated from Gypsophila trichotoma roots, was evaluated for cytotoxic activity., Materials and Methods: The structure of the compound was elucidated by spectral methods. The cell survival fraction was determined by the MTT dye reduction assay, performed with some modifications., Results: Gypsogenic acid was tested in a panel of human tumor cell lines and was found to inhibit the proliferation of malignant cells. It was active against leukemic cells with lymphoid (SKW-3 and BV-173) or myeloid phenotype (HL-60, K-562, and LAMA-84), as well as against the EJ bladder carcinoma cell line. Bcr-Abl expressing myeloid cells (LAMA-84 and especially K-562) displayed lower sensitivity. HL-60/Dox cells were less sensitive to gypsogenic acid than the parent cell line, which shows that gypsogenic acid is probably a substrate of MRP-1.

Convolvulaceae provide a rich source of tropane alkaloids, however, 2-substituted tropanes have been described for only few species of this taxon. In this note, 2,7-diesters such as ipvelutine [7β-acetoxy-2α-(tigloyloxy)tropane] isolated from the vegetative parts of the Australian Ipomoea velutina R. BR. are described as a new group of tropane diesters.

The stereochemistry of consabatine, which was isolated from the roots of Convolvulus sabatius Viv. as a novel natural compound, has now been determined by the synthesis of its Mosher esters. Consabatine was found to be 1'R-configurated.

Tumor-targeting protein toxins are composed of a toxic enzyme coupled to a specific cell binding domain that targets cancer-associated antigens. The anti-tumor treatment by targeted toxins is accompanied by dose-limiting side effects. The future prospects of targeted toxins for therapeutic use in humans will be determined by reduce side effects. Certain plant secondary metabolites (saponins) were shown to increase the efficacy of a particular epidermal growth factor receptor (EGFR)-targeted toxin, paralleled by a tremendous decrease of side effects. This study was conducted in order to investigate the effects of substituting different toxin moieties fused to an EGF ligand binding domain on the augmentative ability of saponins for each against therapeutic potential of the saponin-mediated efficacy increase for different anti-tumor toxins targeting the EGFR. We designed several EGFR-targeted toxins varying in the toxic moiety. Each targeted toxin was used in combination with a purified saponin (SA1641), isolated from the ornamental plant Gypsophila paniculata L. SA1641 was characterized and the SA1641-mediated efficacy increase was investigated on EGFR-transfected NIH-3T3 cells. We observed a high dependency of the SA1641-mediated efficacy increase on the nature of toxin used for the construction of the targeted toxin, indicating high specificity. Structural alignments revealed a high homology between saporin and dianthin-30, the two toxic moieties that benefit most from the combination with SA1641. We further demonstrate that SA1641 did not influence the plasma membrane permeability, indicating an intracellular interaction of SA1641 and the toxin components of targeted toxins. Surface plasmon resonance measurements point to a transient binding of SA1641 to the toxin components of targeted toxins., (Copyright © 2012 Federation of European Biochemical Societies. All rights reserved.)