scispace - formally typeset

Journal ArticleDOI

In Vitro study of Vellozia pusilla pohl (Velloziaceae), a Brazilian plant species: antitumoral activity and labeling of blood elements

01 Oct 2005-Brazilian Archives of Biology and Technology (Tecpar)-Vol. 48, pp 63-67

TL;DR: The methanol extract of roots, stem and leaf sheaths of this species showed an antitumoral activity through the inhibition of the enzyme Topoisomerase I when analyzed by an in vitro bioassay employing DNA repair or recombination deficient mutants of the yeast Saccharomyces cerevisiae.

AbstractVellozia pusilla Pohl is a species of the botanic family Velloziaceae that occurs in the subtropical regions of South America and, although it lives under conditions of high solar irradiation and low water availability, shows great longevity. The methanol extract of roots, stem and leaf sheaths of this species showed an antitumoral activity through the inhibition of the enzyme Topoisomerase I when analyzed by an in vitro bioassay employing DNA repair or recombination deficient mutants of the yeast Saccharomyces cerevisiae. In the evaluation of the effect of Vellozia pusilla methanol extract on the labeling of RBC, blood of mice was treated with 99mTc tracer solutions. The percentage of radioactivity (%ATI) bound to plasma (P) and blood cells (BC) was determined. The %ATI in the insoluble fraction of plasma (IF) was also evaluate, and the results showed that there was a decrease in %ATI in this fraction that represents the plasmatic proteins.

Topics: Velloziaceae (51%)

...read more

Content maybe subject to copyright    Report

Citations
More filters

Journal ArticleDOI
TL;DR: In the mechanism of cytotoxic action, halimane 1 interferes in two major phases of the cell cycle: in S phase, in which DNA synthesis occurs and where it is very sensitive to damage, and G2M phase which is the phase of preparation for mitosis and mitosis itself, showing apoptosis‐inducing properties.
Abstract: A new halimane diterpene was isolated from Vellozia kolbekii Alves (Velloziaceae) and identified as (5R,8R,9S,13R)-halim-1,10-ene-15,16-diol (1). It showed cytotoxicity against three human cancer cell lines, SF-295 (glioblastoma), MDA-MB-435 (melanoma), and HCT-8 (colon adenocarcinoma). In the mechanism of cytotoxic action, halimane 1 interferes in two major phases of the cell cycle: in S phase, in which DNA synthesis occurs and where it is very sensitive to damage, and G2M phase which is the phase of preparation for mitosis and mitosis itself, showing apoptosis-inducing properties. Antimicrobial activity towards Gram-positive and Gram-negative bacteria was studied and, against Bacillus cereus, B. subtilis, Escherichia coli, and Pseudomonas aeruginosa, a MIC value of 0.025 μM was observed for halimane 1, which is more active than the positive control chloramphenicol.

9 citations


Journal ArticleDOI
TL;DR: The analysis of the results of the in vivo and in vitro study indicates that there is no significant alteration on the uptake of Tc-99m by the blood constituents, but it significantly decrease the labeling of blood constituents by in vitro methods.
Abstract: The influence (in vivo and in vitro) of an Uncaria tomentosa extract (Cats claw) on the labeling of red blood cells (RBCs) and plasma and cellular proteins with technetium-99m (Tc-99m) was evaluated. For the in vivo treatment, animals were treated with Cats claw. For the in vitro treatment, heparinized blood was incubated with Cats claw before the addition of stannous chloride (SnCl2) and Tc-99m. Samples of plasma (P) and RBCs were separated and also precipitated with trichloroacetic acid. The soluble and insoluble fractions of P and RBCs were isolated. The analysis of the results of the in vivo study, indicates that there is no significant alteration on the uptake of Tc-99m by the blood constituents, but it significantly decrease (p<0.05) the labeling of blood constituents by in vitro methods. These effects could be due to chelation of stannous and /or pertechnetate ions and blockage of the Tc-99m bindings sites.

7 citations


Additional excerpts

  • ...…blood constituents using technetium-99m (Tc-99m) (Lima et al., 2002; Oliveira et al., 1997; Braga et al., 2000; Oliveira et al., 2002; Oliveira et al., 2003; Dantas et al., 2005; Oliveira-Fernandes et al., 2005; Abreu et al., 2006; Neves et al., 2007; Rebello et al., 2007; Sinzinger et al., 2007)....

    [...]

  • ...It has been reported that Fucus vesiculosus (Oliveira et al., 2003), Ginkgo biloba (Moreno et al., 2004), Psidium guajava (Abreu et al., 2006), Vellozia pusilla (Dantas et al., 2005) and Arctium lappa (Neves et al., 2007) extracts are capable of altering the radiolabeling of blood constituents....

    [...]


Journal ArticleDOI
TL;DR: Results suggested that the proteic extract of R. communis changed the capability of binding of the red blood cells due to the stannous ion oxidation, modifying the cells structure.
Abstract: The aim of this study was to evaluate the influence of the proteic extract of R. communis on the cell physiology by the osmotic fragility, labeling of the blood elements with the 99mTc and cell morphology. To evaluate the osmotic fragility, the blood samples of the Wistar rats were incubated with the concentrations of R. communis and with the solutions of NaCl (0.4; 0.7; 0.9%). In the labeling of the blood elements procedure, the rat blood was treated with a solution of Tc-99m and TCA at 5%, determining the rate of radioactivity (%ATI) in the plasma (P) and in the red blood cells (RBC). The soluble and insoluble fractions of the plasma were also evaluated. The cells morphology submitted to the extract was evaluated by the optical microscopy (x40). The results indicated that the rate of the hemolysis increased in the presence of 0.125 mg/mL of the extract. There was a decay of 49.69% in the rate of ATI in the insoluble fraction of the cells, with the morphological alterations in the red blood cells. These results suggested that the extract changed the capability of binding of the red blood cells due to the stannous ion oxidation, modifying the cells structure.

4 citations


Cites methods from "In Vitro study of Vellozia pusilla ..."

  • ...It is used in the study of the natural or synthetic drugs influence in the labeling of the RBC and the plasma proteins (Braga et al., 2000; Dantas et al., 2005; Holanda, 2004; Oliveira et al., 2000; Souza et al., 2005)....

    [...]


Journal ArticleDOI
01 Sep 2015
TL;DR: There is antitumor activity in the NOFRC, but that it alters the biodistribution of Tc-99m, a fact which may result in failures in the diagnostic imaging process using this radioisotope as a marker.
Abstract: Ricinus communis is a plant belonging to the Euforbiaceae family. From its fruits, it is extracted the castor oil and another highly toxic fraction (non-oily fraction). In this study, we evaluated the effect of the non-oily fraction of R. communis (NOFRC) on the bio distribution of Tc-99m in healthy mice and in animals transplanted with Sarcoma-180 (S180). To evaluate the bio distribution of theTc-99m, the percentage of the total injected radioactivity (% TIR) was measured through a gamma counter. There was an increase in the capitation of Tc-99m after the treatment with NOFRC in the kidneys, brain, and stomach of healthy animals. A decrease in the reception of this radionuclide was only found in the muscles. In animals with tumour, there was a significant reduction in the uptake of Tc-99m in the heart, lungs and tumour. An increase in the capitation was only observed in the kidneys. It was also observed a reduction in the total plasma protein concentration in animals with tumours after the treatment with NOFRC, besides significant antitumor activity. We concluded that there is antitumor activity in the NOFRC, but that it alters the biodistribution of Tc-99m, a fact which may result in failures in the diagnostic imaging process using this radioisotope as a marker.

References
More filters

Journal ArticleDOI
TL;DR: This study shows that extracts of some medicinal plants can affect the radiolabeling of red blood cells with 99mTc using an in vitro technique.
Abstract: The influence of drugs on the labeling of red blood cells and plasma proteins with 99mTc has been reported. Any drug, which alters the labeling of the tracer, could be expected to modify the disposition of the radiopharmaceuticals. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used for several evaluations in nuclear medicine. We have evaluated the effect of Thuya occidentalis, Peumus boldus and Nicotiana tabacum (tobacco) extracts on the labeling of RBC and plasma and cellular proteins with 99mTc. Blood was incubated with the drugs. Stannous chloride (SnCl2) solutions and 99mTc were added. Plasma (P) and blood cells (BC) were separated. The percentage of radioactivity (%ATI) bound to P and BC was determined. The %ATI on the plasma and cellular proteins was also evaluated by precipitation of P and BC samples with trichloroacetic acid (TCA) and isolation of soluble (SF) and insoluble (IF) fractions. The analysis of the results shows that there is a decrease in %ATI (from 97.64 to 75.89 percent) in BC with Thuya occidentalis extract. The labeling of RBC and plasma proteins can be decreased in presence of tobacco. This can be due either a direct or indirect effect (reactive oxygen species) of tobacco. The analysis of radioactivity in samples of P and BC isolated from samples of whole blood treated with Peumus boldus showed a rapid uptake of the radioactivity by blood cells in the presence of the Peumus boldus, whereas there was a slight decrease in the amount of 99mTc radioactivity in the TCA-insoluble fraction of plasma. This study shows that extracts of some medicinal plants can affect the radiolabeling of red blood cells with 99mTc using an in vitro technique.

64 citations


"In Vitro study of Vellozia pusilla ..." refers background in this paper

  • ...In the evaluation of the effect of Vellozia pusil la methanol extract on the labeling of RBC, blood of mice was treated with 99mTc tracer solutions....

    [...]

  • ...It has also been used in basic research to study the influence of drugs on the labeling of red blood cells (RBC) and plasma proteins and in the biodistribution of this radionuclide in vivo....

    [...]

  • ...The use of medicinal plants or natural products has increased all over the world, and there are some studies about the effect of the medicinal plants on the labeling of RBC (Braga et al., 2000)....

    [...]

  • ...In the present work, the effect of Vellozia pusill a extract on the labeling of RBC, plasma and cellular proteins with 99mTc was evaluated....

    [...]

  • ...The labeling technique involves pre-tinning the RBC with stannous ions, followed by exposure to technetium 99m pertechnetate, which is reduced within the cell and remains trapped intracellulary by binding to the beta chain of hemoglobin....

    [...]


Journal ArticleDOI
TL;DR: Interesting structural features of some representative examples of natural products active in mechanism-based bioassay and cytotoxicity assays along with structure-activity relationships of synthetic analogs of some of them are presented.
Abstract: Application of a mechanism-based anticancer bioassay employing DNA repair- or recombination-deficient mutants of the yeast Saccharomyces cerevisiae for screening and subsequent bioassay-guided fractionation of bioactive higher plant and bryophyte extracts led to the isolation of a variety of natural products with potential anticancer activity. Presented herein are interesting structural features of some representative examples of natural products active in our mechanism-based bioassay and cytotoxicity assays along with structure-activity relationships of synthetic analogs of some of them.

31 citations


"In Vitro study of Vellozia pusilla ..." refers background in this paper

  • ...This mechanism-based screening depends on differential responses of DNA repair-deficient and repair-proficient yeast strains to the sample under investigation (Gunatilaka et al. 1994)....

    [...]


Journal ArticleDOI
TL;DR: The leaves of Vellozii?
Abstract: Recent field and laboratory observations are the basis of a review of various aspects of the biology of the Velloziaceae. Some of the pollinators of the flowers have been identified. Fruit, seed and seedling morphology, rate of germination, phenology, the effect of rainfall on flowering as well as the effect of ecological shift on the habit of the species have been studied. Attention is drawn to the future survival of the Velloziaceae in view of current destruction of the areas in which the plants grow. THE VELLOZIACEAE is one of the most interesting plant families that occurs in Africa and South America on account of the difficulties surrounding its generic limits and its distributional pattern. The family contains about 250 species of perennial herbs and shrubs. The type genus Vellozia Vand. contains the largest number of species with approximately 140, followed by Barbacefzia Vand. with about 70. Xerophyta Juss. with about 38 species includes all the Madagascan and African species, except for Talbotia elegafzs Balfour which occurs in South Africa. The habitats in which the Velloziaceae grow in the Malagasy Republic, southern Africa, and South America are more or less similar. Most species are lithophytes, growing in stony places such as on exposed granite rocks, but some are found on dry plains in alpine environments. For example, among the Brazilian members, Vellozia cafzdida and V . plicata grow on barren soil while Burbacenia par$area prefers humus on rocks. The plants have become adapted to highly variable climatic conditions, for during the day they are subjected to intense solar radiation but occasionally the sunny conditions give way to short but violent rainstorms. At night there is often dense cloud cover which provides enough condensation to moisten the plants and, to a lesser extent, the substrate. Many plants in xeric environments have succulent leaves which help reduce the rate of transpiration as in the cactus-like euphorbias, succulent melastomes, and many bromeliads that grow in the same habitats as the Velloziaceae. The leaves of Vellozii? have developed a mechanism for regulating transpiration by the reduction of the rate of water loss per unit area and/or by the contraction of the transpiring surface area. The rate of transpiration is reduced by the placement of the stomata in abaxial furrows in the leaves. These furrows permit contractions, inrolling, outrolling, and lengthwise folding of the leaves in response to water loss from the mesophyll. The leaves of most of the South American species of Barbacecia do not have furrows, although a few such as B. irwifziafza have them on the abaxial side. Barboceniopsis boliviensis and B. vmgusiuna have furrows on both surfaces as do the Old World species with barbacenioid features (Ayensu 1968). Another adaptation against water loss is revealed by a longitudinal section through the stem which shows that the bulk of the mass consists of persistent leaf sheaths surrounding a slender woody stem. Apart from the slender stem and its lateral branches, there are long aerial roots that are completely encircled by leaf bases. The roots grow down through the entire length of the main stem until they reach the ground, where they spread out and assume the normal role of anchorage. The long aerial roots grow rather rapidly because the leaf bases that encircle them help in the maintenance of an ideal microclimate. When the leaf sheaths are removed from an uprooted Xerophyta, Vellozia or Barbace.nia, the aerial roots are especially moist and may be dripping with water even though the plants are growing in a dry habitat. The water-holding capacity of the leaf sheath is demonstrated by removing one from an herbarium specimen and placing it in water or a wetting agent such as Aerosol O T Solution (Ayensu 1967). It absorbs the medium rapidly as if made of blotting paper. TAXONOMIC R E V I E W Earlier authors like Kunth ( 1822 ) confused the Velloziaceae with the Bromeliaceae because of strong resemblances in habit. The primary classification was based on three sets of characters: presence or absence of a perianth-tube above the ovary, number of stamens, and type of filament. Baker (1875) and Hutchinson ( 1934) also relied on the presence or absence of an extension of the perianth-tube above the ovary as a key character. Although this reliance is valid at the extremes, it is not infallible. Pax (1887) used the distinction between six stamens and more than six stamens as an important character. Again such a distinction works well with most of the species, but it places under Burbaceniu species that in every other respect are indistinguishable from VellozM. It is additionally misleading because in some species with nine stamens the petals subtend a single stamen, as in Bu~buce?zia, whereas in other spec& they subtend more than one, as in Velloziu. Seubert (1847) used the form of the filament in conjunction with other morphological characters to separate the genera. Basifixed anthers with elongate fiiaments were attributed to Vellozia and dorsifixed anthers with short filaments assigned to Burbacenia. Smith's classification ( 1962 ) of the New World Velloziaceae was essentially a refinement of Seubert's work based on a study of more species. In earlier publications (Ayensu 1968, 1969a, 1969b, 1973) emphasis has been placed upon the systematic importance of three types of sclerenchyma patterns associated with the vascular bundles in the leaves. The Vellozia-type refers to species whose adaxial sclerenchyma is generally inverted crrscentiform or cap-shaped and abaxial sclerenchyma either Uor Y-shaped. The Burbuce.~liu-type is found in species where the adaxial side of the vascular bundle has an inverted Y-shaped sclerenchyma girder and the abaxial girder is either Y-shaped or three-pronged ( the flanges of the Y's do not meet directly but contact is made by thin-walled parenchymatous cells). The Xerophytu-type occurs in species where the vascular bundles are accompanied on the adaxial side by an inverted crescentiform or V-shaped cap while the abaxial sclerenchyma is a Uor W-shaped cap. Because of recent taxonomic changes (Smith and Ayensu 1974) and further anatomical studies of the New World species (Ayensu 1974), this type is now referable to the Madagascan species and a few vellozias. The mesophyll, on the other hand, is of two types: ( a ) dorsiventral, with distinct palisade and spongy tissues, and ( b ) isolateral, that has not differentiated into palisade and spongy tissues. All the Old World species classified under Vellozia and Xeroghytu which I listed earlier (Ayensu 1969) and the American species of Velloziu have dorsiventral mesophyll patterns while species of Ba~bace?zia have isolateral mesophyll. Under the newly proposed classification of the Velloziaceae, based partly on leaf anatomy (Smith and Ayensu 1974), two genera accommodate the Old World species: the monotypic genus Tnlbotia and the polytypic Xerophytu (with three sections, Xeroghytu, Vellozioides. and Bu~buce?zioides). Almost all species in the section Vellozioides occur in Arabia, Malagasy Republic, southern Africa, south West Africa, and Nigeria while most species of Bn~bnce?zioik?es occur in East Africa. The development of large translucent cells above the abaxial sclerenchyma girders and sometimes subjacent to the abaxial epidermis along its entire length is quite common in species of New World Velloziaceae. In the Old World species, such translucent cells are mostly absent, bur in some species they occur between vascular bundles near the adaxial and abaxial epidermal surfaces. The water-holding capacity of translucent cells is well known in various plants in which such cells occur, and their importance may be ascribed to the environmental conditions to which the plants are subjected (Diogo 1926). Floral Anatomy: Unlike the vegetative anatomy, the floral anatomv of the Velloziaceae has been little explored, and our general knowledge of the reproductive anatomy of this family is quite meager. Recently Dutt ( 1970) reviewed the earlier embryological snidies made by Stenar (1925) on Velloziu elegmzs ( =Talbotia ) , Bnrbuce~ziaf i.agru?zs, and Vellozia conzpacta. Dutt noted that the embryo sac in Bnrbnce?ziu. bicolor and Vellozia elegafzr is of the 'Polygonum' type. One feature of interest is the development of an integumentary tapetum formed by the inner integument. Furthermore, he observed that an obturator is developed from the funicle. However, Stenar's study lacked details regarding fertilization, endosperm development, and embryogeny. On the basis of Stenar's study, Dutt remarked that embryologically the Velloziaceae resemble the Amaryllidaceae. Of special significance is the development of a funicular obturator in Vellozin garpztrea and the amaryllidaceous species Bo772areu caldasii. On the basis of this observation Dutt stated, \"Therefore, it appears a matter of opinion whether to include the two genera Vellozia and Ba~bace?ziu under the Amaryllidaceae or to group them together under a separate family, the Velloziaceae, considering the xerophytic nature of the plants, the dichotomous branching of the stem, the branched nature of the stamens in most species, and the stalked and thickened placentae in the ovary \" In earlier taxonomic treatments (Pax and Hoffman 1930; Durand and Schinz 1895), Velloziaceae was treated as a tribe under Amaryllidaceae. Recent preferred treatments consider the Velloziaceae as a distinct family. However, \"The xerophytic nature of the plants\" and \"the dichotomous branching of the stem\" which Dutt indicated are poor characters for considering this as a family separate from the

30 citations


"In Vitro study of Vellozia pusilla ..." refers background in this paper

  • ...There are reports concerning the use of some species of Velloziaceae in Brazilian and African folk medicine (Ayensu, 1973)....

    [...]

  • ...Although plants in the Velloziaceae family li ve under conditions of high solar irradiation and low water availabil ity, they show surprising longevity (Ayensu, 1973)....

    [...]


Journal ArticleDOI
TL;DR: In vitro cytotoxicities of SN-38, the active form of irinotecan, and two newer water soluble camptothecin derivatives and effects on cellular metabolism, induction of apoptosis, and overall cell survival were evaluated to evaluate chemosensitivity.
Abstract: The topoisomerase I inhibitor camptothecin and its analogs have potent activity against a wide range of solid tumors and several hematologic malignancies. Previous studies with these compounds using the MTT metabolic inhibition assay have shown significant cytotoxicity against lymphocytes from patients with chronic B-cell lymphocytic leukemia (B-CLL). Yet the water soluble analogue, topotecan, which was inhibitory at \1 mM in vitro, had no clinical activity in vivo. In the present study, we evaluated the in vitro cytotoxicities of SN-38, the active form of irinotecan, and two newer water soluble camptothecin derivatives 10,11-methylenedioxy-20(S)-camptothecin glycinate (MDCG) and 7-chloromethyl-10,11-methylenedioxy-20(S)-camptothecin glycinate (CMMDCG). These two glycinate esters are prodrugs for 10,11-methylenedioxy-20(S)-camptothecin (MDC) and 7chloromethyl-10,11-methylenedioxy-20(S)-camptothecin (CMMDC), respectively. Effects on cellular metabolism, induction of apoptosis, and overall cell survival were used to evaluate chemosensitivity. We report that the relative cytotoxic potency for these compounds is MDC]CMMDC]SN-38TPT\CPT-11, where MDC, CMMDC, and SN-38 were over an order of magnitude more cytotoxic than TPT and CPT-11. We also investigated potential mechanisms underlying the unexpected cytotoxicity of these camptothecin derivatives in B-CLL cells that are known to be arrested in G0:G1 of the cell cycle, and found that this class of compounds inhibited [ 3 H]uridine incorporation. We therefore postulate that the inhibition of RNA rather than DNA synthesis may be responsible for the observed cytotoxicity in non-cycling B-CLL cells. © 1999 Elsevier Science Ltd. All rights reserved.

11 citations


"In Vitro study of Vellozia pusilla ..." refers result in this paper

  • ...This type of activity is similar to that of compounds like Camptothecin and Topotecan, both used in chemotherapy for solid tumor and hematologic malignancies (Cohen et al., 1999)....

    [...]


Journal ArticleDOI
Abstract: New norditerpenoids and a series of known di-and triterpenoids were isolated from Vellozia pusilla and their structures were elucidated by spectroscopic methods and chemical transformations.

6 citations


Additional excerpts

  • ...Previous studies on the specie Vellozia pusil la Pohl have afforded several terpenoids, including isopimarane nor-diterpenoid and diterpenoids, cleistantane diterpenoids and lupenone (Pinto et al.,1988; Dantas et al., 2003)....

    [...]