Showing papers on "Toad published in 2016"

A New Indole Alkaloid from the Toad Venom of Bufo bufo gargarizans

Abstract: A new indole alkaloid named bufobutarginine (1), along with three known bufotenines, namely, serotonin (2), bufotenidine (3), and bufotenine (4), were isolated from the water extract of toad venom. Their structures were elucidated by spectral methods. This is the first time that arginine has been found to be involved in the biosynthesis of bufotenines in parotid of toad. The cytotoxic activities of these compounds have been assayed against A375 and A549 cell lines by the MTT method; however, they showed no cytotoxic activities.

Aqueous and Ethanol Extracts of Australian Cane Toad Skins Suppress Pro-Inflammatory Cytokine Secretion in U937 Cells via NF-κB Signaling Pathway.

Abstract: Toad skin extracts, such as aqueous extracts (AE) of Chinese toad skins, have demonstrated therapeutic benefits for a range of diseases including pain, inflammation, swelling, heart failure, and various types of cancers. In this study, we investigated the anti-inflammatory potential of an AE (0.1-10 μg/mL) and a 60% ethanol extract (EE; 0.1-10 μg/mL) from Australian cane toad (Bufo marinus) skins and the known bioactive compound, bufotenine (BT; 0.1-10 nM). The assay employed a model of the human monocyte cell line U937 stimulated with lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA) for the release of tumor necrosis factor (TNF)-α and interleukin (IL)-6. We demonstrated that AE, EE, and BT significantly inhibited the release and expression of TNF-α and IL-6 in a dose-dependent manner when the cells were pre-treated at non-cytotoxic concentrations. Further investigation revealed that the inhibition of TNF-α and IL-6 release and expression was associated with the suppression of nuclear factor (NF)-kappa (κ)B activation. These results indicate that AE, EE, and BT are strong inflammation inhibitors, thus have the potential for further development as anti-inflammatory therapeutic agents from a natural source regarded as a feral pest in Australia. J. Cell. Biochem. 117: 2769-2780, 2016. © 2016 Wiley Periodicals, Inc.

Structures and inhibitory activity against breast cancer cells of new bufadienolides from the eggs of toad Bufo bufo gargarizans

Abstract: Two new 19-norbufadienolides (1 and 2), one new 14,15-epoxy bufadienolide (3), and eight rare bufadienolide–fatty acid conjugates (4–11), together with four known ones (12–15) were isolated from the eggs of toad Bufo bufo gargarizans. Their chemical structures were elucidated by extensive spectroscopic methods in combination with X-ray diffraction analyses. Furthermore, we tested the inhibitory effect of these compounds against breast cancer cell lines MCF-7 and MDA-MB-231. Most of them showed strong cytotoxicity with IC50 values less than 0.1 μM. The further mechanistic study showed that they could induce apoptosis and cycle arrest in the G2/M phase in MCF-7 cells.

Toad Parotoid Pores Shelter Tick Larvae

Abstract: . Several reports are available regarding ticks parasitizing toads of the family Bufonidae. Although ticks can attach to different regions of the body, occurrence of these ectoparasites on parotoid macroglands is unfrequent when compared with other regions of body. In this study, using histology and scanning electron microscopy, we analysed a rare case of ticks that were found exclusively lodged inside pores of parotoid macroglands in the cane toad Rhinella marina. Our results indicate that the morphology of toad parotoid pores offers physical protection to tick larvae, favoring successful attachment. Evidences of secretion release from the accessory glands arranged around the parasitized pores seem to constitute a defensive chemical response against parasitism, suggesting a role for these poorly known glands.

Large populations of the common toad Bufo bufo in Norway

Abstract: widespread species with an extensive Euro-Asiatic distribution (note that the taxonomy of B. bufo has recently been revised: Recuero et al., 2012; Arntzen et al., 2013; 2014). Its northern distribution reaches 68° N in Finland (Sinsch et al., 2009) and in Norway, on the Dønna island, almost 66° 15’ N)(Pedersen and Dolmen, 1994). The common toad is, for the most part in and north of the Alps, an explosive breeder, i.e. the animals come together in large numbers at a breeding site for a short breeding period (Wells, 1977; Hartel et al., 2007; for exceptions see Sinsch et al., 2009). Population sizes can vary enormously both on a regional and a temporal scale, from less than 100 up to several thousands of individuals, and by a factor of up to 40 even between successive years (see Sinsch et al., 2009 for an overview). In Scandinavia, published maximum numbers for single populations (i.e. within one breeding locality) so far are in the range of 300–500 individuals. The data are from the Trondheim area (Hemelaar, 1988) and the Bømlo area (Roth, 2011) both in Norway, and the Lund area in Sweden (Loman and Madsen, 1986). The pond in Lund is part of a complex of breeding ponds with a total maximum number of 1054 males and 614 females (Loman and Madsen, 2010). Although the common toad is not a threatened animal in Norway (see Dolmen, 2015) and it is very common for instance on the western coastland (Salvidio et al., 1993), the species has undergone an unexplained decline regionally in south-eastern parts of the country (Semb-Johansson, 1992; Semb-Johansson et al., 2012). In this article we present detailed information about two much larger Scandinavian toad populations, both in western Norway, with several thousand individuals. We have collected data from two localities: the lakes Nesvatnet in the county of Hordaland and Litlevatnet in the county of Møre & Romsdal. Nesvatnet is located near Mundheim (Kvam municipality, province Hordaland; 60.1652°N�� 5.9375°E). The lake is eutrophic with moderate. transparency, about 70000 m2 in area and situated 20 m a.s.l. There exist extensive shallow water areas with dense vegetation dominated by bottle sedge Carex rostrata, bogbean Menyanthes trifoliata and water lilies Nymphaea alba and Nuphar lutea. As part of a typical Norwegian fjord landscape, the lake is located on a peninsula surrounded by suitable terrestrial toad habitats such as natural pine Pinus sylvestris and mixed forest, bogs, heather Calluna vulgaris/Erica spp., and, in more than half of the immediate surroundings, meadows with groups of trees (Nord et al., 2013). The catchment area of the lake is quite large, and Nesvatnet is the only suitable water body for toads in an area of about 15 km2 that is bordered by the sea and by steep rocks to the north rising to 300–400 m a.s.l. In Nesvatnet our data are based mainly on head counting by Torstein Solhøy (TS), SR and KN in 2010–2014. We usually counted once per breeding period on a relatively mild evening after sunset. The lake was covered once either by walking or by rowboat or a combination of both. Male and female toads were counted separately using hand counters. Sex determination was based on size only. In doing so, small females that were not in Herpetology Notes, volume 9: 325-330 (2016) (published online on 06 December 2016)

Morphological and morphometric study on the early developmental stages of the Egyptian toad Bufo regularies Reuss

Abstract: Aims: this study aimed to examine the developmental changes in external morphology characters for some embryonic larval period of Bufo regularis from river Nile, Assuit, Egypt. Methods: Our experiment started when tadpoles began to feed. the adapted embryos were divided into three large tanks, each with 200 embryos. collecting of samples started from feeding age every three days until end of metamorphosis (the absorption of tail). External measurements of the early developmental stages including body height (bH), body width (bW), eye diameter (ED), forelimb length (FLL), head-body length (H-bL), hind limb length (HLL), internarial distance (IND), interorbital distance (IOD), nostril diameter (ND), distance between nariel and orbital (NOD), tail length (tAL), tail height (tH), total length (tL), tail muscle height (tMH) and body weight (bWE) were recorded. results: the morphological description reported for each stage indicated many differences between the different developmental stages. conclusion: this study may be considered as morphological key for the different developmental stages of the Egyptian toad tadpoles (Bufo regularis). Alaa El-Din H. Sayed1, Ekbal T. Wassif1, Afaf I. Elballouz1,2 Affiliations: 1Zoology department, Faculty of Science, Assiut University, 71516Assiut, Egypt; 1, 2Zoology department, Faculty of Science, Misurate University, Misurate, Libya. Corresponding Author: Alaa El-Din Hamid Sayed, Zoology department, Faculty of Science, Assiut University, 71516Assiut, Egypt; Email: alaa_h254@yahoo.com (A. H. Sayed) Received: 21 October 2015 Accepted: 17 December 2015 Published: 29 February 2016

Effects of Cr(3+) ions on electrophysiological parameters of isolated skin of toad Pleurodema thaul.

Abstract: In view of the toxicity of chromium (Cr(3+)) ions, it was explored the damaging effects that this ion could induce in cell membranes. The measurement of the effects induced by Cr(3+) ions on electrophysiological parameters of short-circuit current and on the potential difference were investigated using the outer side (mucosal) and the inner side (serosal) of toad Pleurodema thaul skin. The results showed a decreased on electrophysiological parameters when it were administered concentrations of 33, 100 and 200 μM of Cr(3+), the results also suggest that the administration of Cr(3+) inhibits the ion transport in toad skin by the interaction of Cr(3+) with lipid bilayers or protein constituents of membrane, and not by an inhibition of the active transport of ions across Na(+) channels.

Inhibition of Acetylcholinesterase in the Anaxyrus cognatus Liver by Chlorpyrifos Oxon

Abstract: This study investigated the effects of a commonly used organophosphate pesticide, chlorpyrifos, on the liver of the Great Plains toad, Anaxyrus cognatus . The activity of acetylcholinesterase in the liver of the toad was evaluated by the Ellman method using a plate reader, and its in vitro sensitivity to a range of concentrations of chlorpyrifos oxon, the active metabolite of chlorpyrifos. At chlorpyrifos oxon concentrations from 100 nM to 100 µM, concentration-dependent inhibition was noted (IC50 [concentration that inhibited 50% of the enzyme activity] = 1.8 µM). This concentration is about 100-fold higher than published for mammalian brain acetylcholinesterase inhibition; thus, the data suggest the toad may be resistant to acute toxicity of this pesticide. The findings suggest that organophosphate pesticides may have lesser acute toxicity potential in the Great Plains toad compared to mammals.

Proliferative events and apoptotic remodelling in retinal development of common toad (Bufo bufo)

Abstract: Proliferation and apoptosis are fundamental processes in the development of the retina, and a proper balance of the two phenomena is crucial to correct development of the organ. Despite intense investigation in different vertebrates, only a few studies have analyzed the cell death and the cell division quantitatively in the same species during development. Here we studied the time course of apoptosis and proliferation in the retina of common toad, Bufo bufo, and discuss the findings in an evolutionary perspective. We found cells that were dividing first scattered throughout the retina, then, in later stages, proliferation was confined to the ciliary marginal zone. This pattern was confirmed by the expression of the proliferative marker PCNA. Both proliferation and apoptosis occurred in successive waves, and two apoptotic peaks were detected: one at premetamorphosis 1 and the second at prometamorphosis. PARP-1, a known molecular marker of apoptosis, was used to confirm the data obtained by counting pyknotic nuclei. In summary, proliferative and apoptotic waves display an inverse time-relationship through development, with apoptotic peaks coinciding with low proliferation phases. In a comparative perspective, amphibians follow a developmental pattern similar to other vertebrates, although with different timing.