Pharmaco-toxicological study of Kageneckia oblonga, Rosaceae

The probable antipyretic, antiinflammatory, analgesic and antioxidant properties of Kageneckia oblonga, Rosaceae, were investigated and the major compounds of its active extracts were isolated. The study comprised the acute toxicity of the extracts of global methanol, hexane, dichloromethane and methanol. The cytotoxicity of global methanol extract was studied in three tumoral cell lines. All the extracts exhibited the pharmacological activities under study. Methanol and dichloromethane were the most toxic extracts. From the global methanol extract, isolations were performed of prunasin, 23,24- dihydro-cucurbitacin F, and a new cucurbitacin, 3beta-(beta-D-glucosyloxy)-16alpha,23alpha-epoxycucurbita-5,24-diene-11-one. The cytotoxicity of both cucurbitacins on human neutrophils at the assayed concentrations was not statistically significant. In-vitro assays showed that both cucurbitacins can be partly responsible for the analgesic, antipyretic, and anti-inflammatory activities. Evaluation was done of the cytotoxicity of global methanol extract, 23, 24-dihydrocucurbitacin F, aqueous extracts and prunasin against P-388 murine leukaemia, A-549 human lung carcinoma and HT-29 colon carcinoma. Since global methanol extract presented a strong cytotoxicity against P-388 murine leukaemia, A-549 human lung carcinoma, and HT-29 cell lines, it is highly probable that this extract contain one or more cytotoxic compounds that could be investigated for their potential use as an agent against cancer.     

A new procedure to produce lignocellulosic anion exchangers from agricultural waste materials

Two lignocellulosic agricultural waste materials (LCM), sugarcane bagasse (BG) and rice hull (RH), were converted into weak-base anion exchanger and evaluated for their exchanger capacity for nitrate. Pure cellulose (PC) and pure alkaline lignin (PL) were also used as reference materials to elucidate possible reactivity in LCM. Epoxy and amino groups were introduced into BG, RH, PC and PL substrates after the reaction with epichlorohydrin and dimethylamine in the presence of pyridine and an organic solvent N,N-dimethylformamide (DMF). Amino group incorporation into cellulose decreased with the presence of water in the reaction mixture and increased with the reaction time and presence of a catalyst (pyridine). The highest maximum nitrate exchange capacity (Qmax) and yields of the prepared exchangers was obtained from PL (1.8 mmol g(-1) and 412.5%), followed by BG (1.41 mmol g(-1) and 300%), PC (1.34 mmol g(-1) and 166%) and RH (1.32 mmol g(-1) and 180%). The proposed synthetic procedure was effective in modifying PL, PC and LCM chemically resulting in a higher yield and nitrate removal capacity.     

Ancient DNA analysis reveals woolly rhino evolutionary relationships

With ancient DNA technology, DNA sequences have been added to the list of characters available to infer the phyletic position of extinct species in evolutionary trees. We have sequenced the entire 12S rRNA and partial cytochrome b (cyt b) genes of one 60-70,000-year-old sample, and partial 12S rRNA and cyt b sequences of two 40-45,000-year-old samples of the extinct woolly rhinoceros (Coelodonta antiquitatis). Based on these two mitochondrial markers, phylogenetic analyses show that C. antiquitatis is most closely related to one of the three extant Asian rhinoceros species, Dicerorhinus sumatrensis. Calculations based on a molecular clock suggest that the lineage leading to C. antiquitatis and D. sumatrensis diverged in the Oligocene, 21-26 MYA. Both results agree with morphological models deduced from palaeontological data. Nuclear inserts of mitochondrial DNA were identified in the ancient specimens. These data should encourage the use of nuclear DNA in future ancient DNA studies. It also further establishes that the degraded nature of ancient DNA does not completely protect ancient DNA studies based on mitochondrial data from the problems associated with nuclear inserts.     

Desialylated N-CAM and chromatin-derived acidic peptide effects in the hypothalamus

Chromatin-derived acidic peptides (ACPs) have been shown to acutely modulate hypothalamic catecholamine release. To investigate whether this effect is mediated through membrane polysialylated neural-cell adhesion molecule (PSA-N-CAM), we pretreated rat hypothalamic synaptosomes with neuraminidase enzyme, which partially cleaves sialic acid residues from N-CAM, and perfused them with ACP-1 (Asp-Asp-Ser-Asp-Glu-Glu-Asn) or a more lipophilic derivative, ACP-2 ([Ala-Ile-Ser-Pro]-Asp-Asp-Ser-Asp-Glu-Glu-Asn). We have found that neuraminidase completely abolish the inhibitory effect of ACP-1 on dopamine release, while the inhibitory activity of ACP-1 on norepinephrine release is partially lost. On the other hand, ACP-2 inhibition of dopamine release is not modified by neuraminidase pretreatment.     

Antiendotoxin activity of protegrin analog IB-367 alone or in combination with piperacillin in different animal models of septic shock

The therapeutic efficacy of protegrin peptide IB-367 was investigated in three rat models of septic shock: (i) rats injected intraperitoneally with 1mg Escherichia coli 0111:B4 lipopolysaccharide, (ii) rats given an intraperitoneal injection of 2 X 10(10) CFU of E. coli ATCC 25922, and (iii) rats in which intra-abdominal sepsis was induced via cecal ligation and puncture. All animals were randomized to receive parenterally isotonic sodium chloride solution, 1mg/kg of IB-367, 60mg/kg piperacillin and 1mg/kg of IB-367 plus 60mg/kg piperacillin. The peptide demonstrated lower level of antimicrobial activity than piperacillin, nevertheless it exhibited the dual properties of antimicrobial and antiendotoxin agent. Finally IB-367 and piperacillin association showed to be the most effective therapeutic approach.     

Lumen-to-surface pH gradients in opossum and rabbit esophagi: role of submucosal glands

The opossum esophagus, like that of humans, contains a network of submucosal glands with the capacity to secrete bicarbonate ions into the esophageal lumen. To evaluate the role of these glands in protecting the epithelial surface from acid insult, we measured the lumen-to-surface pH gradient in opossum esophagus at different luminal pH and compared it to that of rabbit esophagus, an organ devoid of submucosal glands. Sections of opossum and rabbit esophageal epithelium were mounted luminal side up in a modified Ussing chamber. pH-sensitive microelectrodes, positioned within 5 microm of the epithelial cell surface, were used to monitor surface pH during perfusion with solutions of different pH. At luminal pH 7. 5, the pH(s) of both opossum and rabbit were similar (pH(s) = 7.5). Lowering luminal pH from 7.5 to 3.5 in opossum decreased pH(s) to 4.2+/-0.16, a value significantly higher than pH of perfusate, whereas in rabbit this maneuver decreased pH(s) to 3.69+/-0.08, a value not significantly different from pH of perfusate. In opossum but not in rabbit, addition of carbachol to the serosal solution increased basal pH(s) to 7.8+/- 0.1 and significantly blunted the decline in pH(s) on perfusion with acidic Ringer solution (pH 3.5), with pH(s) falling to 5.6+/-0.45. The effect of carbachol on surface buffering was inhibited by prior treatment with atropine. Luminal acidification to pH 2.0 in opossum (as in rabbit) abolished the lumen-to-surface pH gradient even after addition of serosal carbachol. We conclude that the presence of submucosal glands in esophagus contributes through bicarbonate secretion to creation of a lumen-to-surface pH gradient. Although this gradient can be modulated by carbachol, its capacity to buffer (and therefore to protect) the epithelial surface against back-diffusing H(+) is limited and dissipated at pH 2.0.     

Nucleolar Organizing Regions, 18S and 5S rDNA in Astyanax Scabripinnis (Pisces, Characidae): Populations Distribution and Functional Diversity

Astyanax scabripinnis specimens from four distinct populations in Brazil were studied with respect to their karyotype macrostructure, nucleolar organizer regions, and 18S and 5S rRNA genes. The four populations showed a 2n = 50 chromosomes (3 M + 11 SM + 5 ST + 6 A pairs) and 1–2 B chromosomes. No chromosomal differentiations were observed between sexes. Although a karyotypic diversity has been characterized in this fish group, the populations now analyzed presented the same macrokaryotypic pattern. Chromosome mapping of 5S rDNA showed a total of eight sites located in four distinct chromosomal pairs, with no apparent differences among populations. A comparative study on 18S rDNA locations and Ag-NORs showed some secondary NOR sites that are not usually expressed in karyotypes and a probable differential NOR activity among populations. Correlations between these data, environmental conditions and B chromosomes are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Morphological Differentiation and Possible Origin of B Chromosomes in Natural Brazilian Population of Astyanax Scabripinnis (PISCES, CHARACIDAE)

Specimens of Astyanax scabripinnisfrom three different altitudes (1920, 1800 and 700?m) along the Ribeirão Grande stream in the Campos do Jordão region (São Paulo State, Brazil) were investigated. The same diploid number, 2n?=?50, was detected in the three populations, with the following karyotypic constitution: 6M, 22SM, 10ST and 12A. The populations located at 1920 and 1800?m altitude presented a high incidence of B chromosomes varying in number (0–2), shape (meta- and submetacentrics), size (large and small) and sex-related frequency (they were more frequent among females). The two morphologically variant B chromosomes probably evolved from a metacentric macrochromosome, which is the most commonly observed B chromosome in several A. scabripinnispopulations.     

An endogenous sulfated inhibitor of neuronal inositol trisphosphate receptors

In cerebellum, inositol trisphosphate- (InsP(3)-) gated Ca channels play a key role in learning, though they exhibit a low sensitivity to InsP(3) compared to peripheral tissues. In the present study, the cerebellar InsP(3) receptor is shown to be associated with a novel inhibitor of InsP(3) binding. (3)H-InsP(3) binding studies indicated that this inositol trisphosphate receptor inhibitor (IRI) could completely inhibit InsP(3) binding to the purified cerebellar InsP(3) receptor and acted as a competitive inhibitor. Gel filtration of IRI showed a predominant peak at 6500 Da, though this peak appeared to be an aggregate (with a monomeric molecular mass of approximately 1500 Da). Mass spectrometry of IRI showed a predominant peak at 1635 m/z, consistent with this low molecular mass estimate. The inhibitory activity of IRI was prevented by pretreatment with aryl sulfatase, suggesting the presence of a critical sulfo ester in IRI. IRI was insensitive to proteases and organic extraction but bound to concanavalin A, suggesting that IRI is a sulfated glycan. IRI was present in cerebellum but below the level of detection in aorta. IRI was also present in the neuronal cell line N1E115 (which exhibits a low sensitivity to InsP(3)). We conclude that IRI is a novel endogenous sulfated inhibitor of the InsP(3) receptor that modulates the sensitivity of the InsP(3) receptor and thus may explain the low InsP(3) sensitivity of neurons.